bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Amount of Salinomycin Greatly Increases Akt Activation, but Reduces Activated p70S6K Levels
Authors: Kim Ju-Hwa , Choi Ae-Ran , Kim Yong , Kim Hyung , Yoon Sungpil
Published: August 2013

The present study identified a novel salinomycin (Sal)-sensitization mechanism in cancer cells. We analyzed the signal proteins Akt, Jnk, p38, Jak, and Erk1/2 in cancer cell lines that had arrested growth following low amounts of Sal treatment. We also tested the signal molecules PI3K, PDK1, GSK3β, p70S6K, mTOR, and PTEN to analyze the PI3K/Akt/mTOR pathway. The results showed that Sal sensitization positively correlates with large reductions in p70S6K activation. Interestingly, Akt was the only signal protein to be significantly activated by Sal treatment. The Akt activation appeared to require the PI3K pathway as its activation was abolished by the PI3K inhibitors LY294002 and wortmannin. The Akt activation by Sal was conserved in the other cell lines analyzed, which originated from other organs. Both Akt activation and C-PARP production were proportionally increased with increased doses of Sal. In addition, the increased levels of pAkt were not reduced over the time course of the experiment. Co-treatment with Akt inhibitors sensitized the Sal-treated cancer cells. The results thereby suggest that Akt activation is increased in cells that survive Sal treatment and resist the cytotoxic effect of Sal. Taken together; these results indicate that Akt activation may promote the resistance of cancer cells to Sal.
Palladium and Organocatalysis: An Excellent Recipe for Asymmetric Synthesis
Authors: Fernández-Ibañez M. , Maciá Beatriz , Alonso Diego , Pastor Isidro
Published: August 2013

The dual activation of simple substrates by the combination of organocatalysis and palladium catalysis has been successfully applied in a variety of different asymmetric transformations. Thus, the asymmetric a-allylation of carbonyl compounds, a-fluorination of acyl derivatives, decarboxylative protonation of β-dicarbonyl compounds, cyclization reactions of alkynyl carbonyl compounds and β-functionalization of aldehydes have been efficiently achieved employing this double-catalytic methodology.
River Discharge Estimation by Using Altimetry Data and Simplified Flood Routing Modeling
Authors: Tarpanelli Angelica , Barbetta Silvia , Brocca Luca , Moramarco Tommaso
Published: August 2013

A methodology to estimate the discharge along rivers, even poorly gauged ones, taking advantage of water level measurements derived from satellite altimetry is proposed. The procedure is based on the application of the Rating Curve Model (RCM), a simple method allowing for the estimation of the flow conditions in a river section using only water levels recorded at that site and the discharges observed at another upstream section. The European Remote-Sensing Satellite 2, ERS-2, and the Environmental Satellite, ENVISAT, altimetry data are used to provide time series of water levels needed for the application of RCM. In order to evaluate the usefulness of the approach, the results are compared with the ones obtained by applying an empirical formula that allows discharge estimation from remotely sensed hydraulic information. To test the proposed procedure, the 236 km-reach of the Po River is investigated, for which five in situ stations and four satellite tracks are available. Results show that RCM is able to appropriately represent the discharge, and its performance is better than the empirical formula, although this latter does not require upstream hydrometric data. Given its simple formal structure, the proposed approach can be conveniently utilized in ungauged sites where only the survey of the cross-section is needed.
Cognitive Radio Wireless Sensor Networks: Applications, Challenges and Research Trends
Authors: Joshi Gyanendra , Nam Seung , Kim Sung
Published: August 2013

A cognitive radio wireless sensor network is one of the candidate areas where cognitive techniques can be used for opportunistic spectrum access. Research in this area is still in its infancy, but it is progressing rapidly. The aim of this study is to classify the existing literature of this fast emerging application area of cognitive radio wireless sensor networks, highlight the key research that has already been undertaken, and indicate open problems. This paper describes the advantages of cognitive radio wireless sensor networks, the difference between ad hoc cognitive radio networks, wireless sensor networks, and cognitive radio wireless sensor networks, potential application areas of cognitive radio wireless sensor networks, challenges and research trend in cognitive radio wireless sensor networks. The sensing schemes suited for cognitive radio wireless sensor networks scenarios are discussed with an emphasis on cooperation and spectrum access methods that ensure the availability of the required QoS. Finally, this paper lists several open research challenges aimed at drawing the attention of the readers toward the important issues that need to be addressed before the vision of completely autonomous cognitive radio wireless sensor networks can be realized.
Finger Vein Recognition with Personalized Feature Selection
Authors: Xi Xiaoming , Yang Gongping , Yin Yilong , Meng Xianjing
Published: August 2013

