bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Follow-Up Study of Genome Damage Elimination in Patients with Testicular Seminoma Exposed to Ionising Radiation during Radiotherapy
Authors: Gamulin Marija , Katić Jelena , Milić Mirta , Grgić Mislav , Fučić Aleksandra
Published: March 2011

Long-Term Follow-Up Study of Genome Damage Elimination in Patients with Testicular Seminoma Exposed to Ionising Radiation during Radiotherapy

The rate of genome damage elimination after therapeutic exposure to ionising radiation was estimated in stage I testicular seminoma patients monitored over a seven-year follow-up. DNA damage elimination in peripheral lymphocytes of ten subjects was analysed by the chromosome aberration assay. Seven years after the end of radiotherapy, significantly increased frequency of ring and dicentric chromosomes was still detected in comparison with baseline values. These results indicate the induction of genome instability. Long-term follow-up studies of cancer patients after radiotherapy could give us valuable information on the rate of genome damage elimination after exposure to ionising radiation and about the duration and manifestation of genome instability. This may be used in health risk assessment related to the possible development of secondary neoplasia. Studies such as this could have a great value both for oncology and radiation protection management protocols, especially after accidental overexposures.
Assessment of Tryptophol Genotoxicity in Four Cell Lines In Vitro: A Pilot Study with Alkaline Comet Assay
Authors: Kosalec Ivan , Ramić Snježana , Jelić Dubravko , Antolović Roberto , Pepeljnjak Stjepan , Kopjar Nevenka
Published: March 2011

Assessment of Tryptophol Genotoxicity in Four Cell LinesIn Vitro: A Pilot Study with Alkaline Comet Assay

Tryptophol is an aromatic alcohol and secondary metabolite of the opportunistic fungusCandida albicans. Although its toxicity profile at cell level has been poorly investigated, recent data point to cytotoxic, cytostatic, and genotoxic effects in lymphocytes and the induction of apoptosis in leukaemic blood monocytes. In this pilot study we evaluated the genotoxicity of tryptopholin vitroon four permanent cell lines of animal and human origin: ovary cells, alveolar epithelium, liver cells, and blood monocytes using the alkaline comet assay. We selected cells that might be principal targets of tryptophol and other low-molecular geno(toxins) secreted byCandida albicansduring host invasion. Our results suggest that tryptophol appliedin vitroat 2 mmol L-1for 24 h damages DNA in HepG2, A549 and THP-1 cells, obviously due to bioactivation and/or decomposition of the parent compound, which results in the formation of more genotoxic compound(s) and production of reactive species that additionally damage DNA. On the other hand, notably lower levels of primary DNA damage were recorded in CHO cells, which lack metabolic activity. Future studies with tryptophol should look further into mechanisms involved in its toxic action and should focus on other cell types prone to infection withCandidaspp. such as vaginal epithelial cells or keratinocytes of human origin.
The Space of Difference in Law: Inquests into Aboriginal Deaths in Custody
Authors: Razack Sherene H.
Published: March 2011

Paul Alphonse, a 67 year-old Aboriginal died in hospital while in police custody. A significant contributing factor to his death was that he was stomped on so hard that there was a boot print on his chest and several ribs were broken. His family alleged police brutality. The inquest into the death of Paul Alphonse offers an opportunity to explore the contemporary relationship between Aboriginal people and Canadian society and, significantly, how law operates as a site for managing that relationship. I suggest that we consider the boot print on Alphonse's chest and its significance at the inquest in these two different ways. First, although it cannot be traced to the boot of the arresting officer, we can examine the boot print as an event around which swirls Aboriginal/police relations in Williams Lake, both the specific relation between the arresting officer and Alphonse, and the wider relations between the Aboriginal community and the police. Second, the response to the boot print at the inquest sheds light on how law is a site for obscuring the violence in Aboriginal people's lives. A boot print on the chest of an Aboriginal man, a clear sign of violence, comes to mean little because Aboriginal bodies are considered violable – both prone to violence, and bodies that can be violated with impunity. Law, in this instance in the form of an inquest, stages Aboriginal abjection, installing Aboriginal bodies as too damaged to be helped and, simultaneously to harm. In this sense, the Aboriginal body is homo sacer, the body that maybe killed but not murdered. I propose that the construction of the Aboriginal body as inherently violable is required in order for settlers to become owners of the land.
Transnational Bio/Necropolitics: Hindutva and its Avatars (Australia/India)
Authors: Osuri Goldie
Published: March 2011

In the US diasporic context, Kamat and Matthews (2003) have traced how Hindu nationalists draw on multiculturalist discourse for their presence while simultaneously funding cultural and political projects in India that incite hate and conduct violence against Muslim and Christian communities.

