bluuebunny/crossref_metadata_2025 huggingface dataset:
Commission 37: Star Clusters
Authors: Sarajedini Ata , Spurzem Rainer , Cannon Russell , Castellani Vittorio , Cudworth Kyle , Da Costa Gary , Deng Licai , Giersz Mirek , Hatzidimitriou Despina , Lada Charles
Published: March 2007

During the period 2004 to 2005, the following symposia and colloquia were related to the activities of the commission: The A-Star Puzzle (IAUS224), Massive Star Birth: A Crossroads of Astrophysics (IAUS227), and From Lithium to Uranium: Elemental Tracers of Early Cosmic Evolution (IAUS228).
Division VIII: Galaxies and the Universe
Authors: Bertola Francesco , Birkinshaw M. , Combes F. , Lilly S. , Okamura S. , Peacock J. , Sadler E.M. , Trimble V. , Webster R.
Published: March 2007

As documented by the reports of the Presidents of Commission 28 and Commission 47 the fields of extra-galactic research and cosmology have experienced a higher and higher development leading to a vast harvest of results and discoveries. They range from the description of the overall structure of the universe to that of the individual properties of galaxies. The availability of very large telescopes and the coverage of regions of the sky with deep surveys, on the observational side, and the wide use of sophisticated numerical simulations on the theoretical one are starting to produce a satisfactory understanding of the physical processes taking place during the evolution of galaxies. Very often there is an profitable interplay between the subjects of the two Commissions without clearcut boundaries. This makes Division VIII, which is one of the largest of the IAU, counting 1373 members, very well balanced and deserving to remain without modifications for the future.
The Supernova Working Group
Authors: Hillebrandt Wolfgang , Schmidt Brian
Published: March 2007

The Supernova Working Group (SNWG) was re-established at the General Assembly in Sidney on July 21, 2003, sponsored by Commissions 28 (Galaxies) and 47 (Cosmology). Here we report on some of its activities since 2003.
Division X: Radio Astronomy
Authors: Rodríguez Luis F. , Nan Ren-Dong , Diamond Philip J. , Dubner Gloria , Garrett Michael , Green Anne , Ishiguro Masato , Goss W. Miller , Taylor Russ , Padrielli Lucia , Rao A. Pramesh , Torrelles José M. , Turner Jean L.
Published: March 2007

There have been important advances in radio astronomy in the last three years. New discoveries both at the galactic and extragalactic scale have been reported over this period and we highlight here several of them. The outstanding results of the Wilkinson Microwave Anisotropy Probe satellite, allowing an accurate determination of the main cosmological constants, are certainly among the most important. At the international level, the consolidation of the Atacama Large Millimeter Array project, with participation of the USA, Europe, and Japan and an estimated cost of around one billion US dollars, takes the construction of radio telescopes to a new level of complexity and potential. We also include the Progress Report of the Working Group on Historic Radio Astronomy, that includes a description of the duties and activities of this recently created working group.
Commission 41: History of Astronomy
Authors: Gurshtein Alexander A. , Il-Seong Nha , Ruggles Clive , DeVorkin David , Dick Wolfgang , Kochhar Radesh , Nakamura Tsuko , Pigatto Luisa , Stephenson Richard , Warner Brian
Published: March 2007

Following the Sydney General Assembly, the membership of C41 stood at 352, of whom, at the time of writing, three are known to have deceased. Since the formation of the Inter-Union Commission for the History of Astronomy (ICHA) prior to the Sydney General Assembly, C41/ICHA has subsequently acted, in effect, as an integrated Commission with a single OC. In this triennium the C41/ICHA OC made strong efforts to clarify and simplify the controversial issue of admitting non-IAU members to the ICHA. After prolonged and active consultation, the OC approved the document “Procedures for Admitting non-IAU members to the ICHA” and the OC Secretary Prof. Clive Ruggles officially presented this document to the history of astronomy community in C41/ICHA Newsletter no. 6. It is subject to ratification by the C41/ICHA Business Meeting in Prague in 2006.
Working Group on Communication Astronomy with the Public
Authors: Christensen Lars Lindberg , Crabtree Dennis R. , Robson Ian
Published: March 2007

The Working Group on Communicating Astronomy with the Public is under Division XII - Union-Wide Activities. Formed in early 2004, this Working Group has been very active in establishing itself and promoting its core goals.
Division I: Fundamental Astronomy
Authors: Fukushima Toshio , Vondrak Jan , Capitaine Nicole , Dehant Veronique , Krasinsky George , Matsakis Demetrios , Milani Andrea , Platais Imant
Published: March 2007

IAU Division I includes Commission 4 (Ephemerides), Commission 7 (Celestial Mechanics and Dynamical Astronomy), Commission 8 (Astrometry), Commission 19 (Rotation of the Earth) and Commission 31 (Time). The Division has in addition five Working Groups on, respectively, Future Development of Ground-Based Astrometry, Nomenclature for Fundamental Astrometry, Definition of Coordinated Universal Time, and Precession and the Ecliptic.
Pseudogap formation in MnPt and MnPd alloys
Authors: Kubota Masato , Ono Kanta , Umetsu Rie Y. , Akinaga Hiroyuki , Sakuma Akimasa , Fukamichi Kazuaki
Published: March 2007

