bluuebunny/crossref_metadata_2025 huggingface dataset:
Voix de femme, corps de danse
Authors: Vassas Claudine
Published: June 2011

Résumé L’une des premières réalisations de Pina Bausch, un « opéra dansé » de 1974 (l’Orphée de Gluck) très récemment redécouverte, semble se détacher de l’ensemble de son œuvre. Pourtant une mise en perspective de cette pièce avec une œuvre postérieure comme Café Müller permet de faire l’hypothèse d’une esthétique du corps tragique propre à la chorégraphe, portée par des voix de femmes. Ce tragique qu’elle incarne tout particulièrement quand elle danse, au point d’y déceler sa signature, est lisible dans le rapport singulier qu’elle instaure entre les chanteurs et les danseurs, les passages qu’elle ménage de la voix au corps, du corps à la voix.
L'opposition parlementaire en Italie et au Royaume-Uni : une opposition systémique ou axée sur les enjeux ?
Authors: De Giorgi Elisabetta
Published: June 2011

Résumé Les typologies de l’opposition qui ont été établies au fil des années ont souvent tenu compte des facteurs systémiques dont on pensait qu’ils avaient un impact sur les caractéristiques principales de l’opposition dans toute démocratie parlementaire, tels que le système électoral ou le régime des partis, la force et la composition de l’exécutif et les règles du jeu parlementaire. Ce travail tente d’aller un pas plus loin afin de mieux appréhender l’influence que ces variables exercent sur l’exercice concret de l’opposition au parlement aujourd’hui, en distinguant deux niveaux d’analyse différents : un niveau interne, centré sur les rapports entre les acteurs de l’opposition et, plus particulièrement, sur leur cohésion organisationnelle, et un niveau externe, centré sur les rapports entre le gouvernement et l’opposition. Ce travail examine deux cas très différents en ce qui concerne les principales variables systémiques prises en considération : l’Italie et le Royaume-Uni.
L'opposition au Parlement Quelques éléments de comparaison
Authors: Surel Yves
Published: June 2011

Résumé L’objectif de cet article est de proposer des éléments et pistes de réflexion sur l’opposition parlementaire dans une perspective de politique comparée. Plus particulièrement, cette contribution identifie quatre séries de facteurs explicatifs permettant d’analyser le pouvoir relatif de l’opposition parlementaire : la forme du régime et la position institutionnelle des chambres législatives dans le système politique ; les droits et dispositifs juridiques et/ou procéduraux garantis à l’opposition dans l’enceinte parlementaire ; les pratiques informelles de l’opposition et enfin, les caractéristiques des parlementaires. La prise en compte et l’analyse de ces quatre dimensions devraient permettre de déterminer la puissance relative de l’opposition parlementaire, de ses capacités d’action et d’influence et de mesurer empiriquement les variations entre pays.
Simulation in an Undergraduate Nursing Curriculum: Implementation and Impact Evaluation
Authors: Schlairet Maura C.
Published: June 2011

Although endorsed by nursing professional bodies and incorporated into undergraduate nursing curricula, high-fidelity simulation has undergone little evaluation at the program or curriculum levels. A comprehensive program evaluation of a Simulation Demonstration Project was undertaken to explore the influence of simulation across an undergraduate curriculum in a college of nursing. The focus of the evaluation was on program activities accomplished (implementation evaluation) and the extent to which program objectives and outcomes were met (impact evaluation). The Nursing Education Simulation Framework (NESF) was used to arrange multiple variables to be explored and to support the use of diverse simulation-related data sources. The framework was helpful in both guiding the evaluation and interpreting the results at the curriculum level from implementation and impact perspectives. Although continued use and testing of the NESF is warranted, findings from the study supported the utility of the NESF in program evaluation of simulation at the curriculum level.
Retropupillary Fixation of Iris-claw Intraocular Lens Versus Transscleral Suturing Fixation for Aphakic Eyes Without Capsular Support
Authors: Hara Shuya , Borkenstein Andreas F.M. , Ehmer Angela , Auffarth Gerd U.
Published: June 2011

PURPOSE:

Retropupillary fixation of an iris-claw intraocular lens (IOL) (Verisyse, Abbott Medical Optics) was performed for aphakic eyes without sufficient capsular support, and safety and recovery of the procedure were compared with transscleral suturing fixation.

METHODS:

This interventional case series comprised 11 eyes of 10 aphakic patients without capsular support undergoing retropupillary fixation of the Verisyse, and 21 eyes of 20 patients undergoing transscleral suturing fixation of foldable acrylic IOLs (15 eyes of 14 patients, SuperFlex620H [Rayner Intraocular Lenses Ltd]) and polymethylmethacrylate IOLs (6 eyes of 6 patients, CP60NS [CORNEAL Laboratoire]). Surgical time was measured. Corrected distance visual acuity (CDVA) and intraocular pressure (IOP) were examined preoperatively and 1 day, 1 and 2 weeks, and 1 and 6 months postoperatively.

RESULTS:

No complications occurred in the Verisyse group, whereas complications were reported in seven eyes in the transscleral suturing fixation group throughout follow-up. Mean CDVA (logMAR) in the transscleral suturing group 1 day after surgery was significantly worse than preoperative CDVA (
P
<.05). In the Verisyse group, no significant changes in CDVA were noted at any time point. Mean IOP at postoperative day 1 in the transscleral suturing fixation group was significantly higher than that in the Verisyse group (
P
=.0126). Mean surgical time of Verisyse implantation (20.0±8.9 min) was significantly shorter than transscleral suturing fixation (49.7±18.9 min) (
P
<.0001).

