bluuebunny/crossref_metadata_2025 huggingface dataset:
Minimal Tolerance to a Tumor Antigen Encoded by a Cancer-Germline Gene
Authors: Huijbers Ivo J. , Soudja Saïdi M. , Uyttenhove Catherine , Buferne Michel , Inderberg-Suso Else-Marit , Colau Didier , Pilotte Luc , Powis de Tenbossche Céline G. , Chomez Patrick , Brasseur Francis , Schmitt-Verhulst Anne-Marie , Van den Eynde Benoît J.
Published: December 2011

Central tolerance toward tissue-restricted Ags is considered to rely on ectopic expression in the thymus, which was also observed for tumor Ags encoded by cancer-germline genes. It is unknown whether endogenous expression shapes the T cell repertoire against the latter Ags and explains their weak immunogenicity. We addressed this question using mouse cancer-germline gene P1A, which encodes antigenic peptide P1A35–43 presented by H-2Ld. We made P1A-knockout (P1A-KO) mice and asked whether their anti-P1A35–43 immune responses were stronger than those of wild-type mice and whether P1A-KO mice responded to other P1A epitopes, against which wild-type mice were tolerized. We observed that both types of mice mounted similar P1A35–43-specific CD8 T cell responses, although the frequency of P1A35–43-specific CD8 T cells generated in response to P1A-expressing tumors was slightly higher in P1A-KO mice. This higher reactivity allowed naive P1A-KO mice to reject spontaneously P1A-expressing tumors, which progressed in wild-type mice. TCR-Vβ usage of P1A35–43-specific CD8 cells was slightly modified in P1A-KO mice. Peptide P1A35–43 remained the only P1A epitope recognized by CD8 T cells in both types of mice, which also displayed similar thymic selection of a transgenic TCR recognizing P1A35–43. These results indicate the existence of a minimal tolerance to an Ag encoded by a cancer-germline gene and suggest that its endogenous expression only slightly affects diversification of the T cell repertoire against this Ag.
The Cytokine Midkine and Its Receptor RPTPζ Regulate B Cell Survival in a Pathway Induced by CD74
Authors: Cohen Sivan , Shoshana Or-yam , Zelman-Toister Einat , Maharshak Nitsan , Binsky-Ehrenreich Inbal , Gordin Maya , Hazan-Halevy Inbal , Herishanu Yair , Shvidel Lev , Haran Michal , Leng Lin , Bucala Richard , Harroch Sheila , Shachar Idit
Published: December 2011

Lasting B cell persistence depends on survival signals that are transduced by cell surface receptors. In this study, we describe a novel biological mechanism essential for survival and homeostasis of normal peripheral mature B cells and chronic lymphocytic leukemia cells, regulated by the heparin-binding cytokine, midkine (MK), and its proteoglycan receptor, the receptor-type tyrosine phosphatase ζ (RPTPζ). We demonstrate that MK initiates a signaling cascade leading to B cell survival by binding to RPTPζ. In mice lacking PTPRZ, the proportion and number of the mature B cell population are reduced. Our results emphasize a unique and critical function for MK signaling in the previously described MIF/CD74-induced survival pathway. Stimulation of CD74 with MIF leads to c-Met activation, resulting in elevation of MK expression in both normal mouse splenic B and chronic lymphocytic leukemia cells. Our results indicate that MK and RPTPζ are important regulators of the B cell repertoire. These findings could pave the way toward understanding the mechanisms shaping B cell survival and suggest novel therapeutic strategies based on the blockade of the MK/RPTPζ-dependent survival pathway.
Acquisition of Complement Factor H Is Important for Pathogenesis ofStreptococcus pyogenesInfections: Evidence from Bacterial In Vitro Survival and Human Genetic Association
Authors: Haapasalo Karita , Vuopio Jaana , Syrjänen Jaana , Suvilehto Jari , Massinen Satu , Karppelin Matti , Järvelä Irma , Meri Seppo , Kere Juha , Jokiranta T. Sakari
Published: December 2011

Streptococcus pyogenes (or group A streptococcus [GAS]) is a major human pathogen causing infections, such as tonsillitis, erysipelas, and sepsis. Several GAS strains bind host complement regulator factor H (CFH) via its domain 7 and, thereby, evade complement attack and C3b-mediated opsonophagocytosis. Importance of CFH binding for survival of GAS has been poorly studied because removal of CFH from plasma or blood causes vigorous complement activation, and specific inhibitors of the interaction have not been available. In this study, we found that activation of human complement by different GAS strains (n = 38) correlated negatively with binding of CFH via its domains 5–7. The importance of acquisition of host CFH for survival of GAS in vitro was studied next by blocking the binding with recombinant CFH5–7 lacking the regulatory domains 1–4. Using this fragment in full human blood resulted in death or radically reduced multiplication of all of the studied CFH-binding GAS strains. To study the importance of CFH binding in vivo (i.e., for pathogenesis of streptococcal infections), we used our recent finding that GAS binding to CFH is diminished in vitro by polymorphism 402H, which is also associated with age-related macular degeneration. We showed that allele 402H is suggested to be associated with protection from erysipelas (n = 278) and streptococcal tonsillitis (n = 209) compared with controls (n = 455) (p < 0.05). Taken together, the bacterial in vitro survival data and human genetic association revealed that binding of CFH is important for pathogenesis of GAS infections and suggested that inhibition of CFH binding can be a novel therapeutic approach in GAS infections.
White Matter Changes in Bipolar Disorder, Alzheimer Disease, and Mild Cognitive Impairment: New Insights from DTI
Authors: Xekardaki Aikaterini , Giannakopoulos Panteleimon , Haller Sven
Published: December 2011