The authors performed an optical spectroscopy to observe the electronic structure of L10-type ordered Mn-based alloys. The effect of disorder on pseudogap formation in Mn1−xPtx (x=0.47, 0.50, 0.51, and 0.54) and Mn1−xPdx (x=0.502, 0.515, and 0.535) alloys has been clarified. The optical reflectivity shows a clear dip around 0.5eV for both MnPt and MnPd alloys, which corresponds to the pseudogap formation. On the other hand, the pseudogap is rather unclear in the other nonequiatomic compositions. This indicates that the pseudogap formation is deeply related to the degree of the ordering in the Mn-based alloys.
Surface micromachined freestanding ZnO microbridge and cantilever structures on Si(111) substrates
Authors: Vicknesh S. , Tripathy S. , Lin Vivian K. X. , Chua S. J. , Kumar Bhupendra , Gong Hao
Published: March 2007

In this study, the authors report on the fabrication processes to realize the freestanding ZnO micromechanical structures on Si(111) substrates. Arrays of freestanding cantilevers and microbridges have been fabricated using a combination of dry etching techniques. The mechanical properties of the released ZnO structures are characterized by micro-Raman spectroscopy. The residual stress in these freestanding micromechanical structures is determined from the E2(2) phonon peak shift. Such a method to realize the freestanding structures on Si platform would be useful for the fabrication of ZnO-based microelectromechanical systems and sensors.
Emission of hybrid organic-inorganic exciton/plasmon mixed states
Authors: Symonds C. , Bellessa J. , Plenet J. C. , Bréhier A. , Parashkov R. , Lauret J. S. , Deleporte E.
Published: March 2007

In this letter the authors experimentally demonstrate the strong coupling regime at room temperature between a surface plasmon and an exciton from an auto-organized quantum well. The sample is formed by a two dimensional layered perovskite-type semiconductor: s(C6H5C2H4–NH3)PbI4, spin coated onto a silver film. The dispersion lines resulting from reflectometry experiments performed at room temperature in the Kretschmann geometry present an anticrossing with a Rabi splitting of 167meV. The emission of the low energy polariton is presented.
Complementary inverter using high mobility air-stable perylene di-imide derivatives
Authors: Ling Mang-mang , Bao Zhenan , Erk Peter , Koenemann Martin , Gomez Marcos
Published: March 2007

The authors report the fabrication and electrical characterization of organic complementary inverters using pentacene as p-type material and our previously reported air-stable perylene di-imide derivatives tetrachloro-perylene-tetracarboxyldi-imide (TC-PTCDI) and N,N′-bis(2-phenylethyl)perylene-3,4:9:10-bis-(dicarboximide) (BPE-PTCDI) as n-type materials. Both p- and n-type thin film transistors were integrated onto the same substrate using a top contact configuration. The corresponding inverters show good performance with gains about 12 and 10 for TC-PTCDI and BPE-PTCDI inverters, respectively.
Controlled formation of multiple Taylor cones in electrospinning process
Authors: Vaseashta A.
Published: March 2007

Electrospinning is a versatile technique for preparation of micro- and nanoscale fibers using polymer solutions. The study presented here describes an observation of multiple Taylor cones in electrospinning processes. Plausible physical models explaining the formation and modeling of multiple Taylor cones in terms of the process and polymer solution parameters are presented. A thorough understanding of the process will lead to the preparation of fibers by design, system on fibers, and e-textiles having applications ranging from biomedical devices, environmental pollution and prevention, to global security and defense.
Monte Carlo simulation of electron transport in degenerate and inhomogeneous semiconductors
Authors: Zebarjadi Mona , Bulutay Ceyhun , Esfarjani Keivan , Shakouri Ali
Published: March 2007

An algorithm is proposed to include Pauli exclusion principle in Monte Carlo simulations. This algorithm has significant advantages to implement in terms of simplicity, speed, and memory storage; therefore it is ideal for the three-dimensional device simulators. The authors show that even in moderately high applied fields, one can obtain the correct electronic distribution. They give the correct definition for electronic temperature and show that in high applied fields, the quasi-Fermi level and electronic temperature become valley dependent. The effect of including Pauli exclusion principle on the band profile, electronic temperature, and quasi-Fermi level for the inhomogeneous case of a single barrier heterostructure is illustrated.
Highly efficient oxidation of silicon at low temperatures using atmospheric pressure plasma
Authors: Kakiuchi Hiroaki , Ohmi Hiromasa , Harada Makoto , Watanabe Heiji , Yasutake Kiyoshi
Published: March 2007

Silicon oxide (SiO2) layers were formed with initial oxidation rates in the range of 6.2–14.1nm∕min in the temperature range of 150–400°C by oxidizing Si(001) wafers. Such a high-rate and low-temperature oxidation was realized by using a stable glow He∕O2 plasma excited at atmospheric pressure by a 150MHz very high-frequency power. Increasing the temperature led to both the higher oxidation rate and the better quality of SiO2 and SiO2∕Si interface. The oxidation at 400°C showed an interface trap density of 6.2×1010eV−1cm−2, which is considerably lower than that in a radical oxidation process using low-pressure He∕O2 plasma at the same temperature.
Experimental observation of oxygen-related defect state in pentacene thin films
Authors: Nádaždy V. , Durný R. , Puigdollers J. , Voz C. , Cheylan S. , Gmucová K.
Published: March 2007

The authors report on a metastable defect observed in pentacene thin films. The defect, which is characterized by a hole trap at Ev+0.6eV and attempt-to-escape frequency of 5×1012s−1, can be reversibly created/removed under a negative/positive bias voltage applied to the aluminum/pentacene Schottky diode at room temperature in air. Annealing the sample in vacuum at 360K removes the defect and prevents its creation by application of any bias voltage in vacuum. Considering recent calculations of defects in pentacene the authors assume that the defect is formed by replacing one of the hydrogen atoms by an oxygen atom (C22H13O).
Suppression of electron-phonon scattering in double-quantum-dot based-quantum gates
Authors: Zhao Peiji , Woolard Dwight L.
Published: March 2007

