bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulsed Ultraviolet Light Reduces Immunoglobulin E Binding to Atlantic White Shrimp (Litopenaeus setiferus) Extract
Authors: Shriver Sandra , Yang Wade , Chung Si-Yin , Percival Susan
Published: June 2011

Pulsed ultraviolet light (PUV), a novel food processing and preservation technology, has been shown to reduce allergen levels in peanut and soybean samples. In this study, the efficacy of using PUV to reduce the reactivity of the major shrimp allergen, tropomyosin (36-kDa), and to attenuate immunoglobulin E (IgE) binding to shrimp extract was examined. Atlantic white shrimp (Litopenaeus setiferus) extract was treated with PUV (3 pulses/s, 10 cm from light source) for 4 min. Tropomyosin was compared in the untreated, boiled, PUV-treated and [boiled+PUV]-treated samples, and changes in the tropomyosin levels were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). IgE binding of the treated extract was analyzed via immunoblot and enzyme-linked immunosorbent assay (ELISA) using pooled human plasma containing IgE antibodies against shrimp allergens. Results showed that levels of tropomyosin and IgE binding were reduced following PUV treatment. However, boiling increased IgE binding, while PUV treatment could offset the increased allergen reactivity caused by boiling. In conclusion, PUV treatment reduced the reactivity of the major shrimp allergen, tropomyosin, and decreased the IgE binding capacity of the shrimp extract.
Energy Efficient Supply Boosted Comparator Design
Authors: Ay Suat U.
Published: June 2011

This paper presents a new mixed-signal design technique called supply boosting technique (SBT) and the design of an energy efficient, sub-1 V supply boosted comparator (SBC) in a standard complementary metal oxide semiconductor (CMOS) process. The selected CMOS process does not allow sub-1 V operation with a wide input range due to high threshold voltage (high-VTH) of MOS transistors (+0.8 V/−0.9 V). Despite this, the proposed comparator operates sub-1 V supply voltages with input common mode voltage larger than 60% of supply voltage by utilizing a supply boosting technique. The measured power consumption of the supply boosted comparator for 1 V supply was 90 nW and speed was 6500 conversions per second, resulting in 14 pJ per conversion energy efficiency.
A Single Polyaniline Nanofiber Field Effect Transistor and Its Gas Sensing Mechanisms
Authors: Chen Dajing , Lei Sheng , Chen Yuquan
Published: June 2011

A single polyaniline nanofiber field effect transistor (FET) gas sensor fabricated by means of electrospinning was investigated to understand its sensing mechanisms and optimize its performance. We studied the morphology, field effect characteristics and gas sensitivity of conductive nanofibers. The fibers showed Schottky and Ohmic contacts based on different electrode materials. Higher applied gate voltage contributes to an increase in gas sensitivity. The nanofiber transistor showed a 7% reversible resistance change to 1 ppm NH3 with 10 V gate voltage. The FET characteristics of the sensor when exposed to different gas concentrations indicate that adsorption of NH3 molecules reduces the carrier mobility in the polyaniline nanofiber. As such, nanofiber-based sensors could be promising for environmental and industrial applications.
Sustainable and Innovative Solutions for Sewage Sludge Management
Authors: Spinosa Ludovico , Ayol Azize , Baudez Jean-Christophe , Canziani Roberto , Jenicek Pavel , Leonard Angelique , Rulkens Wim , Xu Guoren , Van Dijk Lex
Published: June 2011

Sludge produced by municipal wastewater treatment plants (WWTPs) amounts to only a few percent by volume of the processed wastewater, but its handling accounts for up to 50% of total operating costs. Moreover, the need to achieve a sustainable sludge management strategy has become of great concern. It follows that as conventional and more traditional options, such as land spreading for agricultural purposes, are progressively restricted, and often legally banned, the development of innovative systems to maximize the recovery of useful materials and/or energy is required. A change toward more sustainable procedures can be promoted through an integrated approach, including the assessment of management routes capable of maximizing the recycle/recovery benefits, through low energy impact systems, and the development of operational systems appropriate to local circumstances. Based on the above considerations, an integrated system is proposed in this paper. It includes Anaerobic digestion, Dewatering/Drying, and Pyrolysis/Gasification processes which are efficiently coupled for the recovery of products for material reuse and/or energy purposes. Such an integrated system should also allow the recovery of one or more materials, depending on the combination of processes which best fit specific local situations.
Formation of precise 2D Au particle arrays via thermally induced dewetting on pre-patterned substrates
Authors: Wang Dong , Ji Ran , Schaaf Peter
Published: June 2011

The fabrication of precise 2D Au nanoparticle arrays over a large area is presented. The technique was based on pre-patterning of the substrate before the deposition of a thin Au film, and the creation of periodic particle arrays by subsequent dewetting induced by annealing. Two types of pre-patterned substrates were used: The first comprised an array of pyramidal pits and the second an array of circular holes. For the dewetting of Au films on the pyramidal pit substrate, the structural curvature-driven diffusion cooperates with capillarity-driven diffusion, resulting in the formation of precise 2D particle arrays for films within a structure dependent thickness-window. For the dewetting of Au films on the circular hole substrate, the periodic discontinuities in the films, induced by the deposition, can limit the diffusion paths and lead to the formation of one particle per individual separated region (holes or mesas between holes), and thus, result in the evolution of precise 2D particle arrays. The influence of the pre-patterned structures and the film thickness is analyzed and discussed. For both types of pre-patterned substrate, the Au film thickness had to be adjusted in a certain thickness-window in order to achieve the precise 2D particle arrays.
When gold can do what iodine cannot do: A critical comparison
Authors: Hummel Sara , Kirsch Stefan F
Published: June 2011