Neuropathological and neuroimaging studies have reported significant changes in white matter in psychiatric and neurodegenerative diseases. Diffusion tensor imaging (DTI), a recently developed technique, enables the detection of microstructural changes in white matter. It is a noninvasivein vivotechnique that assesses water molecules' diffusion in brain tissues. The most commonly used parameters are axial and radial diffusivity reflecting diffusion along and perpendicular to the axons, as well as mean diffusivity and fractional anisotropy representing global diffusion. Although the combination of these parameters provides valuable information about the integrity of brain circuits, their physiological meaning still remains controversial. After reviewing the basic principles of DTI, we report on recent contributions that used this technique to explore subtle structural changes in white matter occurring in elderly patients with bipolar disorder and Alzheimer disease.
Wnt/ß-Catenin: A New Therapeutic Approach to Acute Myeloid Leukemia
Authors: Kim Y. , Thanendrarajan S. , Schmidt-Wolf I. G. H.
Published: December 2011

Recent studies have shown genetic and epigenetic aberrations resulting in aberrant activation of the Wingless-Int (Wnt) pathway, thus influencing the initiation and progression of acute myeloid leukemia (AML). Of major importance, these findings may lead to novel treatment strategies exploiting targeted modulation of Wnt signaling. This paper comprises the latest status of knowledge concerning the role of Wnt pathway alteration in AML and outlines future lines of research and their clinical perspectives.
Unilateral Sudden Hearing Loss Due to Otosyphilis
Authors: de Goffau Maaike J. , Doelman Jan C. , van Rijswijk Jeroen B.
Published: December 2011

The differential diagnosis of sudden hearing loss is very extensive. However, in most patients, no underlying pathology will be found and the patient is consequently diagnosed with idiopathic sudden hearing loss. Nevertheless, it is important that one stays alert in everyday routine practice to less common but potentially treatable pathology. We report a case of a 53- year old patient with sudden unilateral hearing loss and tinnitus caused by otosyphilis. Diagnosis, therapy and the incidence of (oto)syphilis are discussed. Also, as ENT-surgeons, it is important to realise that syphilis is still with us, and that its prevalence might well increase in the near future.
Urogenital symptoms in postmenopausal women: a hospital-based prevalence study
Authors: Soontrapa Nisarath , Soontrapa Sukree , Kaewrudee Srinaree , Somboonporn Woraluk , Sakondhavat Chuanchom
Published: December 2011

Objectives. To determine the prevalence of urogenital symptoms (vaginal dryness, dyspareunia, urinary incontinence) and assess patient’s consultation rate and desire for treatment. Design and Methods. This study was prospective descriptive study, performed with the participation of 125 women who presented in menopausal clinic, Srinagarind Hospital. Women completed the questionnaire including questions about their demographic properties and were interviewed by pre-validated questionnaire and in-depth interview to determine the prevalence of urogenital symptoms, consultation rate and patient’s desire for treatment. Results. The mean age of the participants was 57.1 years. Vaginal dryness was found to be the most common postmenopausal urogenital symptoms (71.2%), followed by urinary incontinence (62.4%) and dyspareunia (52.0%). The consultation rates were 62.2% in vaginal dryness, 46.2% in dyspareunia and 38.5% in urinary incontinence. Patient’s desire for treatment was 66.7% in vaginal dryness, 62.1% in dyspareunia and 53.8% in urinary incontinence. Conclusions. Urogenital symptoms are highly prevalent. Physicians need to improve patient-physician communication and increase their attention to these symptoms and their patient’s attitudes to improve patient’s quality of life.
Prevalence, profile and obstetric experience of fistula patients in Abakaliki, Southeast Nigeria
Authors: Sunday-Adeoye Ileogben , Okonta Patrick , Ulu Ogbonnaya Lawrence
Published: December 2011