The authors propose a nanostructure design which can significantly suppress longitudinal-acoustic-phonon–lectron scattering in double-quantum-dot based quantum gates for quantum computing. The calculated relaxation rates versus voltage exhibit a double-peak feature with a minimum approaching 105s−1. In this matter, the energy conservation law prohibits scattering contributions from phonons with large momenta; furthermore, increasing the barrier height between the double quantum dots reduces coupling strength between the dots. Hence, the joint action of the energy conservation law and the decoupling greatly reduces the scattering rates.
Nanostenciling for fabrication and interconnection of nanopatterns and microelectrodes
Authors: Guo Haiming , Martrou David , Zambelli Tomaso , Polesel-Maris Jérôme , Piednoir Agnès , Dujardin Erik , Gauthier Sébastien , van den Boogaart Marc A. F. , Doeswijk Lianne M. , Brugger Jürgen
Published: March 2007

Stencil lithography is used for patterning and connecting nanostructures with metallic microelectrodes in ultrahigh vacuum. Microelectrodes are fabricated by static stencil deposition through a thin silicon nitride membrane. Arbitrary nanoscale patterns are then deposited at a predefined position relative to the microelectrodes, using as a movable stencil mask an atomic force microscopy (AFM) cantilever in which apertures have been drilled by focused ion beam. Large scale AFM imaging, combined with the use of a high precision positioning table, allows inspecting the microelectrodes and positioning the nanoscale pattern with accuracy better than 100nm.
Enhanced photoluminescence of Nd2O3 nanoparticles modified with silane-coupling agent: Fluorescent resonance energy transfer analysis
Authors: Yu Kehan , Qiu Xiaoming , Xu Xiangxing , Wei Wei , Peng Bo , Zhou Zhiwei
Published: March 2007

A liquid laser medium with a lifetime of 492μs and a fluorescent quantum efficiency of 52.5% has been presented by stably dispersing dimethyl dichorosilane-modified Nd2O3 nanoparticles in dimethylsulfoxide. Its optical properties and mechanism were investigated and explained by fluorescence resonance energy transfer theory. The calculation result shows that the quenching of NdIII F3∕24→I11∕24 transition via O–H vibrational excitation can be eventually neglected. The main reason is that the silane-coupling agent molecules remove the –OH groups on Nd2O3 nanoparticles and form a protective out layer.
Adenosine regulation of alveolar fluid clearance
Authors: Factor Phillip , Mutlu Göskhan M. , Chen Lan , Mohameed Jameel , Akhmedov Alexander T. , Meng Fan Jing , Jilling Tamas , Lewis Erin Rachel , Johnson Meshell D. , Xu Anna , Kass Daniel , Martino Janice M. , Bellmeyer Amy , Albazi John S. , Emala Charles , Lee H. T. , Dobbs Leland G. , Matalon Sadis
Published: March 2007

Adenosine is a purine nucleoside that regulates cell function through G protein-coupled receptors that activate or inhibit adenylyl cyclase. Based on the understanding that cAMP regulates alveolar epithelial active Na
+
transport, we hypothesized that adenosine and its receptors have the potential to regulate alveolar ion transport and airspace fluid content. Herein, we report that type 1 (A
1
R), 2a (A
2a
R), 2b (A
2b
R), and 3 (A
3
R) adenosine receptors are present in rat and mouse lungs and alveolar type 1 and 2 epithelial cells (AT1 and AT2). Rat AT2 cells generated and produced cAMP in response to adenosine, and micromolar concentrations of adenosine were measured in bronchoalveolar lavage fluid from mice. Ussing chamber studies of rat AT2 cells indicated that adenosine affects ion transport through engagement of A
1
R, A
2a
R, and/or A
3
R through a mechanism that increases CFTR and amiloride-sensitive channel function. Intratracheal instillation of low concentrations of adenosine (≤10
−8
M) or either A
2a
R- or A
3
R-specific agonists increased alveolar fluid clearance (AFC), whereas physiologic concentrations of adenosine (≥10
−6
M) reduced AFC in mice and rats via an A
1
R-dependent pathway. Instillation of a CFTR inhibitor (CFTR
inh-172
) attenuated adenosine-mediated down-regulation of AFC, suggesting that adenosine causes Cl
−
efflux by means of CFTR. These studies report a role for adenosine in regulation of alveolar ion transport and fluid clearance. These findings suggest that physiologic concentrations of adenosine allow the alveolar epithelium to counterbalance active Na
+
absorption with Cl
−
efflux through engagement of the A
1
R and raise the possibility that adenosine receptor ligands can be used to treat pulmonary edema.
A coherent neurobiological framework for functional neuroimaging provided by a model integrating compartmentalized energy metabolism
Authors: Aubert Agnès , Pellerin Luc , Magistretti Pierre J. , Costalat Robert
Published: March 2007

Functional neuroimaging has undergone spectacular developments in recent years. Paradoxically, its neurobiological bases have remained elusive, resulting in an intense debate around the cellular mechanisms taking place upon activation that could contribute to the signals measured. Taking advantage of a modeling approach, we propose here a coherent neurobiological framework that not only explains several
in vitro
and
in vivo
observations but also provides a physiological basis to interpret imaging signals. First, based on a model of compartmentalized energy metabolism, we show that complex kinetics of NADH changes observed
in vitro
can be accounted for by distinct metabolic responses in two cell populations reminiscent of neurons and astrocytes. Second, extended application of the model to an
in vivo
situation allowed us to reproduce the evolution of intraparenchymal oxygen levels upon activation as measured experimentally without substantially altering the initial parameter values. Finally, applying the same model to functional neuroimaging in humans, we were able to determine that the early negative component of the blood oxygenation level-dependent response recorded with functional MRI, known as the initial dip, critically depends on the oxidative response of neurons, whereas the late aspects of the signal correspond to a combination of responses from cell types with two distinct metabolic profiles that could be neurons and astrocytes. In summary, our results, obtained with such a modeling approach, support the concept that both neuronal and glial metabolic responses form essential components of neuroimaging signals.
Selective gene silencing in activated leukocytes by targeting siRNAs to the integrin lymphocyte function-associated antigen-1
Authors: Peer Dan , Zhu Pengcheng , Carman Christopher V. , Lieberman Judy , Shimaoka Motomu
Published: March 2007

