bluuebunny/crossref_metadata_2025 huggingface dataset:
Decoding the Regulation of Mast Cell Exocytosis by Networks of Rab GTPases
Authors: Azouz Nurit P. , Matsui Takahide , Fukuda Mitsunori , Sagi-Eisenberg Ronit
Published: July 2012

Exocytosis is a key event in mast cell functions. By this process, mast cells release inflammatory mediators, contained in secretory granules (SGs), which play important roles in immunity and wound healing but also provoke allergic and inflammatory responses. The mechanisms underlying mast cell exocytosis remained poorly understood. An essential step toward deciphering the mechanisms behind exocytosis is the identification of the cellular components that regulate this process. Because Rab GTPases regulate specific trafficking pathways, we screened 44 Rabs for their functional impacts on exocytosis triggered by the FcεRI or combination of Ca2+ ionophore and phorbol ester. Because exocytosis involves the continuous reorganization of the actin cytoskeleton, we also repeated our screen in the presence of cytochalasin D that inhibits actin polymerization. In this paper, we report on the identification of 30 Rabs as regulators of mast cell exocytosis, the involvement of 26 of which has heretofore not been recognized. Unexpectedly, these Rabs regulated exocytosis in a stimulus-dependent fashion, unless the actin skeleton was disrupted. Functional clustering of the identified Rabs suggested their classification as Rabs involved in SGs biogenesis or Rabs that control late steps of exocytosis. The latter could be further divided into Rabs that localize to the SGs and Rabs that regulate transport from the endocytic recycling compartment. Taken together, these findings unveil the Rab networks that control mast cell exocytosis and provide novel insights into their mechanisms of action.
CD8 T Cells Are Essential for Recovery from a Respiratory Vaccinia Virus Infection
Authors: Goulding John , Bogue Rebecka , Tahiliani Vikas , Croft Michael , Salek-Ardakani Shahram
Published: July 2012

The precise immune components required for protection against a respiratory Orthopoxvirus infection, such as human smallpox or monkeypox, remain to be fully identified. In this study, we used the virulent Western Reserve strain of vaccinia virus (VACV-WR) to model a primary respiratory Orthopoxvirus infection. Naive mice infected with VACV-WR mounted an early CD8 T cell response directed against dominant and subdominant VACV-WR Ags, followed by a CD4 T cell and Ig response. In contrast to other VACV-WR infection models that highlight the critical requirement for CD4 T cells and Ig, we found that only mice deficient in CD8 T cells presented with severe cachexia, pulmonary inflammation, viral dissemination, and 100% mortality. Depletion of CD8 T cells at specified times throughout infection highlighted that they perform their critical function between days 4 and 6 postinfection and that their protective requirement is critically dictated by initial viral load and virulence. Finally, the ability of adoptively transferred naive CD8 T cells to protect RAG−/− mice against a lethal VACV-WR infection demonstrated that they are both necessary and sufficient in protecting against a primary VACV-WR infection of the respiratory tract.
Chitinase 1 Is a Biomarker for and Therapeutic Target in Scleroderma-Associated Interstitial Lung Disease That Augments TGF-β1 Signaling
Authors: Lee Chun Geun , Herzog Erica L. , Ahangari Farida , Zhou Yang , Gulati Mridu , Lee Chang-Min , Peng Xueyan , Feghali-Bostwick Carol , Jimenez Sergio A. , Varga John , Elias Jack A.
Published: July 2012

Interstitial lung disease (ILD) with pulmonary fibrosis is an important manifestation in systemic sclerosis (SSc, scleroderma) where it portends a poor prognosis. However, biomarkers that predict the development and or severity of SSc-ILD have not been validated, and the pathogenetic mechanisms that engender this pulmonary response are poorly understood. In this study, we demonstrate in two different patient cohorts that the levels of chitotriosidase (Chit1) bioactivity and protein are significantly increased in the circulation and lungs of SSc patients compared with demographically matched controls. We also demonstrate that, compared with patients without lung involvement, patients with ILD show high levels of circulating Chit1 activity that correlate with disease severity. Murine modeling shows that in comparison with wild-type mice, bleomycin-induced pulmonary fibrosis was significantly reduced in Chit1−/− mice and significantly enhanced in lungs from Chit1 overexpressing transgenic animals. In vitro studies also demonstrated that Chit1 interacts with TGF-β1 to augment fibroblast TGF-β receptors 1 and 2 expression and TGF-β–induced Smad and MAPK/ERK activation. These studies indicate that Chit1 is potential biomarker for ILD in SSc and a therapeutic target in SSc-associated lung fibrosis and demonstrate that Chit1 augments TGF-β1 effects by increasing receptor expression and canonical and noncanonical TGF-β1 signaling.
The Bible in Afrikaans: A direct translation – A new type of church Bible
Authors: Van der Merwe Christo H.J.
Published: July 2012

Translating the Bible so that target audiences can easily understand the meaning of the text has dominated the theory and practice of Bible translation since the 1960s. Source oriented translations that are typically associated with word-for-word translations received little theoretical reflection. However, developments in Translation Studies have made it clear that the latter type of translations do not provide the type of equivalence more conservative churches really call for. The story of the Bible in Afrikaans relates to how the Bible Society of South Africa (BSSA) has taken seriously the needs of churches in South Africa for a source- oriented translation and teamed up with scholars to develop an academically justifiable model for a new type of church Bible. The functionalist model of Christiane Nord (1997) was used as point of departure and complimented by that of Ernst-August Gutt (2000). Pointing out the accomplishments and challenges of this pioneering project, this article paves the way for a scholarly discourse on source-oriented translations of the Bible.
Homotopy Batalin–Vilkovisky algebras
Authors: Gálvez-Carrillo Imma , Tonks Andrew , Valette Bruno
Published: July 2012

This paper provides an explicit cofibrant resolution of the operad encoding Batalin–Vilkovisky algebras. Thus it defines the notion of
homotopy Batalin–Vilkovisky algebras
with the required homotopy properties.

