bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitric Oxide Signaling inPseudomonas aeruginosaBiofilms Mediates Phosphodiesterase Activity, Decreased Cyclic Di-GMP Levels, and Enhanced Dispersal
Authors: Barraud Nicolas , Schleheck David , Klebensberger Janosch , Webb Jeremy S. , Hassett Daniel J. , Rice Scott A. , Kjelleberg Staffan 
Published: October 2009

ABSTRACTBacteria in biofilms often undergo active dispersal events and revert to a free-swimming, planktonic state to complete the biofilm life cycle. The signaling molecule nitric oxide (NO) was previously found to trigger biofilm dispersal in the opportunistic pathogenPseudomonas aeruginosaat low, nontoxic concentrations (N. Barraud, D. J. Hassett, S. H. Hwang, S. A. Rice, S. Kjelleberg, and J. S. Webb, J. Bacteriol. 188:7344-7353, 2006). NO was further shown to increase cell motility and susceptibility to antimicrobials. Recently, numerous studies revealed that increased degradation of the secondary messenger cyclic di-GMP (c-di-GMP) by specific phosphodiesterases (PDEs) triggers a planktonic mode of growth in eubacteria. In this study, the potential link between NO and c-di-GMP signaling was investigated by performing (i) PDE inhibitor studies, (ii) enzymatic assays to measure PDE activity, and (iii) direct quantification of intracellular c-di-GMP levels. The results suggest a role for c-di-GMP signaling in triggering the biofilm dispersal event induced by NO, as dispersal requires PDE activity and addition of NO stimulates PDE and induces the concomitant decrease in intracellular c-di-GMP levels inP. aeruginosa. Furthermore, gene expression studies indicated global responses to low, nontoxic levels of NO inP. aeruginosabiofilms, including upregulation of genes involved in motility and energy metabolism and downregulation of adhesins and virulence factors. Finally, site-directed mutagenesis of candidate genes and physiological characterization of the corresponding mutant strains uncovered that the chemotaxis transducer BdlA is involved in the biofilm dispersal response induced by NO.
ScoC Regulates Bacilysin Production at the Transcription Level in
Bacillus subtilis
Authors: Inaoka Takashi , Wang Guojun , Ochi Kozo 
Published: October 2009

ABSTRACT

Bacillus subtilis
mutants with high expression of the bacilysin operon
ywfBCDEFG
were isolated. Comparative genome sequencing analysis revealed that all of these mutants have a mutation in the
scoC
gene. The disruption of
scoC
by genetic engineering also resulted in increased expression of
ywfBCDEFG
. Primer extension and gel mobility shift analyses showed that the ScoC protein binds directly to the promoter region of
ywfBCDEFG
. Our results indicate that the transition state regulator ScoC, together with CodY and AbrB, negatively regulates bacilysin production in
B. subtilis
.
Emergence of the Academic Computing Clouds
Authors: Delic Kemal A. , Walker Martin Anthony 
Published: October 2009

Computational grids are very large-scale aggregates of communication and computation resources enabling new types of applications and bringing several benefits of economy-of-scale. The first computational grids were established in academic environments during the previous decade, and today are making inroads into the realm of corporate and enterprise computing.Very recently, we observe the emergence of cloud computing as a new potential super structure for corporate, enterprise and academic computing. While cloud computing shares the same original vision of grid computing articulated in the 1990s by Foster, Kesselman and others, there are significant differences.In this paper, we first briefly outline the architecture, technologies and standards of computational grids. We then point at some of notable examples of academic use of grids and sketch the future of research in grids. In the third section, we draw some architectural lines of cloud computing, hint at the design and technology choices and indicate some future challenges. In conclusion, we claim that academic computing clouds might appear soon, supporting the emergence of Science 2.0 activities, some of which we list shortly.
Balancing four factors in system development projects
Authors: Subramanian Girish H. , Klein Gary , Jiang James J. , Chan Chien-Lung 
Published: October 2009

IntroductionThe success of system development is most often gauged by three primary indicators: the number of days of deviation from scheduled delivery date, the percentage of deviation from the proposed budget, and meeting the needs of the client users. Tools and techniques to help perform well along these dimensions abound in practice and research. However, the project view of systems development should be broader than any particular development tool or methodology.Any given development philosophy or approach can be inserted into a systems development project to best fit the conditions, product, talent, and goals of the markets and organization. In order to best satisfy the three criteria, system development project managers must focus on the process of task completion and look to apply controls that ensure success, promote learning within the team and organization, and end up with a software product that not only meets the requirements of the client but operates efficiently and is flexible enough to be modified to meet changing needs of the organization. In this fashion, the project view must examine both process and product.Often, tasks required for project completion seem contradictory to organizational goals. Within the process, managerial controls are applied in order to retain alignment of the product to the initial, and changing, requirements of the organization. However, freedom from tight controls promotes learning. The product also has contradictions among desired outcomes. Designers must consider tradeoffs between product efficiency and flexibility, with the trend in processing power leading us ever more toward the flexibility side. Still, we rage between conflicting criteria, with the advocates of a waterfall system development lifecycle (SDLC) usually pushing more for control aspects and efficient operations while agile proponents seek more of a learning process and flexible product.Regardless of the development methodology followed, project managers must strive to deliver the system on time, within budget, and to meet the requirements of the user. Thus, both product and process are crucial in the determination of success. To compound the difficulties, those in control of choosing an appropriate methodology view success criteria from a different perspective than other stakeholders. Understanding how different stakeholders perceive these factors impacting eventual project success can be valuable in adjusting appropriate methodologies. Our study looks at these relationships using well established instruments in a survey of IS development professionals to better clarify the importance of these variables in system project success and any perceived differences among different players in IS development (see the sidebar on "How the Study Was Conducted").
Overcoming the J-shaped distribution of product reviews
Authors: Hu Nan , Zhang Jie , Pavlou Paul A. 
Published: October 2009