Silencing gene expression by RNAi is a powerful method for exploring gene function and validating drug targets and potentially for therapy. Lymphocytes and other primary blood cells are resistant to lipid-based transfectionin vitroand are difficult to targetin vivo. We show here that antibody-protamine fusion proteins targeting the human integrin lymphocyte function-associated antigen-1 (LFA-1) efficiently deliver siRNAs and specifically induce silencing in primary lymphocytes, monocytes, and dendritic cells. Moreover, a fusion protein constructed from an antibody that preferentially recognizes activation-dependent conformational changes in LFA-1 selectively targets activated leukocytes and can be used to suppress gene expression and cell proliferation only in activated lymphocytes. The siRNA-fusion protein complexes do not cause lymphocyte activation or induce IFN responses. K562 cells expressing latent WT or constitutively activated LFA-1 engrafted in the lungs of SCID mice are selectively targeted by intravenously injected fusion protein–siRNA complexes, demonstrating the potentialin vivoapplicability of LFA-1-directed siRNA delivery.
Innate response to self-antigen significantly exacerbates burn wound depth
Authors: Suber Freeman , Carroll Michael C. , Moore Francis D.
Published: March 2007

A major component of burn injury is caused by additional local damage from acute inflammation. Using a scald burn model in mice, we find that this part of the injury is dependent on recognition of self-antigen by specific natural IgM, leading to activation of the complement system. We propose that the depth of a burn wound is a sum of the thermal energy applied and of the degree of host inflammatory response.
Systematic genome instability screens in yeast and their potential relevance to cancer
Authors: Yuen Karen W. Y. , Warren Cheryl D. , Chen Ou , Kwok Teresa , Hieter Phil , Spencer Forrest A.
Published: March 2007

To systematically identify genes that maintain genome structure, yeast knockout mutants were examined by using three assays that followed marker inheritance in different chromosomal contexts. These screens identified 130 null mutant strains exhibiting chromosome instability (CIN) phenotypes. Differences in both phenotype severity and assay specificity were observed. The results demonstrate the advantages of using complementary assays to comprehensively identify genome maintenance determinants. Genome structure was important in determining the spectrum of gene and pathway mutations causing a chromosome instability phenotype. Protein similarity identified homologues in other species, including human genes with relevance to cancer. This extensive genome instability catalog can be combined with emerging genetic interaction data from yeast to support the identification of candidate targets for therapeutic elimination of chromosomally unstable cancer cells by selective cell killing.
Predicting response to breast cancer neoadjuvant chemotherapy using diffuse optical spectroscopy
Authors: Cerussi Albert , Hsiang David , Shah Natasha , Mehta Rita , Durkin Amanda , Butler John , Tromberg Bruce J.
Published: March 2007

Diffuse optical spectroscopy (DOS) and imaging are emerging diagnostic techniques that quantitatively measure the concentration of deoxy-hemoglobin (ctHHb), oxy-hemoglobin (ctO
2
Hb), water (ctH
2
O), and lipid in cm-thick tissues. In early-stage clinical studies, diffuse optical imaging and DOS have been used to characterize breast tumor biochemical composition and monitor therapeutic response in stage II/III neoadjuvant chemotherapy patients. We investigated whether DOS measurements obtained before and 1 week into a 3-month adriamycin/cytoxan neoadjuvant chemotherapy regimen can predict final, postsurgical pathological response. Baseline DOS measurements of 11 patients before therapy revealed significant increases in tumor ctHHb, ctO
2
Hb, ctH
2
O, and spectral scattering slope, and decreases in bulk lipids, relative to normal breast tissue. Tumor concentrations of ctHHb, ctO
2
Hb, and ctH
2
O dropped 27 ± 15%, 33 ± 7%, and 11 ± 15%, respectively, within 1 week (6.5 ± 1.4 days) of the first treatment for pathology-confirmed responders (
n
= 6), whereas nonresponders (
n
= 5) and normal side controls showed no significant changes in these parameters. The best single predictor of therapeutic response 1 week posttreatment was ctHHb (83% sensitivity, 100% specificity), while discrimination analysis based on combined ctHHb and ctH
2
O changes classified responders vs. nonresponders with 100% sensitivity and specificity. In addition, the pretreatment tumor-to-normal ctO
2
Hb ratio was significantly higher in responders (2.82 ± 0.44) vs. nonresponders (1.82 ± 0.49). These results highlight DOS sensitivity to tumor cellular metabolism and biochemical composition and demonstrate its potential for predicting and monitoring an individual's response to treatment.
Mathematical modeling of cell population dynamics in the colonic crypt and in colorectal cancer
Authors: Johnston Matthew D. , Edwards Carina M. , Bodmer Walter F. , Maini Philip K. , Chapman S. Jonathan
Published: March 2007