Objective. Fistula has always been thought to be a scourge of the Northern region of Nigeria only. This study was aimed at providing data on the prevalence, profile and obstetric experience of fistula patients in Abakaliki, Southeast Nigeria and to demonstrate that fistula is also a burden in the southern parts of Nigeria. Materials and Methods. This was a prospective descriptive study conducted between 2003 and 2009. Sample size and sampling method. Four hundred and sixty-two fistula patients who were operated at the Fistula Unit of the Teaching Hospital and later at the Southeast Fistula Centre was consecutively recruited and interviewed during the study period. Results. The prevalence of fistula was 4.3%, the mean age was 35±9.5 years and 8.4% was less than 20 years, majority of them had no formal education. A quarter had no occupation and majority had no regular monthly income. Twenty percent were married by the age of 14 years and majority were multiparous. In about 40%, the fistula occurred during the first child birth. About 34% were still sexually active and 30% of the married clients had achieved childbirth after development of fistula. The average height and weight were 1.47m±0.08 and 46.4kg±7.2 respectively. Majority had fistula following prolonged obstructed labour, though 42.6% eventually had caesarean section for prolonged obstructed labour. Majority of the patients were older, had a longer urine leakage and presented latter for corrective surgery than those reported from other parts of Nigeria. Conclusions. There is a high prevalence (43.6/1000 deliveries) of obstetric fistula in this Centre, and majority of the vesico-vaginal fistula (VVF) was due to prolonged obstructed labour. Majority of the patients were older, had a longer urine leakage and presented latter for corrective surgery than those reported from other parts of Nigeria. However, 30% of the married patients achieved a pregnancy and delivered vaginally even in the presence of the fistula.
Counting on Frank: Using bibliotherapy in mathematics teaching to prevent de-geniusing
Authors: Furner Joseph M. , Kenney Cheryl
Published: December 2011

Today the understanding of mathematics is critical in an increasingly technological age. Teachers must play an important role to ensure that all students display confidence in their ability to do mathematics. Often gifted students of mathematics can be made to feel bad by their peers just because they know mathematics and things come easily to them. Children’s and adolescent literature has now been recognised as a means of teaching mathematics to students through the use of stories to make the mathematics concepts relevant and meaningful. Literature can also be used as a form of therapy to reach students who may be frustrated with children picking on them for being good at mathematics. Story and picture books such as Counting on Frank, Math Curse and A Gebra Named Al are now available to use in the classroom as forms of bibliotherapy in helping students come to terms with issues relating to mathematics that haunt them. In this article we discuss the phenomenon of dumbing down by the gifted population to fit in with their peers. We propose using reading and discussion (bibliotherapy) to aid in preventing de-geniusing of mathematically gifted students.
Dermatofibrosarcoma Protuberans of the Scalp with Fibrosarcomatous Degeneration and Pulmonary Metastasis
Authors: Gatlin Joseph L , Hosch Richard , Khan Majid
Published: December 2011

Dermatofibrosarcoma protuberans is a rare locally aggressive cutaneous tumor of intermediate malignancy. It is a slow-growing neoplasm with a marked propensity to recur after resection. Head and neck involvement is unusual and distant metastases are quite rare but tend to be more frequent in tumors that undergo fibrosarcomatous degeneration. We present the imaging and corresponding histopathology in a case of dermatofibrosarcoma protuberans of the scalp demonstrating fibrosarcomatous degeneration and lung metastasis.
Sedentary Habits, Health, and Function in Older Women and Men
Authors: Blair Steven N. , Wei Ming
Published: December 2011

Purpose.

To evaluate the relation of physical activity and cardiorespiratory fitness to morbidity, mortality, and functional limitations in older persons.

Data Sources.

We reviewed published reports related to the review's purpose. Sources were identified from recent major reports and position statements from scientific and public health organizations, our files, and reference lists of published papers.

Study Inclusion and Exclusion Criteria.

We included prospective epidemiological studies and clinical trials published in the peer-reviewed literature that included data from age groups of people 60 years and older. We evaluated study methods and included studies that used valid measures of exposures, clearly specified outcomes, and controlled for confounders.

Data Extraction Methods.

We extracted by detailed review data on sample characteristics, outcomes, and rates and relative risks.

Data Synthesis.

Extracted data were included in tables, figures, or the text and were synthesized by nonquantitative methods.

Major Conclusions.

Active and fit individuals were at much lower risk for morbidity, mortality, and loss of function when compared with sedentary and unfit persons. Data from the studies generally conformed to a steep inverse dose-response gradient across activity or fitness categories. Results were consistent, temporally appropriate, strong, and graded, and therefore support a causal hypothesis that a fit and active way of life improves health and function in older individuals.
The Validity of Health Claims on the World Wide Web: A Systematic Survey of the Herbal Remedy Opuntia
Authors: Veronin Michael A. , Ramirez Gilbert
Published: December 2011

Purpose.

The World Wide Web has become a significant source of health information for the public, but there is concern that much of the information is inaccurate, misleading, and unsupported by scientific evidence. To explore this issue, the validity of health claims for the herb Opuntia on the World Wide Web was analyzed.

Data Sources.

From December 1998 to May 1999, health claims were identified from Web sites utilizing nine search engines. A corresponding search was conducted of the scientific literature. Search terms included common and botanical names for Opuntia.

Inclusion and Exclusion Criteria.

Nutritional support guidelines for herbs were used to identify claims from relevant sites. Scientific studies included established methodological designs with no restrictions on source, language, type of subjects, or dosage forms for Opuntia.

Data Extraction Methods.

A checklist of significant information was prepared for Web sites and scientific studies. The quality of scientific studies was assessed with two instruments, the Jadad and the Journal of the American Medical Association (JAMA) scales.

Data Synthesis.

Validity of health claims on Web sites was compared with scientific reports. Searches retrieved 184 Web sites, 98 with health claims and 51 with research studies. Only 34% of the claims were addressed in the scientific literature, and evidence was conflicting or contradictory. For human studies, none met the criteria for high quality as determined by the Jadad and JAMA scales.