To define this resolution, we extend the theory of Koszul duality to operads and properads that are defined by quadratic and linear relations. The operad encoding Batalin–Vilkovisky algebras is shown to be Koszul in this sense. This allows us to prove a Poincaré–Birkhoff–Witt Theorem for such an operad and to give an explicit small quasi-free resolution for it.

This particular resolution enables us to describe the deformation theory and homotopy theory of BV-algebras and of homotopy BV-algebras. We show that any topological conformal field theory carries a homotopy BV-algebra structure which lifts the BV-algebra structure on homology. The same result is proved for the singular chain complex of the double loop space of a topological space endowed with an action of the circle. We also prove the cyclic Deligne conjecture with this cofibrant resolution of the operad

\mathcal{BV}

. We develop the general obstruction theory for algebras over the Koszul resolution of a properad and apply it to extend a conjecture of Lian–Zuckerman, showing that certain vertex algebras have an explicit homotopy BV-algebra structure.
Very High Dimensional Semiparametric Models
Authors: Janssen Arnold , van der Vaart Aad , Wellner Jon A.
Published: July 2012

Very high dimensional semiparametric models play a major role in many areas, in particular in signal detection problems when sparse signals or sparse events are hidden among high dimensional noise. Concrete examples are genomic studies in biostatistics or imaging problems. In a broad context all kind of statistical inference and model selection problems were discussed for high dimensional data.
Correlations and Interactions for Random Quantum Systems
Authors: Hislop Peter D. , Kirsch Werner , Müller Peter , Warzel Simone
Published: July 2012

Random quantum systems cover a broad range of mathematical models from random Schr¨odinger operators to random matrices and quantum spin models with random parameters. Their understanding requires techniques which combine functional analysis and probability. The workshop brought together researchers from these various branches which discussed new results, methods and future challenges. This is a report on the meeting containing extended abstracts of the lectures.
Combinatorial Optimization
Authors: Goemans Michel X. , Laurent Monique , Vygen Jens
Published: July 2012

Combinatorial Optimization is a very active field that benefits from bringing together ideas from different areas, e.g., graph theory and combinatorics, matroids and submodularity, connectivity and network flows, approximation algorithms and mathematical programming, discrete and computational geometry, discrete and continuous problems, algebraic and geometric methods, and applications. We continued the long tradition of triannual Oberwolfach workshops, bringing together the best researchers from the above areas, discovering new connections, and establishing new and deepening existing international collaborations.
Perception of Patients with Amalgam Fillings about Toxicity of Mercury in Dental Amalgam
Authors: Bamise CT , Oginni Adeleke O , Adedigba Michael A , Olagundoye OO
Published: July 2012

Objective

The objective of this study is to evaluate the awareness of patients with dental fillings about the toxicity of mercury in dental amalgam.

Materials and methods

Adult patients having at least one amalgam filling in their mouth were recruited in the Oral Diagnosis Department of OAUTHC, Ile-Ife Dental Hospital. Participants were recruited consecutively as they report in the clinic. Data were collected using a structured questionnaire developed based on standard questions from relevant publications. They were asked to indicate the type of filling material in their mouth, ingredients of the material, previous knowledge of mercury in dental amalgam and ailments due to mercury.

They were to indicate their level of agreement with filling their cavities with dental amalgam despite prior information about its mercury content.

Results

There were about 446 respondents analyzed; male, 194 (43.5%); female 252 (56.5%). Six (1.4%) and 21 (4.7%) respondents were primary and secondary schools students respectively; 15(3.4%) had no formal education while about 410 (91.9%) were either undergraduate or graduate. All of them had at least one amalgam filling. 249 (55%) participants know the type of filling on their teeth; 156 (34.5%) had the knowledge of the presence of mercury in dental amalgam while 26.1% believed mercury can cause problems in human beings. About 90 (19.9%) participants claimed to have heard about adverse reactions to dental amalgams and 34 (7.5%) of them have heard about people recovering from an illness after removal of their filling.

The level of agreement with filling their cavities with amalgam despite prior knowledge of its mercury content was 74% while 60% was observed for allowing just any material to be placed on their teeth.

Conclusion

Awareness of toxicity of mercury in dental amalgam was slightly low among the respondents studied. This may be suggested to be a reflection of nonexistent of global amalgam controversy in Nigeria.

How to cite this article

Bamise CT, Oginni AO, Adedigba MA, Olagundoye OO. Perception of Patients with Amalgam Fillings about Toxicity of Mercury in Dental Amalgam. J Contemp Dent Pract 2012;13(3):289-293.
Oral Health-Related Quality of Life (OHQoL) among Adolescents Seeking Orthodontic Treatment
Authors: Manjith CM , Karnam Srinivas Kumar , Manglam Sunil , Praveen MN , Mathur Anirudh
Published: July 2012

Aim

The aim of this study was to assess the effect of different orthodontic treatment needs on the OHQoL of adolescents.

