bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation and characterization of immunoglobulin M of Asian sea bass, Lates calcarifer and its level in serum
Authors: Choudhury Malay , Pani Prasad K.
Published: January 2011

Asian sea bass immunoglobulin M (IgM) was purified from the sera of Lates calcarifer by affinity chromatography. Analysis of the purified IgM on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing and non-reducing conditions revealed that the sea bass IgM was a tetrameric protein with a molecular weight of 896 kDa; it contained an equimolar heavy chain and light chain with molecular weight of 83 kDa and 27 kDa respectively. However, besides the covalently linked tetrameric IgM, noncovalently linked tetramer dissociated into dimeric and monomeric forms also demonstrated by non-reducing SDS-PAGE. Carbohydrate moieties were found to be linked with both heavy and light chains. A polyclonal rabbit anti-Asian sea bass IgM was prepared which showed a specific reaction of anti-fish IgM antibody with IgM of sea bass. Sea bass IgM concentration was determined in the serum by indirect ELISA. The average IgM concentration in the sera of the healthy sea bass was 5.4±1.8 mg ml−1; it amounted to 16.7% of the total serum protein.
The antifungal effect of peptides from hymenoptera venom and their analogs
Authors: Slaninová Jiřina , Putnová Helena , Borovičková Lenka , Šácha Pavel , Čeřovský Václav , Monincová Lenka , Fučík Vladimír
Published: January 2011

As the occurrence of Candida species infections increases, so does resistance against commonly-used antifungal agents. It is therefore necessary to look for new antifungal drugs. This study investigated the antifungal activity of recently isolated, synthesized and characterized antimicrobial α-helical amphipathic peptides (12–18 amino acids long) from the venom of hymenoptera (melectin, lasioglossins I, II, and III, halictines I and II) as well as a whole series of synthetic analogs. The minimal inhibitory concentrations (MICs) against different Candida species (C. albicans, C. krusei, C. glabrata, C. tropicalis and C. parapsilosis) of the natural peptides amounted to 4–20 µM (7–40 mg/l). The most active were the synthetic analog all-D-lasioglossin III and lasioglossin III analog KNWKK-Aib-LGK-Aib-IK-Aib-VK-NH2. As shown using a) colony forming unit determination on agar plates, b) the efflux of the dye from rhodamine 6B-loaded cells, c) propidium iodide and DAPI staining, and d) fluorescently labeled antimicrobial peptide (5(6)-carboxyfluorescein lasioglossin-III), the killing of fungi by the peptides studied occurs within minutes and might be accompanied by a disturbance of all membrane barriers. The peptides represent a promising lead for the development of new, effective antifungal drugs.
Universities and neoliberal models of urban development: using ethnographic fieldwork to understand the 'Death and Rebirth of North Central Philadelphia'
Authors: Hyatt Susan Brin
Published: January 2011

As a political and economic philosophy, neoliberalism has been used to reshape schools and universities, making them far more responsive to the pressures of the market. The principles associated with neoliberalism have also extended to programmes for urban economic development, particularly with respect to the largescale gentrification of neighbourhoods rendering them amenable to investments aimed at creating spaces attractive to white, middle-and-upper class consumers. In this article, I discuss how universities themselves have come to play a significant role as urban developers and investors, promoting commercial retail development and building upscale housing in neighbourhoods adjacent to their campuses. My entry point into this discussion is through describing an ethnographic methods class I taught in 2003, whereby students carried out collaborative research in the African-American neighbourhood surrounding Temple University's main campus in Philadelphia. As a result of their work, we produced a neighbourhood newspaper that sought to disrupt the commonplace assumptions about 'rescuing' the neighbourhood from what was presented as an inexorable spiral of decline; rather, our work showed that actions taken by the university, itself, had helped to produce the very symptoms of decline that the new development project now purported to remedy.
Functional and clinical outcomes following surgical treatment in patients with cervical spondylotic myelopathy: a prospective study of 81 cases
Authors: Furlan Julio C. , Kalsi-Ryan Sukhvinder , Kailaya-Vasan Ahilan , Massicotte Eric M. , Fehlings Michael G.
Published: January 2011

Object

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal dysfunction in the elderly. Operative management is beneficial for most patients with moderate/severe myelopathy. This study examines the potential confounding effects of age, sex, duration of symptoms, and comorbidities on the functional outcomes and postoperative complications in patients who underwent cervical decompressive surgery.

Methods

We included consecutive patients who underwent surgery from December 2005 to October 2007. Functional outcomes were assessed using the Nurick grading system and the modified Japanese Orthopaedic Association and Berg Balance scales. Comorbidity indices included the Charlson Comorbidity Index and the number of ICD-9 codes.

Results

There were 57 men and 24 women with a mean age of 57 years (range 32–88 years). The mean duration of symptoms was 25.2 months (range 1–120 months). There was a significant functional recovery from baseline to 6 months after surgery (p < 0.01). Postoperative complications occurred in 18.5% of cases. Although the occurrence of complications was not significantly associated with sex (p = 0.188), number of ICD-9 codes (p = 0.113), duration of symptoms (p = 0.309), surgical approach (p = 0.248), or number of spine levels treated (p = 0.454), logistic regression analysis showed that patients who developed complications were significantly older than patients who had no complications (p = 0.018). Only older age (p < 0.002) and greater number of ICD-9 codes (p < 0.01) were significantly associated with poorer functional recovery after surgical treatment. However, none of the studied factors were significantly associated with clinically relevant functional recovery after surgical treatment for CSM (p > 0.05).