Major Conclusions.

The majority of health claims were based on folklore or indirect scientific evidence and could not be validated by scientific research. This suggests a need to check the validity of herbal information on the World Wide Web.
Depressive Symptoms, Health Promotion, and Health Risk Behaviors
Authors: Green Carla A. , Pope Clyde R.
Published: December 2011

Objectives.

To assess the relationships between history of depressive symptoms and smoking, alcohol consumption, dietary changes, attempts to lose weight or increase exercise, use of health services, and the likelihood of receiving influenza and pneumonia vaccinations, mammograms, and Pap tests.

Methods.

A survey of randomly sampled members of a large health maintenance organization (n = 5841).

Results.

Individuals with past depressive symptoms were more likely to smoke cigarettes (despite making more attempts to quit smoking); to drink more alcohol; to attempt to lose weight, increase exercise, reduce fat intake, increase fiber intake; and, for women, to have a mammogram.

Conclusions.

Individuals with histories of depressive symptoms engage in more positive and negative health behaviors. Additionally, their increased service use provides opportunities to achieve positive health changes and improve treatment outcomes.
Impact of a Telephone-Based Intervention on the Reduction of Health Risks
Authors: Gold Daniel B. , Anderson David R. , Serxner Seth A.
Published: December 2011

Purpose.

Evaluate the long-term impact of telephone-based interventions that target high risk, ready-to-change individuals.

Design.

Quasi-experimental design with pre/post comparisons of lifestyle-related health risks between participants and nonparticipants.

Setting.

Six organizations from the private and public sectors.

Subjects.

Subjects were 607 intervention participants who were compared with a control group of 1134 eligible nonparticipants.

Measures.

Health risk assessment at baseline and at an average of 2 years later measured risk in 13 lifestyle areas.

Intervention.

Programs were offered in seven areas: back care, cholesterol control, eating habits, exercise and activities, stress management, tobacco use, and weight control. Each program was conducted by a trained health educator who provided information and counseling to facilitate change in the area selected by the participant. All counseling was done by telephone and included three to five contacts over a 1-year period.

Results.

Binary logistic regression models controlling for gender and age revealed both specific and general effects. Participants were 1.8 to 3.5 times as likely as nonparticipants to reduce the targeted risk in six of seven risk areas. In addition, participants were 1.7 to 3.5 times as likely as nonparticipants to reduce their risks in nine of 13 areas not targeted by the intervention (i.e., general effect). Overall, participants significantly reduced their number of risks, whereas nonparticipants significantly increased their risk (difference of .85 risks).

Conclusions.

Results show that at-risk participants make long-term improvements in health risks directly related to the intervention in which they participate. Results also suggest that this intervention may help individuals develop behavior-change skills they can apply to other lifestyle issues.
Using surface remote sensors to derive radiative characteristics of Mixed-Phase Clouds: an example from M-PACE
Authors: de Boer G. , Collins W. D. , Menon S. , Long C. N.
Published: December 2011

Abstract. Measurements from ground-based cloud radar, high spectral resolution lidar and microwave radiometer are used in conjunction with a column version of the Rapid Radiative Transfer Model (RRTMG) and radiosonde measurements to derive the surface radiative properties under mixed-phase cloud conditions. These clouds were observed during the United States Department of Energy (US DOE) Atmospheric Radiation Measurement (ARM) Mixed-Phase Arctic Clouds Experiment (M-PACE) between September and November of 2004. In total, sixteen half hour time periods are reviewed due to their coincidence with radiosonde launches. Cloud liquid (ice) water paths are found to range between 11.0–366.4 (0.5–114.1) gm−2, and cloud physical thicknesses fall between 286–2075 m. Combined with temperature and hydrometeor size estimates, this information is used to calculate surface radiative flux densities using RRTMG, which are demonstrated to generally agree with measured flux densities from surface-based radiometric instrumentation. Errors in longwave flux density estimates are found to be largest for thin clouds, while shortwave flux density errors are generally largest for thicker clouds. A sensitivity study is performed to understand the impact of retrieval assumptions and uncertainties on derived surface radiation estimates. Cloud radiative forcing is calculated for all profiles, illustrating longwave dominance during this time of year, with net cloud forcing generally between 50 and 90 Wm−2.
A multi-angle aerosol optical depth retrieval algorithm for geostationary satellite data over the United States
Authors: Zhang H. , Lyapustin A. , Wang Y. , Kondragunta S. , Laszlo I. , Ciren P. , Hoff R. M.
Published: December 2011

