bluuebunny/crossref_metadata_2025 huggingface dataset:
Robust output stabilization: Improving performance via supervisory control
Authors: Efimov D. , Loria A. , Panteley E.
Published: November 2010

We analyze robust stability, in an input–output sense, of switched systems. The primary goal (and contribution) of this paper is to design switching strategies to guarantee that input–output stable systems remain so under switching. We propose two types ofsupervisors: dwell‐time and hysteresis based. While our results are stated as tools of analysis they serve a clear purpose in design: to improve performance by appropriately switching among given stabilizing controllers with different performance features. Copyright © 2010 John Wiley & Sons, Ltd.
ISS feedback control redesign for continuous stirred tank reactors
Authors: Pepe Pierdomenico , Di Ciccio Maria Paola
Published: November 2010

In this paper a new nonlinear feedback control law for continuous stirred tank reactors, obtained by exact Input/Output (I/O) linearization and Sontag's input‐to‐state stability feedback control redesign methods, is studied. By the new feedback control law, a significant attenuation of the disturbance effect is guaranteed, with evident improvement with respect to control laws obtained by the exact I/O linearization method. The performed simulations validate the theoretical results. Copyright © 2010 John Wiley & Sons, Ltd.
Integrating distributed work: comparing task design, communication, and tacit coordination mechanisms
Authors: Srikanth Kannan , Puranam Phanish
Published: November 2010

We investigate coordination strategies in integrating distributed work. In the context of Business Process Offshoring (BPO), we analyze survey data from 126 offshored processes to understand both the sources of difficulty in integrating distributed work as well as how organizations overcome these difficulties. We find that interdependence between offshored and onshore processes can lower offshored process performance, and investing in coordination mechanisms can ameliorate the performance impact of interdependence. In particular, we outline a distinctive set of coordination mechanisms that rely on tacit coordination—and theoretically articulate and empirically show that tacit coordination mechanisms are distinct from the well‐known duo of coordination strategies: building communication channels or modularizing processes to minimize the need for communication. We discuss implications for the study of coordination in organizations. Copyright © 2010 John Wiley & Sons, Ltd.
The effects of board human and social capital on investor reactions to new CEO selection
Authors: Tian Jie (Jenny) , Haleblian Jerayr (John) , Rajagopalan Nandini
Published: November 2010

This study extends work on independent directors to examine the influence of their human capital and social capital on investor reactions to the board's CEO selection decision. We predict that human capital, as represented by the board's CEO experience and industry experience, and social capital, as represented by directors' co‐working experience on the board and external directorship ties to other corporate boards, will influence the stock market reactions to new CEO appointments. In a sample of 208 new CEO appointment events in U.S. manufacturing firms between 1999 and 2003, we found that the stock market reacted favorably to the appointments made by boards with higher levels of human and social capital. We also found that the effect of internal social capital was stronger when the new CEO was an insider rather than an outsider. The implications of the results for director selection and CEO succession are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Global equity offerings, corporate valuation, and subsequent international diversification
Authors: Hasan Iftekhar , Kobeissi Nada , Wang Haizhi
Published: November 2010

Researchers have long wondered why U.S. firms offer their equity in multiple global capital markets even though they have access to a deep domestic capital market. Based on a propensity score‐matching sample of IPOs for U.S. firms from 1990 to 2003, this paper offers some potential answers. We find strong evidence that issuers who choose global equity offerings experience higher valuations at the IPO stage, as measured by Tobin's q. Our evidence also shows that global equity offerings serve as a deliberate strategic tool to increase issuers' international visibility and their propensity to diversify operationally to international markets. Copyright © 2010 John Wiley & Sons, Ltd.
Epithelial-Connective Tissue Interactions Induced by Thyroid Hormone Receptor Are Essential for Adult Stem Cell Development in the Xenopus laevis Intestine
Authors: Hasebe Takashi , Buchholz Daniel R. , Shi Yun-Bo , Ishizuya-Oka Atsuko
Published: November 2010

In the amphibian intestine during metamorphosis, stem cells appear and generate the adult absorptive epithelium, analogous to the mammalian one, under the control of thyroid hormone (TH). We have previously shown that the adult stem cells originate from differentiated larval epithelial cells in the Xenopus laevis intestine. To clarify whether TH signaling in the epithelium alone is sufficient for inducing the stem cells, we have now performed tissue recombinant culture experiments using transgenic X. laevis tadpoles that express a dominant-positive TH receptor (dpTR) under a control of heat shock promoter. Wild-type (Wt) or dpTR transgenic (Tg) larval epithelium (Ep) was isolated from the tadpole intestine, recombined with homologous or heterologous nonepithelial tissues (non-Ep), and then cultivated in the absence of TH with daily heat shocks to induce transgenic dpTR expression. Adult epithelial progenitor cells expressing sonic hedgehog became detectable on day 5 in both the recombinant intestine of Tg Ep and Tg non-Ep (Tg/Tg) and that of Tg Ep and Wt non-Ep (Tg/Wt). However, in Tg/Wt intestine, they did not express other stem cell markers such as Musashi-1 and never generated the adult epithelium expressing a marker for absorptive epithelial cells. Our results indicate that, while it is unclear why some larval epithelial cells dedifferentiate into adult progenitor/stem cells, TR-mediated gene expression in the surrounding tissues other than the epithelium is required for them to develop into adult stem cells, suggesting the importance of TH-inducible epithelial-connective tissue interactions in establishment of the stem cell niche in the amphibian intestine.
Seismic nonlinear static new method of spatial asymmetric multi‐storey reinforced concrete buildings
Authors: Makarios Triantafyllos K.
Published: November 2010