Conclusions

Our results indicate that surgery for CSM is associated with significant functional recovery, which appears to reach a plateau at 6 months after surgery. Age is a potential predictor of complications after decompressive surgery for CSM. Whereas older patients with a greater number of preexisting medical comorbidities had less favorable functional outcomes after surgery for CSM in the multivariate regression analysis, none of the studied factors were associated with clinically relevant functional recovery after surgery in the logistic regression analysis. Therefore, age-matched protocols based on preexisting medical comorbidities may reduce the risk for postoperative complications and improve functional outcomes after surgical treatment for CSM.
A method to map the visual cortex during an awake craniotomy
Authors: Nguyen Ha Son , Sundaram Seema Vishnu , Mosier Kristine M. , Cohen-Gadol Aaron A.
Published: January 2011

Much has been reported regarding the technique of performing an awake craniotomy with cortical mapping for the functional cortex responsible for sensorimotor activity and language. However, documentation for mapping the visual cortex during an awake craniotomy with a description of its technical details is rare. The authors report the case of a patient who underwent an awake craniotomy with mapping of the visual cortex to remove a glioma situated in the left medial occipital lobe. The techniques that made such a mapping procedure possible are discussed.
Homotopic organization of essential language sites in right and bilateral cerebral hemispheric dominance
Authors: Chang Edward F. , Wang Doris D. , Perry David W. , Barbaro Nicholas M. , Berger Mitchel S.
Published: January 2011

Object

Language dominance in the right hemisphere is rare. Therefore, the organization of essential language sites in the dominant right hemisphere is unclear, especially compared with cases involving the more prevalent left dominant hemisphere.

Methods

The authors reviewed the medical records of 15 patients who underwent awake craniotomy for tumor or epilepsy surgery and speech mapping of right hemisphere perisylvian language areas at the University of California, San Francisco. All patients were determined to have either complete right-sided or bilateral language dominance by preoperative Wada testing.

Results

All patients but one were left-handed. Of more than 331 total stimulation sites, 27 total sites were identified as essential for language function (14 sites for speech arrest/anarthria; 12 for anomia; and 1 for alexia). While significant interindividual variability was observed, the general pattern of language organization was similar to classic descriptions of frontal language production and posterior temporal language integration for the left hemisphere. Speech arrest sites were clustered in the ventral precentral gyrus and pars opercularis. Anomia sites were more widely distributed, but were focused in the posterior superior and middle temporal gyri as well as the inferior parietal gyrus. One alexia site was found over the superior temporal gyrus. Face sensory and motor cortical sites were also identified along the ventral sensorimotor strip. The prevalence and specificity of essential language sites were greater in unilateral right hemisphere–dominant patients, compared with those with bilateral dominance by Wada testing.

Conclusions

The authors' results suggest that the organization of language in right hemisphere dominance mirrors that of left hemisphere dominance. Awake speech mapping is a safe and reliable surgical adjunct in these rare clinical cases and should be done in the setting of right hemisphere dominance to avoid preventable postoperative aphasia.
Enteric Bacteria and Cancer Stem Cells
Authors: Sun Jun
Published: January 2011

Intestinal bacteria can contribute to cell proliferation and cancer development, particularly in chronic infectious diseases in which bacteria and/or bacterial components might interfere with cell function. The number of microbial cells within the gut lumen is estimated to be 100 trillion, which is about 10-times larger than the number of eukaryotic cells in the human body. Because of the complexity of the gut flora, identifying the specific microbial agents related to human diseases remains challenging. Recent studies have demonstrated that the stemness of colon cancer cells is, in part, orchestrated by the microenvironment and is defined by high Wnt activity. In this review article, we will discuss recent progress with respect to intestinal stem cells, cancer stem cells, and the molecular mechanisms of enteric bacteria in the activation of the Wnt pathway. We will also discuss the roles of other pathways, including JAK-STAT, JNK, and Notch, in regulating stem cell niches during bacterial infections using Drosophila models. Insights gained from understanding how host-bacterial interaction during inflammation and cancer may serve as a paradigm for understanding the nature of self-renewal signals.
The Role of Colorectal Cancer Stem Cells in Metastatic Disease and Therapeutic Response
Authors: Anderson Eric C. , Hessman Crystal , Levin Trevor G. , Monroe Marcus M. , Wong Melissa H.
Published: January 2011

Colorectal cancer is the third-leading cause of cancer related mortality in the United States. The intricate molecular mechanisms involved in the regenerative process of the normal intestine and the identity of putative somatic intestinal stem cells have become clear. In parallel with this, experiment evidence has emerged supporting the century old hypothesis that solid tumor initiation, progression, chemoresistance and recurrence is the result of a small population of cancer cells with self-renewal and pluripotency capabilities. These “cancer stem cells” (CSCs) present a unique opportunity to better understand the biology of solid tumors in general, as well as targets for future therapeutics. In this review, we will summarize the current understanding of intestinal stem cell biology and translate it to colorectal CSCs to provide a basis for understanding chemoresistance, cancer recurrence and metastasis. A more complete understanding of the biology of colorectal CSCs will translate into the development of better chemotherapeutic and biological agents for the treatment of colorectal cancer.
Finite-Time Thermoeconomic Optimization of a Solar-Driven Heat Engine Model
Authors: Barranco-Jimenez Marco A. , Sanchez-Salas Norma , Angulo-Brown Fernando
Published: January 2011