Colorectal cancer is initiated in colonic crypts. A succession of genetic mutations or epigenetic changes can lead to homeostasis in the crypt being overcome, and subsequent unbounded growth. We consider the dynamics of a single colorectal crypt by using a compartmental approach [Tomlinson IPM, Bodmer WF (1995)
Proc Natl Acad Sci USA
92:
11130–11134
], which accounts for populations of stem cells, differentiated cells, and transit cells. That original model made the simplifying assumptions that each cell population divides synchronously, but we relax these assumptions by adopting an age-structured approach that models asynchronous cell division, and by using a continuum model. We discuss two mechanisms that could regulate the growth of cell numbers and maintain the equilibrium that is normally observed in the crypt. The first will always maintain an equilibrium for all parameter values, whereas the second can allow unbounded proliferation if the net per capita growth rates are large enough. Results show that an increase in cell renewal, which is equivalent to a failure of programmed cell death or of differentiation, can lead to the growth of cancers. The second model can be used to explain the long lag phases in tumor growth, during which new, higher equilibria are reached, before unlimited growth in cell numbers ensues.
Gallium (III) triflate catalyzed efficient Strecker reaction of ketones and their fluorinated analogs
Authors: Prakash G. K. Surya , Mathew Thomas , Panja Chiradeep , Alconcel Steevens , Vaghoo Habiba , Do Clement , Olah George A.
Published: March 2007

The synthesis of α-aminonitriles and their fluorinated analogs has been carried out in high yield and purity by the Strecker reaction from the corresponding ketones and amines with trimethylsilyl cyanide using gallium triflate in dichloromethane. Monofluoro-, difluro-, or trifluoromethyl groups can be incorporated into the α-aminonitrile product by varying the nature of the fluorinated ketones. Study with various fluorinated and nonfluorinated ketones reveals that the choice of proper catalyst and the solvent system (suitable metal triflates as a catalyst and dichloromethane as a solvent) plays the key role in the direct Strecker reactions of ketones.
Lifting cusp forms to Maass forms with an application to partitions
Authors: Bringmann Kathrin , Ono Ken
Published: March 2007

For 2 <
k
∈

1
2

ℤ

, we define lifts of cuspidal Poincaré series in

S
k

(Γ
0
(
N
)) to weight 2 −
k
harmonic weak Maass forms. This construction answers a question of Dyson by providing the general framework “explaining” Ramanujan's mock theta functions. As an application, we show that the number of partitions of a positive integer
n
is the “trace” of singular moduli of a Maass form arising from the lift of a weight 4 cusp form corresponding to a Calabi–Yau threefold.
Neuronal growth and survival mediated by eIF5A, a polyamine-modified translation initiation factor
Authors: Huang Yunfei , Higginson Daniel S. , Hester Lynda , Park Myung Hee , Snyder Solomon H.
Published: March 2007

Eukaryotic translation initiation factor 5A (eIF5A), the only known protein containing the polyamine-derived amino acid hypusine, modulates protein synthesis. We show that neurotrophic and neuroprotective actions of nerve growth factor (NGF) are mediated by hypusinated eIF5A, which can account for the known roles of polyamines in cell growth and survival. NGF treatment of PC12 cells stimulates eIF5A formation. Moreover, prevention of hypusine formation by a selective inhibitor of deoxyhypusine synthase and by its depletion with RNA interference blocks the NGF-elicited augmentation of neurite outgrowth and cell survival of PC12 cells. In brain cultures, inhibition of hypusine formation also inhibits neuronal process extension.
The proton pumping pathway of bovine heart cytochrome
c
oxidase
Authors: Shimokata Kunitoshi , Katayama Yukie , Murayama Haruka , Suematsu Makoto , Tsukihara Tomitake , Muramoto Kazumasa , Aoyama Hiroshi , Yoshikawa Shinya , Shimada Hideo
Published: March 2007

X-ray structures of bovine heart cytochrome
c
oxidase have suggested that the enzyme, which reduces O
2
in a process coupled with a proton pumping process, contains a proton pumping pathway (H-pathway) composed of a hydrogen bond network and a water channel located in tandem across the enzyme. The hydrogen bond network includes the peptide bond between Tyr-440 and Ser-441, which could facilitate unidirectional proton transfer. Replacement of a possible proton-ejecting aspartate (Asp-51) at one end of the H-pathway with asparagine, using a stable bovine gene expression system, abolishes the proton pumping activity without influencing the O
2
reduction function. Blockage of either the water channel by a double mutation (Val386Leu and Met390Trp) or proton transfer through the peptide by a Ser441Pro mutation was found to abolish the proton pumping activity without impairment of the O
2
reduction activity. These results significantly strengthen the proposal that H-pathway is involved in proton pumping.
Steroid receptor coactivator 3 is a coactivator for myocardin, the regulator of smooth muscle transcription and differentiation
Authors: Li Hui Joyce , Haque Zaffar , Lu Qing , Li Li , Karas Richard , Mendelsohn Michael
Published: March 2007