In order to obtain the seismic demands of spatial asymmetric multi‐storey reinforced concrete (r/c) buildings, a new seismic nonlinear static (pushover) procedure that uses inelastic response acceleration spectra is presented in this paper. The latter makes use of the optimum equivalent nonlinear single degree of freedom system, which is used to represent the general spatial asymmetric multi‐storey r/c building. For each asymmetric multi‐storey building, a total of 12 suitable nonlinear static analyses are needed according to the new proposed procedure, whereas at least 96 suitable nonlinear dynamic analyses are required in the case of nonlinear response history analysis (NLRHA), respectively. In addition, the present paper provides answers to a series of further questions with reference to the spatial action of the two horizontal seismic components in the static nonlinear (pushover) analyses, as well as to the documented calculation of the available behaviour factor of the asymmetric multi‐storey r/c building. According to the paper, this new proposed seismic nonlinear static procedure is a natural extension of the documented equivalent seismic static linear (simplified spectral) method that is recommended by the established contemporary seismic codes, with reference to torsional provisions. Finally, through a restricted parametric analysis carried out in this paper, a relevant numerical example of a two‐storey r/c building is presented for illustration purposes, where the seismic demand floor inelastic displacements are compared with the respective displacements obtained by the NLRHA. Consequently, the new proposed seismic nonlinear static procedure, which uses inelastic response acceleration spectra, can reliably evaluate the extreme values of floor inelastic displacements (on the flexible and stiff side of the building), as is shown by the above comparisons. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of stress levels applied to pre‐stressing strands on post‐tensioned beam‐to‐column connections
Authors: Kaya Mustafa , Arslan A. Samet
Published: November 2010

This article presents an experiment study on precast beam‐to‐column connections with 15.24 mm diameter pre‐stressing strands. Stress levels of 40%, 50% and 60% tensile stress were applied to the pre‐stressing strands. Following the experiments, precast specimens were compared with those of the reference specimen. The load capacity of the precast specimen stressed at the level of 60% tensile stress reached 98% of the load capacity of the reference specimen, and the amount of energy dissipated by the same specimen reached 48% of that dissipated by the reference specimen. The stiffness of the same precast specimen at 1.5% drift was observed to be 71% of the reference specimen at the same drift. In the experimental studies, it was seen that the maximum stress determined in this specimen, which pre‐stressing strands provide connection, reached approximately 75% of the tensile strength of the pre‐stressing strands. It could not be said that topping concrete in experiment specimens increased strength. Copyright © 2010 John Wiley & Sons, Ltd.
On the dynamics of a very slender building under winds: response reduction using MR dampers with lever mechanism
Authors: Aly Aly Mousaad , Zasso Alberto , Resta Ferruccio
Published: November 2010

This paper presents wind‐induced response reduction in a very slender building using magneto‐rheological (MR) dampers with lever mechanism. The building presents a case study of an engineered design that is instructive. The paper shows that shear response and flexural response of tall buildings present two very different cases for vibration suppression. MR dampers are implemented optimally in the building to reduce its response in the lateral directions for both structural safety and occupant comfort concerns. A proposed lever mechanism is used with the dampers to improve their performance. The study shows how a lever mechanism can enable application to flexural response and scenarios where the inter‐story drift is not enough for dampers to work effectively. Furthermore, the decentralized bang‐bang controller produced additional improvement to the performance of the MR dampers. Copyright © 2010 John Wiley & Sons, Ltd.
Beam‐attached steel plate shear walls
Authors: Pirmoz Akbar
Published: November 2010

Connecting to their surrounding beams and columns, unstiffened steel plate shear walls (SPSWs) are widely used as an appropriate lateral resisting system for designing and retrofitting of structures against lateral loads. The base philosophy for the performance of such systems, post‐buckling tension field formation, needs strong enough boundary elements to form. However, in some cases, relatively low performance demand needs panels with impractical thickness. To overcome the construction limitations, the designer is forced to use thicker plates, and consequently to satisfy the post‐buckling tension field philosophy, heavier column sections must be used. A novel configuration of steel shear walls, beam‐attached SPSWs, in which the size of the column section is released to be as a function of the plate thickness and removes the wasteful need for heavy columns, is proposed in this paper. Copyright © 2010 John Wiley & Sons, Ltd.
Nanostructure control in polymer solar cells by self‐organization
Authors: Tajima Keisuke , Hashimoto Kazuhito
Published: November 2010

Recently, polymer solar cells (PSCs) based on “bulk heterojunctions” using a simple mixture of electron donor and acceptor materials in thin films have been extensively studied. Although relatively high power conversion efficiencies have been achieved by using this approach, further improvement is necessary to precisely construct stable, reproducible nanostructures that are suitable for both efficient charge separation and transport inside such films. For this purpose, it is highly desirable to utilize a bottom‐up approach, such as the self‐organized formation of inorganic and organic nanostructures. In this review, an overview of our recent studies on the control of nanostructures in PSCs is presented. DOI 10.1002/tcr.201000015
Energy equilibrium based on corona structure for wireless sensor networks
Authors: Lin Kai , Chen Min
Published: November 2010

