bluuebunny/crossref_metadata_2025 huggingface dataset:
Meteorological information in GPS-RO reflected signals
Authors: Boniface K. , Aparicio J. M. , Cardellach E.
Published: February 2011

Abstract. Vertical profiles of the atmosphere can be obtained globally with the radio-occultation technique. However, the lowest layers of the atmosphere are less accurately extracted. A good description of these layers is important for the good performance of Numerical Weather Prediction (NWP) systems, and an improvement of the observational data available for the low troposphere would thus be of great interest for data assimilation. We outline here how supplemental meteorological information close to the surface can be extracted whenever reflected signals are available. We separate the reflected signal through a radioholographic filter, and we interpret it with a ray tracing procedure, analyzing the trajectories of the electromagnetic waves over a three-dimensional field of refractive index. A perturbation approach is then used to perform an inversion, identifying the relevant contribution of the lowest layers of the atmosphere to the properties of the reflected signal, and extracting some supplemental information to the solution of the inversion of the direct propagation signals. The methodology is applied to one reflection case.
Barriers to predicting changes in global terrestrial methane fluxes: analyses using CLM4Me, a methane biogeochemistry model integrated in CESM
Authors: Riley W. J. , Subin Z. M. , Lawrence D. M. , Swenson S. C. , Torn M. S. , Meng L. , Mahowald N. M. , Hess P.
Published: February 2011

Abstract. Terrestrial net CH4 surface fluxes often represent the difference between much larger gross production and consumption fluxes and depend on multiple physical, biological, and chemical mechanisms that are poorly understood and represented in regional- and global-scale biogeochemical models. To characterize uncertainties, study feedbacks between CH4 fluxes and climate, and to guide future model development and experimentation, we developed and tested a new CH4 biogeochemistry model (CLM4Me) integrated in the land component (Community Land Model; CLM4) of the Community Earth System Model (CESM1). CLM4Me includes representations of CH4 production, oxidation, aerenchymous transport, ebullition, aqueous and gaseous diffusion, and fractional inundation. As with most global models, CLM4Me lacks important features for predicting current and future CH4 fluxes, including: vertical representation of soil organic matter, accurate subgrid scale hydrology, realistic representation of inundated system vegetation, anaerobic decomposition, thermokarst dynamics, and aqueous chemistry. We compared the seasonality and magnitude of predicted CH4 emissions to observations from 18 sites and three global atmospheric inversions. Simulated net CH4 emissions using our baseline parameter set were 270, 160, 50, and 70 Tg CH4 m−2 yr−1 globally, in the tropics, temperate zone, and north of 45° N, respectively; these values are within the range of previous estimates. We then used the model to characterize the sensitivity of regional and global CH4 emission estimates to uncertainties in model parameterizations. Of the parameters we tested, the temperature sensitivity of CH4 production, oxidation parameters, and aerenchyma properties had the largest impacts on net CH4 emissions, up to a factor of 4 and 10 at the regional and gridcell scales, respectively. In spite of these uncertainties, we were able to demonstrate that emissions from dissolved CH4 in the transpiration stream are small (<1 Tg CH4 yr−1) and that uncertainty in CH4 emissions from anoxic microsite production is significant. In a 21st century scenario, we found that predicted declines in high-latitude inundation may limit increases in high-latitude CH4 emissions. Due to the high level of remaining uncertainty, we outline observations and experiments that would facilitate improvement of regional and global CH4 biogeochemical models.
Long-term spatial variations in the Baltic Sea wave fields
Authors: Soomere T. , Räämet A.
Published: February 2011

Abstract. This study focuses on spatial patterns in linear trends of numerically reconstructed basic wave properties (average and extreme wave heights, wave periods) in the Baltic Sea under the assumption of no ice cover. Numerical simulations of wave conditions for 1970–2007, using the WAM wave model and adjusted geostrophic winds, revealed extensive spatial variations in long-term changes in both average and extreme wave heights in the Baltic Sea but almost no changes in the basinwide wave activity and wave periods. There has been a statistically significant decrease in the annual mean significant wave height by more than 10% between the islands of Öland and Gotland and in the southward sea area, and a substantial increase to the south-west of Bornholm, near the coast of Latvia, between the Åland Archipelago and the Swedish mainland, and between the Bothnian Sea and the Bothnian Bay. Variations in extreme wave heights (defined as the threshold for 1% of the highest waves each year) show similar patterns of changes. In several areas the trends in average and extreme wave heights are different. Such a complicated pattern of changes indicates that (i) different regions of the Baltic Sea basin have experienced widespread but essentially different changes in wind properties and (ii) many seemingly controversial trends and variations established in wave properties at different sites in the recent past may reflect the natural spatial variability in the Baltic Sea wave fields.
Effect of tidal stream power generation on the region-wide circulation in a shallow sea
Authors: Shapiro G. I.
Published: February 2011