Gold catalysis has emerged as one of the most dynamic fields in organic synthesis. Only recently, more and more domino processes, for which gold pre-catalysts were found to be outstandingly effective, were paralleled by employing iodine electrophiles in place of gold compounds. This review highlights how, in certain cases, iodonium activation can match gold-catalyzed reactions to construct identical product scaffolds. Likewise, processes are discussed where mostly identical starting materials are transformed into diverse frameworks depending on whether gold or iodonium activation was used to trigger the reaction.
NATO New strategic concept and its implication for capabilities and use of the Czech Armed Forces
Authors: Junek Robert
Published: June 2011

This study deals with NATO New Strategic Concept approved in Lisbon on 19th November 2010. It attempts to examine an implication of the Concept for the capabilities of the Czech Armed Forces. In the first part, the study describes a way that led to the New Concept with special regard to the years 1999-2010. It then analyses the key features of the New Concept, both from the political and military point of view. It is followed by a brief evaluation of relevant Czech strategic documents that are, unfortunately, not up to date. The study is concluded with an identification of the main areas, which Czech Armed Forces should focus on to meet the challenge of NATO New Strategic Concept.
Mondialisation et développement. Quelle soutenabilité au régime de l'Organisation mondiale du commerce ?
Authors: Abbas Mehdi
Published: June 2011

Cet article présente les principales contradictions dans lesquelles est prise l’OMC. Il avance la thèse de l’articulation entre la nature de la régulation commerciale et l’évolution des équilibres de puissance consécutive de l’affirmation des économies émergentes comme source majeure des dysfonctionnements de l’OMC. Elle renouvelle l’antagonisme Nord-Sud au sein du système commercial et suscite une interrogation sur la soutenabilité environnementale et sociale du régime de l’OMC.
La literatura mexicana de transgresión sexual
Authors: Muñoz Mario
Published: June 2011

A partir de la antología titulada : De amores marginales (1996),  de la cual soy autor, se ofrece un panorama de la temática homosexual centrada en el relato de autores mexicanos, desde los textos precursores surgidos a mediados del siglo xx hasta los ejemplos más recientes. Este recorrido establece la diversidad de propuestas literarias de la denominada, por algunos críticos, « literatura gay » como respuesta al poder represivo que ha ejercido la sociedad en contra de las diferencias sexuales. Se trata en principio de poner en evidencia cómo es que la intolerancia moral, escolar, familiar y religiosa condujeron a una autocensura de los propios escritores, que evadieron el abordaje de determinados problemas individuales por considerarlos lesivos para los valores dominantes de la época. En conclusión, el artículo intenta demostrar que la literatura de tema homosexual surge a partir de los narradores pertenecientes a la Generación de Medio Siglo, quienes rompieron con los prejuicios culturales y los tabúes morales de su tiempo, produciendo una auténtica literatura de transgresión que permitió  la apertura a la modernidad.
Les agents français dans la Plata
Authors: Avendaño Marín Clara María
Published: June 2011

Cet article vise à mettre en évidence le poids et la portée politique et diplomatique du stigmate de barbarie qui frappe le Gouverneur de Buenos Aires Juan Manuel Rosas pendant le blocus de la Plata entre 1838 et 1840. Cette barbarie rosiste, dont les agents français ont été les premiers coryphées en France, était définie dans leurs écrits par un rapport dialectique entre civilisation et barbarie. Cette antinomie qui leur sert d’argument pour soutenir non seulement les prétentions françaises,  mais aussi les opposants politiques du rosisme, s’articule autour de l’opposition entre la « ville civilisée » et la « campagne barbare », entre l’Europe, sa culture et son commerce et l’Amérique, ses coutumes et la défense de ses intérêts.
La déglaciation dans le massif du Carlit (Pyrénées orientales) : approches géomorphologique et géochronologique nouvelles
Authors: Delmas Magali
Published: June 2011

Une cartographie détaillée des formes et formations glaciaires, et périglaciaires associées, permet de proposer une relecture des étapes et modalités de la déglaciation dans le massif du Carlit. La découverte d’une tourbière datée à 16 500 BP à 2150 m d’altitude, au débouché immédiat des cirques et précédée de huit stades de retrait échelonnés sur les 16 km de l’auge de la Têt, montre la très grande précocité de la déglaciation dans ce tronçon de la chaîne. Un âge probablement Pléniglaciaire inférieur est proposé pour le Maximum würmien. Cette tourbière fossilisée par un cône proglaciaire fixe également, mais par défaut, la première récurrence glaciaire du stade des cirques qui appartient encore à la fin du Pléniglaciaire supérieur, voire à un Dryas très ancien. Des arguments régionaux permettent d’envisager une déglaciation totale et définitive des cirques dès l’Alleröd et un âge Dryas récent pour les glaciers rocheux des cirques.
Etude du remplissage sédimentaire d’un système hypersalin de la Tunisie orientale au cours du Quaternaire récent : la sebkha de Moknine
Authors: Chairi Raja
Published: June 2011