In the Australian context, Hindu nationalist organisations have legitimised and consolidate themselves through the rhetoric of liberal multiculturalism. Such strategies which draw on state rhetoric of multiculturalism while simultaneously engaging in hate campaigns against Muslim and Christian others demonstrates Hindutva's ability to operate through a transnational necropolitics. This paper explores how a state biopolitics of multiculturalism enables the violence of Hindutva's necropolitics in the transnational routes between Australia and India.
Bodies to the Slaughter: Global Racial Reconstructions, Fanon's Combat Breath, and Wrestling for Life
Authors: Agathangelou Anna M.
Published: March 2011

Throughout the world, a neoliberal leadership has intensified its involvement in the name of (post) and (neo) reconstructions by focusing on ethics of suffering in so-called humanitarian regimes. These reconstructions though disclose the power of a derivative-slave-death discourse by using the vital energies of black states, slave subjects, and black ecologies even at the moment of their execution to generate capable somata (land, bodies) deserving life. In this article, I begin with Fanon's ‘combat breathing’ and critique Mbembe's necropolitics and Montag's necroeconomics to articulate that most of the disputed points during postwar and post financial reconstructions concern ‘bringing back’ (à la Bush). This ‘anew’ constituted imperial order's virile viability with its contingent soma is infinitely regenerated through deadly mediative practices of force, slavery, and the killing ‘anew’ of those already deemed ontologically dead and structurally impossible. I examine the CPA planners in Iraq and the financial derivative discourses in Greece and argue that postwar and (post) debt financial reconstructions are terrains of world political antagonisms moving to resolve global political tensions with a ‘new slave soma’ and a ‘new place’ by engineering ‘anew’ a global order (a nameable place). I conclude with the ‘daily pulsations’, which contest, disfigure and antagonise markets, states and ontological annihilations.
Le choix d'un régime de change dans les pays émergents et en développement peut-il être optimal en dehors des solutions bipolaires ?
Authors: Allegret Jean-Pierre , Ayadi Mohamed , Haouaoui Khouni Leila
Published: March 2011

Résumé Cet article analyse le choix du régime de change dans les pays émergents et en développement. Nous proposons un modèle s’inscrivant dans la littérature caractérisée par la détermination d’un indice d’intervention du taux de change. Nous étendons le modèle élaboré initialement par Aizenman et Hausmann [2001] afin de faire apparaître les principaux facteurs présidant aux choix du régime de change. Le modèle est testé sur un échantillon de pays émergents et en développement. Nous déterminons la probabilité d’occurrence d’un régime de change donné en prenant en compte les déterminants du modèle théorique. Nos résultats suggèrent que les régimes intermédiaires demeurent bien adaptés aux pays émergents et en développement.
Sismondi et la question du progrès
Authors: Gillard Lucien
Published: March 2011

Résumé Contre les engouements nés de la révolution industrielle, Sismondi propose de raison garder. Il préconise d’analyser les effets produits par un choc technologique sur le fonctionnement d’un modèle de croissance équilibrée. Puis, d’analyser aussi comment se répartissent par classes sociales les bénéfices et inconvénients de l’industrialisation. Par-delà l’opposition traditionnelle entre richesse et bonheur, l’œuvre économique de Sismondi ouvre la voie à des recherches techniques sur les questions de « neutralité du progrès » et de « préférences collectives ».
Endogenous Opioid-Mediated Analgesia Is Dependent on Adaptive T Cell Response in Mice
Authors: Boué Jérôme , Blanpied Catherine , Brousset Pierre , Vergnolle Nathalie , Dietrich Gilles
Published: March 2011

Pain is an inherent component of inflammation often accompanying immune response. A large spectrum of molecules released within the inflamed tissue induces pain by stimulating primary afferent neurons in situ. Activity of primary sensitive fibers can be counteracted by local opioid release by leukocytes. In this study, we investigated the endogenous regulation of CFA-induced inflammatory pain in the context of adaptive T cell immune response. The nociceptive response to mechanical stimuli was studied using von Frey filaments in mice immunized with OVA in CFA. The nociceptive response of nude versus wild-type mice was dramatically increased, demonstrating T cell deficiency associated with increased pain sensitivity. Based on adoptive transfer experiments of OVA-specific CD4+ T lymphocytes into nude mice, we show that Ag-specific activated, but not resting T lymphocytes are responsible for the spontaneous relief of inflammation-induced pain following Ag challenge. The analgesia was dependent on opioid release by Ag-primed CD4+ T lymphocytes at the inflammatory site. Indeed, T cell-mediated analgesia was inhibited by local injection of an opioid receptor antagonist, unable to cross the blood-brain barrier. Notably, we found opioid precursor mRNA to be >7-fold increased in Ag-specific activated CD4+ T lymphocytes, as compared with resting T lymphocytes in vivo. Taken together, our results show that CD4+ T lymphocytes acquire antinociceptive effector properties when specifically primed by Ag and point out analgesia as a property linked to the effector phase of adaptive T cell response.
Control of TNF-Induced Dendritic Cell Maturation by Hybrid-Type N-Glycans
Authors: Schlickeiser Stephan , Stanojlovic Svetlana , Appelt Christine , Vogt Katrin , Vogel Simone , Haase Stefanie , Ritter Thomas , Volk Hans-Dieter , Pleyer Uwe , Sawitzki Birgit
Published: March 2011