Abstract. This paper quantifies the backward effect on the ocean currents caused by a tidal stream farm located in the open shallow sea. Recent studies in channels with 1-D models have indicated that the power potential is not given purely by the flux of kinetic energy, as has been commonly assumed. In this study, a 3-D ocean circulation model is used to estimate (i) practically extractable energy resource at different levels of rated generation capacity of the farm, (ii) changes in the strength of currents due to energy extraction, and (iii) alterations in the pattern of residual currents and the pathways of passive tracers. As well as tidal streams, the model also takes into account the wind-driven and density-driven ocean currents. Numerical modelling has been carried out for a hypothetical tidal farm located in the Celtic Sea north of Cornwall, an area known for its high level of tidal energy. Modelling results clearly indicate that the extracted power does not grow linearly with the increase in the rated capacity of the farm. For the case study covered in this paper, a 100-fold increase in the rated generation capacity of the farm results in only 7-fold increase in extracted power. In the case of a high power farm, kinetic energy of currents is altered significantly as far as 10–20 km away from the farm. At high levels of extracted energy the currents tend to avoid flowing through the farm, an effect which is not captured with 1-D models. Residual currents are altered as far as a hundred kilometres away. The magnitude of changes in the dispersion of tracers is highly sensitive to the location. Some of the passive drifters analysed in this study experience significant variations in the end-to-start distance due to energy extraction ranging from 13% to 238% while others are practically unaffected. This study shows that both energy extraction estimates and effects on region wide circulation depend on a complex combination of factors, and the specific figures given in the paper should be generally considered as first estimates.
Time Exposure Period of Bovine Oocytes to Sperm in Relation to Embryo Development Rate and Quality
Authors: Berland Marco , Frei Mario , Peralta Oscar , Ratto Marcelo
Published: February 2011

The objective of the study was to determine the effect of different bovine gamete coincubation times on fertilization and embryo development performance. In vitro matured COCs were co-incubated with sperm at a concentration of 1.5 × 106 spermatozoa/ml in TALP medium for 3 hours (T 3, n=362), 6 hours (T 6, n=358), or 18 hours (T 18, n=350). At the end of the coincubation period COCs from times 3 and 6 groups were post-incubated in a new well of fertilization medium without sperm for additional 15 and 12 h, respectively. Cumulus Oocyte Complexes from the T 18 were co-incubated with the sperm suspension for 18 hours. Presumptive zygotes were cultured for 9 days and embryo development was evaluated on days 2, 8, and 9. Thirty blastocysts from each group were stained and total number of nuclei was recorded. The mean (± SEM) percentages of zygotes to develop into ≥2 cell stage were 71.9 ± 5.0; 72.5 ± 5.3 and 81.2 ± 6.1 % for T 3, 6, and 18, respectively, on day 2 and they did not differ (P=.3) among groups. The mean percentage of blastocysts developed on day 8 (25.6 ± 2.8; 24.2 ± 3.3; 28.4 ± 4.2 % for T 3, 6, and 18, resp.) did not differ (P=.4) among groups. The total number of embryonic nuclei was greater (P<.05) for the blastocysts produced from the shortest co-incubation time (T 3).
Interfacial and Substrate Effects on Local Elastic Properties of Polymers Using Coupled Experiments and Modeling of Nanoindentation
Authors: Watcharotone Supinda , Wood Charles D. , Friedrich Robert , Chen Xinqi , Qiao Rui , Putz Karl , Brinson L. Catherine
Published: February 2011

The mechanical properties of polymers near interfaces are important in a number of different fields. For almost two decades, the local dynamics of thin polymer films have been studied in great detail. However, development of an understanding of local mechanical properties has been hindered by the necessary proximity of stiff substrates: mechanical measurements are confounded by interaction with the substrate, convoluting polymer, and substrate properties. In this paper, local elastic properties of thin polymer films near interfaces are directly probed for the first time via nanoindentation experiments on thin films coupled with finite element modeling. A comprehensive set of experimental and numerical modeling results are presented for poly(methyl methacrylate) (PMMA) revealing separately the effects of substrate and interphase polymer. Results indicate the attractive surface significantly affects the properties up to hundreds of nanometers. This new, direct approach to measure local mechanical properties provides new fundamental understanding of interfacial and small‐scale behaviors in polymers and soft matter for application advances in nanocomposites, microelectronics, and biopolymers.
Annual Clinical Updates in Hematological Malignancies: A Continuing Medical Education Series: Polycythemia vera and essential thrombocythemia: 2011 update on diagnosis, risk‐stratification, and management
Authors: Tefferi Ayalew
Published: February 2011

Disease overview:

Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms primarily characterized by erythrocytosis and thrombocytosis, respectively. Other disease features include leukocytosis, splenomegaly, thrombohemorrhagic complications, vasomotor disturbances, pruritus, and a small risk of disease progression into acute leukemia or myelofibrosis.

Diagnosis:

Diagnosis is based onJAK2mutation status (PV and ET), serum erythropoietin (Epo) level (PV), and bone marrow histopathology (ET). The presence of aJAK2mutation and subnormal serum Epo level confirm a diagnosis of PV. Differential diagnosis in ET should include chronic myelogenous leukemia and prefibrotic myelofibrosis.

Risk stratification:

Current risk stratification in PV and ET is designed to estimate the likelihood of thrombotic complications: high‐risk‐age >60 years or presence of thrombosis history; low‐risk‐absence of both of these two risk factors. Presence of extreme thrombocytosis (platelet count >1,000 × 109/L) might be associated with acquired von Willebrand syndrome (AvWS) and, therefore, risk of bleeding. Risk factors for shortened survival in both PV and ET include age >60 years, leukocytosis, history of thrombosis, and anemia.