Les résultats d’une étude sédimentologique détaillée de la sebkha de Moknine indiquent la présence de deux épisodes de dépôt. Le premier est caractérisé par une abondance du faciès argileux et de la matière organique associée. Le deuxième est le résultat d'une phase de comblement voire même un état de vieillissement de la sebkha, exprimé par une migration du faciès fin et de la matière organique vers l’Est. Deux facteurs importants sont responsables de cette évolution : la dissymétrie de la cuvette basculée vers l’Est et l’abondance du réseau hydrographique à l’Ouest. Elle s’est réalisée sur une période assez longue, en raison de la rareté des averses et de l’écoulement peu abondant durant l’année dans la région de Moknine. La phase argileuse à la base des séquences élémentaires étudiées est un indicateur de la phase transgressive et de l’étendue importante de la sebkha au passé. Cette phase est essentiellement smectitique, minéral caractéristique du centre de la sebkha.  Elle renferme des taux élevés en    matière organique d’origine lacustre montrée par des valeurs importantes en index d’hydrogène et une répartition des n-alcanes centrés sur les légers où le mode est entre nC18 et nC22.
Laccase: Microbial Sources, Production, Purification, and Potential Biotechnological Applications
Authors: Shraddha  , Shekher Ravi , Sehgal Simran , Kamthania Mohit , Kumar Ajay
Published: June 2011

Laccase belongs to the blue multicopper oxidases and participates in cross-linking of monomers, degradation of polymers, and ring cleavage of aromatic compounds. It is widely distributed in higher plants and fungi. It is present in Ascomycetes, Deuteromycetes and Basidiomycetes and abundant in lignin-degrading white-rot fungi. It is also used in the synthesis of organic substance, where typical substrates are amines and phenols, the reaction products are dimers and oligomers derived from the coupling of reactive radical intermediates. In the recent years, these enzymes have gained application in the field of textile, pulp and paper, and food industry. Recently, it is also used in the design of biosensors, biofuel cells, as a medical diagnostics tool and bioremediation agent to clean up herbicides, pesticides and certain explosives in soil. Laccases have received attention of researchers in the last few decades due to their ability to oxidize both phenolic and nonphenolic lignin-related compounds as well as highly recalcitrant environmental pollutants. It has been identified as the principal enzyme associated with cuticular hardening in insects. Two main forms have been found: laccase-1 and laccase-2. This paper reviews the occurrence, mode of action, general properties, production, applications, and immobilization of laccases within different industrial fields.
The Role of Hypothalamic Tri-Iodothyronine Availability in Seasonal Regulation of Energy Balance and Body Weight
Authors: Murphy Michelle , Ebling Francis J. P.
Published: June 2011

Seasonal cycles of body weight provide a natural model system to understand the central control of energy balance. Studies of such cycles in Siberian hamsters suggest that a change in the hypothalamic availability of thyroid hormone is the key determinant of annual weight regulation. Uptake of thyroid hormone into the hypothalamus from the peripheral circulation occurs largely through a specific monocarboxylate transporter expressed by tanycyte cells lining the third ventricle. Tanycytes are the principal brain cell type expressing type II and type III deiodinases, so they control the local concentrations of T4, T3, and inactive metabolites. Type III deiodinase mRNA in tanycytes is photoperiodically upregulated in short photoperiod. This would be expected to reduce the availability of T3 in the hypothalamus by promoting the production of inactive metabolites such as rT3. Experimental microimplantation of T3 directly into the hypothalamus during short-days promotes a long-day phenotype by increasing food intake and body weight without affecting the peripheral thyroid axis. Thus, thyroid hormone exerts anabolic actions within the brain that play a key role in the seasonal regulation of body weight. Understanding the precise actions of thyroid hormone in the brain may identify novel targets for long-term pharmacological manipulation of body weight.
The Impact of Hypertension on Patients with Acute Coronary Syndromes
Authors: Picariello Claudio , Lazzeri Chiara , Attanà Paola , Chiostri Marco , Gensini Gian Franco , Valente Serafina
Published: June 2011

Arterial chronic hypertension (HTN) is a well-known cardiovascular risk factor for development of atherosclerosis. In order to explain the relation between HTN and acute coronary syndromes the following factors should be considered: (1) risk factors are shared by the diseases, such as genetic risk, insulin resistance, sympathetic hyperactivity, and vasoactive substances (i.e., angiotensin II); (2) hypertension is associated with the development of atherosclerosis (which in turn contributes to progression of myocardial infarction). From all the registries and the data available up to now, hypertensive patients with ACS are more likely to be older, female, of nonwhite ethnicity, and having a higher prevalence of comorbidities. Data on the prognostic role of a preexisting hypertensive state in ACS patients are so far contrasting. The aim of the present paper is to focus on hypertensive patients with ACS, in order to better elucidate whether these patients are at higher risk and deserve a tailored approach for management and followup.
Functionalized Palladium Nanoparticles for Hydrogen Peroxide Biosensor
Authors: Baccar H. , Ktari T. , Abdelghani A.
Published: June 2011