Abnormal proliferation of vascular smooth muscle cells (VSMCs) constitutes a key event in atherosclerosis, neointimal hyperplasia, and the response to vascular injury. Estrogen receptor α (ERα) mediates the protective effects of estrogen in injured blood vessels and regulates ligand-dependent gene expression in vascular cells. However, the molecular mechanisms mediating ERα-dependent VSMC gene expression and VSMC proliferation after vascular injury are not well defined. Here, we report that the ER coactivator steroid receptor coactivator 3 (SRC3) is also a coactivator for the major VSMC transcription factor myocardin, which is required for VSMC differentiation to the nonproliferative, contractile state. The N terminus of SRC3, which contains a basic helix-loop-helix/Per-ARNT-Sim protein–protein interaction domain, binds the C-terminal activation domain of myocardin and enhances myocardin-mediated transcriptional activation of VSMC-specific, CArG-containing promoters, including the VSMC-specific genes SM22 and myosin heavy chain. Suppression of endogenous SRC3 expression by specific small interfering RNA attenuates myocardin transcriptional activation in cultured cells. The SRC3–myocardin interaction identifies a site of convergence for nuclear hormone receptor-mediated and VSMC-specific gene regulation and suggests a possible mechanism for the vascular protective effects of estrogen on vascular injury.
A phase I clinical trial with monoclonal antibody ch806 targeting transitional state and mutant epidermal growth factor receptors
Authors: Scott Andrew M. , Lee Fook-Thean , Tebbutt Niall , Herbertson Rebecca , Gill Sanjeev S. , Liu Zhanqi , Skrinos Effie , Murone Carmel , Saunder Timothy H. , Chappell Bridget , Papenfuss Anthony T. , Poon Aurora M. T. , Hopkins Wendie , Smyth Fiona E. , MacGregor Duncan , Cher Lawrence M. , Jungbluth Achim A. , Ritter Gerd , Brechbiel Martin W. , Murphy Roger , Burgess Antony W. , Hoffman Eric W. , Johns Terrance G. , Old Lloyd J.
Published: March 2007

An array of cell-surface antigens expressed by human cancers have been identified as targets for antibody-based therapies. The great majority of these antibodies do not have specificity for cancer but recognize antigens expressed on a range of normal cell types (differentiation antigens). Over the past two decades, our group has analyzed thousands of mouse monoclonal antibodies for cancer specificity and identified a battery of antibodies with limited representation on normal human cells. The most tumor-specific of these antibodies is 806, an antibody that detects a unique epitope on the epidermal growth factor receptor (EGFR) that is exposed only on overexpressed, mutant, or ligand-activated forms of the receptor in cancer.
In vitro
immunohistochemical specificity analysis shows little or no detectable 806 reactivity with normal tissues, even those with high levels of wild-type (wt)EGFR expression. Preclinical studies have demonstrated that 806 specifically targets a subset of EGFR expressed on tumor cells, and has significant anti-tumor effects on human tumor xenografts, primarily through abrogation of signaling pathways. The present clinical study was designed to examine the
in vivo
specificity of a chimeric form of mAb 806 (ch806) in a tumor targeting/biodistribution/pharmacokinetic analysis in patients with diverse tumor types. ch806 showed excellent targeting of tumor sites in all patients, no evidence of normal tissue uptake, and no significant toxicity. These
in vitro
and
in vivo
characteristics of ch806 distinguish it from all other antibodies targeting EGFR.
Ischemic insults promote epigenetic reprogramming of μ opioid receptor expression in hippocampal neurons
Authors: Formisano Luigi , Noh Kyung-Min , Miyawaki Takahiro , Mashiko Toshihiro , Bennett Michael V. L. , Zukin R. Suzanne
Published: March 2007

Transient global ischemia is a neuronal insult that induces delayed, selective death of hippocampal CA1 pyramidal neurons. A mechanism underlying ischemia-induced cell death is activation of the gene silencing transcription factor REST (repressor element-1 silencing transcription factor)/NRSF (neuron-restrictive silencing factor) and REST-dependent suppression of the AMPA receptor subunit GluR2 in CA1 neurons destined to die. Here we show that REST regulates an additional gene target, OPRM1 (μ opioid receptor 1 or MOR-1). MORs are abundantly expressed by basket cells and other inhibitory interneurons of CA1. Global ischemia induces a marked decrease in MOR-1 mRNA and protein expression that is specific to the selectively vulnerable area CA1, as assessed by quantitative real-time RT-PCR, Western blotting, and ChIP. We further show that OPRM1 gene silencing is REST-dependent and occurs via epigenetic modifications. Ischemia promotes deacetylation of core histone proteins H3 and H4 and dimethylation of histone H3 at lysine-9 (H3-K9) over the MOR-1 promoter, an signature of epigenetic gene silencing. Acute knockdown of MOR-1 gene expression by administration of antisense oligodeoxynucleotides to hippocampal slicesin vitroor injection of the MOR antagonist naloxone to ratsin vivoaffords protection against ischemia-induced death of CA1 pyramidal neurons. These findings implicate MORs in ischemia-induced death of CA1 pyramidal neurons and document epigenetic remodeling of expression of OPRM1 in CA1 inhibitory interneurons.
E-Syts, a family of membranous Ca
2+
-sensor proteins with multiple C
2
domains
Authors: Min Sang-Won , Chang Wen-Pin , Südhof Thomas C.
Published: March 2007

C
2
domains are autonomously folded protein modules that generally act as Ca
2+
- and phospholipid-binding domains and/or as protein–protein interaction domains. We now report the primary structures and biochemical properties of a family of evolutionarily conserved mammalian proteins, referred to as E-Syts, for extended synaptotagmin-like proteins. E-Syts contain an N-terminal transmembrane region, a central juxtamembranous domain that is conserved from yeast to human, and five (E-Syt1) or three (E-Syt2 and E-Syt3) C-terminal C
2
domains. Only the first E-Syt C
2
domain, the C
2
A domain, includes the complete sequence motif that is required for Ca
2+
binding in C
2
domains. Recombinant protein fragments of E-Syt2 that include the first C
2
domain are capable of Ca
2+
-dependent phospholipid binding at micromolar concentrations of free Ca
2+
, suggesting that E-Syts bind Ca
2+
through their first C
2
domain in a phospholipid complex. E-Syts are ubiquitously expressed, but enriched in brain. Expression of myc-tagged E-Syt proteins in transfected cells demonstrated localization to intracellular membranes for E-Syt1 and to plasma membranes for E-Syt2 and E-Syt3. Structure/function studies showed that the plasma-membrane localization of E-Syt2 and E-Syt3 was directed by their C-terminal C
2
C domains. This result reveals an unexpected mechanism by which the C
2
C domains of E-Syt2 and E-Syt3 functions as a targeting motif that localizes these proteins into the plasma membrane independent of their transmembrane region. Viewed together, our findings suggest that E-Syts function as Ca
2+
-regulated intrinsic membrane proteins with multiple C
2
domains, expanding the repertoire of such proteins to a fourth class beyond synaptotagmins, ferlins, and MCTPs (multiple C
2
domain and transmembrane region proteins).
Heterotrimeric G protein signaling in theArabidopsisunfolded protein response
Authors: Wang Shiyu , Narendra Savitha , Fedoroff Nina
Published: March 2007