Risk‐adapted therapy:

Survival is near‐normal in ET and reasonably long in PV. The 10‐year risk of leukemic/fibrotic transformation is <1%/1% in ET and <5%/10% in PV. In contrast, the risk of thrombosis exceeds 20%. The main goal of therapy is therefore to prevent thrombohemorrhagic complications and this is effectively and safely accomplished by the use of low‐dose aspirin (PV and ET), phlebotomy (PV), and hydroxyurea (high risk PV and ET). Treatment with busulfan or interferon‐α is usually effective in hydroxyurea failures. Am. J. Hematol. 86:293–301, 2011. © 2011 Wiley‐Liss, Inc.
Town vs. gown: A direct comparison of community residents and student mock jurors
Authors: Hosch Harmon M. , Culhane Scott E. , Tubb V. Anne , Granillo Edgar A.
Published: February 2011

The use of students as mock jurors in the majority of legal psychology studies on jury behavior has been criticized (e.g., Bray & Kerr, 1979; Diamond, 1997). This study examined the degree to which student mock jurors' decisions were generalizable to those of real jurors. The participants of the study included 297 jury‐eligible university students and 297 volunteers from the venire in the same community as that in which the students resided. All participants viewed one of six versions of a videotaped criminal trial. The defendant testified in English or in Spanish. In addition, the race of defendant was varied. Three bilingual individuals served as defendants with one appearing to be of northern European origin, one of Latino background, and one of African origin. Dependent variables included verdict and, for those who found the defendant guilty, the number of years to which he should be sentenced, and whether he should be fined. Student mock jurors differed reliably from their community counterparts on several demographic characteristics. However, the two groups had mixed results in relation to decision‐making tasks. There was no difference in individual verdict preferences, but the students' sentence recommendations were more punitive. These results are interpreted in the context of the generalizability of mock juror studies. Copyright © 2011 John Wiley & Sons, Ltd.
Amidases Have a Hydrogen Bond that Facilitates Nitrogen Inversion, but Esterases Have Not
Authors: Syrén Per‐Olof , Hult Karl
Published: February 2011

The fact that proteases/amidases can hydrolyze amides efficiently whereas esterases can not has been discussed during the last decades. By using molecular modeling we have found a hydrogen bond in the transition state for protease/amidase catalyzed hydrolysis of peptides and amides donated by the scissile NH‐group of the substrate. The hydrogen‐bond acceptor was found either in the enzyme (enzyme assisted) or in the substrate (substrate assisted). This new interaction with the NH‐hydrogen in the transition state (TS) was found in sixteen proteases/amidases, which represent ten different reaction mechanisms and eleven different folding families. Esterases lack this interaction and, therefore, they are slow in hydrolyzing amides. By mimicking the substrate‐assisted catalysis found in amidases we were able to shift reaction specificity of amide over ester synthesis of Candida antarctica lipase B one hundred fold. We propose that the hydrogen bond facilitates nitrogen inversion in amidases.
The Construction of Quaternary Stereocenters by the Henry Reaction: Circumventing the Usual Reactivity of Substituted Glyoxals
Authors: Blay Gonzalo , Hernández‐Olmos Víctor , Pedro José R.
Published: February 2011

The enantioselective Henry reaction between alkyl‐ and arylglyoxal hydrates and nitromethane catalyzed by CuII–iminopyridine complexes takes place regioselectively on the ketone carbonyl group to give chiral tertiary nitroaldols with high functional group density and enantiomeric excesses of up to 96 %. Both aromatic and aliphatic glyoxals are suitable substrates for this reaction.
Surface‐Enhanced Fluorescence from Fluorophore‐Assembled Monolayers by Using Ag@SiO2 Nanoparticles
Authors: Zhang Ruohu , Wang Zhuyuan , Song Chunyuan , Yang Jing , Li Jin , Sadaf Asma , Cui Yiping
Published: February 2011

A new and simple procedure to enhance the fluorescence of analytes on the surfaces of a solid substrate is demonstrated based on Ag@SiO2 nanoparticles. Two kinds of silver–silica core–shell nanoparticles with shell thicknesses of around 3 and 15 nm have been prepared and used as enhancing agents, respectively. By simply pipetting drops of the enhancing agents onto substrate surfaces with Rose Bengal monolayers, an enhancement of about 27 times, compared with the control sample, is achieved by using the Ag@SiO2 nanoparticles with shells of about 3 nm, whereas an enhancement of around 11.7 times is obtained when using those with thicker shells. The effects of shell thickness and surface density of the enhancing agents on the enhancement have been investigated experimentally. The results show that this method can be potentially helpful in fluorescence‐based surface analysis.
Electrochemical Biosensor Assay of the Interaction between [PtCln(NH3)4–n](2–n) (n = 0–4) Complexes and ds‐DNA
Authors: Ravera Mauro , Gabano Elisabetta , Sardi Manuele , Alessio Manuela , Osella Domenico
Published: February 2011