We present a comparison between two biosensors for hydrogen peroxide (H2O2) detection. The first biosensor was developed by the immobilization of Horseradish Peroxidase (HRP) enzyme on thiol-modified gold electrode. The second biosensor was developed by the immobilization of cysteamine functionalizing palladium nanoparticles on modified gold surface. The amino groups can be activated with glutaraldehyde for horseradish peroxidase immobilization. The detection of hydrogen peroxide was successfully observed in PBS for both biosensors using the cyclic voltammetry and the chronoamperometry techniques. The results show that the limit detection depends on the large surface-to-volume ratio attained with palladium nanoparticles. The second biosensor presents a better detection limit of 7.5 μM in comparison with the first one which is equal to 75 μM.
Antithrombotic Medication for Cardioembolic Stroke Prevention
Authors: Font M. Àngels , Krupinski Jerzy , Arboix Adrià
Published: June 2011

Embolism of cardiac origin accounts for about 20% of ischemic strokes. Nonvalvular atrial fibrillation is the most frequent cause of cardioembolic stroke. Approximately 1% of population is affected by atrial fibrillation, and its prevalence is growing with ageing in the modern world. Strokes due to cardioembolism are in general severe and prone to early recurrence and have a higher long-term risk of recurrence and mortality. Despite its enormous preventive potential, continuous oral anticoagulation is prescribed for less than half of patients with atrial fibrillation who have risk factors for cardioembolism and no contraindications for anticoagulation. Available evidence does not support routine immediate anticoagulation of acute cardioembolic stroke. Anticoagulation therapy's associated risk of hemorrhage and monitoring requirements have encouraged the investigation of alternative therapies for individuals with atrial fibrillation. New anticoagulants being tested for prevention of stroke are low-molecular-weight heparins (LMWH), unfractionated heparin, factor Xa inhibitors, or direct thrombin inhibitors like dabigatran etexilate and rivaroxaban. The later exhibit stable pharmacokinetics obviating the need for coagulation monitoring or dose titration, and they lack clinically significant food or drug interaction. Moreover, they offer another potential that includes fixed dosing, oral administration, and rapid onset of action. There are several concerns regarding potential harm, including an increased risk for hepatotoxicity, clinically significant bleeding, and acute coronary events. Therefore, additional trials and postmarketing surveillance will be needed.
Morphological Factor Estimation via High‐Dimensional Reduction: Prediction of MCI Conversion to Probable AD
Authors: Duchesne Simon , Mouiha Abderazzak
Published: June 2011

We propose a novel morphological factor estimate from structural MRI for disease state evaluation. We tested this methodology in the context of Alzheimer′s disease (AD) with 349 subjects. The method consisted in (a) creating a reference MRI feature eigenspace using intensity and local volume change data from 149 healthy, young subjects; (b) projecting MRI data from 75 probable AD, 76 controls (CTRL), and 49 Mild Cognitive Impairment (MCI) in that space; (c) extracting high‐dimensional discriminant functions; (d) calculating a single morphological factor based on various models. We used this methodology in leave‐one‐out experiments to (1) confirm the superiority of an inverse‐squared model over other approaches; (2) obtain accuracy estimates for the discrimination of probable AD from CTRL (90%) and the prediction of conversion of MCI subjects to probable AD (79.4%).
Amiodarone-induced pulmonary toxicity
Authors: Ochi Junichi , Ohkouchi Minoru , Tsukada Yoshikazu , Tominaga Shinichiro , Takayama Satoshi , Taniguchi Yuko , Miyamoto Yumi , Inase Naohiko
Published: June 2011

Amiodarone-induced pulmonary toxicity is a critical and potentially fatal side effect of amiodarone. Our study was designed to reveal its clinical features, including KL-6, as an interstitial marker. The medical records of eight patients (five men and three women) with amiodarone-induced pulmonary toxicity, who had been referred to our hospital, were examined. The mean age at the initiation of amiodarone was 48 years (range, 54-87 years) and mean duration of medication prior to the development of pulmonary toxicity was 18 months (range, 7-33 months). Serum KL-6 was elevated in six of the eight patients with a range of 525-2915 U/mL. Chest computed tomography (CT) findings showed non-segmental consolidation and/or ground glass opacity. Foamy macrophages were found in bronchoalveolar lavage (BAL) fluids of all examined patients and in transbronchial lung biopsy (TBLB) specimens in half of the examined patients. We concluded that serum KL-6, chest CT findings, and foamy macrophages in BAL fluids and TBLB specimens will be helpful for the diagnosis of amiodarone-induced pulmonary toxicity.
Hamiltonian formulation of the Klein–Gordon–Maxwell equations
Authors: Benci Vieri , Fortunato Donato
Published: June 2011

The nonlinear Klein-Gordon-Maxwell equations (NKGM) provide models for the interaction between the electromagnetic field and matter. The relevance of NKGM relies on the fact that they are the "simplest" gauge theory which is invariant under the group of Poincaré. These equations present the interesting phenomenon of solitons. In this paper, we show that NKGM present an Hamiltonian structure and hence they can be written as equations of the first order in

t

. This fact is not trivial since the Lagrangian does not depend on

\partial_{t}\varphi

(see sec. 3.3) and a suitable analysis of its structure is necessary. In the last section, we recall a recent result which states the existence of solitons by using the particular structure of the Hamiltonian.
Propagation of analyticity for a class of nonlinear hyperbolic equations
Authors: Spagnolo Sergio
Published: June 2011

We consider the semilinear hyperbolic equations of the form

\partial_{t}^mu \,+, a_1(t)\,\partial_{t}^{m-1}\partial_{x} u \,+, \cdots \,+, a_m(t)\,\partial_{x}^mu \,=\, f(u)

with

f(u)

entire analytic, where the characteristic roots satisfy

\lambda_i^2(t),+,\lambda_j^2(t) \le M( \lambda_i(t)-\lambda_j(t))^2 \,, \quad \hbox{} \ \ i\neq j.