CONCLUSIONS:

Retropupillary fixation of an iris-claw IOL provides early visual recovery, has a low risk of postoperative increase in IOP, and is a time-saving method compared with transscleral suturing fixation for aphakic eyes without sufficient capsular support.
A Critical Role for Granzymes in Antigen Cross-Presentation through Regulating Phagocytosis of Killed Tumor Cells
Authors: Hoves Sabine , Sutton Vivien R. , Haynes Nicole M. , Hawkins Edwin D. , Fernández Ruiz Daniel , Baschuk Nikola , Sedelies Karin A. , Schnurr Maximilian , Stagg John , Andrews Daniel M. , Villadangos Jose A. , Trapani Joseph A.
Published: June 2011

Granzymes A and B (GrAB) are known principally for their role in mediating perforin-dependent death of virus-infected or malignant cells targeted by CTL. In this study, we show that granzymes also play a critical role as inducers of Ag cross-presentation by dendritic cells (DC). This was demonstrated by the markedly reduced priming of naive CD8+ T cells specific for the model Ag OVA both in vitro and in vivo in response to tumor cells killed in the absence of granzymes. Reduced cross-priming was due to impairment of phagocytosis of tumor cell corpses by CD8α+ DC but not CD8α− DC, demonstrating the importance of granzymes in inducing the exposure of prophagocytic “eat-me” signals on the dying target cell. Our data reveal a critical and previously unsuspected role for granzymes A and B in dictating immunogenicity by influencing the mode of tumor cell death and indicate that granzymes contribute to the efficient generation of immune effector pathways in addition to their well-known role in apoptosis induction.
Proapoptotic and Antiapoptotic Actions of Stat1 versus Stat3 Underlie Neuroprotective and Immunoregulatory Functions of IL-11
Authors: Zhang Jingya , Zhang Yueting , Dutta Dipankar J. , Argaw Azeb T. , Bonnamain Virginie , Seto Jeremy , Braun David A. , Zameer Andleeb , Hayot Fernand , Lòpez Carolina B. , Raine Cedric S. , John Gareth R.
Published: June 2011

Current therapies for multiple sclerosis target inflammation but do not directly address oligodendrocyte protection or myelin repair. The gp130 family cytokines ciliary neurotrophic factor, leukemia inhibitory factor, and IL-11 have been identified as oligodendrocyte growth factors, and IL-11 is also strongly immunoregulatory, but their underlying mechanisms of action are incompletely characterized. In this study, we demonstrate that these effects of IL-11 are mediated via differential regulation of apoptosis in oligodendrocytes versus Ag-presenting dendritic cells (DCs), and are dependent on lineage-specific activity of the transcription factors Stat1 versus Stat3. Focal demyelinating lesions induced in cerebral cortices of IL-11Rα−/− mice using stereotactic microinjection of lysolecithin were larger than in controls, and remyelination was delayed. In IL-11Rα−/− mice, lesions displayed extensive oligodendrocyte loss and axonal transection, and increased infiltration by inflammatory cells including CD11c+ DCs, CD3+ lymphocytes, and CD11b+ phagocytes. In oligodendrocyte progenitor cell (OPC) cultures, IL-11 restricted caspase 9 activation and apoptosis, and it increased myelination in OPC-neuron cocultures. Importantly, siRNA inhibition of Stat1 enhanced the antiapoptotic effects of IL-11 on OPCs, but IL-11 induced apoptosis in the presence of Stat3 silencing. In contrast, IL-11 augmented caspase activation and apoptosis in cultures of CD11c+ DCs, but not in CD11b+ or CD3+ cells. Inhibition of Stat3 exacerbated the proapoptotic effects of IL-11 on DCs, whereas they were ablated in Stat1−/− cultures. Collectively, these findings reveal novel mechanisms underlying the actions of a neuroprotective and immunoregulatory member of the gp130 cytokine family, suggesting avenues to enhance oligodendrocyte viability and restrict CNS inflammation in multiple sclerosis.
Macrophage-Specific Expression of Urokinase-Type Plasminogen Activator Promotes Skeletal Muscle Regeneration
Authors: Novak Margaret L. , Bryer Scott C. , Cheng Ming , Nguyen Mai-Huong , Conley Kevin L. , Cunningham Andrew K. , Xue Bing , Sisson Thomas H. , You Jae-Sung , Hornberger Troy A. , Koh Timothy J.
Published: June 2011

Macrophages (Mp) and the plasminogen system play important roles in tissue repair following injury. We hypothesized that Mp-specific expression of urokinase-type plasminogen activator (uPA) is sufficient for Mp to migrate into damaged muscle and for efficient muscle regeneration. We generated transgenic mice expressing uPA only in Mp, and we assessed the ability of these mice to repair muscle injury. Mp-only uPA expression was sufficient to induce wild-type levels of Mp accumulation, angiogenesis, and new muscle fiber formation. In mice with wild-type uPA expression, Mp-specific overexpression further increased Mp accumulation and enhanced muscle fiber regeneration. Furthermore, Mp expression of uPA regulated the level of active hepatocyte growth factor, which is required for muscle fiber regeneration, in damaged muscle. In vitro studies demonstrated that uPA promotes Mp migration through proteolytic and nonproteolytic mechanisms, including proteolytic activation of hepatocyte growth factor. In summary, Mp-derived uPA promotes muscle regeneration by inducing Mp migration, angiogenesis, and myogenesis.
IL-15Rα of Radiation-Resistant Cells Is Necessary and Sufficient for Thymic Invariant NKT Cell Survival and Functional Maturation
Authors: Chang Chin-Ling , Lai Yein-Gei , Hou Mau-Sheng , Huang Po-Lin , Liao Nan-Shih
Published: June 2011