We report on the results of electrochemical DNA biosensor assay of the interaction between double‐stranded DNA (ds‐DNA) and a series of six neutral, anionic or cationic Pt complexes of the general formula [PtCln(NH3)4–n](2–n) [n = 4, 1; n = 3, 2; n = 2, isomers cisplatin (3) and transplatin (4); n = 1, 5; n = 0, 6]. The ability of the electrophilic PtII agents generated in solution to interact with DNA, and hence to form Pt–DNA adducts, was measured as a function of the decrease in the guanine oxidation signal recorded on a screen‐printed electrode by using square wave voltammetry. Hydrolysis of the platinum complexes was studied by using time‐resolved RP‐HPLC and conductivity measurements to determine the aquation rate, which modulates the formation of the electrophilic agent prone to quickly interact with DNA. Our findings indicate that, if time is allowed for sufficient hydrolysis to occur, the interaction of these PtII complexes with ds‐DNA follows the order 2 > 1 > 3 ≈ 4 > 5 >> 6.
Food insecurity and the relationship between household income and children's health and nutrition in Brazil
Authors: Reis Mauricio
Published: February 2011

Empirical evidence indicates that children living in wealthier households have better health. Food insecurity could be related to lack of adequate nutrition experienced by poor children and may be pointed out as one of the possible explanations for this relationship. This paper investigates the association between food insecurity and children's health and nutrition and the role of the former in the child health income gradient. Using data from the 2006 Brazilian Demographic and Health Survey, the results show that children living in households with food insecurity have worse nutrition and health indicators. In addition, the relationship between household income and many children's health and nutrition measures weakens but remains significant when controlling for food insecurity. Copyright © 2011 John Wiley & Sons, Ltd.
A systematic review of salicylates in foods: Estimated daily intake of a Scottish population
Authors: Wood Adrian , Baxter Gwen , Thies Frank , Kyle Janet , Duthie Garry
Published: February 2011

Several studies suggest that natural salicylates in plant‐based foods may benefit health. However, large variation in published values of the salicylate content of foods means that relating dietary intakes to disease risk is problematical. Consequently, we have systematically reviewed the available literature using prescribed selection criteria. By combining these literature values with in‐house analysis, we have constructed a food composition database describing median salicylate values for 27 different types of fruits, 21 vegetables, 28 herbs, spices and condiments, 2 soups and 11 beverages. Application of a validated food frequency questionnaire estimated median dietary intakes of 4.42 (range 2.90–6.27) and 3.16 (2.35–4.89) mg/day for Scottish males and females, respectively. Major dietary sources of salicylates were alcoholic beverages (22%), herbs and spices (17%), fruits (16%), non‐alcoholic beverages including fruit juices (13%), tomato‐based sauces (12%) and vegetables (9%). Application of the database to populations with differing dietary habits and disease risk profiles may provide further evidence for the role of dietary salicylates in the prevention of chronic diseases.
Oxidative metabolism of the mycotoxins alternariol and alternariol‐9‐methyl ether in precision‐cut rat liver slices in vitro
Authors: Burkhardt Britta , Wittenauer Judith , Pfeiffer Erika , Schauer Ute M. D. , Metzler Manfred
Published: February 2011

Scope: Monohydroxylation of alternariol (AOH) and alternariol‐9‐methyl ether (AME) has previously been reported as a prominent metabolic route under cell‐free conditions. This pathway gives rise to several catechol metabolites and may therefore be of toxicological relevance.

Methods and results: To clarify whether hydroxylation of AOH and AME occurs under in vivo‐like conditions in the presence of conjugation reactions, the metabolism of the Alternaria toxins has now been studied in precision‐cut rat liver slices. Four catechol metabolites of AOH and two of AME, together with several of their O‐methylation products, as catalyzed by catechol‐O‐methyl transferase, were clearly identified after incubation of the liver slices with AOH and AME. These metabolites were predominantly present as conjugates with glucuronic acid and/or sulfate. In preliminary studies with bile duct‐cannulated male rats dosed with AOH by gavage, the four monohydroxylated metabolites of AOH could also be demonstrated in the bile either as catechols or as O‐methyl ethers.

Conclusion: These experiments clearly show that AOH and AME undergo catechol formation in vivo and warrant closer examination of the toxicological significance of this metabolic pathway.
Protective Effect of Proteins Derived from the Latex of Calotropis procera against Inflammatory Hyperalgesia in Monoarthritic Rats
Authors: Kumar Vijay L. , Chaudhary Priyanka , Ramos Marcio V. , Mohan Madan , Matos Mayara P. V.
Published: February 2011

Calotropis procera (family: Apocynaceae) is a plant growing in the wild and has been used in the traditional medicinal system for the treatment of various diseases. The plant produces milky latex that possesses potent antiinflammatory and analgesic properties. In present study the non‐dialysable protein fraction isolated from the latex (LP) of this plant was evaluated for its efficacy against inflammation in rats where paw edema was induced by sub‐plantar injection of carrageenin or monoarthritis was induced by intra‐articular injection of Freund's complete adjuvant (FCA). The effect of LP was evaluated on edema volume in the paw model and on joint diameter, stair climbing ability, motility, dorsal flexion pain, levels of oxidative stress markers and joint histology in arthritis model. The protection afforded by LP was compared with that of standard antiinflammatory drug, diclofenac (5 mg/kg). LP exhibited a dose‐dependent antiinflammatory effect and produced 32% and 60% inhibition of paw edema at 10 and 25 mg/kg doses and 12% and 36% inhibition of joint inflammation at 50 and 150 mg/kg doses. The protective effect of LP was associated with normalization of joint functions, histology and levels of oxidative stress markers in joint tissue. The findings of this study suggest that the protein fraction of latex of Calotropis procera has the potential to relieve inflammation and pain associated with various arthritic conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Multiple testing of treatment‐effect‐modifying biomarkers in a randomized clinical trial with a survival endpoint
Authors: Michiels Stefan , Potthoff Richard F. , George Stephen L.
Published: February 2011