Although multi‐hop routing can reduce communication consumption and extend network scale, energy hole is unavoidable to appear because of the relay nodes being overloaded due to take more tasks. In this paper, we formulate the energy equilibrium problem as an optimal corona division, where data fusion and data slice are both considered in data gathering process. For a circular multi‐hop sensor network with uniform node distribution and constant data reporting, we demonstrate that the energy equilibrium of the whole network is unable to be realized no matter whether data fusion and data slice are adopted. However, the maximum energy equilibrium for a given circular area can be achieved only if the area increases in geometric progression from the outer corona to the neighbor inner corona except for the outermost one. Moreover, we use a zone‐based allocation scheme to guarantee energy equilibrium of intra‐corona. The approach for computing the optimal parameters is presented in terms of maximizing network lifetime. Based on the mathematical model, we propose an energy equilibrium routing based on corona structure (EERCS). Simulating results validate that EERCS can effectively achieve energy equilibrium and prolong the lifetime of network. Copyright © 2010 John Wiley & Sons, Ltd.
Interleave‐division multiple access (IDMA) using low‐rate layered LDGM codes
Authors: Vázquez‐Araújo Francisco J. , González‐López Miguel , Castedo Luis , Garcia‐Frias Javier
Published: November 2010

We propose the use of low‐rate layered serially concatenated low‐density generator matrix (SCLDGM) codes in interleave‐division multiple access (IDMA) systems to approach the multiuser capacity. We study the behavior of the soft interference cancellation (SIC) detector employed in IDMA systems and design the channel codes using EXtrinsic Information Transfer (EXIT) evolution, aiming at optimizing the system performance. Simulation results show that the designed codes approach the theoretical limits and outperform previous IDMA schemes based on Turbo‐Hadamard codes. Copyright © 2010 John Wiley & Sons, Ltd.
Adaptive BU association and resource allocation in integrated PON‐WiMAX networks
Authors: Gong Ming , Lin Bin , Ho Pin‐Han , Hung Patrick
Published: November 2010

This paper addresses the issues of Base station—User Association and Resources Allocation (BUA‐RA) in OFDM‐TDMA based broadband wireless access (BWA) networks under passive optical networks (PON)‐WiMAX integration. With the powerful coordination capability at the optical line terminal (OLT), a key technology of inter‐cell cooperative transmission (CT) is incorporated in the integrated network architecture, which is called cooperative PON‐WiMAX network (CPWN). To achieve an efficient integration and inter‐cell cooperative transmission in the CPWNs, the BUA‐RA scheme is critical to the Quality of Service (QoS) provisioning for each user. In order to minimize the network resource usage, we provide three new BUA‐RA schemes which first time employ the cooperative transmission in a multi‐cell BWA network. The three schemes are designed for three kinds of subscribers with different moving types, and can be adaptively applied based on the network load. Simulations are conducted to verify the proposed BUA‐RA schemes by comparing with those without cooperative transmission technology. Our results demonstrate the efficiency of our proposed schemes, which are based on mathematical formulations and linearization. Copyright © 2010 John Wiley & Sons, Ltd.
A distributed pricing algorithm for achieving network‐wide proportional fairness
Authors: Zhou Hui , Fan Pingyi , Xia Xiang‐Gen , Letaief K. B.
Published: November 2010

Proportional fairness (PF) scheduling achieves a balanced tradeoff between throughput and fairness and has attracted great attention recently. However, most previous work on PF only considers the single cell scenario. This paper focuses on the problem of achieving network‐wide PF in a generalized multiple base station multiple user network. The problem is formulated as a maximization model and solved using the dual method. By decomposing the dual objective function, we get a distributed pricing based algorithm. Optimality of this algorithm is presented. Although the algorithm is derived using fixed link rate assumption, it can still apply in the presence of time‐varying rates. The proposed algorithm is suitable for distributed systems in the sense that it does not need any inter base station communication at all. Simulations illustrate that the proposed distributed network‐wide PF scheduling algorithm achieves almost the same performance as the centralized one. Compared with traditional local PF (LPF) scheduling, the network‐wide PF scheduling achieves higher throughput, lower throughput oscillation, and greater fairness. Copyright © 2010 John Wiley & Sons, Ltd.
CRABSS: CalRAdio‐Based advanced Spectrum Scanner for cognitive networks
Authors: Manfrin Riccardo , Zanella Andrea , Zorzi Michele
Published: November 2010

The first step required by the process of cognition is the intelligent observation of the environment that surrounds the actors of such a process. We present the CalRAdio‐Based advanced Spectrum Scanner (CRABSS), an open platform developed to monitor the ISM 2.4–2.499 GHz band and reveal opportunities for a better utilization of the available spectrum resources. CRABSS is built through a modular approach by integrating the development platform CalRadio 1 with the Unified Link Layer API (ULLA) framework. This solution provides sensing capabilities while preserving the 802.11b standard compatibility on the CalRadio 1 platform. Moreover, it takes advantage of the ULLA framework to export spectrum occupancy information to prospective cognitive radio manager engines, through a standardized set of sensing APIs. Copyright © 2010 John Wiley & Sons, Ltd.
On language ‘utility’: processing complexity and communicative efficiency
Authors: Jaeger T. Florian , Tily Harry
Published: November 2010