In the present paper, the thermoeconomic optimization of an irreversible solar-driven heat engine model has been carried out by using finite-time/finite-size thermodynamic theory. In our study we take into account losses due to heat transfer across finite time temperature differences, heat leakage between thermal reservoirs and internal irreversibilities in terms of a parameter which comes from the Clausius inequality. In the considered heat engine model, the heat transfer from the hot reservoir to the working fluid is assumed to be Dulong-Petit type and the heat transfer to the cold reservoir is assumed of the Newtonian type. In this work, the optimum performance and two design parameters have been investigated under two objective functions: the power output per unit total cost and the ecological function per unit total cost. The effects of the technical and economical parameters on the thermoeconomic performance have been also discussed under the aforementioned two criteria of performance.
Aging Risk and Health Care Expenditure in Korea
Authors: Tchoe Byongho , Nam Sang-Ho
Published: January 2011

This paper analyzes the impact of population aging on health care expenditures in Korea. Examination of the age-expenditure profile reveals that health care resources are allocated more for the older cohort of population over time, suggesting significant growth of health care expenditures due to population aging. We contend, however, that population aging is considered as a parameter rather than an independent variable to explain rising health care expenditures. This paper shows that population aging is not found to be a significant determinant of health care expenditures according to the econometric analysis using OECD health data and time-series data for Korea. Using the components decomposition method, which measures the contribution of each component of health care expenditure, we estimate that population aging contributes only less than 10 percent.
Photovoltaic Properties in Interpenetrating Heterojunction Organic Solar Cells Utilizing MoO3 and ZnO Charge Transport Buffer Layers
Authors: Hori Tetsuro , Moritou Hiroki , Fukuoka Naoki , Sakamoto Junki , Fujii Akihiko , Ozaki Masanori
Published: January 2011

Organic thin-film solar cells with a conducting polymer (CP)/fullerene (C60) interpenetrating heterojunction structure, fabricated by spin-coating a CP onto a C60 deposit thin film, have been investigated and demonstrated to have high efficiency. The photovoltaic properties of solar cells with a structure of indium-tin-oxide/C60/ poly(3-hexylthiophene) (PAT6)/Au have been improved by the insertion of molybdenum trioxide (VI) (MoO3) and zinc oxide charge transport buffer layers. The enhanced photovoltaic properties have been discussed, taking into consideration the ground-state charge transfer between PAT6 and MoO3 by measurement of the differential absorption spectra and the suppressed contact resistance at the interface between the organic and buffer layers.
Levantilides A and B, 20-Membered Macrolides from a Micromonospora Strain Isolated from the Mediterranean Deep Sea Sediment
Authors: Gärtner Andrea , Ohlendorf Birgit , Schulz Dirk , Zinecker Heidi , Wiese Jutta , Imhoff Johannes F.
Published: January 2011

Two new 20-membered macrolides, levantilide A and B, were isolated from the Micromonospora strain M71-A77. Strain M71-A77 was recovered from an Eastern Mediterranean deep-sea sediment sample and revealed to produce the levantilides under in situ salinity of 38.6‰. The chemical structures of the levantilides were elucidated on the basis of different one- and two- dimensional NMR experiments. Levantilide A exhibits a moderate antiproliferative activity against several tumor cell lines.
Structural Necessity of Indole C5-O-Substitution of seco-Duocarmycin Analogs for Their Cytotoxic Activity
Authors: Choi Taeyoung , Ma Eunsook
Published: January 2011

A series of racemic indole C5-O-substituted seco-cyclopropylindole (seco-CI) compounds 1-5 were prepared by coupling in the presence of EDCI of 1-(tert-butyloxycarbonyl)-3-(chloromethyl)indoline (seg-A) with 5-hydroxy-, 5-O-methylsulfonyl, 5-O-aminosulfonyl, 5-O-(N,N-dimethylaminosulfonyl)- and 5-O-benzyl-1H-indole-2-carboxylic acid as seg-B. Compounds 1-5 were tested for cytotoxic activity against four human cancer cell lines (COLO 205, SK-MEL-2, A549, and JEG-3) using a MTT assay. Compounds 2 and 3 with small sized sulfonyl substituents like 5-O-methylsulfonyl and 5-O-aminosulfonyl exhibit a similar level of activity as doxorubicin against all cell lines tested.
Update on the Genetic Polymorphisms of Drug-Metabolizing Enzymes in Antiepileptic Drug Therapy
Authors: Saruwatari Junji , Ishitsu Takateru , Nakagawa Kazuko
Published: January 2011