We prove that, if the

\,a_h(t)

's are analytic functions, al the solutions bounded in

\mathcal {C}^\infty

enjoy the propagation of analyticity; while, if the

a_h(t)

's are

\mathcal {C}^\infty

functions, such a property holds for those solutions which are bounded in some Gevrey class.
Combined effects in quasilinear elliptic problems with lack of compactness
Authors: Pucci Patrizia , Rădulescu Vicenţiu D.
Published: June 2011

We are concerned with the study of weak solutions to a class of subcritical quasilinear elliptic equations with weight, variable parameter, and lack of compactness. By means of variational methods, we establish that this problem does not have any solution if the positive parameter is small enough, while at least two distinct solutions exist, provided that the parameter is sufficiently large.
Critical points for Sobolev homeomorphisms
Authors: Sbordone Carlo , Schiattarella Roberta
Published: June 2011

We consider a class of homeomorphisms

f\colon\Omega\subset\mathbb{R}^2\stackrel{\text{onto}}{\longrightarrow} \Omega'\subset\mathbb{R}^2

of the Sobolev space

\mathscr {W}^{1,1}_{{\rm loc}}(\Omega; \mathbb{R}^2)

whose Jacobian may vanish on a set of positive measure but cannot be zero a.e. in

\Omega

. This class is defined by the bi-Sobolev condition

\tag{1}f \;\text{ and } \; f^{-1} \in \mathscr {W}^{1,1}_{\mathrm{loc}}

and reveals useful also in the theory of changes of variables for Sobolev functions.
Quasi-periodic solutions of nonlinear Schrödinger equations on $\mathbb T^d$
Authors: Berti Massimiliano , Bolle Philippe
Published: June 2011

We present recent existence results of quasi-periodic solutions for Schrödinger equations with a
multiplicative
potential on T_d_,

d \geq 1

, finitely
differentiable
nonlinearities, and tangential frequencies constrained along a
pre-assigned
direction. The solutions have only Sobolev regularity both in time and space. If the nonlinearity and the potential are in

C^\infty

then the solutions are in

C^\infty

. The proofs are based on an improved Nash–Moser iterative scheme and a new multiscale inductive analysis for the inverse linearized operators.
Involutions on Zilber fields
Authors: Mantova Vincenzo
Published: June 2011

In this paper, we briefly outline the definition of Zilber field, which is a structure analogue to the complex field with the exponential function. An open conjecture, including Schanuel’s Conjecture, is whether the complex field is itself one of these structure.

In view of this conjecture, a natural question raised by Zilber, Kirby, Macintyre and others is whether they have an automorphism of order two akin to complex conjugation.

We announce, without proof, the positive answer: for cardinality up to the continuum there exists an involution of the field commuting with the exponential function. Moreover, in the case of cardinality of the continuum, the automorphism can be taken such that its fixed field is exactly

ℝ

, and the kernel of the exponential function is

2\pi i \mathbb Z

.
A Generalized Stationary Algorithm for Resonant Tunneling: Multi-Mode Approximation and High Dimension
Authors: Abdallah Naoufel Ben , Wu Hao
Published: June 2011

The multi-mode approximation is presented to compute the interior wave function of Schrödinger equation. This idea is necessary to handle the multi-barrier and high dimensional resonant tunneling problems where multiple eigenvalues are considered. The accuracy and efficiency of this algorithm is demonstrated via several numerical examples.
Convergence Detection in Direct Simulation Monte Carlo Calculations for Steady State Flows
Authors: Burt Jonathan M. , Boyd Iain D.
Published: June 2011

A new criterion is presented to detect global convergence to steady state, and to identify local transient characteristics, during rarefied gas flow simulations performed using the direct simulation Monte Carlo (DSMC) method. Unlike deterministic computational fluid dynamics (CFD) schemes, DSMC is generally subject to large statistical scatter in instantaneous flow property evaluations, which prevents the use of residual tracking procedures as are often employed in CFD simulations. However, reliable prediction of the time to reach steady state is necessary for initialization of DSMC sampling operations. Techniques currently used in DSMC to identify steady state convergence are usually insensitive to weak transient behavior in small regions of relatively low density or recirculating flow. The proposed convergence criterion is developed with the goal of properly identifying such weak transient behavior, while adding negligible computational expense and allowing simple implementation in any existing DSMC code. Benefits of the proposed technique over existing convergence detection methods are demonstrated for representative nozzle/plume expansion flow, hypersonic blunt body flow and driven cavity flow problems.
A Conservative Modification to the Ghost Fluid Method for Compressible Multiphase Flows
Authors: Liu Wei , Yuan Li , Shu Chi-Wang
Published: June 2011