We present evidence that heterotrimeric G protein signaling is involved in cell death associated with the unfolded protein response (UPR) inArabidopsis. Seedlings of homozygousagb1-2(Gβ-null mutation) mutant plants are markedly more resistant to growth inhibition by the protein glycosylation inhibitor tunicamycin (Tm) than either wild-type plants orgpa1-4(Gα-null mutation) mutants. Leaves of older Gβ mutant plants show much less cell death when infiltrated with Tm than leaves of wild-type plants. The transcriptional response of Gβ mutant plants to Tm is less pronounced than that of wild-type plants, as is the accumulation of BiP chaperone proteins. A majority of theArabidopsisGβ protein is associated with the endoplasmic reticulum (ER) and cofractionates with membrane-associated ER luminal BiP. Consistent with its ER localization, Gβ protein is degraded during the UPR, whereas Gα protein is not. Taken together, these observations imply that the Gβ protein, which forms a stable heterodimer with the Gγ subunit, is involved in the signaling events that trigger UPR-associated cell death. The different Tm sensitivities of Gα and Gβ mutants, the ER localization of Gβ, and the differential stabilities of Gα and Gβ proteins during the UPR suggest that the Gβγ complex serves a signaling function in the ER independent of its function in the Gαβγ heterotrimer.
Loss of a histone deacetylase dramatically alters the genomic distribution of Spo11p-catalyzed DNA breaks in
Saccharomyces cerevisiae
Authors: Mieczkowski Piotr A. , Dominska Margaret , Buck Michael J. , Lieb Jason D. , Petes Thomas D.
Published: March 2007

In eukaryotes, meiotic recombination events are distributed nonrandomly in the genome, with certain regions having high levels of recombination (hotspots) and others having low levels (coldspots). Species with similar DNA sequences (for example, chimpanzees and humans) can have strikingly different patterns of hotspots and coldspots. Below, by using a microarray analysis that allows us to measure the frequency of the meiosis-specific double-strand DNA breaks (DSBs) of all 6,000 yeast genes, we show that mutation of a single gene (
SIR2
), which encodes a histone deacetylase, significantly changes DSB frequencies of 12% of yeast genes, elevating DSBs of 5%, and reducing DSBs of 7%. Many of the genes with repressed recombination are located in large (50–100 kb) regions located near, but not at, the telomeres. Some of the genes with altered frequencies of DSBs (including the ribosomal RNA gene cluster) are known targets of Sir2p deacetylation in the wild-type strain.
On reflections in Jordan curves
Authors: Broch Ole
Published: March 2007

A purely geometric method for constructing reflections in Jordan curves on the Riemann sphere based on hyperbolic geodesics is introduced. It is then possible to investigate the relations between the geometry of a Jordan domain

D
D

and the properties of the reflection by studying properties of hyperbolic geodesics. This idea is used to characterize unbounded Jordan John domains in terms of reflections satisfying a kind of Lipschitz condition.
Meta‐Analysis Comparison of Open Versus Percutaneous Tracheostomy
Authors: Higgins Kevin M. , Punthakee Xerxes
Published: March 2007

Objectives/Hypothesis: Multiple studies have been performed to characterize differences in complications and cost‐effectiveness of open and percutaneous tracheostomy; however, large enough studies have not been performed to determine a clearly superior method. Our primary objective was to compare complication rates of open versus percutaneous tracheostomy in prospective, randomized‐controlled trials using meta‐analysis methodology. Secondary objectives included cost‐effectiveness and procedure length analyses.

Study Design: Meta‐analysis.

Methods: From 368 abstracts, 15 prospective, randomized‐controlled trials involving nearly 1,000 patients were reviewed to extract basic demographic data in addition to complications, case length, and cost‐effectiveness. Pooled odds ratios (OR) with confidence intervals (CI) were calculated in addition to subgroup analyses and meta‐regression.

Results: Pooled OR revealed statistically significant results against percutaneous tracheostomy for the complication of decannulation/obstruction (OR 2.79, 95% CI 1.29‐6.03). There were significantly fewer complications in the percutaneous group with respect to wound infection (0.37, 0.22‐0.62) and unfavorable scarring (0.44, 0.23‐0.83). There was no statistically significant difference for complications of false passage (2.70, 0.89‐8.22), minor hemorrhage (1.09, 0.61‐1.97, P = .77), major hemorrhage (0.60, 0.28‐1.26), subglottic stenosis (0.59, 0.27‐1.29), death (0.70, 0.24‐2.01), and overall complications (0.75, 0.56‐1.00). However, the overall complications trended toward favoring the percutaneous technique. Percutaneous tracheostomy case length was shorter overall by 4.6 minutes, and costs were less by approximately $456 USD.