Genetic polymorphisms in the genes that encode drug-metabolizing enzymes are implicated in the inter-individual variability in the pharmacokinetics and pharmaco-dynamics of antiepileptic drugs (AEDs). However, the clinical impact of these polymorphisms on AED therapy still remains controversial. The defective alleles of cytochrome P450 (CYP) 2C9 and/or CYP2C19 could affect not only the pharmacokinetics, but also the pharmacodynamics of phenytoin therapy. CYP2C19 deficient genotypes were associated with the higher serum concentration of an active metabolite of clobazam, N-desmethylclobazam, and with the higher clinical efficacy of clobazam therapy than the other CYP2C19 genotypes. The defective alleles of CYP2C9 and/or CYP2C19 were also found to have clinically significant effects on the inter-individual variabilities in the population pharmacokinetics of phenobarbital, valproic acid and zonisamide. EPHX1 polymorphisms may be associated with the pharmacokinetics of carbamazepine and the risk of phenytoin-induced congenital malformations. Similarly, the UDP-glucuronosyltransferase 2B7 genotype may affect the pharmacokinetics of lamotrigine. Gluthatione S-transferase null genotypes are implicated in an increased risk of hepatotoxicity caused by carbamazepine and valproic acid. This article summarizes the state of research on the effects of mutations of drug-metabolizing enzymes on the pharmacokinetics and pharmacodynamics of AED therapies. Future directions for the dose-adjustment of AED are discussed.
Hall Sensors for Extreme Temperatures
Authors: Jankowski Jakub , El-Ahmar Semir , Oszwaldowski Maciej
Published: January 2011

We report on the preparation of the first complete extreme temperature Hall sensor. This means that the extreme-temperature magnetic sensitive semiconductor structure is built-in an extreme-temperature package especially designed for that purpose. The working temperature range of the sensor extends from −270 °C to +300 °C. The extreme-temperature Hall-sensor active element is a heavily n-doped InSb layer epitaxially grown on GaAs. The magnetic sensitivity of the sensor is ca. 100 mV/T and its temperature coefficient is less than 0.04 %/K. This sensor may find applications in the car, aircraft, spacecraft, military and oil and gas industries.
The Century Ahead: Searching for Sustainability
Authors: Raskin Paul D. , Electris Christi , Rosen Richard A.
Published: January 2011

The global future lies before us as a highly uncertain and contested landscape with numerous perils along the way. This study explores possible pathways to sustainability by considering in quantitative detail four contrasting scenarios for the twenty-first century. The analysis reveals vividly the risks of conventional development approaches and the real danger of socio-ecological descent. Nonetheless, the paper underscores that a Great Transition scenario—turning toward a civilization of enhanced human well-being and environmental resilience—remains an option, and identifies a suite of strategic and value changes for getting there. A fundamental shift in the development paradigm is found to be an urgent necessity for assuring a sustainable future and, as well, a hopeful opportunity for creating a world of enriched lives, human amity, and a healthy ecosphere.
Agricultural Biodiversity Is Essential for a Sustainable Improvement in Food and Nutrition Security
Authors: Frison Emile A. , Cherfas Jeremy , Hodgkin Toby
Published: January 2011

Agricultural biodiversity has hitherto been valued almost exclusively as a source of traits that can be used in scientific breeding programs to improve the productivity of crop varieties and livestock breeds. We argue that it can make a far greater contribution to increased productivity. In particular, a wider deployment of agricultural biodiversity is an essential component in the sustainable delivery of a more secure food supply. Diversity of kingdoms, species and genepools can increase the productivity of farming systems in a range of growing conditions, and more diverse farming systems are also generally more resilient in the face of perturbations, thus enhancing food security. Diversity can maintain and increase soil fertility and mitigate the impact of pests and diseases. Diversity of diet, founded on diverse farming systems, delivers better nutrition and greater health, with additional benefits for human productivity and livelihoods. Agricultural biodiversity will also be absolutely essential to cope with the predicted impacts of climate change, not simply as a source of traits but as the underpinnings of more resilient farm ecosystems. Many of the benefits of agricultural biodiversity are manifested at different ecological and human scales, and cut across political divisions, requiring a cross-sectoral approach to reassess the role of agricultural biodiversity in sustainable and secure food production.
Analysis of Different Freezing/Thawing Parameterizations using the UTOPIA Model
Authors: Bonanno Riccardo , Loglisci Nicola , Cavalletto Silvia , Cassardo Claudio
Published: January 2011

Soil moisture changes are generally due to external factors (precipitation, evaporation, etc.) and internal forces (gravitational force, capillarity, transpiration, etc.). When soil temperatures remain below 0 °C for a long time (hours or even entire consecutive days), part of the liquid water content of the soil can freeze, thus freezing/thawing effects must be taken into account in those conditions. The present work is devoted to the numerical modeling of the water phase change in the soil. The model used in this study for the land surface processes is UTOPIA (University of TOrino land Process Interaction in Atmosphere) model, which is the updated version of LSPM (Land Surface Process Model). Scientific literature proposes some formulations to account for freezing/thawing processes. Three different parameterizations have been compared using a synthetic dataset in order to assess which one performs best from a physical point of view. Parameterizing freezing/thawing processes creates numerical instability and water overproduction in the UTOPIA model. These problems have been solved and described in the paper by means of synthetic data created to test the new parameterizations. The results show that UTOPIA is able to capture the freezing/thawing physical processes.
An Islet-Specific Pulse of TGF-β Abrogates CTL Function and Promotes β Cell Survival Independent of Foxp3+ T Cells
Authors: Wållberg Maja , Wong F. Susan , Green E. Allison
Published: January 2011