Finger veins are a promising biometric pattern for personalized identification in terms of their advantages over existing biometrics. Based on the spatial pyramid representation and the combination of more effective information such as gray, texture and shape, this paper proposes a simple but powerful feature, called Pyramid Histograms of Gray, Texture and Orientation Gradients (PHGTOG). For a finger vein image, PHGTOG can reflect the global spatial layout and local details of gray, texture and shape. To further improve the recognition performance and reduce the computational complexity, we select a personalized subset of features from PHGTOG for each subject by using the sparse weight vector, which is trained by using LASSO and called PFS-PHGTOG. We conduct extensive experiments to demonstrate the promise of the PHGTOG and PFS-PHGTOG, experimental results on our databases show that PHGTOG outperforms the other existing features. Moreover, PFS-PHGTOG can further boost the performance in comparison with PHGTOG.
Synthesis and quantitative structure–activity relationship study of substituted imidazophosphor ester based tetrazolo[1,5-b]pyridazines as antinociceptive/anti-inflammatory agents
Authors: Abdou Wafaa M , Ganoub Neven A , Sabry Eman
Published: August 2013

A high-yielding general synthesis of imidazophosphor ester based tetrazolo[1,5-b]pyridazines is described. A conjugated reaction between 3,6-diazidopyridazine and different types of phosphonyl carbanion reagents followed by intramolecular cyclization afforded the target products, by using sodium ethanolate solution as a reaction medium. Among the products, five compounds, at a dose of 50 mg per kilogram body weight, showed a notable antinociceptive and anti-inflammatory activity without toxic side-effects.
L'ouragan Katrina, un désastre fondateur pour l'éducation publique : la réforme du système éducatif de La Nouvelle-Orléans
Authors: Sloane Amy L.
Published: August 2013

L’article traite de la logique du raisonnement sur la reconstruction de l’éducation publique après l’ouragan Katrina qui dévasta La Nouvelle-Orléans en 2005. Katrina a été vu, à travers les efforts et les débats incessants pour la reconstruction du système d’enseignement public de Louisiane, comme un moment de grande signification sociale : visibilité du racisme ancré dans tous les aspects de la vie et occasion d’une réforme majeure. En centrant l’analyse sur le raisonnement qui rend inséparables le désastre et les fondements de l’éducation, l’article permet de soulever la question de ses effets, de souligner ce qu’il met en jeu et de comprendre autrement le désastre et la refondation éducative. En puisant dans l’œuvre méthodologique d’Agamben et dans celle de Foucault, plusieurs aspects de cette inséparabilité sont étudiés : l’opportunité du changement, l’éducabilité et la qualité des enseignants, l’histoire et la communauté. L’analyse des vues contradictoires des réformateurs et de leurs critiques montre qu’ils partagent la même logique de raisonnement, celle d’un déni à déconstruire et à abandonner. L’analyse veut contribuer à suspendre ce raisonnement pour présenter une tout autre tâche éducative, celle d’unir une communauté dans le partage de ce qui n’a jamais été.
The Structure-Property-Processing Relationship for Sintered Yttria-Stabilized Zirconia (YSZ)/Alumina Bioceramics
Authors: Wang Sea-Fue , Yang Thomas Chung-Kuang , Hsu Ya-Ting , Lee Sheng-Yang , Yang Jen-Chang
Published: August 2013

The objective of this research is to study the effects of alumina addition on the microstructure-mechanical property relationship and sintering behavior of yttria (3 mol%)-stabilized zirconia (YSZ) ceramics. Well-dispersed YSZ / Al 2 O 3 ceramics containing 10–40 wt.% Al 2 O 3 were prepared by solid state reaction method. The relative density, average grain size, lattice parameters, microhardness, and fracture toughness of YSZ / Al 2 O 3 ceramics system sintered in the temperature range of 1250~1500°C as a function of Al 2 O 3 content were investigated. Experimental results showed that the ceramics with high Al 2 O 3 content and low sintering temperature tended to reveal low bulk densities. But the Al 2 O 3 content dependence on relative density for YSZ / Al 2 O 3 ceramics becomed deminishing when increasing the sintering temperature. Dense ceramics with composition of (80/20) ( YSZ / Al 2 O 3) and sintered at temperature of 1400°C and 1450°C revealed the optimal Vickers hardness and fracture toughness properties. These ceramics with high Al 2 O 3 content tended to reveal small grain sizes. The high sintering temperature governs the slow grain growth and high hardness in materials indicating the good correlation between microstructure of fabricated dense and mechanical properties.
THE EFFECTS OF IMPLANTING DIFFERENT STENTS ON THE BLOOD HEMODYNAMIC IN CORONARY ARTERIES
Authors: Sanati Alireza , Hassani Kamran , Navidbakhsh Mahdi
Published: August 2013