Abstract. Aerosol optical depth (AOD) retrievals from geostationary satellites have high temporal resolution compared to the polar orbiting satellites and thus enable us to monitor aerosol motion. However, current Geostationary Operational Environmental Satellites (GOES) have only one visible channel for retrieving aerosols and hence the retrieval accuracy is lower than those from the multichannel polar-orbiting satellite instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS). The operational GOES AOD retrieval algorithm (GOES Aerosol/Smoke Product, GASP) uses 28-day composite images from the visible channel to derive surface reflectance, which can produce large uncertainties. In this work, we develop a new AOD retrieval algorithm for the GOES imager by applying a modified Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm. The algorithm assumes the surface Bidirectional Reflectance Distribution Function (BRDF) in the channel 1 of GOES is proportional to seasonal average MODIS BRDF in the 2.1 μm channel. The ratios between them are derived through time series analysis of the GOES visible channel images. The results of AOD and surface reflectance retrievals are evaluated through comparisons against those from Aerosol Robotic Network (AERONET), GASP, and MODIS. The AOD retrievals from the new algorithm demonstrate good agreement with AERONET retrievals at several sites across the US with correlation coefficients ranges from 0.71 to 0.85 at five out of six sites. At the two western sites Railroad Valley and UCSB, the MAIAC AOD retrievals have correlations of 0.8 and 0.85 with AERONET AOD, and are more accurate than GASP retrievals, which have correlations of 0.7 and 0.74 with AERONET AOD. At the three eastern sites, the correlations with AERONET AOD are from 0.71 to 0.81, comparable to the GASP retrievals. In the western US where surface reflectance is higher than 0.15, the new algorithm also produces larger AOD retrieval coverage than both GASP and MODIS.
Transpacific transport of benzo[a]pyrene emitted from Asia
Authors: Zhang Y. , Tao S. , Ma J. , Simonich S.
Published: December 2011

Abstract. A global-scale three dimensional atmospheric transport and chemistry model was applied to simulate transpacific transport of Benzo[a]pyrene (BaP) emitted from Asia. The model results were compared with observations at six monitoring sites. The annual mean and seasonal variation of transport patterns and the contributions of different Asian source regions to transpacific transport flux were investigated. The episodic nature of transpacific transport was also systematically explored. Interannual variability of transpacific transport of BaP was also assessed during the period of 1948–2007. Results showed that strong enhancements of modeled BaP occurred in an area bounded by 70–80° E and 100–120° E. Air containing these elevated BaP concentrations was then delivered eastward by westerly winds. When approaching the West Coast of North America, the descending atmospheric motion carried BaP-laden air into the lower atmosphere. The transpacific transport flux was 1.6 times higher in the winter than in the summer. East Asian emission dominates the transpacific transport flux with a contribution of about 97%. Near ground concentration of BaP induced by Asian sources in North America varied between 1–20 pg m−3. A case study for observation at Cheeka Peak Observatory during March 2002–May 2002 reveals the importance of warm conveyor belt for transpacific transport. The number of days with transpacific transport flux with a factor of 0.5, 1.0, 1.5, and 2.0 larger than the running mean were 9.4%, 0.72%, 0.06% and 0.01%, respectively, implying a mild contribution of episodic transport to the long-term mean transport flux. Significant interannual fluctuation of transpacific transport of BaP was found, including a general decreasing trend during 1948–2007, and especially after the 1970s. The transpacific transport was found to be positively correlated with the Southern Oscillation Index.
Global NOx emission estimates derived from an assimilation of OMI tropospheric NO2 columns
Authors: Miyazaki K. , Eskes H. J. , Sudo K.
Published: December 2011

Abstract. A data assimilation system has been developed to estimate global nitrogen oxides (NOx) emissions using OMI tropospheric NO2 columns (DOMINO product) and a global chemical transport model (CTM), CHASER. The data assimilation system, based on an ensemble Kalman filter approach, was applied to optimize daily NOx emissions with a horizontal resolution of 2.8° during the years 2005 and 2006. The background error covariance estimated from the ensemble CTM forecasts explicitly represents non-direct relationships between the emissions and tropospheric columns caused by atmospheric transport and chemical processes. In comparison to the a priori emissions based on bottom-up inventories, the optimized emissions were higher over Eastern China, the Eastern United States, Southern Africa, and Central-Western Europe, suggesting that the anthropogenic emissions are mostly underestimated in the inventories. In addition, the seasonality of the estimated emissions differed from that of the a priori emission over several biomass burning regions, with a large increase over Southeast Asia in April and over South America in October. The data assimilation results were validated against independent data: SCIAMACHY tropospheric NO2 columns and vertical NO2 profiles obtained from aircraft and lidar measurements. The emission correction greatly improved the agreement between the simulated and observed NO2 fields; this implies that the data assimilation system efficiently derives NOx emissions from concentration observations. We also demonstrated that biases in the satellite retrieval and model settings used in the data assimilation largely affect the magnitude of estimated emissions. These dependences should be carefully considered for better understanding NOx sources from top-down approaches.
Variability of aerosol, gaseous pollutants and meteorological characteristics associated with continental, urban and marine air masses at the SW Atlantic coast of Iberia
Authors: Diesch J.-M. , Drewnick F. , Zorn S. R. , von der Weiden-Reinmüller S.-L. , Martinez M. , Borrmann S.
Published: December 2011