Effective therapies that prevent chronic inflammation from developing into type 1 diabetes remain elusive. In this study, we show that expression of TGF-β for just 1 wk in inflamed islets of NOD mice significantly delays diabetes development. Time course studies demonstrated that the brief TGF-β pulse protects only if administered when extensive β cell destruction has occurred. Surprisingly, TGF-β–mediated protection is not linked to enhanced Foxp3+ regulatory T cell activity or to decreased intrapancreatic presentation of islet Ags. Instead, TGF-β disables the transition of primed autoreactive CD8+ T cells to cytotoxic effectors and decreases generation, or maintenance, of CD8+ memory T cells within the pancreas, significantly impairing their diabetogenic capacity.
Th17 Cells, Not IL-17+ γδ T Cells, Drive Arthritic Bone Destruction in Mice and Humans
Authors: Pöllinger Bernadette , Junt Tobias , Metzler Barbara , Walker Ulrich A. , Tyndall Alan , Allard Cyril , Bay Serkan , Keller Roland , Raulf Friedrich , Di Padova Franco , O’Reilly Terrence , Horwood Nicole J. , Patel Dhavalkumar D. , Littlewood-Evans Amanda
Published: January 2011

The mechanism whereby IL-17 drives rheumatoid arthritis remains incompletely understood. We demonstrate that anti–IL-17 therapy in collagen-induced arthritis ameliorates bone damage by reducing the number of osteoclasts in joints. We found equal numbers of CD4+ Th17 and IL-17 producing γδ T cells in the joints of arthritic mice, and in vitro, both populations similarly induced osteoclastogenesis. However, individual depletion and adoptive transfer studies revealed that in vivo, Th17 cells dominated with regard to bone destruction. Unlike γδ T cells, Th17 cells were found in apposition to tartrate-resistant acid phosphatase positive osteoclasts in subchondral areas of inflamed joints, a pattern reproduced in patient biopsies. This localization was caused by Ag-specific retention, because OVA-primed Th17 cells showed a γδ T cell-like diffuse distribution. Because IL-23, as produced by osteoclasts, enhanced T cell-mediated osteoclastogenesis, we propose that Ag-specific juxtaposition is key to foster the molecular cross talk of Th17 cells and osteoclasts, thus driving arthritic bone destruction.
Median Arcuate Ligament Compression of the Celiomesenteric Trunk
Authors: Lee Victor , Alvarez Mauricio Daniel , Bhatt Shweta , Dogra Vikram S.
Published: January 2011

Median arcuate ligament (MAL) syndrome is a controversial condition characterized by compression of the celiac trunk and symptoms of intestinal angina. We present a case of MAL compressing the celiomesenteric trunk, a rare variation. We report computed tomography (CT) angiography and three-dimensional reconstructions of this rare phenomenon.
Evidence for heterogeneous chlorine activation in the tropical UTLS
Authors: von Hobe M. , Grooß J.-U. , Günther G. , Konopka P. , Gensch I. , Krämer M. , Spelten N. , Afchine A. , Schiller C. , Ulanovsky A. , Sitnikov N. , Shur G. , Yushkov V. , Ravegnani F. , Cairo F. , Roiger A. , Voigt C. , Schlager H. , Weigel R. , Frey W. , Borrmann S. , Müller R. , Stroh F.
Published: January 2011

Abstract. Airborne in-situ observations of ClO in the tropics were made during the TROCCINOX (Aracatuba, Brazil, February 2005) and SCOUT-O3 (Darwin, Australia, November/December 2005) field campaigns. While during most flights significant amounts of ClO (≈10–20 parts per trillion, ppt) were present only in aged stratospheric air, instances of enhanced ClO mixing ratios of up to 40 ppt – significantly exceeding those expected from gas phase chemistry – were observed in air masses of a more tropospheric character. Most of these observations are associated with low temperatures or with the presence of cirrus clouds (often both), suggesting that cirrus ice particles and/or liquid aerosol at low temperatures may promote significant heterogeneous chlorine activation in the tropical upper troposphere lower stratosphere (UTLS). In two case studies, particularly high levels of ClO observed were reproduced by chemistry simulations only under the assumption that significant denoxification had occurred in the observed air. However, to reproduce the ClO observations in these simulations, O3 mixing ratios higher than observed had to be assumed, and at least for one of these flights, a significant denoxification is in contrast to the observed NO levels, suggesting that the coupling of chlorine and nitrogen compounds in the tropical UTLS may not be completely understood.
Modeling natural emissions in the Community Multiscale Air Quality (CMAQ) model – Part 2: Modifications for simulating natural emissions
Authors: Mueller S. F. , Mao Q. , Mallard J. W.
Published: January 2011