The recent revolution in genomics and the advent of targeted therapies have increased interest in biomarker‐defined subgroups of patients who respond to therapy or exhibit specific toxicities. Such biomarker‐defined subgroups are also being investigated for non‐targeted therapies (e.g. chemotherapy and statins). However, even when the targeting pathway has been identified, a broadly available test to identify the appropriate subgroup will rarely exist prior to the launch of the pivotal phase III trial.

Our aim in this paper is to provide guidance for the analysis of a phase III clinical trial with a survival endpoint, in order to ascertain whether a therapy is more effective in the biomarker‐positive patients as compared with biomarker‐negative patients, when the trial is conducted on the entire population and when there are multiple candidate biomarkers. We studied treatment‐by‐biomarker interactions in a Weibull regression model. Different permutation procedures, using single‐biomarker statistics and novel composite statistics, are proposed in order to control the family‐wise error rate accounting for dependence structures among the biomarkers. A simulation study was performed to compare the operational characteristics of the permutation tests under different scenarios. The tests were applied to a phase III trial of adjuvant chemotherapy in early breast cancer, for which 10 biomarkers were measured in tumor samples from 798 patients.

These permutation tests can be applied to retrospective biomarker studies and to prospective phase III trials of new drugs for which a few clues are known about the targeting pathway at the start of the trial. Copyright © 2011 John Wiley & Sons, Ltd.
Proportional odds model for dose‐finding clinical trial designs with ordinal toxicity grading
Authors: Meter Emily M. Van , Garrett‐Mayer Elizabeth , Bandyopadhyay Dipankar
Published: February 2011

Currently many dose‐finding clinical trial designs, including the continual reassessment method (CRM) and the standard ‘ 3 + 3’ design, dichotomize toxicity outcomes based on the pre‐specified dose‐limiting toxicity (DLT) criteria. This loss of information is particularly inefficient due to the small sample sizes in phase I trials. Common Toxicity Criteria (CTCAEv3.0) classify adverse events into grades 1–5, which range from 1 as a mild adverse event to 5 as death related to an adverse event. In this paper, we extend the CRM to include ordinal toxicity outcomes as specified by CTCAEv3.0 using the proportional odds model (POM) and compare results with the dichotomous CRM. A sensitivity analysis of the new design compares various target DLT rates, sample sizes, and cohort sizes. This design is also assessed under various dose–toxicity relationship models including POMs as well as those that violate the proportional odds assumption. A simulation study shows that the proportional odds CRM performs as well as the dichotomous CRM on all criteria compared (including safety criteria such as percentage of patients treated at highly toxic or suboptimal dose levels) and with improved estimation of the maximum tolerated dose when the PO assumption is not violated. These findings suggest that it is beneficial to incorporate ordinal toxicity endpoints into phase I trial designs. Copyright © 2011 John Wiley & Sons, Ltd.
Measurements and Calculation of Interfacial Tension between Commercial Steels and Mould Flux Slags
Authors: Elfsberg Jessica , Matsushita Taishi
Published: February 2011

Surface quality of continuously cast is strongly influenced by the interfacial tension between steel and mould flux slag. The meniscus shape and the inclusion entrapment are directly determined by interfacial tension. To achieve a better understanding of the continuous casting process, the interface between four commercial steels and the mould fluxes used at the continuous casting of each steel grade have been investigated. The situation at this interface is determined by the surface tension of steel and slag respectively and also by the mass transfer occurring across the interface. The surface tensions of the mould flux slags have been measured by sessile drop method. The results indicate that the surface tension of mould flux slags decreases with increasing temperature but does not vary so much within the present composition range. Interfacial tensions between steel samples and mould flux slags have been measured in the same way with the aid of X‐ray unit. Estimation of interfacial tension from the steel and slag composition was done by applying empirical models. The measured and the calculated values were in agreement. The interfacial tension was lower for higher alloyed steel grades according to both experiments and calculations though the influence of surface active elements is significant.
Mathematical Modeling of Fluid Flow in Bath during Combined Side and Top Blowing AOD Refining Process of Stainless Steel: Mathematical Model of the Fluid Flow
Authors: Wei Ji‐He , He Yuan , Shi Guo‐Min
Published: February 2011