The activity of α-1,2-mannosidase I is required for the conversion of high-mannose to hybrid-type (ConA reactive) and complex-type N-glycans (Phaseolus vulgaris-leukoagglutinin [PHA-L] reactive) during posttranslational protein N-glycosylation. We recently demonstrated that α-1,2-mannosidase I mRNA decreases in graft-infiltrating CD11c+ dendritic cells (DCs) prior to allograft rejection. Although highly expressed in immature DCs, little is known about its role in DC functions. In this study, analysis of surface complex-type N-glycan expression by lectin staining revealed the existence of PHA-Llow and PHA-Lhigh subpopulations in murine splenic conventional DCs, as well as in bone marrow-derived DC (BMDCs), whereas plasmacytoid DCs are nearly exclusively PHA-Lhigh. Interestingly, all PHA-Lhigh DCs displayed a strongly reduced responsiveness to TNF-α–induced p38-MAPK activation compared with PHA-Llow DCs, indicating differences in PHA-L–binding capacities between DCs with different inflammatory properties. However, p38 phosphorylation levels were increased in BMDCs overexpressing α-1,2-mannosidase I mRNA. Moreover, hybrid-type, but not complex-type, N-glycans are required for TNF-α–induced p38-MAPK activation and subsequent phenotypic maturation of BMDCs (MHC-II, CD86, CCR7 upregulation). α-1,2-mannosidase I inhibitor-treated DCs displayed diminished transendothelial migration in response to CCL19, homing to regional lymph nodes, and priming of IFN-γ–producing T cells in vivo. In contrast, the activity of α-1,2-mannosidase I is dispensable for LPS-induced signaling, as well as the DCs’ general capability for phenotypic and functional maturation. Systemic application of an α-1,2-mannosidase I inhibitor was able to significantly prolong allograft survival in a murine high-responder corneal transplantation model, further highlighting the importance of N-glycan processing by α-1,2-mannosidase I for alloantigen presentation and T cell priming.
IL-6 Production Is Positively Regulated by Two Distinct Src Homology Domain 2-Containing Tyrosine Phosphatase-1 (SHP-1)–Dependent CCAAT/Enhancer-Binding Protein β and NF-κB Pathways and an SHP-1–Independent NF-κB Pathway in Lipopolysaccharide-Stimulated Bone Marrow-Derived Macrophages
Authors: Rego Dorothy , Kumar Ashok , Nilchi Ladan , Wright Kathryn , Huang Stephen , Kozlowski Maya
Published: March 2011

Comparison of the inflammatory cytokine profile in bone marrow-derived macrophages (BMDMs) from normal and Src homology domain 2-containing tyrosine phosphatase-1 (SHP-1)–deficient Motheaten (me/me) mice revealed a dramatic suppression of IL-6 transcript and protein in me/me BMDMs after LPS stimulation. Interfering with SHP-1 expression using antisense SHP-1 oligonucleotides led to a significant downregulation of IL-6 in normal BMDMs. Conversely, reconstitution of me/me BMDMs with the SHP-1 gene using adenoviral vectors restored IL-6 production. Expression of only SHP-1 Src homology region 2 domains in normal BMDMs inhibited IL-6 production, confirming that IL-6 regulation depends on SHP-1 phosphatase activity. We further demonstrated that loss of SHP-1 function affects proper phosphorylation of Erk1/2 MAPKs and, to a lesser degree, of NF-κB downstream of TLR4 in BMDMs. Inefficient phosphorylation of Erk1/2 MAPKs abrogated the activation of C/EBPβ transcription factor, which was reversed on restoration of SHP-1 function and led to a concomitant enhancement of IL-6 production. We demonstrate that IL-6 production is regulated by a complex network of signaling pathways that include SHP-1–dependent activation of Erk1/2–C/EBPβ and NF-κB, in addition to SHP-1–independent IκB pathway through the activation of protein tyrosine kinases downstream of TLR4. Taken together, these results revealed for the first time, to our knowledge, a positive and critical role of SHP-1 in IL-6 regulation and dependence of Erk1/2–C/EBPβ pathway in addition to that of IκB on SHP-1 activity required for IL-6 induction after LPS stimulation.
Mitochondria, Amyloid β, and Alzheimer′s Disease
Authors: Readnower Ryan D. , Sauerbeck Andrew D. , Sullivan Patrick G.
Published: March 2011

Hypometabolism is a hallmark of Alzheimer′s disease (AD) and implicates a mitochondrial role in the neuropathology associated with AD. Mitochondrial amyloid‐beta (Aβ) accumulation precedes extracellular Aβ deposition. In addition to increasing oxidative stress, Aβ has been shown to directly inhibit mitochondrial enzymes. Inhibition of mitochondrial enzymes as a result of oxidative damage or Aβ interaction perpetuates oxidative stress and leads to a hypometabolic state. Additionally, Aβ has also been shown to interact with cyclophilin D, a component of the mitochondrial permeability transition pore, which may promote cell death. Therefore, ample evidence exists indicating that the mitochondrion plays a vital role in the pathophysiology observed in AD.
Enzyme Mechanism and Slow-Onset Inhibition ofPlasmodium falciparumEnoyl-Acyl Carrier Protein Reductase by an Inorganic Complex
Authors: Medeiros Patrícia Soares de Maria de , Ducati Rodrigo Gay , Basso Luiz Augusto , Santos Diógenes Santiago , da Silva Luiz Hildebrando Pereira
Published: March 2011

Malaria continues to be a major cause of children's morbidity and mortality worldwide, causing nearly one million deaths annually. The human malaria parasite,Plasmodium falciparum, synthesizes fatty acids employing the Type II fatty acid biosynthesis system (FAS II), unlike humans that rely on the Type I (FAS I) pathway. The FAS II system elongates acyl fatty acid precursors of the cell membrane inPlasmodium. Enoyl reductase (ENR) enzyme is a member of the FAS II system. Here we present steady-state kinetics, pre-steady-state kinetics, and equilibrium fluorescence spectroscopy data that allowed proposal ofP. falciparumENR (PfENR) enzyme mechanism. Moreover, building on previous results, the present study also evaluates the PfENR inhibition by the pentacyano(isoniazid)ferrateII compound. This inorganic complex represents a new class of lead compounds for the development of antimalarial agents focused on the inhibition of PfENR.
Macrodystrophia Lipomatosa: Radiologic-Pathologic Correlation
Authors: Upadhyay Deepika , Parashari Umesh C , Khanduri Sachin , Bhadury Samarjit
Published: March 2011