Stent implantation alters coronary artery hemodynamic and wall shear stress during cardiac cycles. In this study, three-dimensional models were used to analyze the effects of different stent designs and strut thicknesses on the hemodynamic of the artery. The flow was assumed to be pulsatile and stent models were expanded in the artery the same as angioplasty procedure that uses balloon. The data was applied to Fluent-ANSYS package as a UDF MATLAB code. A non-slip condition was applied to the artery walls. The pressure variation in different stents and the wall shear stress distribution were studied. Furthermore, the hemodynamic effects on the flow were investigated for two different thickness values of the same stent design. These results showed that stent implanting is one of the main parameters of pressure drop in the artery. Moreover, the surface of the stent is the location of maximum wall shear stress and the thicker stent strut did not vary this stress much. Our study implies that some design parameters such as thickness affect the hemodynamic factors of blood after stent implantation. Even stent implanting causes re-stenosis in the coronary artery. Using new real models is suggested to investigate new aspects of stent design and related effects on the hemodynamic of coronary arteries.
Visibility of the Airport Sector
Authors: Haro de Rosario Arturo , Pérez Carmen Caba , Cañadas María del Mar Sánchez
Published: August 2013

The aim of this chapter is to analyse the use of social communication media and Web 2.0 tools at airports to determine whether these technologies are being used as a means of raising the airports’ visibility, enhancing their level of e-participation and improving corporate dialogue. In addition, the authors seek to determine which variables influence the use and development of these tools. The results obtained reveal a moderate use of Web 2.0 tools by airports, with the most noteworthy finding being their presence in social networks and the use of the latter as channels through which to increase e-participation.
How to Design a Virtualized Platform?
Authors: Fernandez Valérie , Marrauld Laurie
Published: August 2013

In this chapter, the authors present the project “WITE 2.0.” This project is at the crossroads of various issues related to mobility (Urry, 2007) and use of Information and Communication Technologies. WITE 2.0 is a part of the designing process of a collaborative communication tool: “a virtualized and unified platform.” The authors define scenarios of teleworking practices, “equipped” by ICTs, and use these scenarios to better specify the platform. The project started at the end of 2010 and continued for a period of 18 months. The analysis is based on several complementary methodologies: a qualitative study (47 semi-structured interviews) and an experimentation of the platform. They present the main results of the interview survey through the following themes: remote management, skills, articulation of private and professional spheres, and the maturity of technologies. The authors also describe how these elements help the understanding of the evolution of workers’ practices.
Explaining Mobile Services Adoption between China and Developed Countries from a Cultural Perspective
Authors: Gao Shang
Published: August 2013

Little research has been done to explore the adoption of mobile information services from a cultural perspective. This research is designed to study mobile information services adoption from a cultural perspective. Based on the two cultural dimensions (individualism/collectivism, uncertainty avoidance), two research hypotheses are presented. To examine these hypotheses, an exploratory study is carried out with a mobile information service called Mobile Tourist Service Recommender (MTSR) system with both respondents from developed countries and China. According to the results, one research hypothesis is supported, while the other research hypothesis (H1) is not supported in this exploratory study. The findings indicate that the cultural dimensions play important roles in how mobile information services are used and adopted in two different cultural settings: culture in developed countries and the Chinese culture. The results also highlight the relevance of the cultural dimensions (individualism/collectivism, uncertainty avoidance) as the factors affecting the adoption of mobile information services.
Telepresence, Flow, and Behaviour in the Virtual Retail Environment
Authors: Ettis Saïd
Published: August 2013

Flow theory, as a basis to facilitate the development of compelling experiences, has received growing attention over the past two decades. Facing this plethora of interest, it is obvious that telepresence and flow in human-computer interactions are important issues. The objectives of this chapter is to review and empirically analyze the relationships among flow theory, the telepresence concept, and online behaviour. Particularly, this research investigates the impact of telepresence and flow on Websites visitors’ visit time, perceived visit time, and number of visited pages. An online survey was conducted. The findings indicate that telepresence has a positive effect on the flow state, as measured by concentration and enjoyment. The consumers’ level of concentration positively influenced their visit time, perceived visit time, and number of visited pages. Enjoyment has a positive effect on perceived visit time, but no significant effect on actual visit time and number of visited pages. Discussion and implications of these results are exhibited. Suggestions concerning future research are also presented.
Economy Based Resource Allocation in IaaS Cloud
Authors: Mehta Hemant Kumar , Gupta Eshan
Published: August 2013

Infrastructure as a Service (IaaS) offers hardware resources (computing power, storage and network) as a service to its customers. The customers order these resources in the form of a lease. Aim of any service provider is to make a leasing plan to maximize the number of accepted leases. Opennebula is popular open source toolkit for building IaaS cloud. Opennebula has its own lease manager and it can also be integrated with Haizea which is an open source lease manager. An economy based algorithm should focus on incentives of both the consumers and the providers. In this paper, an economy based leasing algorithm is developed and integrated with Haizea. This economy based algorithm takes care of incentives of both the parties i.e. customer and service provider. It uses the concept of optimization techniques to optimize the costs. The incentive for customers is lower cost of execution of its lease on the capable node as compare to existing non-economy based algorithms. If an appropriate resource is not found, then the algorithm uses negotiation on budget and resource demand; that increases the number of accepted lease. Thus, incentive for providers is an increase in profit as the amount of accepted leases increase. Experimental results show that the proposed economy based leasing algorithm reduces the cost of execution of the consumer’s lease and increases the profit of the provider to a considerable extent.
A Value Based Dynamic Resource Provisioning Model in Cloud
Authors: Sood Sandeep K.
Published: August 2013