The development of invariant NKT (iNKT) cells depends on the thymus. After positive selection by CD4+CD8+CD1d+ cortical thymocytes, iNKT cells proceed from CD44lowNK1.1− (stage 1) to CD44highNK1.1− (stage 2), and then to CD44highNK1.1+ (stage 3) cells. The programming of cytokine production occurs along the three differentiation stages, whereas the acquisition of NK receptors occurs at stage 3. Stage 3 thymic iNKT cells are specifically reduced in Il15ra−/− mice. The mechanism underlying this homeostatic deficiency and whether the IL-15 system affects other thymic iNKT cell developmental events remain elusive. In this study, we demonstrate that increased cell death contributed to the reduction of stage 3 cells in Il15ra−/− mice, as knockout of Bim restored this population. IL-15–dependent upregulation of Bcl-2 in stage 3 cells affected cell survival, as overexpression of hBcl-2 partially restored stage 3 cells in Il15ra−/− mice. Moreover, thymic iNKT cells in Il15ra−/− mice were impaired in functional maturation, including the acquisition of Ly49 and NKG2 receptors and the programming of cytokine production. Finally, IL-15Rα expressed by radiation-resistant cells is necessary and sufficient to support the survival as well as the examined maturation events of thymic iNKT cells.
Cytosolic DNA-Activated Human Dendritic Cells Are Potent Activators of the Adaptive Immune Response
Authors: Kis-Toth Katalin , Szanto Attila , Thai To-Ha , Tsokos George C.
Published: June 2011

Recent studies in cell lines and genetically engineered mice have demonstrated that cytosolic dsDNA could activate dendritic cells (DCs) to become effector APCs. Recognition of DNA might be a major factor in antimicrobial immune responses against cytosolic pathogens and also in human autoimmune diseases such as systemic lupus erythematosus. However, the role of cytosolic dsDNA in human DC activation and its effects on effector T and B cells are still elusive. In this study, we demonstrate that intracellular dsDNA is a potent activator of human monocyte-derived DCs as well as primary DCs. Activation by dsDNA depends on NF-κB activation, partially on the adaptor molecule IFN-promoter stimulator-1 and the novel cytosolic dsDNA receptor IFI16, but not on the previously recognized dsDNA sentinels absent in melanoma 2, DNA-dependent activator of IFN regulatory factor 3, RNA polymerase III, or high-mobility group boxes. More importantly, we report for the first time, to our knowledge, that human dsDNA-activated DCs, rather than LPS- or inflammatory cytokine mixture-activated DCs, represent the most potent inducers of naive CD4+ T cells to promote Th1-type cytokine production and generate CD4+ and CD8+ cytotoxic T cells. dsDNA-DCs, but not LPS- or mixture-activated DCs, induce B cells to produce complement-fixing IgG1 and IgG3 Abs. We propose that cytosolic dsDNA represents a novel, more effective approach to generate DCs to enhance vaccine effectiveness in reprogramming the adaptive immune system to eradicate infectious agents, autoimmunity, allergy, and cancer.
TpF1 fromTreponema pallidumActivates Inflammasome and Promotes the Development of Regulatory T Cells
Authors: Babolin Chiara , Amedei Amedeo , Ozoliņš Dzintars , Žileviča Aija , D’Elios Mario Milco , de Bernard Marina
Published: June 2011

Human syphilis is a multistage disease, with diverse and wide-ranging manifestations caused by Treponema pallidum. Despite the fact that a cell-mediated immune response takes part in the course of syphilis, T. pallidum often manages to evade host immunity and, in untreated individuals, may trigger chronic infection. With this study, we demonstrate for the first time, to our knowledge, that Treponema pallidum induces a regulatory T (Treg) response in patients with secondary syphilis and we found that the miniferritin TpF1, produced by the bacterium, is able to expand this response and promote the production of TGF-β. Accordingly, TpF1 stimulates monocytes to release IL-10 and TGF-β, the key cytokines in driving Treg cell differentiation. Interestingly, we also found that TpF1 stimulates monocytes to synthesize and release several proinflammatory cytokines, such as TNF-α, IL-6, and IL-1β, the latter following the activation of the multiprotein complex inflammasome. Collectively, these data strongly support a central role for TpF1 both in the inflammation process, which occurs in particular during the early stage of syphilis, and in the long-term persistence of the spirochete within the host by promoting Treg response and TGF-β production.
Inorganic Phosphate as an Important Regulator of Phosphatases
Authors: Dick Claudia Fernanda , Dos-Santos André Luiz Araújo , Meyer-Fernandes José Roberto
Published: June 2011

Cellular metabolism depends on the appropriate concentration of intracellular inorganic phosphate (Pi). Pi starvation-responsive genes appear to be involved in multiple metabolic pathways, implying a complex Pi regulation system in microorganisms and plants. A group of enzymes is required for absorption and maintenance of adequate phosphate levels, which is released from phosphate esters and anhydrides. The phosphatase system is particularly suited for the study of regulatory mechanisms because phosphatase activity is easily measured using specific methods and the difference between the repressed and derepressed levels of phosphatase activity is easily detected. This paper analyzes the protein phosphatase system induced during phosphate starvation in different organisms.
Electrochemical Synthesis of Polyaniline/Poly-O-Aminophenol Copolymers in Chloride Medium
Authors: Mascaro Lucia H. , Berton Alessandra N. , Micaroni Liliana
Published: June 2011