Functionalist typologists have long argued that pressures associated with language usage influence the distribution of grammatical properties across the world's languages. Specifically, grammatical properties may be observed more often across languages because they improve a language'sutilityor decrease itscomplexity. While this approach to the study of typology offers the potential of explaining grammatical patterns in terms of general principles rather than domain‐specific constraints, the notions of utility and complexity are more often grounded in intuition than empirical findings. A suitable empirical foundation might be found in the terms of processing preferences: in that case, psycholinguistic measures of complexity are then expected correlate with typological patterns. We summarize half a century of psycholinguistic work on ‘processing complexity’ in an attempt to make this work accessible to a broader audience: What makes something hard to process for comprehenders, and what determines speakers' preferences in production? We also briefly discuss recently emerging approaches that link preferences in production to communicative efficiency. These approaches can be seen as providing well‐defined measures of utility. With these psycholinguistic findings in mind, it is possible to investigate the extent to which language usage is reflected in typological patterns. We close with a summary of paradigms that allow the link between language usage and typology to be studied empirically.WIREs Cogni Sci2011 2 323–335 DOI: 10.1002/wcs.126

This article is categorized under:

Linguistics > Linguistic Theory
Mononuclear Formamidinate Complexes of Lithium and Sodium
Authors: Cole Marcus L. , Davies Aaron J. , Jones Cameron , Junk Peter C.
Published: November 2010

Treatment of N,N′‐bis(aryl)formamidines (FXylH = N,N′‐bis(2,6‐dimethylphenyl)formamidine, FEtH = N,N′‐bis(2,6‐diethylphenyl)formamidine, FisoH = N,N′‐bis(2,6‐diisopropylphenyl)formamidine) with nBuLi in the presence of tmeda (= N,N,N′,N′‐tetramethylethylenediamine) led to deprotonation of the amidine affording [Li(FXyl)(tmeda)] (1), [Li(FEt)(tmeda)] (2) and [Li(Fiso)(tmeda)] (3) respectively. Similar treatment of FXylH and FisoH with [Na{N(SiMe3)2}] in THF and pmdeta (= N,N,N′,N″,N″‐pentamethyldiethylenetriamine) yielded [Na(FXyl)(pmdeta)] (4) and [Na(Fiso)(pmdeta)] (5). All complexes were characterised by spectroscopy (NMR and IR) and X‐ray crystallography. Due to the bulkiness of the formamidinate ligands and the multidentate nature of the supporting neutral amine ligands (tmeda and pmdeta), all compounds were mononuclear with η2‐chelating formamidinate ligands in the solid state.
Endoscopic Minimally Invasive Thyroidectomy (eMIT): A Prospective Proof‐of‐Concept Study in Humans
Authors: Wilhelm Thomas , Metzig Andreas
Published: November 2010

Background

We have developed a new approach for endoscopic minimally invasive thyroidectomy (eMIT) in anatomical studies. Safety and feasibility were demonstrated in an animal study and then the eMIT technique was applied for the first time successfully in humans on the 18 March 2009.

Methods

In a prospective study, we performed this eMIT technique on eight patients suffering from nodular change of the thyroid gland. All patients were evaluated regarding recurrent laryngeal nerve function, intra‐ and postoperative complications, and postoperative outcome, particularly with respect to swallowing disorders.

Results

A total thyroidectomy and a partial resection were performed in four cases each. In three cases, a conversion to open surgery was necessary due to specimen size. No local infection at the incision site or within the cervical spaces occurred within the direct postoperative course. No intraoperative bleeding necessitating conversion to open surgery was observed. In one case, a permanent palsy of the right recurrent laryngeal nerve was noted. Voice function and breathing were not affected. Paresthesia of the mental nerve did not occur in all patients and in those in which it did occur, it resolved within 3 weeks. Mean follow‐up time was 10.9 months.

Conclusions

The experimental development of the eMIT technique has led to its first clinical application in humans. In this prospective proof‐of‐concept study in humans, the thyroid gland was reached via the transoral endoscopic approach in an anatomically defined layer without any relevant damage to vessels. Limitations to this technique are determined by specimen volume (up to 30 ml) and nodule size (up to 20 mm).
Novel ETF dehydrogenase mutations in a patient with mild glutaric aciduria type II and complex II‐III deficiency in liver and muscle
Authors: Wolfe Lynne A. , He Miao , Vockley Jerry , Payne Nicole , Rhead William , Hoppel Charles , Spector Elaine , Gernert Kim , Gibson K. Michael
Published: November 2010

We describe a 22‐year‐old male who developed severe hypoglycemia and lethargy during an acute illness at 4 months of age and subsequently grew and developed normally. At age 4 years he developed recurrent vomiting with mild hyperammonemia and dehydration requiring frequent hospitalizations. Glutaric aciduria Type II was suspected based upon biochemical findings and managed with cornstarch, carnitine and riboflavin supplements. He did not experience metabolic crises between ages 4‐12 years. He experienced recurrent vomiting, mild hyperammonemia, and generalized weakness associated with acute illnesses and growth spurts. At age 18 years, he developed exercise intolerance and proximal muscle weakness leading to the identification of multiple acyl‐CoA dehydrogenase and complex II/III deficiencies in both skeletal muscle and liver. Subsequent molecular characterization of the ETFDH gene revealed novel heterozygous mutations, p.G274X:c.820 G > T (exon 7) and p.P534L: c.1601 C > T (exon 12), the latter within the iron sulfur‐cluster and predicted to affect ubiquinone reductase activity of ETFDH and the docking of ETF to ETFDH. Our case supports the concept of a structural interaction between ETFDH and other enzyme partners, and suggests that the conformational change upon ETF binding to ETFDH may play a key role in linking ETFDH to II/III super‐complex formation.
Preferred Sleep Position on the Side is Associated with Carpal Tunnel Syndrome
Authors: McCabe Steven J. , Gupta Amit , Tate David E. , Myers John
Published: November 2010