Macrodystrophia lipomatosa (MDL) is a rare cause of congenital macrodactyly, characterised by progressive proliferation of all mesenchymal elements, with disproportionate increase in fibro-adipose tissue. It occurs most frequently in lower limbs along the distribution of the medial plantar nerve. MDL presents as localised gigantism of the hand or foot and comes to clinical attention for cosmetic reasons, mechanical problems secondary to degenerative joint disease, or development of neurovascular compression. Here, we report a case of MDL, with altered soft tissue growth due to an earlier surgery, making clinical diagnosis difficult. However, with a complete radio-clinical work-up and review of the history, a provisional diagnosis of MDL was made, which was confirmed by histopathology and during surgery.
Current and Emerging Therapies in Peripheral T-cell Lymphoma: Focus on Pralatrexate
Authors: Reungwetwattana Thanyanan , Jaramillo Sylvia , Molina Julian R.
Published: March 2011

Peripheral T-cell lymphomas (PTCL) represent about 12%–15% of non-Hodgkin lymphomas and are characterized for being a molecularly heterogenous group of diseases. The optimal treatment for PTCLs remains to be defined as they are usually refractory to existing therapies and carry a poor prognosis. Pralatrexate (PDX), a rationally designed antifolate drug, was granted FDA approval as a single agent for the treatment of relapsed/refractory PTCL in 2009. Because of its favorable toxicity profile and activity, Pralatrexate has become a major compound for patients with refractory PTCL.
Cloning and Initial Functional Characterization of Mlk4α and Mlk4β
Authors: Kashuba Vladimir I. , Grigorieva Elvira V. , Kvasha Sergei M. , Pavlova Tatiana V. , Grigoriev Vladimir , Protopopov Alexei , Kharchenko Olga , Gizatullin Rinat , Rynditch Alla V. , Zabarovsky Eugene R.
Published: March 2011

We have cloned a novel human mixed-lineage kinase gene, MLK4. Two alternatively spliced forms, MLK4α (580 aa) and MLKβ (1036 aa), have been identified and mapped to chromosomal band lq42. MLK4 shows high amino acid homology to the kinase catalytic domain of MLK3 (72%), MLK1 (71%) and MLK2 (69%). Strong expression of MLK4 was detected in the human pancreas and kidneys. pCMV-MLK4β c-myc-tagged protein (human) was expressed in the cytoplasm and nucleus of transiently transfected COS-1 cells, while pCMV-MLK4α c-myc-tagged protein (human) was expressed in cytoplasm only. Both MLK4 isoforms reduced the colony formation ability of MCF7 cells by 85%–95% and almost totally suppressed cell proliferation in the CyQUANT cell proliferation assay. Human pCMV-MLK4β transgenic mice expressed the MLK4β in all tissues examined but no phenotypic abnormalities were observed. Thus, in this work, we present the cloning and sequencing of MLK4α and MLK4β for the first time; the data obtained suggest that MLK4 may function as a MAP kinase.
Genetics Meets Proteomics: Correlating the Portuguese Water Dog Blood Serum Proteome with Genetic Markers
Authors: Sénéchal Sandra , Kussmann Martin
Published: March 2011

Blood serum is a body fluid widely used for biomarker discovery and therefore numerous studies aim at defining its proteome. The serum proteome is subject to fluctuations resulting from biological variability (eg, diurnal variations) reflecting both healthy and/or disease-related conditions. Inter-individual differences originate partly at the genetic level and may influence clinical blood profile including the serum proteome. Therefore we investigated whether serum protein abundance is genetically determined: we report the study of a cohort of 146 Portuguese Water Dogs, a dog breed whose genetic background has been well characterized. We generated protein profiles of dog sera on 1D-gels and correlated them with microsatellite markers. We detected correlations between 7 gel bands and 11 genetic regions and developed a label-free protein quantification method to identify and quantify the proteins most accountable for serum proteome variation. An association between the abundance of RBP4 in dog serum and the adiponectin gene was detected.
Analysis and simulation of debonding membranes
Authors: Durus Ioana , Lux Anne
Published: March 2011

The paper deals with the numerical analysis and simulation of debonding membranes in the framework of quasistatic processes modeled by minimizing movements. Depending on parameters of the model, the “support” of the membrane is a quasi-open set (i.e. the membrane is debonded or glued) or a capacitary measure (i.e. fractions of glue remain active). Time discretization is associated to gradient methods based on shape (measure) derivative and genetic shape (measure) optimization.
Reflections on the impact of theChildren Act1989: child care policy, the knowledge base and the evolving role of social work
Authors: Blewett James
Published: March 2011

The Children Act 1989 sought to be evidence based in that its development reflected a growing body of research in the field of child care. This article explores the dynamic relationship between research, policy and practice in child welfare in the UK over the subsequent 21 years. It looks at the implications for the workforce and professional expertise, with a particular focus on social work. Initially, the implementation of the Act was closely associated with social services but provision has become more integrated and multidisciplinary. This has led to a far‐reaching debate about the roles and tasks of social work and its efficacy in safeguarding and promoting children's welfare. Social work can make a broad contribution to child welfare but to realise this both the role of social work and the knowledge base on which it is based must not be defined in a narrow or prescriptive way.
Characteristics of CALIOP attenuated backscatter noise: implication for cloud/aerosol detection
Authors: Wu D. L. , Chae J. H. , Lambert A. , Zhang F. F.
Published: March 2011