Considering that the liquid flow field under the conditions of the combined side and top blowing would be a combined result from the common action of the side blowing gas streams and a gas top blowing jet, as the first attempt, the three‐dimensional mathematical models for the flows of molten steel in an AOD converter bath during the simple side and top blowing processes have been proposed and developed, respectively. And the mathematical model of the flow in the bath during the combined blowing AOD refining process of stainless steel has been given by the composition and superposition of the two models. In the composed model, the gas‐liquid two‐phase flow is described and treated in terms of the two‐fluid (Eulerian‐Eulerian) model. The especially modified two‐equation k−ε model for the turbulence in the liquid phase is employed. And, the surface of the sunken pit formed by impact of the gas jet blown from a top lance at the central location of the bath liquid surface is regarded as a revolution paraboloid. The related details of the composed model are shown.
Efficient Synthesis of the Very‐Long‐Chain n‐3 Fatty Acids, Tetracosahexaenoic Acid (C24:6n‐3) and Tricosahexaenoic Acid (C23:6n‐3)
Authors: Itoh Toshimasa , Tomiyasu Ayako , Yamamoto Keiko
Published: February 2011

Tetracosahexaenoic acid (C24:6n‐3, THA, 3) is an essential biosynthetic precursor in mammals of docosahexaenoic acid (C22:6n‐3, DHA, 1), the end‐product of the metabolism of n‐3 fatty acids. THA 3 is present in commercially valuable fishes, such as flathead flounder. Tricosahexaenoic acid (C23:6n‐3, TrHA, 2), an odd‐numbered‐chain fatty acid, has been identified from marine organisms such as the dinoflagellate, Amphidinium carterae. To date, few studies have examined THA 3 and TrHA 2 due to difficulties in detecting and identifying these compounds, so their chemical and biological properties remain poorly characterized. Only one methodology for the chemical synthesis of THA 3 has been presented, and no method for the synthesis of TrHA 2 has been reported. We report here the efficient synthesis of THA 3 in four steps in 56% overall yield, and the synthesis of TrHA 2 in six steps in 48% overall yield. We also present the synthesis of Δ2‐THA 4, an intermediate of β‐oxidation of THA 3 to DHA 1, in three steps in 73% overall yield.
The role of Intelectin-2 in resistance toAscaris suumlung larval burdens in susceptible and resistant mouse strains
Authors: DOLD CHRISTINA , PEMBERTON ALAN D. , STAFFORD PETER , HOLLAND CELIA V. , BEHNKE JERZY M.
Published: February 2011

The underlying mechanism of predisposition toAscarisinfection is not yet understood but host genetics are thought to play a fundamental role. We investigated the association between the Intelectin-2 gene and resistance in F2mice derived from mouse strains known to be susceptible and resistant to infection.Ascarislarvae were isolated from murine lungs and the number of copies of the Intelectin-2 gene was determined in F2mice. Intelectin-2 gene copy number was not significantly linked to larval burden. In a pilot experiment, the response to infection in parental mice of both sexes was observed in order to address the suitablity of female F2mice. No overall significant sex effect was detected. However, a divergence in resistance/susceptibility status was observed between male and, female hybrid offspring. The responsiveness toAscarisin mice is likely to be controlled by multiple genes and, despite a unique absence from the susceptible C57BL/6j strain, the Intelectin-2 gene does not play a significant role in resistance. The observed intra-strain variation in larval burden requires further investigation but we hypothesize that it stems from social/dominance hierarchies created by the presence of female mice and possibly subsequent hormonal perturbations that modify the intensity of the immune response.
In vitroeffects of arylimidamides againstBesnoitia besnoitiinfection in Vero cells
Authors: CORTES H. C. E. , MULLER N. , BOYKIN D. , STEPHENS C. E. , HEMPHILL A.
Published: February 2011

Thein vitroeffects of 4 arylimidamides (DB811, DB786, DB750 and DB766) against the proliferative tachyzoite stage of the apicomplexan parasiteBesnoitia besnoitiwere investigated. These four compounds had been shown earlier to exhibitin vitroactivities in the nanomolar range against the related apicomplexansNeospora caninumandToxoplasma gondii.Real-time-PCR was used to assessB. besnoitiintracellular proliferationin vitro. Preliminary assessment by light microscopy identified DB811 and DB750 as the most promising compounds, while DB786 and DB766 were much less effective. Three-day-growth assays and quantitative real-time PCR was used for IC50determination of DB811 (0·079μM) and DB750 (0·56μM). Complete growth inhibition was observed at 1·6μM for DB 811 and 1·7μM for DB750. However, when infected cultures were treated for 14 days, proliferation of parasites occurred again in cultures treated with DB750 from day 4 onwards, while the proliferation of DB811-treated tachyzoites remained inhibited. Electron microscopy ofB. besnoiti-infected fibroblast cultures fixed and processed at different time-points following the initiation of drug treatments revealed that DB811 exerted a much higher degree of ultrastructural alterations compared to DB750. These results show that arylimidamides such as DB811 could potentially become an important addition to the anti-parasitic arsenal for food animal production, especially in cattle.
Osteoporosis treatment and the older patient
Authors: Jay Roger H , Marrinan Sarah L
Published: February 2011

Osteoporosis is a common, chronic condition. Fracture risk assessment tools are increasingly being used to identify those patients who may benefit from treatment, but in older patients clinical judgement is still essential in deciding whom to treat. The treatment of osteoporosis in older people has seen several important developments in recent years. Whilst bisphosphonates are the mainstay of treatment, several newer medications have proven benefit in terms of increases in bone mineral density and fracture prevention. Additionally, some of the newer therapies have characteristics that particularly lend themselves to use in an older population group. This article focuses upon treatment of osteoporosis in older people with an emphasis on newer drug and therapeutic options.
Introduction: Equality and Human Rights in Britain
Authors: Riddell Sheila , Watson Nick
Published: February 2011