Abstract. Measurements of the ambient aerosol were performed at the Southern coast of Spain, within the framework of the DOMINO (Diel Oxidant Mechanisms In relation to Nitrogen Oxides) project. The field campaign took place from 20 November until 9 December 2008 at the atmospheric research station "El Arenosillo" (37°5'47.76" N, 6°44'6.94" W). As the monitoring station is located at the interface between a natural park, industrial cities (Huelva, Seville) and the Atlantic Ocean a variety of physical and chemical parameters of aerosols and gas phase could be characterized in dependency on the origin of air masses. Backwards trajectories were examined and compared with local meteorology to classify characteristic air mass types for several source regions. Aerosol number and mass as well as polycyclic aromatic hydrocarbons and black carbon concentrations were measured in PM1 and size distributions were registered covering a size range from 7 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) and a weather station provided meteorological parameters. Lowest average submicron particle mass and number concentrations were found in air masses arriving from the Atlantic Ocean with values around 2 μg m−3 and 1000 cm−3. These mass concentrations were about two to four times lower than the values recorded in air masses of continental and urban origins. For some species PM1-fractions in marine air were significantly larger than in air masses originating from Huelva, a closely located city with extensive industrial activities. The largest fraction of sulfate (54%) was detected in marine air masses and was to a high degree not neutralized. In addition small concentrations of methanesulfonic acid (MSA), a product of biogenic dimethyl sulfate (DMS) emissions could be identified in the particle phase. In all air masses passing the continent the organic aerosol fraction dominated the total NR-PM1. For this reason, using Positive Matrix Factorization (PMF) four organic aerosol (OA) classes that can be associated with various aerosol sources and components were identified: a highly-oxygenated OA is the major component contributing an average of 43% of the particulate organic mass while the semi-volatile OA accounts for 23%. A hydrocarbon-like OA mainly resulting from industries, traffic and shipping emissions as well as particles from wood burning emissions also contribute to total OA dependent on the air mass origin. The variability of ozone is not only affected by different types of air masses but also significantly by the diurnal variation as a consequence of the solar radiation as well as local meteorological parameters.
The equilibrium response to idealized thermal forcings in a comprehensive GCM: implications for recent tropical expansion
Authors: Allen R. J. , Sherwood S. C. , Norris J. R. , Zender C. S.
Published: December 2011

Abstract. Several recent studies have shown the width of the tropical belt has increased over the last several decades. The mechanisms driving tropical expansion are not well known and the recent expansion is underpredicted by state-of-the art GCMs. We use the CAM3 GCM to investigate how tropical width responds to idealized atmospheric heat sources, focusing on zonal displacement of the tropospheric jets (TJ). The heat sources include global and zonally restricted lower-tropospheric warmings and stratospheric coolings, which coarsely represent possible impacts of ozone or aerosol changes. Similar to prior studies with simplified GCMs, we find that stratospheric cooling-particularly at high-latitudes-shifts jets poleward and excites Northern and Southern Annular Mode (NAM/SAM)-type responses. We also find, however, that modest heating of the midlatitude boundary layer drives a similar response; heating at high latitudes provokes a weaker, equatorward shift and tropical heating produces no shift. Responses to stratospheric cooling are consistent with a wave-mean flow interaction involving increased wave refraction, and downward propagation of the stratospheric wind anomaly. Over 70% of the variance in annual mean jet displacements across 27 experiments, however, is accounted for by a newly proposed "Expansion Index", which compares mid-latitude tropospheric warming to that at other latitudes. We find that previously proposed factors, including tropopause height and tropospheric stability, do not fully explain the results. Results suggest recently observed tropical expansion could have been driven not only by stratospheric cooling, but also by mid-latitude heating sources due for example to ozone or aerosol changes.
Simultaneous stable isotope analysis of methane and nitrous oxide on ice core samples
Authors: Sapart C. J. , van der Veen C. , Vigano I. , Brass, M. , van de Wal R. S. W. , Bock M. , Fischer H. , Sowers T. , Buizert C. , Sperlich P. , Blunier T. , Behrens M. , Schmitt J. , Seth B. , Röckmann T.
Published: December 2011

Abstract. Methane and nitrous oxide are important greenhouse gases which show a strong increase in atmospheric mixing ratios since pre-industrial time as well as large variations during past climate changes. The understanding of their biogeochemical cycles can be improved using stable isotope analysis. However, high-precision isotope measurements on air trapped in ice cores are challenging because of the high susceptibility to contamination and fractionation. Here, we present a dry extraction system for combined CH4 and N2O stable isotope analysis from ice core air, using an ice grating device. The system allows simultaneous analysis of δD(CH4) or δ13C(CH4), together with δ15N(N2O), δ18O(N2O) and δ15N(NO+ fragment) on a single ice core sample, using two isotope mass spectrometry systems. The optimum quantity of ice for analysis is about 600 g with typical "Holocene" mixing ratios for CH4 and N2O. In this case, the reproducibility (1σ ) is 2.1‰ for δD(CH4), 0.18‰ for δ13C(CH4), 0.51‰ for δ15N(N2O), 0.69‰ for δ18O(N2O) and 1.12‰ for δ15N(NO+ fragment). For smaller amounts of ice the standard deviation increases, particularly for N2O isotopologues. For both gases, small-scale intercalibrations using air and/or ice samples have been carried out in collaboration with other institutes that are currently involved in isotope measurements of ice core air. Significant differences are shown between the calibration scales, but those offsets are consistent and can therefore be corrected for.
Where microorganisms meet rocks in the Earth's Critical Zone
Authors: Akob D. M. , Küsel K.
Published: December 2011