The copolymerization ofo-aminophenol (OAP) and aniline (ANI) on Pt and ITO electrodes was studied using cyclic voltammetry in 0.1 M HCl/0.4 M NaCl solution. The films were characterized by SEM, cyclic voltammetry, and UV-Vis spectroscopy. The properties of the copolymer were compared with PANI and POAP films. The results strongly suggest that the growth of PANI-POAP films does not consist of the simple buildup of layers of homopolymers on the electrode surface as a result of OAP or ANI oxidation products in the monomer mixture, but that a new conducting polymer is formed by copolymerization.
Oxidative Stress in Cardiovascular Inflammation: Its Involvement in Autoimmune Responses
Authors: Profumo Elisabetta , Buttari Brigitta , Riganò Rachele
Published: June 2011

Recently, it has become clear that atherosclerosis is a chronic inflammatory disease in which inflammation and immune responses play a key role. Accelerated atherosclerosis has been reported in patients with autoimmune diseases, suggesting an involvement of autoimmune mechanisms in atherogenesis. Different self-antigens or modified self-molecules have been identified as target of humoral and cellular immune responses in patients with atherosclerotic disease. Oxidative stress, increasingly reported in these patients, is the major event causing structural modification of proteins with consequent appearance of neoepitopes. Self-molecules modified by oxidative events can become targets of autoimmune reactions, thus sustaining the inflammatory mechanisms involved in endothelial dysfunction and plaque development. In this paper, we will summarize the best characterized autoantigens in atherosclerosis and their possible role in cardiovascular inflammation.
Low-Protein Diet Supplemented with Keto Acids Is Associated with Suppression of Small-Solute Peritoneal Transport Rate in Peritoneal Dialysis Patients
Authors: Jiang Na , Qian Jiaqi , Lin Aiwu , Fang Wei , Zhang Weiming , Cao Liou , Wang Qin , Ni Zhaohui , Yao Qiang
Published: June 2011

Objective.We investigate whether low-protein diet would show benefits in suppressing peritoneal transport rate in peritoneal dialysis (PD) patients.Methods.This is a supplemented analysis of our previously published trial, which randomized 60 PD patients to receive low- (LP: dietary protein intake of 0.6–0.8 g/kg/d), keto-acid-supplemented low- (sLP: 0.6–0.8 g/kg/d with 0.12 g/kg/d of keto acids), or high- (HP: 1.0–1.2 g/kg/d) protein diet and lasted for one year. In this study, the variations of peritoneal transport rate were assessed.Results.While baseline D/Pcr(dialysate-to-plasma concentration ratio for creatinine at 4 hour) and D/D0glu(dialysate glucose at 4 hour to baseline dialysate glucose concentration ratio) were similar, D/Pcrin group sLP was lower, and D/D0gluwas higher than those in the other two groups (P<0.05) at 12th month. D/D0gluincreased (P<0.05), and D/Pcrtended to decrease,(P=0.071)in group sLP.Conclusions. Low-protein diet with keto acids may benefit PD patients by maintaining peritoneum at a lower transport rate.
Molecular Cloning and Characterization of P4 Nuclease from Leishmania infantum
Authors: Farajnia Safar , Rahbarnia Leila , Maleki zanjani Bahram , Alimohammadian Mohammad Hossein , Abdoli Oskoee Shahin , Beh-pajooh Abbas , Saeedi Nazli , Montazer Saheb Soheila
Published: June 2011

Parasite of the genus Leishmania is reliant on the salvage pathway for recycling of ribonucleotides. A class I nuclease enzyme also known as P4 nuclease is involved in salvage of purines in cutaneous Leishmania species but the relevant enzymes have not been characterized in Leishmania infantum (L. infantum). The aim of this study was to clone and characterize the gene encoding class I nuclease in L. infantum. DNA extracted from L. infantum was used for amplification of P4 nuclease gene (Li-P4) by PCR. The product was cloned, sequenced, and expressed in E. coli for further characterization. Analysis of the sequence of Li-P4 revealed that the gene consists of an ORF of 951 bp. Sequence similarity analysis indicated that Li-P4 has a high homology to relevant enzymes of other kintoplastids with the highest homology (88%) to p1/s1 class I nuclease from L. donovani. Western blotting of antirecombinant Li-P4 with promastigote and amastigote stages of L. infantum showed that this nuclease is present in both stages of parasite with higher expression in amastigote stage. The highly conserved nature of this essential enzyme in Leishmania parasites suggests it as a promising drug target for leishmaniasis.
Effects of Human Alpha-Synuclein A53T-A30P Mutations on SVZ and Local Olfactory Bulb Cell Proliferation in a Transgenic Rat Model of Parkinson Disease
Authors: Lelan Faustine , Boyer Cécile , Thinard Reynald , Rémy Séverine , Usal Claire , Tesson Laurent , Anegon Ignacio , Neveu Isabelle , Damier Philippe , Naveilhan Philippe , Lescaudron Laurent
Published: June 2011