Abstract. A research algorithm is developed for noise evaluation and feature detection of the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) Level 1 (L1) backscatter data with an emphasis on cloud/aerosol features in the upper troposphere and lower stratosphere (UT/LS). CALIOP measurement noise of the version v2.01 and v2.02 L1 backscatter data aggregated to (5 km) horizontal resolution is analyzed with two approaches in this study. One is to compare the observed and modeled molecular scatter profiles by scaling the modeled profile (with a fitted scaling factor α) to the observed clear-sky backscatter profiles. This scaling α value is sensitive to errors in the calibrated backscatter and the atmospheric model used. Most of the nighttime 532-nm α values are close to unity, as expected, but an abrupt drop occurred in October 2008 in the daytime 532-nm α, which is likely indicative of a problem in the v2.02 daytime calibrated data. The 1064-nm night α is generally close to 2 while its day α is ~3. The other approach to evaluate the lidar measurement noise is to use the calibrated lidar backscatter data at altitudes above 19 km. With this method, the 532-nm and 1064-nm measurement noises are analyzed and characterized individually for each profile in terms of the mean (μ) and standard deviation (σ), showing larger σ values in general over landmasses or bright surfaces during day and in radiation-hard regions during night. A significant increasing trend is evident in the nighttime 1064-nm σ, which is likely responsible for the increasing difference between the feature occurrence frequencies (532-nm vs. 1064-nm) derived from this study. For feature detection with the research algorithm, we apply a σ–based method to the aggregated L1 data. The derived morphology of feature occurrence frequency is in general agreement with that obtained from the Level 2 (L2) 05 km_CLAY+05 km_ALAY products at 5 km horizontal resolution. Finally, a normalized probability density function (PDF) method is employed to evaluate the day-night backscatter data in which noise levels are largely different. CALIOP observations reveal a higher probability of daytime cloud/aerosol occurrence than nighttime in the tropical UT/LS region for 532-nm total backscatters >0.01 km−1 sr−1.
Impact of deep convection and dehydration on bromine loading in the upper troposphere and lower stratosphere
Authors: Aschmann J. , Sinnhuber B.-M. , Chipperfield M. P. , Hossaini R.
Published: March 2011

Abstract. Stratospheric bromine loading due to very short-lived substances is investigated with a three-dimensional chemical transport model over a period of 21 years using meteorological input data from the European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis from 1989 to the end of 2009. Within this framework we analyze the impact of dehydration and deep convection on the amount of stratospheric bromine using an idealized and a detailed full chemistry approach. We model the two most important brominated short-lived substances, bromoform (CHBr3) and dibromomethane (CH2Br2), assuming a uniform convective detrainment mixing ratio of 1 part per trillion by volume (pptv) for both species. The contribution of very short-lived substances to stratospheric bromine varies drastically with the applied dehydration mechanism and the associated scavenging of soluble species ranging from 3.4 pptv in the idealized setup up to 5 pptv using the full chemistry scheme. In the latter case virtually the entire amount of bromine originating from very short-lived source gases is able to reach the stratosphere thus rendering the impact of dehydration and scavenging on inorganic bromine in the tropopause insignificant. Furthermore, our long-term calculations show that the mixing ratios of very short-lived substances are strongly correlated to convective activity, i.e. intensified convection leads to higher amounts of very short-lived substances in the upper troposphere/lower stratosphere especially under extreme conditions like El Niño seasons. However, this does not apply to the inorganic brominated product gases whose concentrations are anti-correlated to convective activity mainly due to convective dilution and possible scavenging, depending on the applied approach.
Global precipitation response to changing external forcings since 1870
Authors: Bichet A. , Wild M. , Folini D. , Schär C.
Published: March 2011

Abstract. Predicting and adapting to changes in the hydrological cycle is one of the major challenges for the twenty-first century. To better estimate how it will respond to future changes in climate forcings, it is crucial to understand how it has evolved in the past and why. In our study, we use an atmospheric global climate model with prescribed sea surface temperatures (SSTs) to investigate how changing external climate forcings have affected global land temperature and precipitation in the period 1870–2005. We show that prescribed SSTs (encapsulating other forcings) are the dominant forcing driving the decadal variability of land temperature and precipitation since 1870. On top of this SSTs forcing, we also find that the atmosphere-only response to increasing aerosol emissions is a reduction in global land temperature and precipitation by up to 0.4 °C and 30 mm year−1, respectively, between about 1930 and 2000. Similarly, the atmosphere-only response to increasing greenhouse gas concentrations is an increase in global land temperature and precipitation by up to 0.25 °C and 10 mm year−1, respectively, between about 1950 and 2000. Finally, our results also suggest that between about 1950 and 1970, increasing aerosol emissions had a larger impact on the hydrological cycle than increasing greenhouse gases concentrations.
Composition changes after the "Halloween" solar proton event: the High-Energy Particle Precipitation in the Atmosphere (HEPPA) model versus MIPAS data intercomparison study
Authors: Funke B. , Baumgaertner A. , Calisto M. , Egorova T. , Jackman C. H. , Kieser J. , Krivolutsky A. , López-Puertas M. , Marsh D. R. , Reddmann T. , Rozanov E. , Salmi S.-M. , Sinnhuber M. , Stiller G. P. , Verronen P. T. , Versick S. , von Clarmann T. , Vyushkova T. Y. , Wieters N. , Wissing J. M.
Published: March 2011