A conservative modification to the ghost fluid method (GFM) is developed for compressible multiphase flows. The motivation is to eliminate or reduce the conservation error of the GFM without affecting its performance. We track the conservative variables near the material interface and use this information to modify the numerical solution for an interfacing cell when the interface has passed the cell. The modification procedure can be used on the GFM with any base schemes. In this paper we use the fifth order finite difference WENO scheme for the spatial discretization and the third order TVD Runge-Kutta method for the time discretization. The level set method is used to capture the interface. Numerical experiments show that the method is at least mass and momentum conservative and is in general comparable in numerical resolution with the original GFM.
Risky business: Gambling problems amongst gaming venue employees in Queensland, Australia
Authors: Hing Nerilee , Gainsbury Sally
Published: June 2011

This study examines gambling and problem gambling among gaming venue staff and provides a quantitative analysis that is directly comparable to the general population. A sample of 511 staff from casinos, hotels, and clubs in Queensland, Australia completed a questionnaire. Results indicate that employees exceed the average for gambling participation, regular gambling, and usual gambling duration for every type of gambling for which comparisons could be made. Problem gambling rates amongst staff were 9.6 times higher than for the Queensland population. Problem and moderate-risk gamblers were typically males who worked around gambling facilities and assisted patrons with gambling. A substantial proportion of problem and moderate-risk gamblers report increasing their gambling since commencing work. These results are of interest, given the importance of understanding how exposure interacts with gambling behaviour, of debates about the nature of this interaction, and of industry-based responsible gambling policies that particularly focus on gaming venue employees.
NLC and the background atmosphere above ALOMAR
Authors: Fiedler J. , Baumgarten G. , Berger U. , Hoffmann P. , Kaifler N. , Lübken F.-J.
Published: June 2011

Abstract. Noctilucent clouds (NLC) have been measured by the Rayleigh/Mie/Raman-lidar at the ALOMAR research facility in Northern Norway (69° N, 16° E). From 1997 to 2010 NLC were detected during more than 1850 h on 440 different days. Colocated MF-radar measurements and calculations with the Leibniz-Institute Middle Atmosphere (LIMA-) model are used to characterize the background atmosphere. Temperatures as well as horizontal winds at 83 km altitude show distinct differences during NLC observations compared to when NLC are absent. The seasonally averaged temperature is lower and the winds are stronger westward when NLC are detected. The wind separation is a robust feature as it shows up in measurements as well as in model results and it is consistent with the current understanding that lower temperatures support the existence of ice particles. For the whole 14-year data set there is no statistically significant relation between NLC occurrence and solar Lyman-α radiation. On the other hand NLC occurrence and temperatures at 83 km show a significant anti-correlation, which suggests that the thermal state plays a major role for the existence of ice particles and dominates the pure Lyman-α influence on water vapor during certain years. We find the seasonal mean NLC altitudes to be correlated to both Lyman-α radiation and temperature. NLC above ALOMAR are strongly influenced by atmospheric tides. The cloud water content varies by a factor of 2.8 over the diurnal cycle. Diurnal and semidiurnal amplitudes and phases show some pronounced year-to-year variations. In general, amplitudes as well as phases vary in a different manner. Amplitudes change by a factor of more than 3 and phases vary by up to 7 h. Such variability could impact long-term NLC observations which do not cover the full diurnal cycle.
Global multi-year O3-CO correlation patterns from models and TES satellite observations
Authors: Voulgarakis A. , Telford P. J. , Aghedo A. M. , Braesicke P. , Faluvegi G. , Abraham N. L. , Bowman K. W. , Pyle J. A. , Shindell D. T.
Published: June 2011

Abstract. The correlation between measured tropospheric ozone (O3) and carbon monoxide (CO) has been used extensively in tropospheric chemistry studies to explore the photochemical characteristics of different regions and to evaluate the ability of models to capture these characteristics. Here, we present the first study that uses multi-year, global, vertically resolved, simultaneous and collocated O3 and CO satellite (Tropospheric Emission Spectrometer) measurements, to determine this correlation in the middle/lower free troposphere for two different seasons, and to evaluate two chemistry-climate models. We find results that are fairly robust across different years, altitudes and timescales considered, which indicates that the correlation maps presented here could be used in future model evaluations. The highest positive correlations (around 0.8) are found in the northern Pacific during summer, which is a common feature in the observations and the G-PUCCINI model. We make quantitative comparisons between the models using a single-figure metric (C), which we define as the correlation coefficient between the modeled and the observed O3-CO correlations for different regions of the globe. On a global scale, the G-PUCCINI model shows a good performance in the summer (C=0.71) and a satisfactory performance in the winter (C=0.52). It captures midlatitude features very well, especially in the summer, whereas the performance in regions like South America or Central Africa is weaker. The UKCA model (C=0.46/0.15 for July–August/December–January on a global scale) performs better in certain regions, such as the tropics in winter, and it captures some of the broad characteristics of summer extratropical correlations, but it systematically underestimates the O3-CO correlations over much of the globe. It is noteworthy that the correlations look very different in the two models, even though the ozone distributions are similar. This demonstrates that this technique provides a powerful global constraint for understanding modeled tropospheric chemical processes. We investigated the sources of the correlations by performing a series of sensitivity experiments. In these, the sign of the correlation is, in most cases, insensitive to removing different individual emissions, but its magnitude changes downwind of emission regions when applying such perturbations. Interestingly, we find that the O3-CO correlation does not solely reflect the strength of O3 photochemical production, as often assumed by earlier studies, but is more complicated and may reflect a mixture of different processes such as transport.
Ice nucleation properties of fine ash particles from the Eyjafjallajökull eruption in April 2010
Authors: Steinke I. , Möhler O. , Kiselev A. , Niemand M. , Saathoff H. , Schnaiter M. , Skrotzki J. , Hoose C. , Leisner T.
Published: June 2011