A transgenic Sprague Dawley rat bearing the A30P and A53Tα-synuclein (α-syn) human mutations under the control of the tyrosine hydroxylase promoter was generated in order to get a better understanding of the role of the humanα-syn mutations on the neuropathological events involved in the progression of the Parkinson’s disease (PD). This rat displayed olfactory deficits in the absence of motor impairments as observed in most early PD cases. In order to investigate the role of the mutatedα-syn on cell proliferation, we focused on the subventricular zone (SVZ) and the olfactory bulbs (OB) as a change of the proliferation could affect OB function. The effect on OB dopaminergic innervation was investigated. The humanα-syn co-localized in TH-positive OB neurons. No humanα-syn was visualized in the SVZ. A significant increase in resident cell proliferation in the glomerular but not in the granular layers of the OB and in the SVZ was observed. TH innervation was significantly increased within the glomerular layer without an increase in the size of the glomeruli. Our rat could be a good model to investigate the role of human mutatedα-syn on the development of olfactory deficits.
Bucindolol: A Pharmacogenomic Perspective on its Use in Chronic Heart Failure
Authors: Smart Neil A. , Kwok Nigel , Holland David J. , Jayasighe Rohan , Giallauria Francesco
Published: June 2011

Bucindolol is a non-selective β-adrenergic receptor blocker with α-1 blocker properties and mild intrinsic sympatholytic activity. The Beta-Blocker Evaluation of Survival Trial (BEST), which is the largest clinical trial of bucindolol in patients with heart failure, was terminated prematurely and failed to show an overall mortality benefit. However, benefits on cardiac mortality and re-hospitalization rates were observed in the BEST trial. Bucindolol has not shown benefits in African Americans, those with significantly low ejection fraction and those in NYHA class IV heart failure. These observations could be due to the exaggerated sympatholytic response to bucindolol in these sub-groups that may be mediated by genetic polymorphisms or changes in gene regulation due to advanced heart failure. This paper provides a timely clinical update on the use of bucindolol in chronic heart failure.
Three-Dimensional Structure of Arabidopsis thaliana Lipase Predicted by Homology Modeling Method
Authors: Messaoudi Abdelmonaem , Belguith Hatem , Hamida Jeannette Ben
Published: June 2011

Triacylglycerol lipases have been thoroughly characterized in mammals and microorganisms. By contrast, very little is known about plant lipases. In this investigation, a homology model of Arabidopsis thaliana lipase (NP_179126) was constructed using a human gastric lipase (PDB ID: 1HLG), as a template for model building. This model was then assessed for stereochemical quality and side chain environment. Natural substrates: tributyrin, trioctanoin and triolen were docked into the model to investigate ligand-substrate interaction.
The Income-Based Human Capital Valuation Methods in Public Health Economics Used by Forensic Economics
Authors: Grosse Scott D. , Krueger Kurt V.
Published: June 2011

This paper surveys the development of income-based human capital methods in public health economics which, with the exception of worklife expectancy, forms the methodological core of forensic economics. The main differences in the application of human capital valuation between the two disciplines are the use of statistical population averages and gross costs in public health economics and individual-specific estimates and net costs in forensic economics. The paper provides examples of the public health economics application of the human capital approach in cost-of-illness (COI) analyses of disease or injury, disability, and premature mortality with specific discussion of cerebral palsy.
Role of sea surface temperature responses in simulation of the climatic effect of mineral dust aerosol
Authors: Yue X. , Liao H. , Wang H. J. , Li S. L. , Tang J. P.
Published: June 2011

Abstract. Mineral dust aerosol can be transported over the nearby oceans and influence the energy balance at the sea surface. The role of dust-induced sea surface temperature (SST) responses in simulations of the climatic effect of dust is examined by using a general circulation model with online simulation of mineral dust and a coupled mixed-layer ocean model. Both the longwave and shortwave radiative effects of mineral dust aerosol are considered in climate simulations. The SST responses are found to be very influential on simulated dust-induced climate change, especially when climate simulations consider the two-way dust-climate coupling to account for the feedbacks. With prescribed SSTs and dust concentrations, we obtain an increase of 0.02 K in the global and annual mean surface air temperature (SAT) in response to dust radiative effects. In contrast, when SSTs are allowed to respond to radiative forcing of dust in the presence of the dust cycle-climate interactions, we obtain a global and annual mean cooling of 0.09 K in SAT by dust. The extra cooling simulated with the SST responses can be attributed to the following two factors: (1) The negative net (shortwave plus longwave) radiative forcing of dust at the surface reduces SST, which decreases latent heat fluxes and upward transport of water vapor, resulting in less warming in the atmosphere; (2) The positive feedback between SST responses and dust cycle. The dust-induced reductions in SST lead to reductions in precipitation (or wet deposition of dust) and hence increase the global burden of small dust particles. These small particles have strong scattering effects, which enhance the dust cooling at the surface and further reduce SSTs.
Detection of HO2 by laser-induced fluorescence: calibration and interferences from RO2 radicals
Authors: Fuchs H. , Bohn B. , Hofzumahaus A. , Holland F. , Lu K. D. , Nehr S. , Rohrer F. , Wahner A.
Published: June 2011