Materials and methods

200 subjects (100 males and 100 females), 11 to 15 years of age were recruited for the study. OHQoL was assessed with the short form of the oral health impact profile (OHIP-14), and malocclusion severity was assessed with the index of orthodontic treatment need (IOTN). The Chi-square test was used to analyse the qualitative data. The level of significance was 0.05.

Results

The more severe the malocclusion the worse was the impact on the OHQoL. Orthodontic treatment need had almost similar impact on the daily activities of both males and females. Pronunciation and taste was not significantly affected by the need for orthodontic treatment in either males or females. The proportions of orthodontic patients who found it uncomfortable to eat any food and had to interrupt their meals were significantly correlated with orthodontic treatment needs in both males and females.

Conclusion

Orthodontic treatment need had an impact on OHQoL of adolescents with no significant difference between males and females.

Clinical significance

Orthodontists should be aware of the impact caused by malocclusion and orthodontic treatment on the quality of life of the patients and should provide regular positive reinforcements to them.

How to cite this article

Manjith CM, Karnam SK, Manglam S, Praveen MN, Mathur A. Oral Health-Related Quality of Life (OHQoL) among Adolescents Seeking Orthodontic Treatment. J Contemp Dent Pract 2012;13(3):294-298.
Assessment of Skeletal and Dental Maturity Levels for a given Chronological Age among Indian Children
Authors: Murthy K Krishna , Srinivas C Nagendra , LNU Varalakshmi , Kumar C Vijay , Krishnaveni M
Published: July 2012

Aim

The aim of this study was to evaluate the maturity levels of the individual by comparing the correlation between dental, skeletal and the chronological ages.

Materials and methods

Intraoral periapical radiographs of the complete right side of the dentition and posteroanterior radiographs of the hand and wrist were obtained from 260 subjects, ranged from 3 to 15 years of age. Evaluation of handwrist roentgenograms for skeletal age and intraoral roentgenograms for dental age was done.

Results

The findings of present study indicated that participated children were skeletally and dentally, retarded in maturation as compared with the standards except at 3 and 6 years of age. The girls were found to be skeletally more advanced than boys at all ages except 7 and 10 years of age. The dental maturity is more for girls than that of boys.

Conclusion

No significant correlation was found among skeletal age, dental age and chronological age. Dental age and skeletal age was found to be correlated at 6, 10 and 11 years in boys and 6 and 9 years of age in girls.

Clinical significance

The results of this study could enhance the diagnosis and treatment planning in orthodontics and other dental disciplines.

How to cite this article

Murthy KK, Srinivas CN, Varalakshmi, Kumar CV, Krishnaveni M. Assessment of Skeletal and Dental Maturity Levels for a given Chronological Age among Indian Children. J Contemp Dent Pract 2012;13(3):310-315.
Comparative Analysis of Postcementation Hypersensitivity with Glass Ionomer Cement and a Resin Cement: An in vivo Study
Authors: Mehta Deepak , Shetty Rohit M , Bhat Sonia , Srivatsa G , Shetty Y Bharath
Published: July 2012

Aim

The aim of this clinical study was to compare the postoperative sensitivity of abutment teeth restored with full coverage restorations retained with either conventional glassionomer cement (GIC) or resin cement.

Materials and methods

Fifty patients received full-coverage restorations on vital abutment teeth. Of these, 25 were cemented with GIC (GC Luting and Lining cement) and the other 25 using an adhesive resin cement (Smartcem 2). A randomized single blind study was undertaken for acquiring and evaluating the data. The teeth were examined before cementation, after cementation, 24 hours postcementation and 7 days postcementation. A visual analog scale was used to help the patient rate hypersensitivity.

Results

The statistical analysis of the result was done using students paired t-test. No statistically significant difference between Smartcem 2 and GIC was observed, when tested immediately and 24 hours after cementation. Statistically significant difference was seen between Smartcem 2 and GIC when tested 7 days postcementation with a significance level of 0.05. Higher postoperative sensitivity was seen with GIC when compared to resin cement.

Conclusion

In this study, the incidence of postoperative hypersensitivity after cementation of full-crown restorations with GIC and resin cement was similar when tested immediately. However, 7 days postcementation, abutments with GIC showed higher response compared to resin cement.

Clinical significance

A self-adhesive resin cement can be the material of choice for luting if presence of postoperative sensitivity is of prime consideration. In case GIC is being used, patient should be informed about the presence of sensitivity for a more prolonged period than with resin cement.