The first ten years of the twenty-first century has seen the British Government introduce radical change to its equality policy. These changes have included the creation of a single equalities body, the Equality and Human Rights Commission (EHRC); the expansion of the equality terrain to include age, sexuality and sexual orientation and faith and belief in addition to gender, race and disability as protected grounds; the decision to coalesce human rights and equality legislation under the direction the EHRC; the development of an Equalities Framework; the promulgation of a new Equality Act (2009) with the aim of creating a single legal framework to cover all equality legislation together with the development of specific Equality Duties for the public sector around the areas of gender, race and disability with the aim of ‘mainstreaming’ equality. Barbara Roche, the then Minister responsible for equality co-ordination across the UK Government described these changes as ‘the most significant review of equality in over a quarter of a century’.
Developing Key Indicators of ‘Fairness’: Competing Frameworks, Multiple Strands and Ten Domains – an Array of Statistics
Authors: Walby Sylvia , Armstrong Jo
Published: February 2011

This article argues that it is possible to develop key indicators to assess the broad agenda of ‘fairness’, even in the context of competing frameworks (e.g. equality, capabilities), multiple equality strands (gender, race/ethnicity, disability, age, religion/belief, sexual orientation, gender identity and social class) and several domains (e.g. health, education). Indicators are required to summarise complex statistical information to make it accessible to a wide audience. Methods for selecting indicators are discussed: identifying overlaps in frameworks, finding commonalities and applying quality criteria. Synthesising in this way enables identification of ‘key indicators’ of equality, including: intimate partner violence, risk of poverty and pay gaps.
Educational Expansion and Social Mobility: The Scottish Case
Authors: Iannelli Cristina
Published: February 2011

For over a century, the goal of reducing class inequalities in educational attainment has been based at least in part on the belief that this would help to equalise life chances. Drawing upon the main findings of three ESRC-funded projects, this paper reviews the empirical evidence on trends in social class inequalities in educational attainment and the role of education in promoting social mobility in Scotland. The findings show that in the second half of the twentieth century, despite the increase in overall levels of attainment, class differences in educational attainment persisted. Educational policies in Scotland supported educational expansion which allowed larger numbers of working-class children to climb the social class ladder than in the past. However, these did not translate into any break with the patterns of social inequalities in the chances of entering the top-level occupations. The conclusions highlight that educational policies on their own are not powerful enough to change patterns of social mobility which are mainly driven by labour market and social class structures.
The jet in the galactic center: An ideal laboratory for magnetohydrodynamics and general relativity
Authors: Falcke Heino , Markoff Sera , Bower Geoffrey C. , Gammie Charles F. , Mościbrodzka Monika , Maitra Dipankar
Published: February 2011

Of all possible black hole sources, the event horizon of the Galactic Center black hole, Sgr A*, subtends the largest angular scale on the sky. It is therefore a prime candidate to study and image plasma processes in strong gravity and it even allows imaging of the shadow cast by the event horizon. Recent mm-wave VLBI and radio timing observations as well as numerical GRMHD simulations now have provided several breakthroughs that put Sgr A* back into the focus. Firstly, VLBI observations have now measured the intrinsic size of Sgr A* at multiple frequencies, where the highest frequency measurements have approached the scale of the black hole shadow. Moreover, measurements of the radio variability show a clear time lag between 22 GHz and 43 GHz. The combination of size and timing measurements, allows one to actually measure the flow speed and direction of magnetized plasma at some tens of Schwarzschild radii. This data strongly support a moderately relativistic outflow, consistent with an accelerating jet model. This is compared to recent GRMHD simulation that show the presence of a moderately relativistic outflow coupled to an accretion flow Sgr A*. Further VLBI and timing observations coupled to simulations have the potential to map out the velocity profile from 5-40 Schwarzschild radii and to provide a first glimpse at the appearance of a jet-disk system near the event horizon. Future submm-VLBI experiments would even be able to directly image those processes in strong gravity and directly confirm the presence of an event horizon.
Modelling magnetically dominated and radiatively cooling jets
Authors: Huarte-Espinosa Martín , Frank Adam , Blackman Eric
Published: February 2011

Using 3D-MHD Eulerian-grid numerical simulations, we study the formation and evolution of rising magnetic towers propagating into an ambient medium. The towers are generated from a localized injection of pure magnetic energy. No rotation is imposed on the plasma. We compare the evolution of a radiatively cooling tower with an adiabatic one, and find that both bend due to pinch instabilities. Collimation is stronger in the radiative cooling case; the adiabatic tower tends to expand radially. Structural similarities are found between these towers and the millimeter scale magnetic towers produced in laboratory experiments.
The astrophysical jets
Authors: Kundt Wolfgang
Published: February 2011