Abstract. HO2 concentration measurements are widely accomplished by chemical conversion of HO2 to OH including reaction with NO and subsequent detection of OH by laser-induced fluorescence. RO2 radicals can be converted to OH via a similar radical reaction sequence including reaction with NO, so that they are potential interferences for HO2 measurements. Here, the conversion efficiency of various RO2 species to HO2 is investigated. Experiments were conducted with a radical source that produces OH and HO2 by water photolysis at 185 nm, which is frequently used for calibration of LIF instruments. The ratio of HO2 and the sum of OH and HO2 concentrations provided by the radical source was investigated and was found to be 0.50 ± 0.02. RO2 radicals are produced by the reaction of various organic compounds with OH in the radical source. Interferences via chemical conversion from RO2 radicals produced by the reaction of OH with methane and ethane (H-atom abstraction) are negligible consistent with measurements in the past. However, RO2 radicals from OH plus alkene- and aromatic-precursors including isoprene (mainly OH-addition) are detected with a relative sensitivity larger than 80 % with respect to that for HO2 for the configuration of the instrument with which it was operated during field campaigns. Also RO2 from OH plus methyl vinyl ketone and methacrolein exhibit a relative detection sensitivity of 60 %. Thus, previous measurements of HO2 radical concentrations with this instrument were biased in the presence of high RO2 radical concentrations from isoprene, alkenes or aromatics, but were not affected by interferences in remote clean environment with no significant emissions of biogenic VOCs, when the OH reactivity was dominated by small alkanes. By reducing the NO concentration and/or the transport time between NO addition and OH detection, interference from these RO2 species are suppressed to values below 20 % relative to the HO2 detection sensitivity. The HO2 conversion efficiency is also smaller by a factor of four, but this is still sufficient for atmospheric HO2 concentration measurements for a wide range of conditions.
Diode laser-based cavity ring-down instrument for NO3, N2O5, NO, NO2 and O3 from aircraft
Authors: Wagner N. L. , Dubé W. P. , Washenfelder R. A. , Young C. J. , Pollack I. B. , Ryerson T. B. , Brown S. S.
Published: June 2011

Abstract. This article presents a diode laser-based, cavity ring-down spectrometer for simultaneous in situ measurements of four nitrogen oxide species, NO3, N2O5, NO, NO2, as well as O3, designed for deployment on aircraft. The instrument measures NO3 and NO2 by optical extinction at 662 nm and 405 nm, respectively; N2O5 is measured by thermal conversion to NO3, while NO and O3 are measured by chemical conversion to NO2. The instrument has several advantages over previous instruments developed by our group for measurement of NO2, NO3 and N2O5 alone, based on a pulsed Nd:YAG and dye laser. First, the use of continuous wave diode lasers reduces the requirements for power and weight and eliminates hazardous materials. Second, detection of NO2 at 405 nm is more sensitive than our previously reported 532 nm instrument, and does not have a measurable interference from O3. Third, the instrument includes chemical conversion of NO and O3 to NO2 to provide measurements of total NOx (= NO + NO2) and Ox (= NO2 + O3) on two separate channels; mixing ratios of NO and O3 are determined by subtraction of NO2. Finally, all five species are calibrated against a single standard based on 254 nm O3 absorption to provide high accuracy. Disadvantages include an increased sensitivity to water vapor on the 662 nm NO3 and N2O5 channels and a modest reduction in sensitivity for these species compared to the pulsed laser instrument. The in-flight detection limit for both NO3 and N2O5 is 3 pptv (2 σ, 1 s) and for NO, NO2 and O3 is 140, 90, and 120 pptv (2 σ, 1 s) respectively. Demonstrated performance of the instrument in a laboratory/ground based environment is better by approximately a factor of 2–3. The NO and NO2 measurements are less precise than research-grade chemiluminescence instruments. However, the combination of these five species in a single instrument, calibrated to a single analytical standard, provides a complete and accurate picture of nighttime nitrogen oxide chemistry. The instrument performance is demonstrated using data acquired during a recent field campaign in California.
Airborne DOAS limb measurements of tropospheric trace gas profiles: case studies on the profile retrieval of O4 and BrO
Authors: Prados-Roman C. , Butz A. , Deutschmann T. , Dorf M. , Kritten L. , Minikin A. , Platt U. , Schlager H. , Sihler H. , Theys N. , Van Roozendael M. , Wagner T. , Pfeilsticker K.
Published: June 2011

Abstract. A novel limb scanning mini-DOAS spectrometer for the detection of UV/vis absorbing radicals (e.g., O3, BrO, IO, HONO) was deployed on the DLR-Falcon (Deutsches Zentrum für Luft- und Raumfahrt) aircraft and tested during the ASTAR 2007 campaign (Arctic Study of Tropospheric Aerosol, Clouds and Radiation) that took place at Svalbard (78° N) in spring 2007. Our main objectives during this campaign were to test the instrument, and to perform spectral and profile retrievals of tropospheric trace gases, with particular interest on investigating the distribution of halogen compounds (e.g., BrO) during the so-called ozone depletion events (ODEs). In the present work, a new method for the retrieval of vertical profiles of tropospheric trace gases from tropospheric DOAS limb observations is presented. Major challenges arise from modeling the radiative transfer in an aerosol and cloud particle loaded atmosphere, and from overcoming the lack of a priori knowledge of the targeted trace gas vertical distribution (e.g., unknown tropospheric BrO vertical distribution). Here, those challenges are tackled by a mathematical inversion of tropospheric trace gas profiles using a regularization approach constrained by a retrieved vertical profile of the aerosols extinction coefficient EM. The validity and limitations of the algorithm are tested with in situ measured EM, and with an absorber of known vertical profile (O4). The method is then used for retrieving vertical profiles of tropospheric BrO. Results indicate that, for aircraft ascent/descent observations, the limit for the BrO detection is roughly 1.5 pptv (pmol mol−1), and the BrO profiles inferred from the boundary layer up to the upper troposphere and lower stratosphere have around 10 degrees of freedom. For the ASTAR 2007 deployments during ODEs, the retrieved BrO vertical profiles consistently indicate high BrO mixing ratios (∼15 pptv) within the boundary layer, low BrO mixing ratios (≤1.5 pptv) in the free troposphere, occasionally enhanced BrO mixing ratios (∼1.5 pptv) in the upper troposphere, and increasing BrO mixing ratios with altitude in the lowermost stratosphere. These findings agree reasonably well with satellite and balloon-borne soundings of total and partial BrO atmospheric column densities.
The 11 May 2011 earthquake at Lorca (SE Spain) viewed in a structural-tectonic context
Authors: Vissers R. L. M. , Meijninger B. M. L.
Published: June 2011