Abstract. The Critical Zone (CZ) is the Earth's outer shell where all the fundamental physical, chemical, and biological processes critical for sustaining life occur and interact. As microbes in the CZ drive many of these biogeochemical cycles, understanding their impact on life-sustaining processes starts with an understanding of their biodiversity. In this review, we summarize the factors controlling where terrestrial CZ microbes (prokaryotes and micro-eukaryotes) live and what is known about their diversity and function. Microbes are found throughout the CZ, down to 5 km below the surface, but their functional roles change with depth due to habitat complexity, e.g. variability in pore spaces, water, oxygen, and nutrients. Abundances of prokaryotes and micro-eukaryotes decrease from 1010 or 107 cells g soil−1 or rock−1, or ml water−1 by up to eight orders of magnitude with depth. Although symbiotic mycorrhizal fungi and free-living decomposers have been studied extensively in soil habitats, where they occur up to 103 cells g soil−1, little is known regarding their identity or impact on weathering in the deep subsurface. The relatively low abundance of micro-eukaryotes in the deep subsurface suggests that they are limited in space, nutrients, are unable to cope with oxygen limitations, or some combination thereof. Since deep regions of the CZ have limited access to recent photosynthesis-derived carbon, microbes there depend on deposited organic material or a chemolithoautotrophic metabolism that allows for a complete food chain, independent from the surface, although limited energy flux means cell growth may take tens to thousands of years. Microbes are found in all regions of the CZ and can mediate important biogeochemical processes, but more work is needed to understand how microbial populations influence the links between different regions of the CZ and weathering processes. With the recent development of "omics" technologies, microbial ecologists have new methods that can be used to link the composition and function of in situ microbial communities. In particular, these methods can be used to search for new metabolic pathways that are relevant to biogeochemical nutrient cycling and determine how the activity of microorganisms can affect transport of carbon, particulates, and reactive gases between and within CZ regions.
The moisture response of soil heterotrophic respiration: interaction with soil properties
Authors: Moyano F. E. , Vasilyeva N. , Bouckaert L. , Cook F. , Craine J. , Curiel Yuste J. , Don A. , Epron D. , Formanek P. , Franzluebbers A. , Ilstedt U. , Kätterer T. , Orchard V. , Reichstein M. , Rey A. , Ruamps L. , Subke J.-A. , Thomsen I. K. , Chenu C.
Published: December 2011

Abstract. Soil moisture is of primary importance for predicting the evolution of soil carbon stocks and fluxes, both because it strongly controls organic matter decomposition and because it is predicted to change at global scales in the following decades. However, the soil functions used to model the heterotrophic respiration response to moisture have limited empirical support and introduce an uncertainty of at least 4 % in global soil carbon stock predictions by 2100. The necessity of improving the representation of this relationship in models has been highlighted in recent studies. Here we present a data-driven analysis of soil moisture-respiration relations based on 90 soils. With the use of linear models we show how the relationship between soil heterotrophic respiration and different measures of soil moisture is consistently affected by soil properties. The empirical models derived include main and moisture interaction effects of soil texture, organic carbon content and bulk density. When compared to other functions currently used in different soil biogeochemical models, we observe that our results can correct biases and reconcile differences within and between such functions. Ultimately, accurate predictions of the response of soil carbon to future climate scenarios will require the integration of soil-dependent moisture-respiration functions coupled with realistic representations of soil water dynamics.
Past surface temperatures at the NorthGRIP drill site from the difference in firn diffusion of water isotopes
Authors: Simonsen S. B. , Johnsen S. J. , Popp T. J. , Vinther B. M. , Gkinis V. , Steen-Larsen H. C.
Published: December 2011

Abstract. A new ice core paleothermometer is introduced based on the temperature dependent diffusion of the stable water isotopes in the firn. A new parameter called differential diffusion length is defined as the difference between the diffusion length of the two stable water isotopologues 2H1H16O and 1H218O. A model treatment of the diffusion process of the firn and the ice is presented along with a method of retrieving the diffusion signal from the ice core record of water isotopes using spectral methods. The model shows how the diffusion process is highly dependent on the inter-annual variations in the surface temperatures. It results in a diffusion length longer than if the firn was isothermal. The longer diffusion length can be explained by the strong nonlinearly behaviour of the saturation pressure over ice in the range of the surface temperature fluctuations. The method has been tested on δ18O and δD measurements, spanning the transition from the last glacial to the holocene, from the NorthGRIP ice core. The surface temperature reconstruction based on the differential diffusion resembles other temperature reconstructions for the NorthGRIP ice core. However, the Allerød warming is seen to be significantly warmer than observed in other ice core based temperature reconstructions. The mechanisms behind this behaviour are not fully understood. The method shows the need of an expansion of high resolution stable water isotope datasets from ice cores. However, the new ice core paleothermometer presented here will give valuable insight into past climate, through the physical process of isotope diffusion in the firn column of ice sheets.
Hydrological evidence for a North Atlantic oscillation during the Little Ice Age outside its range observed since 1850
Authors: Martín-Puertas C. , Dorado-Liñán I. , Brauer A. , Zorita E. , Valero-Garcés B. L. , Gutierrez E.
Published: December 2011