Background

Although carpal tunnel syndrome is the most common compressive neuropathy, there is no comprehensive theory of its etiology. Because of the prevalence of night symptoms, we are interested in the role of sleep position in the causation of carpal tunnel syndrome.

Methods

We performed a case–control study comparing the prevalence of preferred sleep position in 68 cases and 138 controls. Analysis was stratified by age and gender and controlled for body mass index.

Results

We found a strong and significant association between a preference for sleeping on the side and the presence of carpal tunnel syndrome in men and in women less than 60 years of age. Body mass index was associated with carpal tunnel syndrome in women but not men.

Conclusions

Our findings of a strong association between the presence of carpal tunnel syndrome and preferred sleeping on the side suggest a comprehensive unifying theory of causation.
Optimization of Biomass and Arachidonic Acid Production by Aureispira maritima Using Response Surface Methodology
Authors: Saelao Sutanate , Kanjana‐Opas Akkharawit , Kaewsuwan Songsri
Published: November 2010

Statistically based experimental designs, based on the Plackett–Burman protocol, were applied to the optimization of biomass and arachidonic acid (ARA) production in Aureispira maritima shake‐flask cultures. Tryptone and culture temperature were identified to have a significant effect on biomass production, whereas ARA production was only affected significantly by the pH and agitation rate. These four factors were subsequently optimized using response surface methodology. The validity of the optimum conditions was verified by separate experiments in which biomass and ARA yield were increased 4.02‐fold (2.05 g l−1) and 3.59‐fold (21.50 mg g−1), respectively, in 3‐day fermentations. Under non‐optimized culture conditions the corresponding values were 0.51 g l−1 and 5.99 mg g−1, respectively. The results suggest that A. maritima might be a potential strain for further large scale investigations to determine whether this bacterium might be suitable for commercial production of ARA. To our knowledge, this is the first report of the statistically optimization of biomass and ARA production from the marine gliding bacterium A. maritima.
Kinetics of Lipid Oxidation and Degradation of Flaxseed Oil Containing Crawfish (Procambarus clarkii) Astaxanthin
Authors: Pu Jianing , Sathivel Subramaniam
Published: November 2010

Flaxseed oil (FO) containing crawfish (Procambarus clarkii) astaxanthin (FOA) was evaluated for lipid oxidation and astaxanthin degradation. The FOA was analyzed for astaxanthin content, free fatty acids (FFA), peroxide value (PV), fatty acid methyl esters (FAMEs) profile, and color. The amount of extractable astaxanthin in the crawfish byproducts was 3.02 mg/100 g of crawfish byproducts. FOA and FO had a similar alpha‐linolenic acid (ALA) content (on a weight% basis). The FO was lighter and more yellow in color than FOA. The oxidation rate of FOA was lower than that of FO. When FO and FOA were heated to 30 °C, both oils exhibited minimal lipid oxidation with increasing heating time, whereas FO, when heated to 40, 50, 60 °C, had a higher lipid oxidation rate than FOA with increasing the heating time from 0 to 4 h. Astaxanthin was an effective antioxidant agent in FO when it was heated from 30 to 60 °C. The degradation of astaxanthin in FOA could be described by first order reaction kinetics. Astaxanthin was stable in flaxseed oil at 30 and 40 °C, while its stability decreased significantly at 50 and 60 °C. The rate of astaxanthin degradation in FOA was significantly influenced by temperature.
Unfinished Business: Challenges for Belarus on Its Way to Democracy
Authors: Łahviniec Alaksandr , Papko Alaksandr
Published: November 2010

This article discusses Belarus’ transition towards democracy and a market economy, and the difficulties it currently faces as it attempts to pursue these changes. Belarus’ historically close relationship with Russia is discussed in detail, as is Russia's continual influence on Belarus's domestic and foreign policy. There are also internal challenges that hinder this transition. The EU strongly supports Belarus in this endeavour, and the authors encourage a proactive EU policy that will further facilitate the country's transition towards achieving a strong democratic tradition and a market economy model.
Prevalence and genotype distribution of human papillomavirus in women with cervical cancer or high‐grade precancerous lesions in Chengdu, western China
Authors: Li Jinke , Zhang Dan , Zhang Yi , Wang Xia , Lin Yong , Hu Lina
Published: November 2010

Objective

To study the prevalence and genotype distribution of human papillomavirus (HPV) among women with cervical cancer or high‐grade squamous intraepithelial lesions (HSIL) in western China.

Methods

Cervical cast‐off cells from 144 women with cervical cancer and 63 women with HSIL were tested for HPV genotypes using an oligonucleotide microarray.