Cloud computing has become an innovative computing paradigm, which aims at providing reliable, customized, Quality of Service (QoS) and guaranteed computing infrastructures for users. Efficient resource provisioning is required in cloud for effective resource utilization. For resource provisioning, cloud provides virtualized computing resources that are dynamically scalable. This property of cloud differentiates it from the traditional computing paradigm. But the initialization of a new virtual instance causes a several minutes delay in the hardware resource allocation. Furthermore, cloud provides a fault tolerant service to its clients using the virtualization. But, in order to attain higher resource utilization over this technology, a technique or a strategy is needed using which virtual machines can be deployed over physical machines by predicting its need in advance so that the delay can be avoided. To address these issues, a value based prediction model in this paper is proposed for resource provisioning in which a resource manager is used for dynamically allocating or releasing a virtual machine depending upon the resource usage rate. In order to know the recent resource usage rate, the resource manager uses sliding window to analyze the resource usage rate and to predict the system behavior in advance. By predicting the resource requirements in advance, a lot of processing time can be saved. Earlier, a server has to perform all the calculations regarding the resource usage that in turn wastes a lot of processing power thus decreasing its overall capacity to handle the incoming request. The main feature of the proposed model is that a lot of load is being shifted from the individual server to the resource manager as it performs all the calculations and therefore the server is free to handle the incoming requests to its full capacity.
From Military Threats to Everyday Fear
Authors: Huhtinen Aki-Mauri
Published: August 2013

The history of combat is primarily the history of radically changing fields of perception. In other words, war consists not so much of scoring territorial, economic or other material victories but of appropriating the immateriality of perceptual field. The function of the eye has become the function of the weapons (Virilio, 1989; 2009). To understand information age warfare we have to understand the concept of representation as a part of our process of violence. The idea of information warfare or an information operation is based on the process where the physical target is no longer destroyed with the kinetic systems, but the process where the non-kinetic systems, like information, scan the symbols-semiotics networks. We like to consume safety different kind of fears. The feeling of the safety fear based on the virtual boundaries, which are set in the movement from “principle” to “practice, in other words in the actualization of the cyber-form. The power of fear is not a form. It is not abstract. It is the movement of form into the content outside of which it is a void of potential function, of the abstract into the particular it cannot be or do without. (see Massumi 1993, 20-21) Today, particularly the advanced mobile technology, the Internet and the entertainment industry immensely exploit the experiences from different wars and conflicts for example as ideas of computer games. In return the military industrial complex represents its own language for example in the concept of information operations with the help of applications particularly rising from the entertainment industry. The roles of Hector and Achilles, the teachings of Jomini and Clausewitz have an effect in the background of games and gaming. Opposite to Clauseiwitz’s thinking, Jomini took the view that the amount of force deployed should be kept to the minimum in order to lower casualties and that war was a science, not an art. The most central genres in gaming are ”strategy”, ”adventure”, ”shooter”, ”sports”, ”simulation”, ”music”, ”role playing” and ”puzzle”. All of these are related to warfare one way or another. Another interesting fact is that in the 1950’s the first computer games were mathematic strategy based games that that had been developed in universities (Czosseck, 2009; Peltoniemi, 2009).
The Comprehensive Approach as a Strategic Design to Run the Military-Industrial Complex in Operations
Authors: Salminen Mirva , Huhtinen Aki-Mauri
Published: August 2013

How to steer military actions that are concurrent both in the real world and in virtual networks? After the great wars of the 20th century and the Cold War with the threat of nuclear warfare, the information revolution, as well as the emergence of new wars and global threats, has led to an increasingly complex security space of the 21st century. A corner of this space is occupied by private military and security contractors that have been introduced to the wide public as previously undetected actors operating in conflict zones. These developments have required the re-thinking of military organisation, planning and conduct. This article scrutinises the basic principle and key concepts of a new western politico-strategic level military planning model called the Comprehensive Approach. It is a Wikileaks type of open door policy: everyone operating in the same real space can participate in the shared virtual planning space. The model’s usability in the new military atmosphere is under theoretical scrutiny. Challenges that the open planning creates to the military organisation are highlighted.
Simulation and ABC to Improve the Performance of Emergency Department
Authors: Al-Refaie Abbas , Shurrab Mohammed , Li Ming-Hsien
Published: August 2013

This study aims at developing an Activity Based Costing (ABC) for the Emergency Department (ED) in a Jordanian hospital to determine associated costs and clarifies the financial practices inside ED rooms. For this purpose, simulation model is built for patients at the current ED activities and determine the costs for each room in ED. The total costs (JD), number of served patients, and profits (JD) are 263562, 10256, and 146677, respectively. Improvement is suggested by studying three three-level controllable factors using simulation. It is noted that focusing on the lowest total costs, B-1 (adding two beds with one added nurse) and B-2 (introducing four beds with two added nurses) provide the two smallest total costs (JD) of 252568 and 253320, respectively. Whereas, for the largest number of served patients is achieved by A-1 (assigning one sharing doctor for Abdominal) and C-1 (adding another room for abdominal with new doctor) of equal number of served patients of 10466. In order to combine these two performance measures, the profit associated with each scenario is considered. It is found that factor A-1 provides the largest profit (= 150,390 JD). The results of this research may provide decision makers valuable cost information that helps them in improving ED performance.
Anti Fuzzy Deductive Systems of BL-Algebras
Authors: Tchikapa Cyrille Nganteu
Published: August 2013