Abstract. The Community Multiscale Air Quality (CMAQ) model version 4.6 has been revised with regard to the representation of chlorine (HCl, ClNO2) and sulfur (dimethylsulfide, or DMS, and H2S), and evaluated against observations and earlier published models. Chemistry parameterizations were based on published reaction kinetic data and a recently developed cloud chemistry model that includes heterogeneous reactions of organic sulfur compounds. Evaluation of the revised model was conducted using a recently enhanced data base of natural emissions that includes ocean and continental sources of DMS, H2S, chlorinated gases and lightning NOx for the continental United States and surrounding regions. Results using 2002 meteorology and emissions indicated that most simulated "natural" (plus background) chemical and aerosol species exhibit the expected seasonal variations at the surface. Ozone exhibits a winter and early spring maximum consistent with ozone data and an earlier published model. Ozone distributions reflect the influences of atmospheric dynamics and pollutant background levels imposed on the CMAQ simulation by boundary conditions derived from a global model. A series of model experiments reveals that the consideration of gas-phase organic sulfur chemistry leads to sulfate aerosol increases over most of the continental United States. Cloud chemistry parameterization changes result in widespread decreases in SO2 across the modeling domain and both increases and decreases in sulfate. Most cloud-mediated sulfate increases occurred mainly over the Pacific Ocean (up to about 0.1 μg m−3) but also over and downwind from the Gulf of Mexico (including parts of the eastern US). Geographic variations in simulated SO2 and sulfate are due to the link between DMS/H2S and their byproduct SO2, the heterogeneity of cloud cover and precipitation (precipitating clouds act as net sinks for SO2 and sulfate), and the persistence of cloud cover (the largest relative sulfate increases occurred over the persistently cloudy Gulf of Mexico and western Atlantic Ocean). Overall, the addition of organic sulfur chemistry increased hourly surface sulfate levels by up to 1–2 μg m−3 but reduced sulfate levels in the vicinity of high SO2 emissions (e.g., wildfires). Simulated surface levels of DMS compare reasonably well with observations in the marine boundary layer where DMS oxidation product levels are lower than observed. This implies either a low bias in model oxidation rates of organic sulfur species or a low bias in the boundary conditions for DMS oxidation products. This revised version of CMAQ provides a tool for realistically simulating the influence of natural emissions on air quality.
Mesoscale processes for super heavy rainfall of Typhoon Morakot (2009) over Southern Taiwan
Authors: Lin C.-Y. , Hsu H.-m. , Sheng Y.-F. , Kuo C.-H. , Liou Y.-A.
Published: January 2011

Abstract. Within 100 h, a record-breaking rainfall, 2855 mm, was brought to Taiwan by typhoon Morakot in August 2009 resulting in devastating landslides and casualties. Analyses and simulations show that under favorable large-scale situations, this unprecedented precipitation was caused first by the convergence of the southerly component of the pre-existing strong southwesterly monsoonal flow and the northerly component of the typhoon circulation. Then the westerly component of southwesterly flow pushed the highly moist air (mean specific humidity >16 g/kg between 950 and 700 hPa from NCEP GFS data set) eastward against the Central Mountain Range, and forced it to lift in the preferred area. From the fine-scale numerical simulation, not only did the convergence itself provide the source of the heavy rainfall when it interacted with the topography, but also convective cells existed within the typhoon's main rainband. The convective cells were in the form of small rainbands perpendicular to the main one, and propagated as wave trains downwind. As the main rainband moved northward and reached the southern CMR, convective cells inside the narrow convergence zone to the south and those to the north as wave trains, both rained heavily as they were lifted by the west-facing mountain slopes. Those mesoscale processes were responsible for the unprecedented heavy rainfall total that accompanied this typhoon.
Assessing observed and modelled spatial distributions of ice water path using satellite data
Authors: Eliasson S. , Buehler S. A. , Milz M. , Eriksson P. , John V. O.
Published: January 2011

Abstract. The climate models used in the IPCC AR4 show large differences in monthly mean ice water path (IWP). The most valuable source of information that can be used to potentially constrain the models is global satellite data. The satellite datasets also have large differences. The retrieved IWP depends on the technique used, as retrievals based on different techniques are sensitive to different parts of the cloud column. Building on the foundation of Waliser et al. (2009), this article provides a more comprehensive comparison between satellite datasets. IWP data from the CloudSat cloud profiling radar provide the most advanced dataset on clouds. For all its unmistakable value, CloudSat data are too short and too sparse to assess climatic distributions of IWP, hence the need to also use longer datasets. We evaluate satellite datasets from CloudSat, PATMOS-x, ISCCP, MODIS and MSPPS in terms of monthly mean IWP, in order to determine the differences and relate them to the sensitivity of the instrument used in the retrievals. This information is also used to evaluate the climate models, to the extent that is possible. ISCCP and MSPPS were shown to have comparatively low IWP values. ISCCP shows particularly low values in the tropics, while MSPPS has particularly low values outside the tropics. MODIS and PATMOS-x were in closest agreement with CloudSat in terms of magnitude and spatial distribution, with MODIS being the better of the two. Additionally PATMOS-x and ISCCP, which have a temporal range long enough to capture the inter-annual variability of IWP, are used in conjunction with CloudSat IWP (after removing profiles that contain precipitation) to assess the IWP variability and mean of the climate models. In general there are large discrepancies between the individual climate models, and all of the models show problems in reproducing the observed spatial distribution of cloud-ice. Comparisons consistently showed that ECHAM-5 is probably the GCM from IPCC AR4 closest to satellite observations.
Insight from ozone and water vapour on transport in the tropical tropopause layer (TTL)
Authors: Ploeger F. , Fueglistaler S. , Grooß J.-U. , Günther G. , Konopka P. , Liu Y.S. , Müller R. , Ravegnani F. , Schiller C. , Ulanovski A. , Riese M.
Published: January 2011