How to cite this article

Shetty RM, Bhat S, Mehta D, Srivatsa G, Shetty YB. Comparative Analysis of Postcementation Hypersensitivity with Glass Ionomer Cement and a Resin Cement: An in vivo Study. J Contemp Dent Pract 2012;13(3): 327-331.
Assessment of Interobserver Variability in Mitotic Figure Counting in Different Histological Grades of Oral Squamous Cell Carcinoma
Authors: Prasanna MD , Yadav K Shailaja , Gonuguntla Sudhir , Velidandla Surekha Reddy , Reddy CR Charan , Bommu Sanjay Reddy
Published: July 2012

Mitotic counting is often used for classification, grading and prognosis of tumors. The count usually stands as a decision point for treatment as well. The easiest way of counting the number of mitoses is done by screening routine H&E stained slides. However, for proper mitotic counting, certain strict protocols should be taken into consideration. This study on 30 cases of different grades of oral squamous cell carcinoma was undertaken to determine the interobserver variations in two different groups: Group1 (A1, A2), who were given certain criteria to be followed during the counting of the mitotic figures and group 2 investigators (B1, B2) who were unaware of such criteria. The paired t-test gives a correlation of 0.988 and a significant difference of 0.000 between the two investigators in group 1. The correlation was 0.650 with a significant difference of 0.058 between two investigators in-group 2, indicating that group 1 observers exhibit good interobserver agreement. The results emphasize that following of strict protocols are of great help in determining the accuracy of mitotic counting.

How to cite this article

Yadav KS, Gonuguntla S, Ealla KKR, Velidandla SR, Reddy CRC, Prasanna MD, Bommu SR. Assessment of Interobserver Variability in Mitotic Figure Counting in Different Histological Grades of Oral Squamous Cell Carcinoma. J Contemp Dent Pract 2012;13(3):339-344.
A Comparative Study to Determine the Wettability and Castability of Different Elastomeric Impression Materials
Authors: Reddy N Simhachalam , Reddy G Vivekananda , Itttigi Jayaprkash
Published: July 2012

Aim

The aim of this study was to determine the wettability of different hydrophilic and hydrophobic elastomeric impression materials and the gypsum castability.

Materials and methods

The wettability was evaluated by determining the contact angles of different elastomeric impression materials. The contact angle was determined by placing a drop of aqueous solution of calcium sulfate dihydrate on the flat surface of impression material and specimens were measured using a profile projector.

Gypsum castability was determined by counting the number of voids formed in the die stone cast made from the impressions of a aluminum die. The voids were counted using an diopter magnifying lens.

Results

Polyether, different viscosities of polyvinyl siloxane, and condensation silicone impression materials exhibited low contact angle values and least number of voids in the die stone cast when compared with polysulfide impression material.

Conclusion

There was significant correlation between the contact angle and voids formed in the die stone casts when fabricating die stone casts from various elastomeric impression material impressions.

Clinical significance

Accurate reproduction of prepared tooth or edentulous arch is of clinical importance in the fabrication of a fixed or removable prosthesis. Inaccuracies in the replication processes will ultimately have an adverse effect on the fit and adaptation of final restoration. The interaction is determined in part by hydrophilic and hydrophobic nature of the elastomeric impression material. Inadequate wetting of an impression results in voids in the stone casts.

How to cite this article

Reddy GV, Reddy NS, Itttigi J, Jagadeesh KN. A Comparative Study to Determine the Wettability and Castability of Different Elastomeric Impression Materials. J Contemp Dent Pract 2012;13(3):356-363.
Effect of Chemical Disinfectant on the Transverse Strength of Heat-polymerized Acrylic Resins Subjected to Mechanical and Chemical Polishing: An in vitro Study
Authors: Kalahasti Deepthi , Sharan Smitha , Konde Harish
Published: July 2012

Aims

To evaluate the effect of chemical disinfectant on the transverse strength of heat-polymerized acrylic resins subjected to mechanical and chemical polishing.

Materials and methods

A total of 256 rectangular specimens (65 × 10 × 3 mm) 128 per resin (Lucitone-199 and Acralyn-H) were fabricated. One side of each specimen was not polished and the other was either mechanically (n = 96) or chemically (n = 96) polished and immersed for 10, 30 and 60 minutes in 2% alkaline glutaraldehyde. Mechanically polished (n = 32) and chemically polished (n = 32) control specimens were immersed only in distilled water. The transverse strength (N/mm2) was tested for failure in a universal testing machine, at a crosshead speed of 5 mm/min. Data were statistically analyzed using 2-way ANOVA and Student t-test.

Results

chemical polishing resulted in significantly lower transverse strength values than mechanical polishing. Lucitone- 199 resin demonstrated the highest overall transverse strength for the materials tested. Heat-polymerized acrylic resins either mechanically or chemically polished, did not demonstrate significant changes in transverse strength during immersion in the disinfecting solution tested, regardless of time of immersion.

Conclusion

Lucitone-199 resin demonstrated the highest overall transverse strength for the materials tested and significantly stronger than Acralyn-H with either type of polishing following immersion in 2% alkaline glutaraldehyde.

Clinical significance

There is a concern that immersion in chemical solutions often used for cleansing and disinfection of prostheses may undermine the strength and structure of denture base resins. In this study it was observed that, the transverse strength of samples of Lucitone-199 was higher than that of the samples of Acralyn-H. The chances of fracture of the denture made of Lucitone-199 are less than that of dentures made of Acralyn-H. The chemically polished dentures may be more prone to fracture than mechanically polished dentures.

How to cite this article

Sharan S, Kavitha HR, Konde H, Kalahasti D. Effect of Chemical Disinfectant on the Transverse Strength of Heat-polymerized Acrylic Resins Subjected to Mechanical and Chemical Polishing: An in vitro Study. J Contemp Dent Pract 2012;13(3):389-393.
Palatal Rugoscopy among Puducherry Population
Authors: Kumar Sathish , Balaji N , Shanthi V , Sumathi MK , Vendhan Priya
Published: July 2012

Background

Human identification is one of the most challenging subjects that man has been confronted with. The fingerprints and DNA comparison are the most commonly used techniques in human identification. Palatoscopy is one of the recently developing methods to identify a victim-based on the palatal rugae pattern.