The aim of this paper is to introduce the notion of anti fuzzy (prime) deductive system in BL-algebra and to investigate their properties. It is shown that the set of all deductive systems (with the empty set) of a BL-algebra X is equipotent to a quotient of the set of all anti fuzzy deductive systems of X. The anti fuzzy prime deductive system theorem of BL-algebras is also proved.
Android Permission System Violation
Authors: Han Kyoung Soo , Lee Yeoreum , Jiang Biao , Im Eul Gyu
Published: August 2013

Android uses permissions for application security management. Android also allows inter-application communication (IAC), which enables cooperation between different applications to perform complex tasks by using some components and Intents. In other words, Android provides more flexibility and places less restriction on application development. This is a major feature that differentiates Android from its competitors. However, IAC also facilitates malicious applications that can collude in attacks of privilege escalation. In this paper, the authors demonstrate with case studies that all IAC channels can potentially be utilized for privilege escalation attacks, and the authors propose a refinement to solve this problem by enforcing IAC permissions and exposing IAC to users.
An Evaluation of Older Adults Use of iPads in Eleven UK Care-Homes
Authors: Jones Tim , Kay Daniel , Upton Penney , Upton Dominic
Published: August 2013

The introduction of the iPad and similar form-factor devices (e.g. Samsung Galaxy Tab, Asus Eee Pad and Motorola Xoom) has provided a unique opportunity for older adults to engage with mobile computing devices and platforms. Engagement with ‘traditional’ computing devices amongst older adults, including arguably mobile devices, such as laptop computers is low due to dexterity issues amongst this population (Hertzum & Hornbaek, 2010). Whilst the iPad removes some of the traditional barriers to computer engagement, new barriers including weight and screen reflection are evident to an older user group. This paper provides an exploratory evaluation of how older adults in 11 UK care-home settings and the staff engaged in their care are using iPads to help improve communication, build physical social networks amongst residents, staff and family members, and map the most frequently used applications by an older population during a six-month pilot period. Results suggest that applications involving information searching for personally related and historical information were most valued by older adults. Further, older adults and care staff alike report mainly positive experiences of iPad use in care settings including the increased opportunities for social interaction and the enhancement of intergenerational communication. Additionally, the barriers to use (e.g. device weight) are often overcome by low-tech adaptations and adjustment when using the device. This paper argues that the portability and adaptive nature of the iPad combined with the increased social interaction afforded by device could increase quality of life in care settings.
The Misuse of Spreadsheets in the Nuclear Fuel Industry
Authors: Thorne Simon
Published: August 2013

This paper considers the management, technological and human factor issues that led to the BNFL fuel rod spreadsheet data falsification incident in 1999. BNFL discovered in 1999 that some data supporting quality assurance and safety processes had been falsified by BNFL workers using spreadsheets. The implication of this finding was that some of the Mixed Oxide Fuel Pellets shipped to customers in Japan for use in nuclear reactors were of an unknown mass and quality. This meant that the use of the MOX pellets fuel produced by BNFL would introduce uncontrolled factors into the safe operation of nuclear reactors. This paper will examine the production of MOX pellets at the Sellafield site, the falsification of data and the report commissioned by HM Nuclear Inspectorate. The paper will then identify a number of managerial and technological failings that led BNFL to use spreadsheets for recording such data. Finally the paper analyses other cases of spreadsheet fraud and explores some strategies for reducing the likelihood and impact of spreadsheet errors and fraud.
Apoptosis-Associated Speck–like Protein Containing a Caspase Recruitment Domain Inflammasomes Mediate IL-1β Response and Host Resistance to Trypanosoma cruzi Infection
Authors: Silva Grace Kelly , Costa Renata Sesti , Silveira Tatiana Nunes , Caetano Braulia Costa , Horta Catarina Veltrini , Gutierrez Fredy Roberto Salazar , Guedes Paulo Marcos da Matta , Andrade Warrison Athanásio , De Niz Mariana , Gazzinelli Ricardo Tostes , Zamboni Dario Simões , Silva João Santana
Published: August 2013