Abstract. The Lorca earthquake of 11 May 2011 in the Betic Cordillera of SE Spain occurred almost exactly on the Alhama de Murcia fault, a marked fault that forms part of a NE-SW trending belt of faults and thrusts. The fault belt is reminiscent of a strike-slip corridor, but recent structural studies have provided clear evidence for reverse motions on these faults. Focal mechanisms of the main earthquake but also of a foreshock are strikingly consistent with structural observations on the Alhama de Murcia fault. This strengthens the conclusion that, rather than a strike-slip fault, the fault is at present a contractional fault with an oblique reverse sense of motion, presumably in response to NW directed motion of Africa with respect to Europe.
Efficiency and Effectiveness Impacts of a Computer-Assisted Scheduling and Dispatching System Implementation
Authors: Metaxatos Paul , Pagano Anthony M.
Published: June 2011

Computer-assisted scheduling and dispatch (CASD) systems have been implemented in many paratransit systems in the United States to improve the effectiveness and efficiency of operations. This paper contributes to the limited literature of studies documenting the impact of such systems on paratransit operations based on the implementation of such a system in a small city in Illinois. The analysis provides evidence of small but measurable efficiency and effectiveness gains. This paper also provides evidence that proper CASD evaluation efforts should allow enough time after implementation so that not only familiarity with the system has been established, but also most or all of the necessary organizational changes related to the new technology have been completed.
Effects of Light and Commuter Rail Transit on Land Prices: Experiences in San Diego County
Authors: Cervero Robert
Published: June 2011

Using hedonic price models, appreciable land-value premiums were found for multiple land uses in different rail corridors of San Diego County. The most appreciable benefits were for condominiums and single-family housing near commuter-rail stations in the north county, multifamily housing near light-rail stations, and commercial properties near downtown commuterrail stations and light-rail stops in the Mission Valley. Elsewhere, commercial properties accrued small or even negative capitalization benefits. Pro-development policies, worsening traffic congestion, and a generally healthy economy are thought to have generally boosted land values in San Diego County, though impacts are corridor- and land-use specific.
Estimating Elasticities for Multi-Modal Public Transport Demand: A Time Series Approach
Authors: Gkritza Konstantina , Golias Ioannis , Karlaftis Matthew G.
Published: June 2011

Research on the demand side of public transportation systems with the use of time series data frequently shows conflicting results with respect to fare elasticities and the factors affecting it. In this analysis we complement prior research by developing seemingly unrelated regression equation models with monthly data for a city served by three different modes of public transportation. The results indicate that, as expected, urban public transport demand in Athens, Greece, is inelastic with respect to fares but, surprisingly, highly inelastic with respect to automobile fuel cost. Further, different transit modes have significantly different fare elasticities, a finding with important practical implications.
Safety and Operational Evaluation of Truck Lane Restriction
Authors: Mussa Renatus
Published: June 2011

This study was aimed at determining the operational and safety impacts of the 24-hour restriction of trucks from using the median lane of the six-lane Interstate 75 freeway corridor. The 139-mile corridor in North Florida is relatively uncongested operating at level of service (LOS) of B or better on typical weekdays. LOS is a measure of driver's freedom to maneuver in a traffic stream. The simulation analysis showed that opening all lanes to trucks increased the number of lane changing maneuvers by 11% in daytime, a phenomenon likely to increase crashes in the corridor given that the review of reported crashes showed that lane changing was a major contributing cause of crashes currently occurring in the corridor. The analysis of field data indicated that the difference between truck and passenger car speeds and travel times were insignificant on the unrestricted middle and shoulder lanes. Approximately two thirds of both passenger cars and trucks were traveling within the 10-mph pace, defined as the 10-mph speed range with the highest number of observations, that ranged from approximately 70 mph to 80 mph in the corridor that has speed limit posted at 70 mph. The field data also showed that trucks were able to use the middle lane to pass with reasonable delay during the truck peak hour period, using various gap acceptance thresholds.
Airlines Entry and Exit and the Impact on Air Traffic Management: An Analytical Framework for Zero-Sum and Positive-Sum Outcomes
Authors: Berry Tom , Bhadra Dipasis , Gentry Jennifer , Nelson Gregory
Published: June 2011

Passenger airline service can have a significant impact on a metropolitan region's economy in terms of direct spending and employment, as well as on indirect spending related to industries such as tourism and the service sector. In the past decade passenger service levels have changed considerably in many markets because of a wide variety of events including increased competition, terrorism, and a downturn in the economy. Airlines have responded to these challenges in a variety of ways. Some of the traditional network carriers have been forced into bankruptcy in an attempt to reduce costs and compete more effectively with low cost carriers. In contrast, the low cost carriers have expanded service and entered new markets at a rapid pace.This paper examines the economic evolutionary process whereby a dominant carrier competes intensely in one market against a similar airline and retreats in another where new, lower-cost entrant expands service. Literature is examined for evidence pertaining to the market's response to a network carrier's financial distress, its impact on airport service levels, and implications for local economies. A zero sum case is explained using a recent example. A positive sum case is explored, where the positive contributions of the entering carrier exceed those left behind by the resident carrier. In the process, depending on the types of gains and nature of the evolving airlines' network, the patterns of air traffic may also change. Using these experiences, an analytical framework is proposed that attempts to explain the emergent behavior of low cost carriers when they enter new markets. In addition, the impact of these changes on the air traffic management system is also examined.
Characteristics of Vehicle Platoons at Isolated Intersections
Authors: Jiang Yi , Li Shuo
Published: June 2011