Aims and objectives

The aim of the study was to analyze the different rugae pattern in Puducherry population and to find whether palatoscopy is a useful tool in human identification and sex determination.

Materials and methods

The studies consist of 100 male and female patients between the age group of 20 to 35 years. The rugae pattern was divided assessed based on Kotze classification. Chi-square test and one-way analysis was used to study the statistical significance.

Results

Wavy pattern appeared to be the most predominant pattern followed by curved, straight, branched and circular pattern in both male and female patients. The shape and number of rugae pattern is similar in male and females.

Conclusion

The present study concludes that wavy pattern appear to be most common rugae pattern among Puducherry population. No significant difference in rugae pattern was noted among the male and female group. Rugae pattern is unique to each individual and can be an effective tool in human identification.

How to cite this article

Kumar S, Vezhavendhan N, Shanthi V, Balaji N, Sumathi MK, Vendhan P. Palatal Rugoscopy among Puducherry Population. J Contemp Dent Pract 2012;13(3): 401-404.
Anthropogenic and forest fire pollution aerosol transported to the Arctic: observations from the POLARCAT-France spring campaign
Authors: Quennehen B. , Schwarzenboeck A. , Matsuki A. , Burkhart J. F. , Stohl A. , Ancellet G. , Law K. S.
Published: July 2012

Abstract. During the POLARCAT-France airborne measurement campaign in spring 2008, several pollution plumes transported from mid-latitude regions were encountered. The study presented here focuses on air masses from two different geographic origins (Europe and Asia) and from 2 different source types (anthropogenic pollution and forest fires). A first case study is dedicated to a European air mass, which was repeatedly sampled and analysed during three consecutive days. Thereby, the evolution of the aerosol properties (size distributions, CO mixing ratio) is characterised and related processes are discussed. In particular, the role of coagulation, condensation and cloud processing in the evolution of the Aitken and the accumulation mode particles are contrasted. A second case study focuses on European air masses impacted solely by biomass burning emissions and Asian air masses with contributions from both biomass burning and anthropogenic emissions. The analysis of aerosol modes highlight a similar behaviour for particle originating from biomass burning (from Europe as well as Asia). In comparison to the predominating aged accumulation mode in biomass burning particles, a still larger aerosol accumulation mode related to Asian anthropogenic emissions can be isolated. These findings corroborate the external mixing of such kind of aerosol size distributions. An electron microscopy study (coupled to X-ray elemental analysis) of particles illustrated soot-like inclusions in several samples. Within samples attributed to forest fire sources, the chemical signature is highly associated with the presence of potassium, which is a characteristic tracer element for biomass burning plumes. The single particle images suggest an internal mixing of sampled individual aerosol particles. Thus, particles are found externally mixed as demonstrated from particle size distributions while they appear internally mixed at the particle scale.
Wet and dry deposition of atmospheric nitrogen at ten sites in Northern China
Authors: Pan Y. P. , Wang Y. S. , Tang G. Q. , Wu D.
Published: July 2012

Abstract. Emissions of reactive nitrogen (N) species can affect surrounding ecosystems via atmospheric deposition. However, few long-term and multi-site measurements have focused on both the wet and the dry deposition of individual N species in large areas of Northern China. Thus, the magnitude of atmospheric deposition of various N species in Northern China remains uncertain. In this study, the wet and dry atmospheric deposition of different N species was investigated during a three-year observation campaign at ten selected sites in Northern China. The results indicate that N deposition levels in Northern China were high with a ten-site, three-year average of 60.6 kg N ha−1 yr−1. The deposition levels showed spatial and temporal variation in the range of 28.5–100.4 kg N ha−1 yr−1. Of the annual total deposition, 40% was deposited via precipitation, and the remaining 60% was comprised of dry-deposited forms. Compared with gaseous N species, particulate N species were not the major contributor of dry-deposited N; they contributed approximately 10% to the total flux. On an annual basis, oxidized species accounted for 21% of total N deposition, thereby implying that other forms of gaseous N, such as NH3, comprised a dominant portion of the total flux. The contribution of NO3− to N deposition was enhanced in certain urban and industrial areas, possibly due to the fossil fuse combustion. As expected, the total N deposition in Northern China was significantly larger than the values reported by national scale monitoring networks in Europe, North America and East Asia because of high rates of wet deposition and gaseous NH3 dry deposition. Taken together, these findings show that NH3 emissions should be abated to mitigate high N deposition and associated potential impacts on ecosystems in Northern China. The present results improve our understanding of spatio-temporal variations of magnitudes, pathways and species of deposited N in the target areas, and are important not only to inform conservation and regulatory bodies but also to initiate further detailed studies. Uncertainties among current observations underscore the need to quantify the impact of vegetation on dry deposition and to refine the simulation of dry deposition velocity.
Diurnal variations of reactive chlorine and nitrogen oxides observed by MIPAS-B inside the January 2010 Arctic vortex
Authors: Wetzel G. , Oelhaf H. , Kirner O. , Friedl-Vallon F. , Ruhnke R. , Ebersoldt A. , Kleinert A. , Maucher G. , Nordmeyer H. , Orphal J.
Published: July 2012