In this published note I attempt to sketch my understanding of the universal working scheme of all the astrophysical jet sources, or ‘bipolar flows’, on both stellar and galactic scales, also called ‘microquasars’, and ‘quasars’. A crucial building block will be their medium: extremely relativistic e±-pair plasma performing quasi loss-free E × B-drifts through self-rammed channels, whose guiding equi-partition E- and B-fields convect the electric potential necessary for eventual single-step post-acceleration, at their terminating ‘knots’, or ‘hotspots’. The indispensible pair plasma is generated in magnetospheric reconnections of the central rotator. Already for this reason, black holes cannot serve as jet engines.
Blazar jet physics in the age of Fermi
Authors: Dermer Charles D.
Published: February 2011

The impact of the Fermi Gamma-ray Space Telescope on blazar research is reviewed. This includes a brief description of the Fermi Large Area Telescope, a summary of the various classes of extragalactic sources found in the First Large Area Telescope AGN Catalog, and more detailed discussion of the flat spectrum radio quasar 3C454.3 and the BL Lac object PKS 2155-304. Some theoretical studies related to ongoing blazar research with Fermi are mentioned, including implications of γ-ray observations of radio galaxies on blazar unification scenarios, variability in colliding shells, and whether blazars are sources of ultra-high energy cosmic rays.
Time-dependent multi-zone radiation transfer modeling of fast blazar variability
Authors: Fossati Giovanni , Chen Xuhui
Published: February 2011

We present the first applications of a new time-dependent multi-zone jet radiation transfer code to the study the multiwavelength emission of the TeV Blazar Mrk 421. The code couples Fokker-Planck and Monte Carlo methods. For the first time all light travel time effects are fully considered as well as proper self-consistent treatment of Compton cooling, which depends on them. The first tests focus on the March 2001 observations of Mrk 421, still one of the best datasets available for phenomenology and X-ray/TeV data coverage. We summarize the results of scenarios of variability induced by injection of relativistic electrons in a blob encountering a shock, and with different combinations with a second component, either co-spatial or independent from the active region.
The picture of relativistic jet from Fermi-LAT and multi-band observations of blazar 3C 279
Authors: Hayashida Masaaki , Madejski Greg
Published: February 2011

Strong and variable radiation detected over all accessible energy bands in blazar arises from a relativistic, Doppler-boosted jet pointing close to our line of sight. Flat Spectrum Radio Quasar 3C 279 was one of the brightest γ-ray blazars in the sky at the time of the discovery with EGRET. Since the successful launch of the Fermi Gamma-ray Space telescope in 2008, we have organized extensive multi-band observational campaign of 3C 279 from radio to γ-ray bands, also including optical polarimetric observations. The uninterrupted monitoring in the γ-ray band by Fermi-LAT together with the multi-band data provide us with new insights of the relativistic jet of blazar. Here, we present the results of the first-year multi-band campaign of 3C 279 including the discovery of a γ-ray flare event associated with a dramatic change of the optical polarization - as well as a discovery of an “orphan” X-ray flare, unassociated with prominent outbursts in other bands.
Longterm X-ray observations of blazars with MAXI
Authors: Naoki Isobe ,   the MAXI team.
Published: February 2011

Longterm continuous X-ray observations of blazars with MAXI are reported. Thanks to its unprecedentedly high sensitivity as an all sky X-ray monitor, MAXI is an ideal observatory to investigate variability of blazars, which should give a clue to particle acceleration in their jet, as well as the jet dynamics. Actually, since it started its operation in the summer of 2009, MAXI has successfully alerted two strong X-ray flares from the BL Lac object Mrk 421. Especially, in one of these flares, the X-ray flux of the object was found to become the highest in history. By closely examining the MAXI data, the physical quantities associated with the flares were estimated. These results clearly demonstrate the potential of MAXI for the variability of blazars.
High-temporal resolution optical observations of the gamma-ray blazar PG 1553+113
Authors: Andruchow I. , Combi J. A. , Cellone S. A. , Muñoz-Arjonilla A. J. , Romero G. E. , Martí J.
Published: February 2011

We present here the results of an observational photo-polarimetry campaign at optical wavelengths of the blazar PG 1553+113, which was recently detected at very high energies (>100 GeV) by the H.E.S.S and MAGIC γ-ray experiments.

Our high-temporal resolution data show significant variations in the linear polarization percentage and position angle at inter-night time-scales, while at shorter (intra-night) time-scales both parameters varied less significantly, if at all. Simultaneous differential photometry (at the B and R bands) shows no significant variability in the total optical flux.
Multi-Epoch VLBI observations of the extreme scintillator J1819+3845
Authors: Cimò Giuseppe , Gurvits Leonid
Published: February 2011

The quasar J1819+3845 has shown extreme variability with flux density variations in the radio regime up to 600% in less than one hour. In case of intrinsic high varibility, the short time scale sets a limit on the size of the emitting region and allows to estimate its brightness temperature. This would exceed 1021 K in the case of J1819+3845. Even an high relativistic jet beamed and doppler boosted in our line of sight cannot explain such an extreme violation of the Inverse Compton limit (1012 K). The variability of this source has been proven to be due to scattering in the Interstellar medium by a number of different experiments. Such an explanation requires a closeby scattering screen (few parsecs) and it results in a brightness temperature of about 1014 K. Many observing campaigns have been carried on to map the innermost jet structures of J1819+3845. Here we present the results of a number of VLBI observations, including space VLBI, to search for the missing jet in this puzzling source.