Abstract. We have compared composition changes of NO, NO2, H2O2, O3, N2O, HNO3, N2O5, HNO4, ClO, HOCl, and ClONO2 as observed by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat in the aftermath of the "Halloween" solar proton event (SPE) in October/November 2003 at 25–0.01 hPa in the Northern Hemisphere (40–90° N) and simulations performed by the following atmospheric models: the Bremen 2d Model (B2dM) and Bremen 3d Chemical Transport Model (B3dCTM), the Central Aerological Observatory (CAO) model, FinROSE, the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), the Karlsruhe Simulation Model of the Middle Atmosphere (KASIMA), the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model, the modeling tool for SOlar Climate Ozone Links studies (SOCOL and SOCOLi), and the Whole Atmosphere Community Climate Model (WACCM4). The large number of participating models allowed for an evaluation of the overall ability of atmospheric models to reproduce observed atmospheric perturbations generated by SPEs, particularly with respect to NOy and ozone changes. We have further assessed the meteorological conditions and their implications on the chemical response to the SPE in both the models and observations by comparing temperature and tracer (CH4 and CO) fields. Simulated SPE-induced ozone losses agree on average within 5% with the observations. Simulated \\noy enhancements around 1 hPa, however, are typically 30% higher than indicated by the observations which can be partly attributed to an overestimation of simulated electron-induced ionization. The analysis of the observed and modeled NOy partitioning in the aftermath of the SPE has demonstrated the need to implement additional ion chemistry (HNO3 formation via ion-ion recombination and water cluster ions) into the chemical schemes. An overestimation of observed H2O enhancements by all models hints at an underestimation of the OH/HO2 ratio in the upper polar stratosphere during the SPE. The analysis of chlorine species perturbations has shown that the encountered differences between models and observations, particularly the underestimation of observed ClONO2 enhancements, are related to a smaller availability of ClO in the polar night region already before the SPE. In general, the intercomparison has demonstrated that differences in the meteorology and/or initial state of the atmosphere in the simulations causes a relevant variability of the model results, even on a short timescale of only a few days.
Boreal forest fire emissions in fresh Canadian smoke plumes: C1–C10 volatile organic compounds (VOCs), CO2, CO, NO2, NO, HCN and CH3CN
Authors: Simpson I. J. , Akagi S. K. , Barletta B. , Blake N. J. , Choi Y. , Diskin G. S. , Fried A. , Fuelberg H. E. , Meinardi S. , Rowland F. S. , Vay S. A. , Weinheimer A. J. , Wennberg P. O. , Wiebring P. , Wisthaler A. , Yang M. , Yokelson R. J. , Blake D. R.
Published: March 2011

Abstract. Boreal regions comprise about 17% of the global land area, and they both affect and are influenced by climate change. To better understand boreal forest fire emissions and plume evolution, 947 whole air samples were collected aboard the NASA DC-8 research aircraft in summer 2008 as part of the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic compounds (NMVOCs) using gas chromatography. Together with simultaneous measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and CH3CN, these measurements represent the most comprehensive assessment of trace gas emissions from boreal forest fires to date. Based on 105 air samples collected in fresh Canadian smoke plumes, 57 of the 80 measured NMVOCs (including CH2O) were emitted from the fires, including 45 species that were quantified from boreal forest fires for the first time. After CO2, CO and CH4, the largest emission factors (EFs) for individual species were formaldehyde (2.1 ± 0.2 g kg−1), followed by methanol, NO2, HCN, ethene, α-pinene, β-pinene, ethane, benzene, propene, acetone and CH3CN. Globally, we estimate that boreal forest fires release 2.4 ± 0.6 Tg C yr−1 in the form of NMVOCs, with approximately 41% of the carbon released as C1–C2 NMVOCs and 21% as pinenes. These are the first reported field measurements of monoterpene emissions from boreal forest fires, and we speculate that the pinenes, which are relatively heavy molecules, were detected in the fire plumes as the result of distillation of stored terpenes as the vegetation is heated. Their inclusion in smoke chemistry models is expected to improve model predictions of secondary organic aerosol (SOA) formation. The fire-averaged EF of dichloromethane or CH2Cl2, (6.9 ± 8.6) ×10−4 g kg−1, was not significantly different from zero and supports recent findings that its global biomass burning source appears to have been overestimated. Similarly, we found no evidence for emissions of chloroform (CHCl3) or methyl chloroform (CH3CCl3) from boreal forest fires. The speciated hydrocarbon measurements presented here show the importance of carbon released by short-chain NMVOCs, the strong contribution of pinene emissions from boreal forest fires, and the wide range of compound classes in the most abundantly emitted NMVOCs, all of which can be used to improve biomass burning inventories in local/global models and reduce uncertainties in model estimates of trace gas emissions and their impact on the atmosphere.
Aerosol optical properties in the North China Plain during HaChi campaign: an in-situ optical closure study
Authors: Ma N. , Zhao C. S. , Nowak A. , Müller T. , Pfeifer S. , Cheng Y. F. , Deng Z. Z. , Liu P. F. , Xu W. Y. , Ran L. , Yan P. , Göbel T. , Hallbauer E. , Mildenberger K. , Henning S. , Yu J. , Cheng L. L. , Zhou X. J. , Stratmann F. , Wiedensohler A.
Published: March 2011