Abstract. We explore the potential of ozone observations to constrain transport processes in the tropical tropopause layer (TTL), and contrast it with insights that can be obtained from water vapour. Global fields from Halogen Occultation Experiment (HALOE) and in-situ observations are predicted using a backtrajectory approach that captures advection, instantaneous freeze-drying and photolytical ozone production. Two different representations of transport (kinematic and diabatic 3-month backtrajectories based on ERA-Interim data) are used to evaluate the sensitivity to differences in transport. Results show that mean profiles and seasonality of both tracers can be reasonably reconstructed. Water vapour predictions are similar for both transport representations, but predictions for ozone are systematically higher for kinematic transport. Compared to global HALOE observations, the diabatic model prediction underestimates the vertical ozone gradient. Comparison of the kinematic prediction with observations obtained during the tropical SCOUT-O3 campaign shows a large high bias above 390 K potential temperature. We show that ozone predictions and vertical dispersion of the trajectories are highly correlated, rendering ozone an interesting tracer for aspects of transport to which water vapour is not sensitive. We show that dispersion and mean upwelling have similar effects on ozone profiles, with slower upwelling and larger dispersion both leading to higher ozone concentrations. Analyses of tropical upwelling based on mean transport characteristics, and model validation have to take into account this ambiguity between tropical ozone production and in-mixing from the stratosphere. In turn, ozone provides constraints on transport in the TTL and lower stratosphere that cannot be obtained from water vapour.
Planetary boundary influence at the Jungfraujoch analyzed by aerosol cycles and synoptic weather types
Authors: Collaud Coen M. , Weingartner E. , Furger M. , Nyeki S. , Prévôt A. S. H. , Steinbacher M. , Baltensperger U.
Published: January 2011

Abstract. Fourteen years of meteorological parameters, aerosol variables (absorption and scattering coefficients, aerosol number concentration) and trace gases (CO, NOx, SO2) measured at the Jungfraujoch (JFJ, 3580 m a.s.l.) have been analyzed as a function of different synoptic weather types. The Alpine Weather Statistics (AWS) classification was used to define the synoptic meteorology over the whole Swiss region. The seasonal contribution of each synoptic weather type to the aerosol concentration was deduced from the aerosol annual cycles while the planetary boundary layer (PBL) influence was estimated by means of the diurnal cycles. Since aerosols are scavenged by precipitation, the diurnal cycle of the CO concentration was also used to identify polluted air masses. SO2 and NOx concentrations were used as precursor tracers for new particle formation and growth. This study confirms the consensus view that the JFJ is mainly influenced by the free troposphere during winter and by injection of air parcels from the PBL during summer. A more detailed picture is, however, drawn where the JFJ is completely influenced by free tropospheric air masses in winter during advective weather types and largely influenced by the PBL also during the night in summer during the subsidence weather type. Between these two extreme situations, the PBL influence at the JFJ depends on both the time of year and the synoptic weather type. The fraction of PBL air transported to the JFJ was estimated by the relative increase of the specific humidity and CO.
CORSiCA: a Mediterranean atmospheric and oceanographic observatory in Corsica within the framework of HyMeX and ChArMEx
Authors: Lambert D. , Mallet M. , Ducrocq V. , Dulac F. , Gheusi F. , Kalthoff N.
Published: January 2011

Abstract. CORSiCA (Corsican Observatory for Research and Studies on Climate and Atmosphere-ocean environment) is a project for a multi-site instrumented platform located in Corsica. It is dedicated to oceanographic and atmospheric studies in the framework of the Mediterranean projects HyMeX (Hydrological cycle in the Mediterranean Experiment) and ChArMEx (Chemistry-Aerosol Mediterranean Experiment). The observatory will provide the international scientific community with facilities for setting up a multiparametric observation platform in a region with little instrumentation at present. HyMeX and ChArMEx objectives and actions in Corsica are presented.
Polar baseline surface radiation measurements during the International Polar Year 2007–2009
Authors: Lanconelli C. , Busetto M. , Dutton E. G. , König-Langlo G. , Maturilli M. , Sieger R. , Vitale V. , Yamanouchi T.
Published: January 2011

Abstract. Downwelling and upwelling shortwave and longwave radiation components from six active polar sites, taking part of the Baseline Surface Radiation Network (BSRN), were selected for the period of the last International Polar Year (March 2007 to March 2009), and included in the BSRN-IPY dataset, along with metadata and supplementary data for some of the stations. Two sites, located at Svalbard archipelago (Ny Ålesund) and Alaska (Barrow), represent Arctic sea-level conditions. Four Antarctic stations represent both sea-level (Dronning Maud Land and Cosmonaut Sea) and high-elevation conditions (South Pole and East Antarctic Plateau). The BSRN-IPY dataset content and quality are discussed. The dataset is now available at doi:10.1594/PANGAEA.737668, and can be used for free after accepting the BSRN data release guidelines. The dataset has been summarized as monthly averages and subject to further evaluation according to strict criteria not previously applied.
A two-layer flow model to represent ice-ocean interactions beneath Antarctic ice shelves
Authors: Lee V. , Payne A. J. , Gregory J. M.
Published: January 2011

Abstract. We develop a two-dimensional two-layer flow model that can calculate melt rates beneath ice shelves from ocean temperature and salinity fields at the shelf front. The cavity motion is split into two layers where the upper plume layer represents buoyant meltwater-rich water rising along the underside of the ice to the shelf front, while the lower layer represents the ambient water connected to the open ocean circulating beneath the plume. Conservation of momentum has been reduced to a frictional geostrophic balance, which when linearized provides algebraic equations for the plume velocity. The turbulent exchange of heat and salt between the two layers is modelled through an entrainment rate which is directed into the faster flowing layer. The numerical model is tested using an idealized geometry based on the dimensions of Pine Island Ice Shelf. We find that the spatial distribution of melt rates is fairly robust. The rates are at least 2.5 times higher than the mean in fast flowing regions corresponding to the steepest section of the underside of the ice shelf close to the grounding line and to the converged geostrophic flow along the rigid lateral boundary. Precise values depend on a combination of entrainment and plume drag coefficients. The flow of the ambient is slow and the spread of ocean scalar properties is dominated by diffusion.
An unsupervised learning algorithm: application to the discrimination of seismic events and quarry blasts in the vicinity of Istanbul
Authors: Kuyuk H. S. , Yildirim E. , Dogan E. , Horasan G.
Published: January 2011