Conclusions: Our meta‐analysis illustrates there is no clear difference but a trend toward fewer complications in percutaneous techniques. Percutaneous tracheotomies are more cost‐effective and provide greater feasibility in terms of bedside capability and nonsurgical operation.
No Negative Outcomes of Childhood Middle Ear Disease in Adulthood
Authors: Welch David , Dawes Patrick
Published: March 2007

Objectives/Hypothesis: To test the hypothesis that childhood middle‐ear disease may have disadvantageous long‐term psychosocial consequences in adulthood.

Study Design: Prospective, longitudinal study of a general‐population birth cohort.

Methods: One thousand thirty‐seven people born in 1972/73 were studied from birth to age 26 when 1,019 (96% of survivors) were followed up. Childhood otitis media was assessed, and effects of it have previously been observed in childhood and adolescence. We considered outcome measures that were plausible adult counterparts of the childhood constructs shown to be impaired by otitis media: socioeconomic status, employment status, educational outcomes, personality, mental health, antisocial and criminal behavior, and subjective ratings of personal health (SF‐36).

Results: No outcome measure was predicted by severity of childhood otitis media.

Conclusions; Adult psychological and socioeconomic outcomes are not related to childhood otitis media when appropriate treatment is available.
Exclusion of pH Artifacts is Essential for Hypopharyngeal pH Monitoring
Authors: Harrell Steven P. , Koopman Jennifer , Woosley Scheryl , Wo John M.
Published: March 2007

Background: Published yields of pH monitoring for suspected laryngopharyngeal reflux (LPR) vary greatly. Hypopharyngeal pH artifacts may be responsible for these inconsistencies.

Objective: To determine the impact of potential artifacts on pH monitoring of the hypopharynx and esophagus.

Methods: Patients with suspected LPR were prospectively studied. Single‐catheter, triple‐sensor pH monitoring was performed off antireflux therapy. Subjects recorded meal times and marked liquid swallows outside of meals on the data recorder. Results were analyzed by excluding six potential pH artifacts individually and all together. Positive pH test was defined as three or more reflux episodes in hypopharynx, total percent of time pH less than 4 was 1.0% or greater in the proximal esophagus, and total percent of time pH less than 4 was 4.2% or greater in the distal esophagus. Wilcoxon rank sum and chi‐square tests were used.

Results: Thirty‐eight subjects (24 females; median age, 47 yr) completed the study. A total of 2,225 hypopharyngeal pH drops less than 4 were identified; 48% were short pH drops at less than 5 seconds, 17% within meal periods, 16% liquid swallows outside of meals, 16% isolated proximal pH drops, 12% pH out of range, and 5% pH drift. Eighty percent of the hypopharyngeal pH drops were at least one of the potential pH artifacts. The yield of the hypopharyngeal sensor was reduced by 45% (from 92% to 47%) after all potential pH artifacts were excluded. Yields of proximal and distal esophageal pH sensors were reduced by 19% and 8%, respectively, significantly less than the hypopharyngeal sensor (P < .01).

Conclusions: Patients should record all liquid swallows outside of meals. It is essential to exclude all potential artifacts for hypopharyngeal pH monitoring in patients with suspected LPR.
Quality of Life After Facial Nerve Repair
Authors: Guntinas‐Lichius Orlando , Straesser Arianna , Streppel Michael
Published: March 2007

Objectives: Analyze the postoperative quality of life (QoL) in patients after surgical nerve repair for facial nerve lesion.

Study Design: Descriptive study using questionnaire data and medical chart review.

Methods: Forty‐nine patients answered the Short Form‐36 (SF‐36), the European Organization for Research and Treatment (EORTC) questionnaires QLQ‐C30 and QLQ‐HN35, and a modification of the Acoustic Neuroma Hospital of Norway Survey. Facial function was self‐evaluated by the patients using the House‐Brackmann (HB) scale and the Stennert index (SI). The questionnaire data were analyzed in relation to the medical chart data.

Results: The follow‐up time ranged from 12 to 202 months. The underlying disease was benign in 34 (61%) patients and malignant in 15 (39%) patients. Facial nerve repair was successful in all patients, with a mean HB scale of 3.1, a mean SI of 4.9, and a mean May grading of 2.7. The facial function self‐evaluation was not significantly different. Seventy‐five percent of the patients were satisfied with the operation. The SF‐36 demonstrated a significantly lower social functioning, emotional role, general mental health, and vitality lower than in the normal German population. In the EORTC QLQ C30, emotional function was low and the insomnia rate high. EORTC QLQ HN35 showed a high rate of trouble with social eating, less sexuality, problems opening mouth, and weight gain problems. Age 45 years or older, female sex, May grading 3 or greater, SI self‐assessment 5 or greater, HB self‐assessment greater than 2 had a significant negative effect on some QoL items, but not factors such as type or histology of the disease or delayed reconstruction.

Conclusions: Although grading of facial function after nerve repair revealed satisfying results, the patients experience a reduced QoL.
New Perspectives for Middle Ear Implants: First Results in Otosclerosis With Mixed Hearing Loss
Authors: Venail Frederic , Lavieille Jean Pierre , Meller Renaud , Deveze Arnaud , Tardivet Laurent , Magnan Jacques
Published: March 2007

Middle ear implantation is an efficient procedure to restore moderate to severe sensorineural hearing loss (HL) in selected patients. Implantation of such devices requires ossicular chain integrity. Patients suffering from otosclerosis with mixed HL should be eligible for this treatment after stapes surgery with air‐bone gap closure. To address this issue, we report four cases of middle ear implantation after or during stapes surgery. Results and complications obtained with Vibrant SoundBridge, MedEl and Middle Ear Transducer, Otologics are reported. Audiologic results were similar to those obtained in cases of sensorineural HL. One case of postoperative labyrinthitis was observed.