It was observed that about 70% of vehicles travel in platoons on Indiana highway corridors in the vicinity of urban areas. Many vehicle platoons were halted at signalized intersections to give the right of way to vehicles on the intersecting minor road, even though there were only one or two vehicles on the minor road. This phenomenon suggested that the total traffic delay at an intersection might be reduced if the approaching vehicle platoons on the major road were allowed to pass through the intersection at the expense of a reasonably prolonged delay of the few vehicles on the minor road. Consequently, a study was conducted to investigate vehicle platoon characteristics and to develop control logic for timing actuated traffic signals in terms of the presence of vehicle platoons. This paper presents some findings of the study on traffic flows in terms of vehicle platoons. Included in this paper are the selection of the fundamental platoon variables and determination of the critical headway value for platoon identification, the appropriate platoon detector placement, and the mathematical distributions of the platoon variables.
The Measurement of Grain Barge Demand on Inland Waterways: A Study of the Upper Mississippi River
Authors: Author Tun-Hsiang (Edward) , Fuller Stephen W.
Published: June 2011

This paper attempts to estimate structural demand for grain barge transportation on the upper Mississippi River. Results suggest an inelastic demand for grain barge transportation on the upper Mississippi in the short run while the price elasticity increases to 1.0 in the longer run. Additionally, foreign grain demand and domestic grain consumption are found to influence grain barge demand. Also, the winter season and floods affect demand negatively. Hausman's specification test shows the ordinary least square and two-stage least square estimates are statistically invariant.
The Rebirth of Airships
Authors: Prentice Barry E. , Beilock Richard E. , Phillips Alfred J. , Thomson Jim
Published: June 2011

Until the outbreak of the Second World War, uncertainty existed whether airships and airplanes would dominate intercontinental passenger transportation. The massive investments in fixed-wing aircraft during these hostilities made airplanes the decisive winner, and relegated airships to a negligible role in transportation. As the 21st Century progresses, airships are making a comeback fueled by the 21st Century progresses, airships are making a comeback fueled by the growing demand for air cargo, the unique environmental and operational characteristics of buoyant flight, and advances in engineering science and materials.

This paper examines the market niche for airships that exists between air and marine transport and the inherent advantages and disadvantages of this mode of transportation. The economics of airships are considered in light of their past achievements and current designs. The paper concludes with the discussion of two potential applications. A long haul mission for airships between Hawaii and the U.S. mainland is considered for perishable freight, and a short haul mission for airships in northern Canada is considered for the transport of freight and passengers to remote communities.
Feasible Activity and Travel Time Allocations with a Discrete Choice Model: An Exploratory Study
Authors: Chen Cynthia
Published: June 2011

An exploratory study using a discrete choice framework for time-use allocations is described. Instead of treating time use as continuous and dependent, it is treated as discrete and independent. By doing this, the restriction that the consumption bundle must lie on the boundary of the budget set can be enforced. Using responses collected from the 1996 travel survey for the San Francisco Bay Area, estimation of the model results is a good fit in terms of adjusted R2. This suggests that a discrete choice framework of time allocation to activities and travel is a worthwhile effort that certainly needs further investigation.
Right-of-Way Acquisition and Property Condemnation: A Comparison of U.S. State Laws
Authors: Hakimi Shadi , Kockelmann Kara M.
Published: June 2011

Recommendations for improvements in U.S. right-of-way (ROW) acquisition processes should consider the environmental, social, political, and economic characteristics of individual states. These characteristics are reflected in state statutes and constitutions, which place restrictions on ROW staff in applying recommended strategies. This work compares state condemnation statutes, noting their weaknesses and strengths. It recommends modifications to current laws to expedite the acquisition process, minimize cost, and build property owners' trust in government. It also examines how various factors are statistically significant in predicting state condemnation rates.
Performance Evaluation of Coordinated Intersections with GPS Devices
Authors: Jiang Yi , Li Shuo , Zhao Zhonghua
Published: June 2011

This paper presents methods for applying GPS devices to evaluate the performance of coordinated intersections in terms of traffic delays. It illustrates that GPS-recorded data provides detailed information on traffic delays of individual intersections as well as traffic delays of coordinated intersections as a whole system, including travel-time delay, stopped-time delay, time-in-queue delay, approach delay, and total delay. Most of these intersection delays are difficult to measure manually; however, with GPS-collected vehicle-positioning data, they can be either directly identified or indirectly derived. Methods for obtaining different types of intersection delays with GPS devices are introduced.
Using a Neural Network to Analyze the Impact of Passenger Activity on Bus Dwell Time and Travel Time
Authors: Chen Mei , Liu Xiaobo
Published: June 2011

This paper applies neural network modeling approach to analyze the impact of passenger activities on bus dwell time and station-to-station travel time. Data used to develop the model was collected by onboard AVL/APC devices. Sensitivity analyses based on a trained neural network were performed to evaluate the relative significance of each passenger activity variable to variation of dwell time and/or station-to-station travel time. Transit providers can use these methods to identify the causes of schedule deviation and to develop improvement measures that are most effective to transit service.