Abstract. An annual-resolved precipitation reconstruction for the last 800 yr in Southern Spain has been performed using stable carbon isotope (δ13C) of Pinus nigra tree rings. The reconstruction exhibits high- to low-frequency variability and distinguishes a Little Ice Age (LIA, AD 1350–1850) characterized by lower averaged rainfall than both in the transition from the Medieval Climate Anomaly to the LIA and in the 20th century. The driest conditions are recorded during the Maunder solar Minimum (mid 17th–early 18th centuries), in good agreement with the Spanish documentary archive. Similar linkage between solar activity (maximum/minimum) and precipitation (increase/decrease) is observed throughout the entire LIA. Additionally, the relationship between the hydrological pattern in the Iberian Peninsula and Morocco during the LIA suggests different spatial distribution of precipitation in the south-eastern sector of the North Atlantic region such as it is known currently. Whereas in the instrumental record the precipitation evolves similarly in both regions and opposite to the North Atlantic oscillation (NAO) index, the coldest periods of the LIA shows a contrasting pattern with drier conditions in the South of Spain and wetter in Northern Africa. We suggest an extreme negative NAO conditions, accompanied by a southward excursion of the winter rainfall band beyond that observed in the last century, can explain this contrast. The sustained NAO conditions could have been triggered by solar minima and higher volcanic activity during the LIA.
Remobilization of silicic intrusion by mafic magmas during the 2010 Eyjafjallajökull eruption
Authors: Sigmarsson O. , Vlastelic I. , Andreasen R. , Bindeman I. , Devidal J.-L. , Moune S. , Keiding J. K. , Larsen G. , Höskuldsson A. , Thordarson Th.
Published: December 2011

Abstract. Injection of basaltic magmas into silicic crustal holding chambers and subsequent magma mingling or mixing is a process that has been recognised since the late seventies as resulting in explosive eruptions. Detailed reconstruction and assessment of the mixing process caused by such intrusion is now possible because of the exceptional time-sequence sample suite available from the tephra fallout of the 2010 summit eruption at Eyjafjallajökull volcano in South Iceland. Fallout from 14 to 19 April contains three glass types of basaltic, intermediate, and silicic compositions recording rapid magma mingling without homogenisation, involving evolved FeTi-basalt and silicic melt with composition identical to that produced by the 1821–1823 AD Eyjafjallajökull summit eruption. The time-dependent change in the magma composition suggests a binary mixing process with changing end-member compositions and proportions. Beginning of May, a new injection of primitive basalt was recorded by deep seismicity, appearance of Mg-rich olivine phenocrysts together with high sulphur dioxide output and presence of sulphide crystals. Thus, the composition of the basaltic injection became more magnesian and hotter with time provoking changes in the silicic mixing end-member from pre-existing melt to the solid carapace of the magma chamber. Finally, decreasing proportions of the mafic end-member with time in the erupted mixed-magma demonstrate that injections of Mg-rich basalt was the motor of the 2010 Eyjafjallajökull explosive eruption, and that its decreasing inflow terminated the eruption. Significant quantity of silicic magma is thus still present in the interior of the volcano. Our results show that detailed sampling during the entire eruption was essential for deciphering the complex magmatic processes at play, i.e. the dynamics of the magma mingling and mixing. Finally, the rapid compositional changes in the eruptive products suggest that magma mingling occurs on a timescale of a few hours to days whereas the interval between the first detected magma injection and eruption was several months.
ORGANIZATIONAL CHANGE FOR THE ENVIRONMENTALLY SUSTAINABLE AIRPORT MANAGEMENT
Authors: Durmaz Vildan
Published: December 2011

Air transportation industry is a globally growing industry. As an inseparable part of this industry, airport management is also becoming more crucial issue to be dealt with. Airports offer economic and social benefits to the society, but also environmental impacts of airport operations are increasing due to high traffic growth. While airport capacity is increasing, airport operators are being responsible for mitigating environmental constraints. Today to implement airport environmental management system is seen as a critical way of solution. To ensure effective implementation of this system, an organizational change with definite roles, responsibilities and structure are needed. This study illustrates a way of organizational response to market forces and national regulations guiding the achievement of sustainable airports by determining the structure and the roles in an airport organization.
Der doppelte Alexander der Grosse?
Authors: Müller Sabine
Published: December 2011

Basierend auf einer antiken Tradition über ihren gemeinsamen Besuch der gefangenen Familie des persischen Großkönigs wurde Hephaistion, der engste Gefährte und Vertraute Alexanders des Großen, in der Rezeption durch europäische Künstler der Renaissance und des Barock als sein äußerlich identischer Doppelgänger gezeigt. Antiker Hintergrund war eine Darstellung der beiden im Sinne der aristotelischen Freundschaftslehre, die von einer Seele in zwei Körpern ausgeht. In der Rezeption des 20. und 21. Jahrhunderts in Populärwissenschaft und Populärkultur erfährt die Darstellung des doppelten Alexanders weitere Facetten: die Abwertung Hephaistions als sein opportunistischer Schatten, die Betonung von Alexanders Hinwendung zur aristotelischen Philosophie und zum heroischen Ideal oder die Darstellung seiner inneren Zerrissenheit.