Results

The overall HPV prevalence was 80.6% in cases of carcinoma and 61.9% in cases of HSIL. The most common genotypes were HPV‐16 (carcinoma, 68.1%; HSIL, 34.9%) and HPV‐58 (carcinoma, 8.3%; HSIL, 17.5%). Other high‐risk types included HPV‐18, −31, −33, −35, −45, and −52, with HPV‐18 more common in adenocarcinomas than in squamous cell carcinomas (21.4% vs 3.1%; P < 0.02). The HPV prevalence was lower among patients older than 49 years (P < 0.02).

Conclusion

The prevalence of HPV‐16 and HPV‐58 was high. This finding may help to improve HPV vaccination and cervical cancer prevention programs in western China.
Structural investigation of supply networks: A social network analysis approach
Authors: Kim Yusoon , Choi Thomas Y. , Yan Tingting , Dooley Kevin
Published: November 2010

A system of interconnected buyers and suppliers is better modeled as a network than as a linear chain. In this paper we demonstrate how to use social network analysis to investigate the structural characteristics of supply networks. Our theoretical framework relates key social network analysis metrics to supply network constructs. We apply this framework to the three automotive supply networks reported inChoi and Hong (2002). Each of the supply networks is analyzed in terms of both materials flow and contractual relationships. We compare the social network analysis results with the case‐based interpretations inChoi and Hong (2002)and conclude that our framework can both supplement and complement case‐based analysis of supply networks.
ON TRUTH-FUNCTIONALITY
Authors: HILL DANIEL J. , McLEOD STEPHEN K.
Published: November 2010

Benjamin Schnieder has argued that several traditional definitions of truth-functionality fail to capture a central intuition informal characterizations of the notion often capture. The intuition is that the truth-value of a sentence that employs a truth-functional operator depends upon the truth-values of the sentences upon which the operator operates. Schnieder proposes an alternative definition of truth-functionality that is designed to accommodate this intuition. We argue that one traditional definition of ‘truth-functionality’ is immune from the counterexamples that Schnieder proposes and is preferable to Schnieder’s alternative.
Injection region propagation outside of geosynchronous orbit
Authors: Spanswick E. , Reeves G. D. , Donovan E. , Friedel R. H. W.
Published: November 2010

Using radial alignments of the Polar and Geotail satellites with the Los Alamos National Laboratory (LANL) fleet of geosynchronous observations, we investigate the radial propagation of the dispersionless substorm injection region outside 6.6 RE. We compare the delay between injection onset observed at geosynchronous orbit and a second spacecraft in the same meridian (within 1 hr of Magnetic Local Time (MLT)) but at a different radial distance. Our results are consistent with earlier studies showing predominantly Earthward propagation of the substorm injection region at or near geosynchronous orbit. However, observations with spacecraft located further down tail (R > ∼9 RE) conclusively show that tailward propagation of the dispersionless injection region must also occur. A statistical study of events using 10 years of Polar, Geotail, and LANL observations shows that dispersionsless injections are most likely to initiate at radial distances of 6.6–9 RE. Injections typically start at this location and expand radially inward toward geosynchronous orbit and outward into the midtail central plasma sheet. Implications of these results on injection region models are discussed.
Characteristics and scaling of bubble plumes from marine hydrocarbon seepage in the Coal Oil Point seep field
Authors: Leifer Ira
Published: November 2010

The fate of marine seep gases in the ocean and atmosphere is intimately connected with bubble and bubble‐plume processes, which are strongly size‐ and depth‐dependent. Size‐dependent flux distributions, Φ, and vertical velocity functions, VZ(r), were measured with a video bubble measurement system in the Santa Barbara Channel, California. Several distinct plume types were identified for which size distributions were measured, major, minor, intermediate, and obstructed. A further vent class is elastic (which was observed but not quantified). In addition, any plume class could be oily. Minor plumes generally produced a lower emission flux, Q, and showed narrow, peaked Φ that were well described as Gaussian. The radius of the dominant peak, RP, of minor plumes varied as Q0.40, with correlation coefficient, R2 = 0.84, in agreement with theoretical relationship of RP∼Q0.4 for Q above a critical flow rate. Oil contamination was found to affect RP and was not used in the fit. A probability distribution, Ψ(RP), for all Gaussian bubble plumes was itself well described by a combination of Gaussian functions, which were different for different seep areas. Major plumes showed a broad distribution including very small and very large bubbles and were well described by a power law with exponent a, which varied with Q according to a = 0.43 + 0.55 log(Q) with R2 = 0.77. One obstructed vent was analyzed and shared characteristics with the minor bubble plumes. Mixed bubble plume size distributions showed characteristics of both major and minor plume classes, i.e., were described by a combination of Gaussian functions and power laws, and were steeper (higher a) than major plumes for the same Q. Oily plumes produced complex, confused bubble size distributions. Upwelling velocities, VUP(r), were derived from VZ(r) and increased as VUP∼Q0.66 (R2 = 0.64); however, consideration of the more intense plumes (Q > 2 cm s−1) showed VUP∼Q0.35 in agreement with other published field measurements. Thus, the weaker bubble plumes were observed during the acceleration phase.
Climate engineering through artificial enhancement of natural forcings: Magnitudes and implied consequences
Authors: Ammann Caspar M. , Washington Warren M. , Meehl Gerald A. , Buja Lawrence , Teng Haiyan
Published: November 2010