The innate immune response to Trypanosoma cruzi infection comprises several pattern recognition receptors (PRRs), including TLR-2, -4, -7, and -9, as well as the cytosolic receptor Nod1. However, there are additional PRRs that account for the host immune responses to T. cruzi. In this context, the nucleotide-binding oligomerization domain–like receptors (NLRs) that activate the inflammasomes are candidate receptors that deserve renewed investigation. Following pathogen infection, NLRs form large molecular platforms, termed inflammasomes, which activate caspase-1 and induce the production of active IL-1β and IL-18. In this study, we evaluated the involvement of inflammasomes in T. cruzi infection and demonstrated that apoptosis-associated speck–like protein containing a caspase recruitment domain (ASC) inflammasomes, including NLR family, pyrin domain–containing 3 (NLRP3), but not NLR family, caspase recruitment domain–containing 4 or NLR family, pyrin domain–containing 6, are required for triggering the activation of caspase-1 and the secretion of IL-1β. The mechanism by which T. cruzi mediates the activation of the ASC/NLRP3 pathway involves K+ efflux, lysosomal acidification, reactive oxygen species generation, and lysosomal damage. We also demonstrate that despite normal IFN-γ production in the heart, ASC−/− and caspase-1−/− infected mice exhibit a higher incidence of mortality, cardiac parasitism, and heart inflammation. These data suggest that ASC inflammasomes are critical determinants of host resistance to infection with T. cruzi.
Transcriptional Regulation of IL-15 Expression during Hematopoiesis
Authors: Colpitts Sara L. , Stonier Spencer W. , Stoklasek Thomas A. , Root Sierra H. , Aguila Hector Leonardo , Schluns Kimberly S. , Lefrançois Leo
Published: August 2013

Dendritic cells (DCs) are the most commonly studied source of the cytokine IL-15. Using an IL-15 reporter transgenic mouse, we have recently shown previously unappreciated differences in the levels of IL-15 expressed by subsets of conventional DCs (CD8+ and CD8−). In this study, we show that IL-15 promoter activity was differentially regulated in subsets of hematopoietically derived cells with IL-15 expression largely limited to myeloid lineages. In contrast, mature cells of the lymphoid lineages expressed little to no IL-15 activity. Surprisingly, we discovered that hematopoietic stem cells (lineage−Sca-1+c-Kit+) expressed high levels of IL-15, suggesting that IL-15 expression was extinguished during lymphoid development. In the case of T cells, this downregulation was Notch-dependent and occurred in a stepwise pattern coincident with increasing maturation and commitment to a T cell fate. Finally, we further demonstrate that IL-15 expression was also controlled throughout DC development, with key regulatory activity of IL-15 production occurring at the pre-DC branch point, leading to the generation of both IL-15+CD8+ and IL-15−/lowCD8− DC subsets. Thus, IL-15 expression is coordinated with cellular fate in myeloid versus lymphoid immune cells.
On the Comaximal Graph of a Commutative Ring
Authors: Samei Karim
Published: August 2013

Let R be a commutative ring with 1. In a 1995 paper in J. Algebra, Sharma and Bhatwadekar defined a graph on R, Γ(R), with vertices as elements of R, where two distinct vertices a and b are adjacent if and only if Ra + Rb = R. In this paper, we consider a subgraph Γ2(R) of Γ(R) that consists of non-unit elements. We investigate the behavior of Γ2(R) and Γ2(R)\J(R), where J(R) is the Jacobson radical of R. We associate the ring properties of R, the graph properties of Γ(R), and the topological properties of Max(R). Diameter, girth, cycles and dominating sets are investigated, and algebraic and topological characterizations are given for graphical properties of these graphs.
High abundances of water-soluble dicarboxylic acids, ketocarboxylic acids and α-dicarbonyls in the mountaintop aerosols over the North China Plain during wheat burning season
Authors: Kawamura K. , Tachibana E. , Okuzawa K. , Aggarwal S. G. , Kanaya Y. , Wang Z. F.
Published: August 2013

Abstract. Aerosol (TSP) samples were collected at the summit of Mount Tai (elevation: 1534 m a.s.l., 36.25° N, 117.10° E) located in the North China Plain using a high-volume air sampler and pre-combusted quartz filters. Sampling was conducted on day/night or 3 h basis in the period from 29 May to 28 June 2006 during the field burning of wheat straw residue and the post-burning season. The filter samples were analyzed for low-molecular-weight dicarboxylic acids, ketoacids and α-dicarbonyls using capillary gas chromatography (GC) and GC-MS employing water extraction and butyl ester derivatization. Molecular distributions of dicarboxylic acids (C2-C11, 220–6070 ng m−3) were characterized by a predominance of oxalic (C2) acid (105–3920 ng m−3) followed by succinic (C4) or malonic (C3) acid. Unsaturated aliphatic diacids, including maleic (M), isomaleic (iM) and fumaric (F) acids, were also detected together with aromatic diacids (phthalic, isophthalic and terephthalic acids). ω-oxocarboxylic acids (C2-C9, 24–610 ng m−3) were detected as the second most abundant compound class with the predominance of glyoxylic acid (11–360 ng m−3), followed by α-ketoacid (pyruvic acid, 3–140 ng m−3) and α-dicarbonyls (glyoxal, 1–230 ng m−3 and methylglyoxal, 2–120 ng m−3). We found that these levels (>6000 ng m−3 for diacids) are several times higher than those reported in Chinese megacities at ground levels. The concentrations of diacids increased from late May to early June, showing a maximum on 7 June, and then significantly decreased during the period 8–11 June, when the wind direction shifted from southerly to northerly. Similar temporal trends were found for ketocarboxylic acids and α-dicarbonyls as well as total carbon (TC) and water-soluble organic carbon (WSOC). The temporal variations of water-soluble organics were interpreted by the direct emission from the field burning of agricultural wastes (wheat straw) in the North China Plain and the subsequent photochemical oxidation of volatile and semi-volatile organic precursors emitted from field burning as well as dark ozonolysis of volatile organic compounds and other organics, accretion reactions and oxidation of nonvolatile organics such as unsaturated fatty acids. This study demonstrates that the field burning of agricultural wastes in early summer strongly influenced the air quality of the free troposphere over the North China Plain.
Quantitative evaluation of emission controls on primary and secondary organic aerosol sources during Beijing 2008 Olympics
Authors: Guo S. , Hu M. , Guo Q. , Zhang X. , Schauer J. J. , Zhang R.
Published: August 2013