Abstract. The winter 2009/2010 was characterized by a strong Arctic vortex with extremely cold mid-winter temperatures in the lower stratosphere associated with an intense activation of reactive chlorine compounds (ClOx) from reservoir species. Stratospheric limb emission spectra were recorded during a flight of the balloon version of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS-B) from Kiruna (Sweden) on 24 January 2010 inside the Arctic vortex. Several fast limb sequences of spectra (in time steps of about 10 min) were measured from nighttime photochemical equilibrium to local noon allowing the retrieval of chlorine- and nitrogen-containing species which change rapidly their concentration around the terminator between night and day. Mixing ratios of species like ClO, NO2, and N2O5 show significant changes around sunrise, which are temporally delayed due to polar stratospheric clouds reducing the direct radiative flux from the sun. ClO variations were derived for the first time from MIPAS-B spectra. Daytime ClO values of up to 1.6 ppbv are visible in a broad chlorine activated layer below 26 km correlated with low values (below 0.1 ppbv) of the chlorine reservoir species ClONO2. Observations are compared and discussed with calculations performed with the 3-dimensional Chemistry Climate Model EMAC (ECHAM5/MESSy Atmospheric Chemistry). Mixing ratios of the species ClO, NO2, and N2O5 are well reproduced by the model during night and noon. However, the onset of ClO production and NO2 loss around the terminator in the model is not consistent with the measurements. The MIPAS-B observations along with Tropospheric Ultraviolet-Visible (TUV) radiation model calculations suggest that polar stratospheric clouds lead to a delayed start followed by a faster increase of the photodissoziation of ClOOCl and NO2 near the morning terminator since stratospheric clouds alter the direct and the diffuse flux of solar radiation. These effects are not considered in the EMAC model simulations which assume a cloudless atmosphere.
Spatial and seasonal variations of fine particle water-soluble organic carbon (WSOC) over the southeastern United States: implications for secondary organic aerosol formation
Authors: Zhang X. , Liu Z. , Hecobian A. , Zheng M. , Frank N. H. , Edgerton E. S. , Weber R. J.
Published: July 2012

Abstract. Secondary organic aerosol (SOA) in the southeastern US is investigated by analyzing the spatial-temporal distribution of water-soluble organic carbon (WSOC) and other PM2.5 components from 900 archived 24-h Teflon filters collected at 15 urban or rural EPA Federal Reference Method (FRM) network sites throughout 2007. Online measurements of WSOC at an urban/rural-paired site in Georgia in the summer of 2008 are contrasted to the filter data. Based on FRM filters, excluding biomass-burning events (levoglucosan < 50 ng m−3), WSOC and sulfate were highly correlated with PM2.5 mass (r2~0.7). Both components comprised a large mass fraction of PM2.5 (13% and 31%, respectively, or ~25% and 50% for WSOM and ammonium sulfate). Sulfate and WSOC both tracked ambient temperature throughout the year, suggesting the temperature effects were mainly linked to faster photochemistry and/or synoptic meteorology and less due to enhanced biogenic hydrocarbon emissions. FRM WSOC, and to a lesser extent sulfate, were spatially homogeneous throughout the region, yet WSOC was moderately enhanced (27%) in locations of greater predicted isoprene emissions in summer. A Positive Matrix Factorization (PMF) analysis identified two major source types for the summer WSOC; 22% of the WSOC were associated with ammonium sulfate, and 56% of the WSOC were associated with brown carbon and oxalate. A small urban excess of FRM WSOC (10%) was observed in the summer of 2007, however, comparisons of online WSOC measurements at one urban/rural pair (Atlanta/Yorkville) in August 2008 showed substantially greater difference in WSOC (31%) relative to the FRM data, suggesting a low bias for urban filters. The measured Atlanta urban excess, combined with the estimated boundary layer heights, gave an estimated Atlanta daily WSOC production rate in August of 0.55 mgC m−2 h−1 between mid-morning and mid-afternoon. This study characterizes the regional nature of fine particles in the southeastern US, confirming the importance of SOA and the roles of both biogenic and anthropogenic emissions.
First middle-atmospheric zonal wind profile measurements with a new ground-based microwave Doppler-spectro-radiometer
Authors: Rüfenacht R. , Kämpfer N. , Murk A.
Published: July 2012

Abstract. We report on the wind radiometer WIRA, a new ground-based microwave Doppler-spectro-radiometer specifically designed for the measurement of middle-atmospheric horizontal wind by observing ozone emission spectra at 142.17504 GHz. Currently, wind speeds in five levels between 30 and 79 km can be retrieved what makes WIRA the first instrument able to continuously measure horizontal wind in this altitude range. For an integration time of one day the measurement error on each level lies at around 25 m s−1. With a planned upgrade this value is expected to be reduced by a factor of 2 in the near future. On the altitude levels where our measurement can be compared to wind data from the European Centre for Medium-Range Weather Forecasts (ECMWF) very good agreement in the long-term statistics as well as in short time structures with a duration of a few days has been found. WIRA uses a passive double sideband heterodyne receiver together with a digital Fourier transform spectrometer for the data acquisition. A big advantage of the radiometric approach is that such instruments can also operate under adverse weather conditions and thus provide a continuous time series for the given location. The optics enables the instrument to scan a wide range of azimuth angles including the directions east, west, north, and south for zonal and meridional wind measurements. The design of the radiometer is fairly compact and its calibration does not rely on liquid nitrogen what makes it transportable and suitable for campaign use. WIRA is conceived in a way that it can be operated remotely and does hardly require any maintenance. In the present paper, a description of the instrument is given, and the used techniques for the wind retrieval based on the determination of the Doppler shift of the measured atmospheric ozone emission spectra are outlined. Their reliability was tested using MonteCarlo simulations. Finally, a first time series of 11 months of zonal wind measurements over Bern (46°57' N, 7°26' E) is presented and compared to ECMWF wind data.
Solar wind plasma interaction with solar probe plus spacecraft
Authors: Guillemant S. , Génot V. , Matéo-Vélez J.-C. , Ergun R. , Louarn P.
Published: July 2012