Abstract. The largest uncertainty in the estimation of radiative forcings on climate stems from atmospheric aerosols. In winter and summer of 2009, two periods of in-situ measurements on aerosol physical and chemical properties were conducted within the HaChi project at Wuqing, a town between Beijing and Tianjin in the North China Plain (NCP). Aerosol optical properties including scattering coefficient (σsp), hemispheric back scattering coefficient (σbsp), absorption coefficient (σap, as well as single scattering albedo (ω) are presented. The characteristics of diurnal and seasonal variations are analyzed together with the meteorological and satellite data. The mean values of σsp, 550 nm of the dry aerosol in winter and summer are 280 ± 253 and 379 ± 251 Mm−1, respectively. The average σap for the two periods are respectively 47 ± 38 and 43 ± 27 Mm−1. The mean values of ω are 0.83 ± 0.05 and 0.87 ± 0.05 for winter and summer, respectively. The relative high levels of σsp and σbsp are representative of the regional polluted aerosol of the North China Plain. Pronounced diurnal cycle of σsp, σap and ω are found, mainly influenced by the evolution of boundary layer and accumulation of local emissions during night-time. Regional transport of pollutants from southwest in the NCP is significant both in winter and summer, while high values of σsp and σap correlate with calm winds in winter, which indicating the significant contribution of local emissions. An optical closure experiment is conducted to better understand uncertainties of the measurements. Good correlations (R>0.98) are found between values measured by nephelometer and values calculated with a modified Mie model. Monte Carlo simulations show an uncertainty of about 30% for the calculations. Considering all possible uncertainties of measurements, calculated σsp and σbsp agree well with measured values, indicating a stable performance of instruments and thus a reliable aerosol optical data.
Cloud-base vertical velocity statistics: a comparison between an atmospheric mesoscale model and remote sensing observations
Authors: Tonttila J. , O'Connor E. J. , Niemelä S. , Räisänen P. , Järvinen H.
Published: March 2011

Abstract. The statistics of cloud-base vertical velocity simulated by the non-hydrostatic mesoscale model AROME are compared with Cloudnet remote sensing observations at two locations: the ARM SGP site in Central Oklahoma, and the DWD observatory at Lindenberg, Germany. The results show that, as expected, AROME significantly underestimates the variability of vertical velocity at cloud-base compared to observations at their nominal resolution; the standard deviation of vertical velocity in the model is typically 4–6 times smaller than observed, and even more during the winter at Lindenberg. Averaging the observations to the horizontal scale corresponding to the physical grid spacing of AROME (2.5 km) explains 70–80% of the underestimation by the model. Further averaging of the observations in the horizontal is required to match the model values for the standard deviation in vertical velocity. This indicates an effective horizontal resolution for the AROME model of at least 4 times the physically-defined grid spacing. The results illustrate the need for special treatment of sub-grid scale variability of vertical velocities in kilometer-scale atmospheric models, if processes such as aerosol-cloud interactions are to be included in the future.
Resolving both entrainment-mixing and number of activated CCN in deep convective clouds
Authors: Freud E. , Rosenfeld D. , Axisa D. , Kulkarni J. R.
Published: March 2011

Abstract. The number concentration of activated CCN (Na) is the most fundamental microphysical property of a convective cloud. It determines the rate of droplet growth with cloud depth and conversion into precipitation-sized particles and affects the radiative properties of the clouds. However, measuring Na is not always possible, even in the cores of the convective clouds, because entrainment of sub-saturated ambient air deeper into the cloud lowers the concentrations by dilution and may cause partial or total droplet evaporation, depending on whether the mixing is homogeneous or extreme inhomogeneous, respectively. Here we describe a methodology to derive Na based on the rate of cloud droplet effective radius (Re) growth with cloud depth and with respect to the cloud mixing with the entrained ambient air. We use the slope of the tight linear relationship between the adiabatic water and Re3 to derive an upper limit for Na assuming extreme inhomogeneous mixing. Then we tune Na down to find the theoretical relative humidity that the entrained ambient air would have for each horizontal cloud penetration, in case of homogeneous mixing. This allows us to evaluate both the entrainment and mixing process in the vertical dimension in addition to getting a better estimation for Na. We found that the derived Na from the entire profile data is highly correlated with the independent CCN measurements from below cloud base. Moreover, it was found that mixing of sub-saturated ambient air into the cloud is inclined towards the extreme inhomogeneous limit, i.e. that the time scale of droplet evaporation is significantly smaller than that for turbulent mixing. This means that ambient air that entrains the cloud is pre-moistened by total evaporation of cloud droplets before it mixes deeper into the clouds where it can hardly change the droplet size distribution, hence Re remains close to its adiabatic value at any given cloud depth. However, the tendency towards the extreme inhomogeneous mixing appeared to slightly decrease with altitude, possibly due to enhanced turbulence and larger cloud drops aloft. Quantifying these effects, based on more examples from other projects and high resolution cloud models is essential for improving our understanding of the interactions between the cloud and its environment. These interactions may play an important role in cloud dynamics and microphysics, by affecting cloud depth and droplet size spectra, for example, and may therefore influence the cloud precipitation formation processes.
Lessons learnt from the snow emergency management of winter season 2008–2009 in Piemonte
Authors: Pelosini R. , Bovo S. , Cordola M.
Published: March 2011