Abstract. To assess the primary and secondary sources of fine organic aerosols after the aggressive implementation of air pollution controls during the 2008 Beijing Olympic Games, 12 h PM2.5 values were measured at an urban site at Peking University (PKU) and an upwind rural site at Yufa during the CAREBEIJING-2008 (Campaigns of Air quality REsearch in BEIJING and surrounding region) summer field campaign. The average PM2.5 concentrations were 72.5 ± 43.6 μg m−3 and 64.3 ± 36.2 μg m−3 (average ± standard deviation, below as the same) at PKU and Yufa, respectively, showing the lowest concentrations in recent years. Combining the results from a CMB (chemical mass balance) model and secondary organic aerosol (SOA) tracer-yield model, five primary and four secondary fine organic aerosol sources were compared with the results from previous studies in Beijing. The relative contribution of mobile sources to PM2.5 concentrations was increased in 2008, with diesel engines contributing 16.2 ± 5.9% and 14.5 ± 4.1% and gasoline vehicles contributing 10.3 ± 8.7% and 7.9 ± 6.2% to organic carbon (OC) at PKU and Yufa, respectively. Due to the implementation of emission controls, the absolute OC concentrations from primary sources were reduced during the Olympics, and the contributions from secondary formation of OC represented a larger relative source of fine organic aerosols. Compared with the non-controlled period prior to the Olympics, primary vehicle contributions were reduced by 30% at the urban site and 24% at the rural site. The reductions in coal combustion contributions were 57% at PKU and 7% at Yufa. Our results demonstrate that the emission control measures implemented in 2008 significantly alleviated the primary organic particle pollution in and around Beijing. However, additional studies are needed to provide a more comprehensive assessment of the emission control effectiveness on SOA formation.
Pauci ex tanto numero: reduce redundancy in multi-model ensembles
Authors: Solazzo E. , Riccio A. , Kioutsioukis I. , Galmarini S.
Published: August 2013

Abstract. We explicitly address the fundamental issue of member diversity in multi-model ensembles. To date, no attempts in this direction have been documented within the air quality (AQ) community despite the extensive use of ensembles in this field. Common biases and redundancy are the two issues directly deriving from lack of independence, undermining the significance of a multi-model ensemble, and are the subject of this study. Shared, dependant biases among models do not cancel out but will instead determine a biased ensemble. Redundancy derives from having too large a portion of common variance among the members of the ensemble, producing overconfidence in the predictions and underestimation of the uncertainty. The two issues of common biases and redundancy are analysed in detail using the AQMEII ensemble of AQ model results for four air pollutants in two European regions. We show that models share large portions of bias and variance, extending well beyond those induced by common inputs. We make use of several techniques to further show that subsets of models can explain the same amount of variance as the full ensemble with the advantage of being poorly correlated. Selecting the members for generating skilful, non-redundant ensembles from such subsets proved, however, non-trivial. We propose and discuss various methods of member selection and rate the ensemble performance they produce. In most cases, the full ensemble is outscored by the reduced ones. We conclude that, although independence of outputs may not always guarantee enhancement of scores (but this depends upon the skill being investigated), we discourage selecting the members of the ensemble simply on the basis of scores; that is, independence and skills need to be considered disjointly.
The cloud–aerosol–radiation (CAR) ensemble modeling system
Authors: Liang X.-Z. , Zhang F.
Published: August 2013