Abstract. 3-D PIC (Particle In Cell) simulations of spacecraft-plasma interactions in the solar wind context of the Solar Probe Plus mission are presented. The SPIS software is used to simulate a simplified probe in the near-Sun environment (at a distance of 0.044 AU or 9.5 RS from the Sun surface). We begin this study with a cross comparison of SPIS with another PIC code, aiming at providing the static potential structure surrounding a spacecraft in a high photoelectron environment. This paper presents then a sensitivity study using generic SPIS capabilities, investigating the role of some physical phenomena and numerical models. It confirms that in the near- sun environment, the Solar Probe Plus spacecraft would rather be negatively charged, despite the high yield of photoemission. This negative potential is explained through the dense sheath of photoelectrons and secondary electrons both emitted with low energies (2–3 eV). Due to this low energy of emission, these particles are not ejected at an infinite distance of the spacecraft and would rather surround it. As involved densities of photoelectrons can reach 106 cm−3 (compared to ambient ions and electrons densities of about 7 × 103 cm−3), those populations affect the surrounding plasma potential generating potential barriers for low energy electrons, leading to high recollection. This charging could interfere with the low energy (up to a few tens of eV) plasma sensors and particle detectors, by biasing the particle distribution functions measured by the instruments. Moreover, if the spacecraft charges to large negative potentials, the problem will be more severe as low energy electrons will not be seen at all. The importance of the modelling requirements in terms of precise prediction of spacecraft potential is also discussed.
Reconstruction of drip-water δ18O based on calcite oxygen and clumped isotopes of speleothems from Bunker Cave (Germany)
Authors: Kluge T. , Affek H. P. , Marx T. , Aeschbach-Hertig W. , Riechelmann D. F. C. , Scholz D. , Riechelmann S. , Immenhauser A. , Richter D. K. , Fohlmeister J. , Wackerbarth A. , Mangini A. , Spötl C.
Published: July 2012

Abstract. The geochemical signature of many speleothems used for reconstruction of past continental climates is affected by kinetic isotope fractionation. This limits quantitative paleoclimate reconstruction and, in cases where the kinetic fractionation varies with time, also affects relative paleoclimate interpretations. In carbonate archive research, clumped isotope thermometry is typically used as proxy for absolute temperatures. In the case of speleothems, however, clumped isotopes provide a sensitive indicator for disequilibrium effects. The extent of kinetic fractionation co-varies in Δ47 and δ18O so that it can be used to account for disequilibrium in δ18O and to extract the past drip-water composition. Here we apply this approach to stalagmites from Bunker Cave (Germany) and calculate drip-water δ18Ow values for the Eemian, Marine Isotope Stage (MIS) 3, and the Holocene, relying on independent temperature estimates and accounting for disequilibrium. Applying the co-variation method to modern calcite precipitates yields drip-water δ18Ow values in agreement with modern cave drip-water δ18Ow of −7.9 ± 0.3‰, despite large and variable disequilibrium effects in both calcite δ18Oc and Δ47. Reconstructed paleo-drip-water δ18Ow values are lower during colder periods (e.g., MIS 3: −8.5 ± 0.4‰ and the early Holocene at 11 kyr: −9.3 ± 0.1‰) and show higher values during warmer climatic periods (e.g., the Eemian: −7.5 ± 0.2‰ and the Holocene Climatic Optimum: −7.2 ± 0.3‰). This new approach offers a unique possibility for quantitative climate reconstruction including the assessment of past hydrological conditions while accounting for disequilibrium effects.
Global marine plankton functional type biomass distributions: coccolithophores
Authors: O'Brien C. J. , Peloquin J. A. , Vogt M. , Heinle M. , Gruber N. , Ajani P. , Andruleit H. , Arístegui J. , Beaufort L. , Estrada M. , Karentz D. , Kopczyńska E. , Lee R. , Pritchard T. , Widdicombe C.
Published: July 2012