Explosive volcanism and solar activity changes have modulated the Earth's temperature over short and century time scales. Associated with these external forcings were systematic changes in circulation. Here, we explore the effect of similar but artificially induced forcings that mimic natural radiative perturbations in order to stabilize surface climate. Injection of sulfate aerosols into the stratosphere, not unlike the effects from large volcanic eruptions, and a direct reduction of insolation, similar to total solar irradiance changes, are tested in their effectiveness to offset global mean temperature rise resulting from a business‐as‐usual scenario, thereby reducing surface temperatures to conditions associated with committed warming of a year 2000 stabilization scenario. This study uses a coupled Atmosphere‐Ocean General Circulation Model to illustrate the character of resulting climate and circulation anomalies when both enhanced greenhouse (A2 scenario) and opposing geoengineering perturbations are considered. First we quantify the magnitude of the required perturbation and compare these artificial perturbations to the natural range of the respective forcing. Then, we test the effectiveness of the “correction” by looking at the regional climate response to the combined forcing. It is shown that widespread warming could be reduced, but overcompensation in the tropics is necessary because sea ice loss in high latitudes cannot be reversed effectively to overcome higher ocean heat content and enhanced zonal winter circulation as well as the continuous IR forcing. The magnitude of new, greenhouse gas‐countering anthropogenic forcing would have to be much larger than what natural forcing from volcanoes and solar irradiance variability commonly provide.
Saturn's periodic magnetic field perturbations caused by a rotating partial ring current
Authors: Brandt P. C. , Khurana K. K. , Mitchell D. G. , Sergis N. , Dialynas K. , Carbary J. F. , Roelof E. C. , Paranicas C. P. , Krimigis S. M. , Mauk B. H.
Published: November 2010

We demonstrate that the periodic magnetic field perturbations as observed from Cassini are caused by the plasma pressure of the energetic (>2 keV) particle distributions that are periodically injected and subsequently drift around Saturn. Plasma pressures inferred from the Cassini Plasma Spectrometer (CAPS) (<2 keV) and the Magnetospheric Imaging Instrument (MIMI) (>2 keV) are used to compute the three‐dimensional pressure‐driven currents and their associated magnetic field perturbations. The distribution of the “hot” (>2 keV) plasma pressure is derived from Energetic Neutral Atom (ENA) images obtained by the Ion Neutral Camera (INCA) and in‐situ spectral measurements. The radial profile of “cold” (<2 keV) plasma pressure is obtained from statistical studies and is assumed to be azimuthally symmetric.
Modeling of kinetic, ionospheric and auroral contributions to the 557.7‐nm nightglow
Authors: Campbell L. , Brunger M. J.
Published: November 2010

Emission of 557.7‐nm radiation from the Earth's upper atmosphere is produced by kinetic, ionospheric and auroral excitation of oxygen atoms. The mechanisms and hence the relative contributions of these three sources are not fully understood. A ground‐based mid‐latitude recording of the 557.7‐nm emissions over the previous solar cycle facilitates a comparison of measurements with theoretical predictions. In this paper the predicted kinetic and ionospheric contributions are simulated and compared with the observations. Semi‐quantitative agreement is found between the kinetic contribution and the observations, particularly in the presence of annual, semi‐annual and solar cycle variations. An observed enhancement in the emissions in the years following solar maximum is not predicted by the kinetic model. However, correlation analysis reveals a component in the observed values that is related to the auroral hemispheric power. When this extra component is included, a better fit to the pre‐midnight observations over the full solar cycle is found.
Low‐latitude measurements of neutral thermospheric helium dominance near 400 km during extreme solar minimum
Authors: Haaser R. A. , Earle G. D. , Heelis R. A. , Coley W. R. , Klenzing J. H.
Published: November 2010

Since the middle of 2008 solar activity has been unusually low, resulting in unusual atmospheric conditions, including significant changes in the pressure and neutral constituents at altitudes near 400 km at low latitudes. These attributes have been measured by the Coupled Ion‐Neutral Dynamics Investigation instruments aboard the Communication/Navigation Outage Forecast System (C/NOFS) satellite. The cross‐track sensor aboard C/NOFS is designed to measure the neutral pressure in an atmosphere with pressures larger than 10−8 Torr, from which the atmospheric scale height can be estimated. In the contracted thermosphere during the current solar minimum (analyzed from June 2008 to August 2009), the instrument data indicate a dominance of neutral helium near the satellite perigee (400 km). This conclusion is found to be consistent with the measured mean drag on the satellite, thus validating the basic functionality of the cross‐track sensor.
Two‐step evolution of auroral acceleration at substorm onset
Authors: Morioka A. , Miyoshi Y. , Miyashita Y. , Kasaba Y. , Misawa H. , Tsuchiya F. , Kataoka R. , Kadokura A. , Mukai T. , Yumoto K. , Menietti D. J. , Parks G. , Liou K. , Honary F. , Donovan E.
Published: November 2010