Abstract. A cloud–aerosol–radiation (CAR) ensemble modeling system has been developed to incorporate the largest choices of alternate parameterizations for cloud properties (cover, water, radius, optics, geometry), aerosol properties (type, profile, optics), radiation transfers (solar, infrared), and their interactions. These schemes form the most comprehensive collection currently available in the literature, including those used by the world's leading general circulation models (GCMs). CAR provides a unique framework to determine (via intercomparison across all schemes), reduce (via optimized ensemble simulations), and attribute specific key factors for (via physical process sensitivity analyses) the model discrepancies and uncertainties in representing greenhouse gas, aerosol, and cloud radiative forcing effects. This study presents a general description of the CAR system and illustrates its capabilities for climate modeling applications, especially in the context of estimating climate sensitivity and uncertainty range caused by cloud–aerosol–radiation interactions. For demonstration purposes, the evaluation is based on several CAR standalone and coupled climate model experiments, each comparing a limited subset of the full system ensemble with up to 896 members. It is shown that the quantification of radiative forcings and climate impacts strongly depends on the choices of the cloud, aerosol, and radiation schemes. The prevailing schemes used in current GCMs are likely insufficient in variety and physically biased in a significant way. There exists large room for improvement by optimally combining radiation transfer with cloud property schemes.
Evaluation of spatio-temporal variability of Hamburg Aerosol Climatology against aerosol datasets from MODIS and CALIOP
Authors: Pappas V. , Hatzianastassiou N. , Papadimas C. , Matsoukas C. , Kinne S. , Vardavas I.
Published: August 2013

Abstract. The new global aerosol climatology named HAC (Hamburg Aerosol Climatology) is compared against MODIS (Collection 5, 2000–2007) and CALIOP (Level 2-version 3, 2006–2011) retrievals. The comparison of aerosol optical depth (AOD) from HAC against MODIS shows larger HAC AOD values over regions with higher aerosol loads and smaller HAC AOD values than MODIS for regions with lower loads. The HAC data are found to be more reliable over land and for low AOD values. The largest differences between HAC and MODIS occur from March to August for the Northern Hemisphere and from September to February for the Southern Hemisphere. In addition, both the spectral variability and vertical distribution of the HAC AOD are examined at selected AERONET (1998–2007) sites, representative of main aerosol types (pollutants, sea salt, biomass and dust). Based on comparisons against spectral AOD values from AERONET, the mean absolute percentage error in HAC AOD data is 25% at ultraviolet wavelengths (400 nm), 6–12% at visible and 18% at near-infrared (1000 nm). For the same AERONET sites, the HAC AOD vertical distribution is compared against CALIOP space lidar data. On a daily average basis, HAD AOD is less by 9% in the lowest 3 km than CALIOP values, especially for sites with biomass burning smoke, desert dust and sea salt spray. Above the boundary layer, the HAC AOD vertical distribution is reliable.
Interpreting SBUV smoothing errors: an example using the quasi-biennial oscillation
Authors: Kramarova N. A. , Bhartia P. K. , Frith S. M. , McPeters R. D. , Stolarski R. S.
Published: August 2013

Abstract. The Solar Backscattered Ultraviolet (SBUV) observing system consists of a series of instruments that have been measuring both total ozone and the ozone profile since 1970. SBUV measures the profile in the upper stratosphere with a resolution that is adequate to resolve most of the important features of that region. In the lower stratosphere the limited vertical resolution of the SBUV system means that there are components of the profile variability that SBUV cannot measure. The smoothing error, as defined in the optimal estimation retrieval method, describes the components of the profile variability that the SBUV observing system cannot measure. In this paper we provide a simple visual interpretation of the SBUV smoothing error by comparing SBUV ozone anomalies in the lower tropical stratosphere associated with the quasi-biennial oscillation (QBO) to anomalies obtained from the Aura Microwave Limb Sounder (MLS). We describe a methodology for estimating the SBUV smoothing error for monthly zonal mean (mzm) profiles. We construct covariance matrices that describe the statistics of the inter-annual ozone variability using a 6 yr record of Aura MLS and ozonesonde data. We find that the smoothing error is of the order of 1% between 10 and 1 hPa, increasing up to 15–20% in the troposphere and up to 5% in the mesosphere. The smoothing error for total ozone columns is small, mostly less than 0.5%. We demonstrate that by merging the partial ozone columns from several layers in the lower stratosphere/troposphere into one thick layer, we can minimize the smoothing error. We recommend using the following layer combinations to reduce the smoothing error to about 1%: surface to 25 hPa (16 hPa) outside (inside) of the narrow equatorial zone 20° S–20° N.
Two fast temperature sensors for probing of the atmospheric boundary layer using small remotely piloted aircraft (RPA)
Authors: Wildmann N. , Mauz M. , Bange J.
Published: August 2013

Abstract. Two types of temperature sensors are designed and tested: a thermocouple and a fine wire resistance thermometer. The intention of this study is to figure out which kind of measurement principle is in general more suited for atmospheric boundary layer meteorology with small remotely piloted aircraft (RPA). The sensors are calibrated in a NIST traceable climate chamber and validated in flight against tower measurements, radiosondes and remote sensing. The sensors have a measurement range of at least −10–50 °C, an absolute RMS error of less than ±0.2 K which is stable over the lifetime of the sensors, and a resolution of about 0.01 K. Both devices are tested for typical errors like radiation error and adiabatic heating, as well as for their dynamic response. Spectral resolutions of up to approximately 10 Hz can be obtained with both sensors, which makes them suitable for turbulence measurement. Their low cost of less than 100 EUR in pure hardware is a major advantage for research with small RPA.