Abstract. The winter season 2008–2009 has been characterized by heavy snowfalls over the western Alps. The snowfalls have been exceptional because of their earliness, persistence, intensity and territorial spread. The impact on the regional environment and territory has been relevant, also from the economical point of view, as well as the effort of the people involved in the forecasting, prevention and fighting actions. The environmental induced effects have been shown until late spring. Several snowfall events affected also the plains and the main towns, causing social impacts. The purpose of this work is to describe the overall effects of the anomalous snowfalls and the emergency response by the local government and institutions to face the hazard scenario and mitigate the risk for people, properties and environment. Arpa Piemonte (Regional Agency for Environmental Protection) gave the technical support to the snow emergency management borrowing the expertise acquired during the heavy hydrological events occurred in the Piemonte region and contributing to minimize losses. A short list of recommendations came out from the experience, as well as the technical tools and products, all highlighting the emergency preparedness relevance.
Can a multi-model approach improve hydrological ensemble forecasting? A study on 29 French catchments using 16 hydrological model structures
Authors: Velázquez J. A. , Anctil F. , Ramos M. H. , Perrin C.
Published: March 2011

Abstract. An operational hydrological ensemble forecasting system based on a meteorological ensemble prediction system (M-EPS) coupled with a hydrological model searches to capture the uncertainties associated with the meteorological prediction to better predict river flows. However, the structure of the hydrological model is also an important source of uncertainty that has to be taken into account. This study aims at evaluating and comparing the performance and the reliability of different types of hydrological ensemble prediction systems (H-EPS), when ensemble weather forecasts are combined with a multi-model approach. The study is based on 29 catchments in France and 16 lumped hydrological model structures, driven by the weather forecasts from the European centre for medium-range weather forecasts (ECMWF). Results show that the ensemble predictions produced by a combination of several hydrological model structures and meteorological ensembles have higher skill and reliability than ensemble predictions given either by one single hydrological model fed by weather ensemble predictions or by several hydrological models and a deterministic meteorological forecast.
Multi-model data fusion as a tool for PUB: example in a Swedish mesoscale catchment
Authors: Exbrayat J.-F. , Viney N. R. , Seibert J. , Frede H.-G. , Breuer L.
Published: March 2011

Abstract. Post-processing the output of different rainfall-runoff models allows one to pool strengths of each model to produce more reliable predictions. As a new approach in the frame of the "Prediction in Ungauged Basins" initiative, this study investigates the geographical transferability of different parameter sets and data-fusion methods which were applied to 5 different rainfall-runoff models for a low-land catchment in Central Sweden. After usual calibration, we adopted a proxy-basin validation approach between two similar but non-nested sub-catchments in order to simulate ungauged conditions. Many model combinations outperformed the best single model predictions with improvements of efficiencies from 0.70 for the best single model predictions to 0.77 for the best ensemble predictions. However no "best" data-fusion method could be determined as similar performances were obtained with different merging schemes. In general, poorer model performance, i.e. lower efficiency, was less likely to occur for ensembles which included more individual models.
Short-term dynamics of microplankton abundance and diversity in NW Mediterranean Sea during late summer conditions (DYNAPROC 2 cruise; 2004)
Authors: Lasternas S. , Tunin-Ley A. , Ibañez F. , Andersen V. , Pizay M.-D. , Lemée R.
Published: March 2011

Abstract. Changes in marine phytoplankton communities at short-time scales have rarely been examined. As a part of the DYNAPROC 2 cruise (14 September–17 October 2004), conducted in the NW Mediterranean Sea, we daily sampled and determined taxonomic composition and abundance of the microphytoplankton and the dominant microzooplanktonic groups from both net and bottle sampling, during 4 cycles of 5 days. Hydrological conditions were characterised by the dominance of a stratified water column and nutrient-depleted conditions. However the stratification index revealed a destabilization of the water column from the beginning of the second cycle, related to a wind stress event accompanied with coastal water intrusion. This conducted to an increase of taxonomic richness and a general decrease of evenness, depicting the dominance of species with the best fitness. We also emphasised on the great interest of taxonomic studies, as able to provide valuable information on biogeochemical-important groups of species, potential water masses indicators and trophic aspects of the community that are ignored or largely underestimated with other kind of phytoplankton studies, such as pigment analysis.
Metazooplankton diversity, community structure and spatial distribution across the Mediterranean Sea in summer: evidence of ecoregions
Authors: Nowaczyk A. , Carlotti F. , Thibault-Botha D. , Pagano M.
Published: March 2011

Abstract. The diversity and distribution of metazooplankton across the Mediterranean Sea was studied along a 3000 km long transect from the eastern to the western basins during the BOUM cruise in summer 2008. Metazooplankton were sampled using both a 120 μm mesh size bongo net and Niskin bottles at 17 stations. Here we report on the stock, the composition and the structure of the metazooplankton community. The abundance was 4 to 8 times higher than in several previously published studies, whereas the biomass remained within the same order of magnitude. An eastward decrease in abundance was evident, although biomass was variable. Spatial (horizontal and vertical) distribution of metazooplankton abundance and biomass was strongly correlated to chlorophyll-a concentration. In addition, a clear association was observed between the vertical distribution of nauplii and small copepods and the depth of the deep chlorophyll maximum. The role of environmental factors is also discussed. Cluster analysis allowed us to define a regionalization of the Mediterranean Sea based on the abundance and diversity of metazooplankton. We found a north-south distinction in the western basin and a longitudinal homogeneity in the eastern basin. The Sicily Channel appeared as an intermediate region. The specific pattern of distribution of remarkable species was also described.