The sudden formation of parallel electric fields in the magnetosphere‐ionosphere (M‐I) coupling system is essential to complete substorm onset. From this standpoint, we focus substorm ignition on field‐aligned acceleration by studying the dynamical behavior of auroral kilometric radiation. Field‐aligned auroral acceleration shows a distinct two‐step evolution at substorm onset: the activation of low‐altitude acceleration (h ∼ 4000–5000 km) which corresponds to auroral initial brightening and the subsequent abrupt breakout of high‐altitude acceleration (h ∼ 6000–12,000 km) which corresponds to auroral breakup. Cases when only low‐altitude acceleration (first‐step evolution) is activated are pseudosubstorms. This indicates that the second evolution of field‐aligned acceleration divides full substorm from pseudosubstorm. The statistical relationship between the plasma flow burst in the plasma sheet and its response to the M‐I coupling region shows that about 65% of flow bursts cause pseudobreakup/initial brightening (low‐altitude acceleration) and one third of them develops into full substorm (low‐altitude and high‐altitude accelerations), while the magnitude of flow velocity does not necessarily distinguish between pseudobreakup and full substorm. This suggests that some plasma flow bursts originate field‐aligned current which first enhance low‐altitude acceleration, and the increasing field‐aligned current induces second acceleration above the preexisting low‐altitude acceleration as a consequence of current/current‐driven instabilities. In this sense, the substorm is finally ignited in the auroral M‐I coupling region.
Influence of the Coriolis force on the velocity structure of gravity currents in straight submarine channel systems
Authors: Cossu R. , Wells M. G. , Wåhlin A. K.
Published: November 2010

Large‐scale turbidity currents in submarine channels often show a significant asymmetry in the heights of their levee banks. In the Northern Hemisphere, there are many observations of the right‐hand channel levee being noticeably higher than the left‐hand levee, a phenomenon that is usually attributed to the effect of Coriolis forces upon turbidity currents. This article presents results from an analog model that documents the influence of Coriolis forces on the dynamics of gravity currents flowing in straight submarine channels. The observations of the transverse velocity structure, downstream velocity, and interface slope show good agreement with a theory that incorporates Ekman boundary layer dynamics. Coriolis forces will be important for most large‐scale turbidity currents and need to be explicitly modeled when the Rossby number of these flows (defined as Ro = ∣U/Wf∣, where U is the mean downstream velocity, W is the channel width, and f is the Coriolis parameter defined as f = 2Ω sin(θ), with Ω being the Earth's rotation rate and θ being the latitude) is less than order 1. When Ro ≪ 1, the flow is substantially slower than a nonrotating flow with the same density contrast. The secondary flow field consists of frictionally induced Ekman transports across the channel in the benthic and interfacial boundary layers and a return flow in the interior. The cross‐channel velocities are of the order of 10% of the along‐channel velocities. The sediment transport associated with such transverse flow patterns should influence the evolution of submarine channel levee systems.
Pyrosequencing reveals highly diverse and species-specific microbial communities in sponges from the Red Sea
Authors: Lee On On , Wang Yong , Yang Jiangke , Lafi Feras F , Al-Suwailem Abdulaziz , Qian Pei-Yuan
Published: November 2010

Marine sponges are associated with a remarkable array of microorganisms. Using a tag pyrosequencing technology, this study was the first to investigate in depth the microbial communities associated with three Red Sea sponges, Hyrtios erectus, Stylissa carteri and Xestospongia testudinaria. We revealed highly diverse sponge-associated bacterial communities with up to 1000 microbial operational taxonomic units (OTUs) and richness estimates of up to 2000 species. Altogether, 26 bacterial phyla were detected from the Red Sea sponges, 11 of which were absent from the surrounding sea water and 4 were recorded in sponges for the first time. Up to 100 OTUs with richness estimates of up to 300 archaeal species were revealed from a single sponge species. This is by far the highest archaeal diversity ever recorded for sponges. A non-negligible proportion of unclassified reads was observed in sponges. Our results demonstrated that the sponge-associated microbial communities remained highly consistent in the same sponge species from different locations, although they varied at different degrees among different sponge species. A significant proportion of the tag sequences from the sponges could be assigned to one of the sponge-specific clusters previously defined. In addition, the sponge-associated microbial communities were consistently divergent from those present in the surrounding sea water. Our results suggest that the Red Sea sponges possess highly sponge-specific or even sponge-species-specific microbial communities that are resistant to environmental disturbance, and much of their microbial diversity remains to be explored.
Examining the global distribution of dominant archaeal populations in soil
Authors: Bates Scott T , Berg-Lyons Donna , Caporaso J Gregory , Walters William A , Knight Rob , Fierer Noah
Published: November 2010

Archaea, primarily Crenarchaeota, are common in soil; however, the structure of soil archaeal communities and the factors regulating their diversity and abundance remain poorly understood. Here, we used barcoded pyrosequencing to comprehensively survey archaeal and bacterial communities in 146 soils, representing a multitude of soil and ecosystem types from across the globe. Relative archaeal abundance, the percentage of all 16S rRNA gene sequences recovered that were archaeal, averaged 2% across all soils and ranged from 0% to >10% in individual soils. Soil C:N ratio was the only factor consistently correlated with archaeal relative abundances, being higher in soils with lower C:N ratios. Soil archaea communities were dominated by just two phylotypes from a constrained clade within the Crenarchaeota, which together accounted for >70% of all archaeal sequences obtained in the survey. As one of these phylotypes was closely related to a previously identified putative ammonia oxidizer, we sampled from two long-term nitrogen (N) addition experiments to determine if this taxon responds to experimental manipulations of N availability. Contrary to expectations, the abundance of this dominant taxon, as well as archaea overall, tended to decline with increasing N. This trend was coupled with a concurrent increase in known N-oxidizing bacteria, suggesting competitive interactions between these groups.