Abstract. During the eruption of the Eyjafjallajökull volcano in the south of Iceland in April/May 2010, about 40 Tg of ash mass were emitted into the atmosphere. However, it was unclear whether volcanic ash particles with d < 10 μm facilitate the glaciation of clouds. Thus, ice nucleation properties of volcanic ash particles were investigated in AIDA (Aerosol Interaction and Dynamics in the Atmosphere) cloud chamber experiments simulating atmospherically relevant conditions. The ash sample that was used for our experiments had been collected at a distance of 58 km from the Eyjafjallajökull during the eruption period in April 2010. The temperature range covered by our ice nucleation experiments extended from 219 to 264 K, and both ice nucleation via immersion freezing and deposition nucleation could be observed. Immersion freezing was first observed at 252 K, whereas the deposition nucleation onset lay at 242 K and RHice = 126 %. About 0.1 % of the volcanic ash particles were active as immersion freezing nuclei at a temperature of 249 K. For deposition nucleation, an ice fraction of 0.1 % was observed at around 233 K and RHice = 116 %. Taking ice-active surface site densities as a measure for the ice nucleation efficiency, volcanic ash particles are similarly efficient ice nuclei in immersion freezing mode (ns, imm ~ 109 m−2 at 247 K) compared to certain mineral dusts. For deposition nucleation, the observed ice-active surface site densities ns, dep were found to be 1011 m−2 at 224 K and RHice = 116 %. Thus, volcanic ash particles initiate deposition nucleation more efficiently than Asian and Saharan dust but appear to be poorer ice nuclei than ATD particles. Based on the experimental data, we have derived ice-active surface site densities as a function of temperature for immersion freezing and of relative humidity over ice and temperature for deposition nucleation.
An improved NO2 retrieval for the GOME-2 satellite instrument
Authors: Richter A. , Begoin M. , Hilboll A. , Burrows J. P.
Published: June 2011

Abstract. Satellite observations of nitrogen dioxide (NO2) provide valuable information on both stratospheric and tropospheric composition. Nadir measurements from GOME, SCIAMACHY, OMI, and GOME-2 have been used in many studies on tropospheric NO2 burdens, the importance of different NOx emissions sources and their change over time. The observations made by the three GOME-2 instruments will extend the existing data set by more than a decade, and a high quality of the data as well as their good consistency with existing time series is of particular importance. In this paper, an improved GOME-2 NO2 retrieval is described which reduces the scatter of the individual NO2 columns globally but in particular in the region of the Southern Atlantic Anomaly. This is achieved by using a larger fitting window including more spectral points, and by applying a two step spike removal algorithm in the fit. The new GOME-2 data set is shown to have good consistency with SCIAMACHY NO2 columns. Remaining small differences are shown to be linked to changes in the daily solar irradiance measurements used in both GOME-2 and SCIAMACHY retrievals. In the large retrieval window, a not previously identified spectral signature was found which is linked to deserts and other regions with bare soil. Inclusion of this empirically derived pseudo cross-section significantly improves the retrievals and potentially provides information on surface properties and desert aerosols. Using the new GOME-2 NO2 data set, a long-term average of tropospheric columns was computed and high-pass filtered. The resulting map shows evidence for pollution from several additional shipping lanes, not previously identified in satellite observations. This illustrates the excellent signal to noise ratio achievable with the improved GOME-2 retrievals.
Inversion of tropospheric profiles of aerosol extinction and HCHO and NO2 mixing ratios from MAX-DOAS observations in Milano during the summer of 2003 and comparison with independent data sets
Authors: Wagner T. , Beirle S. , Brauers T. , Deutschmann T. , Frieß U. , Hak C. , Halla J. D. , Heue K. P. , Junkermann W. , Li X. , Platt U. , Pundt-Gruber I.
Published: June 2011