Abstract. The results of the application of an unsupervised learning (neural network) approach comprising a Self Organizing Map (SOM), to distinguish micro-earthquakes from quarry blasts in the vicinity of Istanbul, Turkey, are presented and discussed. The SOM is constructed as a neural classifier and complementary reliability estimator to distinguish seismic events, and was employed for varying map sizes. Input parameters consisting of frequency and time domain data (complexity, spectral ratio, S/P wave amplitude peak ratio and origin time of events) extracted from the vertical components of digital seismograms were estimated as discriminants for 179 (1.8 < Md < 3.0) local events. The results show that complexity and amplitude peak ratio parameters of the observed velocity seismogram may suffice for a reliable discrimination, while origin time and spectral ratio were found to be fuzzy and misleading classifiers for this problem. The SOM discussed here achieved a discrimination reliability that could be employed routinely in observatory practice; however, about 6% of all events were classified as ambiguous cases. This approach was developed independently for this particular classification, but it could be applied to different earthquake regions.
Regression of Serous Macular Detachment Due to Peripheral Exudative Hemorrhagic Chorioretinopathy following Intravitreal Bevacizumab
Authors: Barkmeier Andrew J. , Kadikoy Huseyin , Holz Eric R. , Carvounis Petros E.
Published: January 2011

Purpose

TO describe a case of exudative macular detachment secondary to peripheral exudative chorioretinopathy with a favorable anatomic and visual outcome following treatment with intravitreal bevacizumab.

Methods

The medical records of a patient with peripheral exudative chorioretinopathy were reviewed.

Results

Macular reattachment was achieved with a corresponding visual acuity improvement that was maintained over an uncomplicated 17-month clinical course.

Conclusions

Bevacizumab may be an effective treatment option for exudative macular detachment secondary to peripheral exudative hemorrhagic chorioretinopathy.
A Simple Description of Age-Related Changes in Crystalline Lens Thickness
Authors: García-Domene Mari Carmen , Díez-Ajenjo Ma Amparo , Gracia Víctor , Felipe Adelina , Artigas José M.
Published: January 2011

Purpose

An increase in lens thickness is often described as a linear function of age. However, contradictory opinions exist about whether the lens thickness continues to increase after 50 years of age. Differences in slope exist between this increase in younger and older people, but these findings are in-consistent with the linear behavior of an increase in the lens thickness throughout life. We investigated among different functions, including slope variation, which would be the best to show the relation between lens thickness and age. An available model portraying lens growth could be advantageous in many practical applications. The possibility of differences between sexes in lens thickness growth is also analyzed.

Methods

We evaluated 102 eyes of patients aged between 15 and 84 years: 41 men, 61 women. The biometric measurements were performed with the aid of the OcuScan® (Alcon, USA).

Results

Both logarithmic and potential functions provide a good fit for the data (R2=0.905 and 0.906, respectively). The results do not show significant differences between men and women in any age range, nor when the data of the whole sample are considered (p=0.29).

Conclusions

The best fits for the data are both logarithmic and double logarithmic functions. According to this model, lens growth continues throughout life, but after 50 years, age-related thickness variations are lower than statistical variability. No differences were found between the sexes.
High Prevalence of Pseudoexfoliation Syndrome and its Complications in Tarragona in Northeast Spain
Authors: Romero-Aroca Pedro , Masip-Serra Robert , Martínez-Salcedo Inmaculada , Salvat-Serra Merce , Fernández-Ballart Joan , Bautista-Pérez Ángel
Published: January 2011

Purpose

To determine the prevalence of Pseudoexfoliation syndrome (PEX) in our health area, in 4 counties of Tarragona, and its involvement in the health status of the population.

Methods

This was a cross-sectional study of a sample of 2,342 inhabitants aged >60 years, randomly selected from the population census. Subjects were classified in 3 groups according to age (group 1 = 60–69 years, group 2 = 70–79 years, group 3 = over 80 years). The diagnosis of PEX was made in all cases by the same ophthalmologist, using biomicroscopic and slit-lamp evaluation. Corneal endothelial study was made by specular microscope.

Results

The prevalence of PEX was 309/2,342 patients (13.19%), unilateral in 219/309 (70.87%). The prevalence of PEX in patients with open-angle glaucoma was 29.48%. Changes in corneal endothelium were higher in patients with PEX, with lower cell density and hexagonality percentage, with higher coefficient of variation, significant in age groups 2 and 3. The prevalence of cataract in patients with PEX was 80.58%, versus 54.64% in patients without PEX. Complications of cataract surgery were higher in patients with PEX and postoperative corneal edema was best correlated with a low hexagonality percentage. No systemic cardiovascular diseases were significant in patients with PEX.

Conclusions

In our health district area, a high prevalence of PEX exists. A more extensive study of the causes of these differences is needed, including analysis of the genetic makeup of the population.