Abstract. Coccolithophores are calcifying marine phytoplankton of the class Prymnesiophyceae. They are considered to play an import role in the global carbon cycle through the production and export of organic carbon and calcite. We have compiled observations of global coccolithophore abundance from several existing databases as well as individual contributions of published and unpublished datasets. We estimate carbon biomass using standardised conversion methods and provide estimates of uncertainty associated with these values. The database contains 58 384 individual observations at various taxonomic levels. This corresponds to 12 391 observations of total coccolithophore abundance and biomass. The data span a time period of 1929–2008, with observations from all ocean basins and all seasons, and at depths ranging from the surface to 500 m. Highest biomass values are reported in the North Atlantic, with a maximum of 501.7 μg C l−1. Lower values are reported for the Pacific (maximum of 79.4 μg C l−1) and Indian Ocean (up to 178.3 μg C l−1). Coccolithophores are reported across all latitudes in the Northern Hemisphere, from the Equator to 89° N, although biomass values fall below 3 μg C l−1 north of 70° N. In the Southern Hemisphere, biomass values fall rapidly south of 50° S, with only a single non-zero observation south of 60° S. Biomass values show a clear seasonal cycle in the Northern Hemisphere, reaching a maximum in the summer months (June–July). In the Southern Hemisphere the seasonal cycle is less evident, possibly due to a greater proportion of low-latitude data. The original and gridded datasets can be downloaded from Pangaea (http://doi.pangaea.de/10.1594/PANGAEA.785092).
Tagged ozone mechanism for MOZART-4, CAM-chem, and other chemical transport models
Authors: Emmons L. K. , Hess P. G. , Lamarque J.-F. , Pfister G. G.
Published: July 2012

Abstract. A procedure for tagging ozone produced from NO sources through updates to an existing chemical mechanism is described, and results from its implementation in the Model for Ozone and Related chemical Tracers (MOZART-4), a global chemical transport model, are presented. Artificial tracers are added to the mechanism, thus not affecting the standard chemistry. The results are linear in the troposphere, i.e., the sum of ozone from individual tagged sources equals the ozone from all sources to within 3% in zonal mean monthly averages. The stratospheric ozone contribution to the troposphere determined from the difference between total ozone and ozone from all tagged sources is significantly less than estimates using a traditional stratospheric ozone tracer (8 vs 20 ppbv at the surface). The commonly used technique of perturbing NO emissions by 20% in a region to determine its ozone contribution is compared to the tagging technique, showing that the tagged ozone is 2–4 times the ozone contribution that was deduced from perturbing emissions.
Effects of peatland drainage management on peak flows
Authors: Ballard C. E. , McIntyre N. , Wheater H. S.
Published: July 2012

Abstract. Open ditch drainage has historically been a common land management practice in upland blanket peats, particularly in the UK. However, peatland drainage is now generally considered to have adverse effects on the upland environment, including increased peak flows. As a result, drain blocking has become a common management strategy in the UK over recent years, although there is only anecdotal evidence to suggest that this might decrease peak flows. The change in the hydrological regime associated with the drainage of blanket peat and the subsequent blocking of drains is poorly understood, therefore a new physics-based model has been developed that allows the exploration of the associated hydrological processes. A series of simulations is used to explore the response of intact, drained and blocked drain sites at field scales. While drainage is generally found to increase peak flows, the effect of drain blocking appears to be dependent on local conditions, sometimes decreasing and sometimes increasing peak flows. Based on insights from these simulations we identify steep smooth drains as those that would experience the greatest reduction in field-scale peak flows if blocked and recommend that future targeted field studies should be focused on examining surface runoff characteristics.
Investigation of solute transport in nonstationary unsaturated flow fields
Authors: Chang C.-M. , Yeh H.-D.
Published: July 2012

Abstract. Most theoretical work on analyzing the plume's spreading at the field scale in a partially saturated heterogeneous formation assumes weak stationarity of velocity field. While this assumption is not applicable to the case of a bounded flow domain, the nonstationarity in fluctuations of unsaturated velocity fields is induced through the presence of the boundary conditions in the flow domain. In this work, we attempt to quantify the large-time macrodispersion in nonstaionary unsaturated velocity fields caused by the presence of a fixed head boundary condition. Application of the perturbation-based nonstationary spectral approach leads to an analytical expression for the macrodispersion describing the field-scale dispersive solute flux in terms of the statistical moments of two formation parameters, i.e. the Gardener's parameter (α) and the saturated hydraulic conductivity (Ks). The results predicted from the expression indicate that the enhanced unsaturated plume's spreading can arise from a larger correlation scale of ln Ks or ln α fields. In addition, the α-parameter takes the role in reducing the field-scale plume spreading.
Active faults and historical earthquakes in the Messina Straits area (Ionian Sea)
Authors: Polonia A. , Torelli L. , Gasperini L. , Mussoni P.
Published: July 2012

Abstract. The Calabrian Arc (CA) subduction complex is located at the toe of the Eurasian Plate in the Ionian Sea, where sediments resting on the lower plate have been scraped off and piled up in the accretionary wedge due to the African/Eurasian plate convergence and back arc extension. The CA has been struck repeatedly by destructive historical earthquakes, but knowledge of active faults and source parameters is relatively poor, particularly for seismogenic structures extending offshore. We analysed the fine structure of major tectonic features likely to have been sources of past earthquakes: (i) the NNW–SSE trending Malta STEP (Slab Transfer Edge Propagator) fault system, representing a lateral tear of the subduction system; (ii) the out-of-sequence thrusts (splay faults) at the rear of the salt-bearing Messinian accretionary wedge; and (iii) the Messina Straits fault system, part of the wide deformation zone separating the western and eastern lobes of the accretionary wedge. Our findings have implications for seismic hazard in southern Italy, as we compile an inventory of first order active faults that may have produced past seismic events such as the 1908, 1693 and 1169 earthquakes. These faults are likely to be source regions for future large magnitude events as they are long, deep and bound sectors of the margin characterized by different deformation and coupling rates on the plate interface.