Abstract. We present aerosol and trace gas profiles derived from MAX-DOAS observations. Our inversion scheme is based on simple profile parameterisations used as input for an atmospheric radiative transfer model (forward model). From a least squares fit of the forward model to the MAX-DOAS measurements, two profile parameters are retrieved including integrated quantities (aerosol optical depth or trace gas vertical column density), and parameters describing the height and shape of the respective profiles. From these results, the aerosol extinction and trace gas mixing ratios can also be calculated. We apply the profile inversion to MAX-DOAS observations during a measurement campaign in Milano, Italy, September 2003, which allowed simultaneous observations from three telescopes (directed to north, west, south). Profile inversions for aerosols and trace gases were possible on 23 days. Especially in the middle of the campaign (17–20 September 2003), enhanced values of aerosol optical depth and NO2 and HCHO mixing ratios were found. The retrieved layer heights were typically similar for HCHO and aerosols. For NO2, lower layer heights were found, which increased during the day. The MAX-DOAS inversion results are compared to independent measurements: (1) aerosol optical depth measured at an AERONET station at Ispra; (2) near-surface NO2 and HCHO (formaldehyde) mixing ratios measured by long path DOAS and Hantzsch instruments at Bresso; (3) vertical profiles of HCHO and aerosols measured by an ultra light aircraft. Depending on the viewing direction, the aerosol optical depths from MAX-DOAS are either smaller or larger than those from AERONET observations. Similar comparison results are found for the MAX-DOAS NO2 mixing ratios versus long path DOAS measurements. In contrast, the MAX-DOAS HCHO mixing ratios are generally higher than those from long path DOAS or Hantzsch instruments. The comparison of the HCHO and aerosol profiles from the aircraft showed reasonable agreement with the respective MAX-DOAS layer heights. From the comparison of the results for the different telescopes, it was possible to investigate the internal consistency of the MAX-DOAS observations. As part of our study, a cloud classification algorithm was developed (based on the MAX-DOAS zenith viewing directions), and the effects of clouds on the profile inversion were investigated. Different effects of clouds on aerosols and trace gas retrievals were found: while the aerosol optical depth is systematically underestimated and the HCHO mixing ratio is systematically overestimated under cloudy conditions, the NO2 mixing ratios are only slightly affected. These findings are in basic agreement with radiative transfer simulations.
Effect of mosaic representation of vegetation in land surface schemes on simulated energy and carbon balances
Authors: Li R. , Arora V. K.
Published: June 2011

Abstract. Energy and carbon balance implications of representing vegetation using a composite or mosaic approach in a land surface scheme are investigated. In the composite approach the attributes of different plant functional types (PFTs) present in a grid cell are aggregated in some fashion for energy and water balance calculations. The resulting physical environmental conditions (including net radiation, soil moisture and soil temperature) are common to all PFTs and affect their ecosystem processes. In the mosaic approach energy and water balance calculations are performed separately for each PFT tile using its own vegetation attributes, so each PFT "sees" different physical environmental conditions and its carbon balance evolves somewhat differently from that in the composite approach. Simulations are performed at selected boreal, temperate and tropical locations to illustrate the differences caused by using the composite versus the mosaic approaches of representing vegetation. Differences in grid averaged primary energy fluxes are generally less than 5 % between the two approaches. Grid-averaged carbon fluxes and pool sizes can, however, differ by as much as 46 %. Simulation results suggest that differences in carbon balance between the two approaches arise primarily through differences in net radiation which directly affects net primary productivity, and thus leaf area index and vegetation biomass.
Hydropedological insights when considering catchment classification
Authors: Bouma J. , Droogers P. , Sonneveld M. P. W. , Ritsema C. J. , Hunink J. E. , Immerzeel W. W. , Kauffman S.
Published: June 2011

Abstract. Soil classification systems are analysed to explore the potential of developing classification systems for catchments. Soil classifications are useful to create systematic order in the overwhelming quantity of different soils in the world and to extrapolate data available for a given soil type to soils elsewhere with identical classifications. This principle also applies to catchments. However, to be useful, soil classifications have to be based on permanent characteristics as formed by the soil forming factors over often very long periods of time. When defining permanent catchment characteristics, discharge data would therefore appear to be less suitable. But permanent soil characteristics do not necessarily match with characteristics and parameters needed for functional soil characterization focusing, for example, on catchment hydrology. Hydropedology has made contributions towards the required functional characterization of soils as is illustrated for three recent hydrological catchment studies. However, much still needs to be learned about the physical behaviour of anisotropic, heterogeneous soils with varying soil structures during the year and about spatial and temporal variability. The suggestion is made therefore to first focus on improving simulation of catchment hydrology, possibly incorporating hydropedological expertise, before embarking on a catchment classification effort which involves major input of time and involves the risk of distraction. In doing so, we suggest to also define other characteristics for catchment performance than the traditionally measured discharge rates. Such characteristics may well be derived from societal issues being studied, as is illustrated for the Green Water Credits program.
Evaluation of the transferability of hydrological model parameters for simulations under changed climatic conditions
Authors: Bastola S. , Murphy C. , Sweeney J.
Published: June 2011

Abstract. Conceptual hydrological models are widely used for climate change impact assessment. The implicit assumption in most such work is that the parameters estimated from observations remain valid for future climatic conditions. This paper evaluates a simple threshold based approach for testing this assumption, where a set of behavioural simulators are identified for different climatic conditions for the future simulation i.e. wet, average and dry conditions. These simulators were derived using three different data sets that are generated by sampling a block of one year of data without replacement from the observations such that they define the different climatic conditions. The simulators estimated from the wet climatic data set showed the tendency to underestimate flow when applied to dry data set and vice versa. However, the performances of the three sets of basin simulators on chronologically coherent data are identical to the simulators identified from a sufficiently long data series that contains both wet and dry climatic conditions. The results presented suggest that the issue of time invariance in the value of parameters has a minimal effect on the simulation if the change in precipitation is less than 10 % of the data used for calibration.