Introduction

While product review systems that collect and disseminate opinions about products from recent buyers (Table 1) are valuable forms of word-of-mouth communication, evidence suggests that they are overwhelmingly positive. Kadet notes that most products receive almost five stars. Chevalier and Mayzlin also show that book reviews on Amazon and Barnes & Noble are overwhelmingly positive. Is this because all products are simply outstanding? However, a graphical representation of product reviews reveals a J-shaped distribution (Figure 1) with mostly 5-star ratings, some 1-star ratings, and hardly any ratings in between. What explains this J-shaped distribution? If products are indeed outstanding, why do we also see many 1-star ratings? Why aren't there any product ratings in between? Is it because there are no "average" products? Or, is it because there are biases in product review systems? If so, how can we overcome them?
The J-shaped distribution also creates some fundamental statistical problems. Conventional wisdom assumes that the average of the product ratings is a sufficient proxy of product quality and product sales. Many studies used the average of product ratings to predict sales. However, these studies showed inconsistent results: some found product reviews to influence product sales, while others did not. The average is statistically meaningful only when it is based on a unimodal distribution, or when it is based on a symmetric bimodal distribution. However, since product review systems have an asymmetric bimodal (J-shaped) distribution, the average is a poor proxy of product quality.
This report aims to first demonstrate the existence of a J-shaped distribution, second to identify the sources of bias that cause the J-shaped distribution, third to propose ways to overcome these biases, and finally to show that overcoming these biases helps product review systems better predict future product sales.
We tested the distribution of product ratings for three product categories (books, DVDs, videos) with data from Amazon collected between February--July 2005: 78%, 73%, and 72% of the product ratings for books, DVDs, and videos are greater or equal to four stars (Figure 1), confirming our proposition that product reviews are overwhelmingly positive.
Figure 1 (left graph) shows a J-shaped distribution of all products. This contradicts the law of "large numbers" that would imply a normal distribution. Figure 1 (middle graph) shows the distribution of three randomly-selected products in each category with over 2,000 reviews. The results show that these reviews still have a J-shaped distribution, implying that the J-shaped distribution is not due to a "small number" problem. Figure 1 (right graph) shows that even products with a median average review (around 3-stars) follow the same pattern.
Gospel Music as a Mirror of the Political and Socio-Economic Developments in Zimbabwe, 1980-2007
Authors: Gwekwerere Gadziro 
Published: October 2009

AbstractThis paper explores, analyses and discusses Zimbabwean gospel song themes from 1980 up to 2007 in relation to the Zimbabwean political and socio-economic situations in the country. The history of the socio-economic and political development of Zimbabwe during 1980-2007 would certainly be incomplete without including gospel music. Until about the mid-1980s, the general atmosphere in the newly-independent state of Zimbabwe was characterized by liberation euphoria and great optimism for the future. Equally so, local gospel music during this period was largely celebrative and conformist as far as the political and socio-economic dispensation was concerned. Socio-economic hardships crept in as a result of the government's implementation of neo-liberal economic reforms under the guidance of the World Bank and the International Monetary Fund (IMF) during the early 1990s. The ruling party soon found itself confronted by a multitude of gospel musicians criticizing its policies and malpractices. Works of various gospel artistes will be used as evidence but due to issues of space, it has not been possible to cover all Zimbabwean gospel artists.
Regional National Autonomy under Challenge: Law, Practice and Recommendations
Authors: Zhou Yong , Lundberg Maria 
Published: October 2009

AbstractRegional national autonomy is claimed to be the "basic policy" of the Chinese Communist Party and a "basic political system" of the State to solve the minority nationalities' issues in China. Within the framework of "basic law", the Regional National Autonomy Law, the rights of the minority nationalities to administer their internal affairs shall be guaranteed. The present severe challenges to this system can be observed through its malfunctions in ethnic conflict solution, the maintenance of cultural diversity and the due regards of the interests of minorities in the quick the economic development. By developing its research methodology based on reviewing previous studies in this field, this article tries to describe this system in law and in practice through four essential elements, which include territory, group, organs of self-government and autonomous power of regional national autonomy. Taking into account the problems of implementation of law and the institutional design of regional national autonomy, this article briefly explores options to provide a meaningful autonomy for minority nationalities in China.
Portrait of an Institution: The US Embassy in London, 1945-53
Authors: Colman Jonathan 
Published: October 2009

AbstractThe US Embassy in London has long played a leading institutional role in the Anglo-American relationship, but few historians have examined that role. This article covers the early Cold War era of 1945-1953 — a formative period in the Anglo-American relationship — and considers issues such as the Embassy's organization, the range of work in which it participated and the contributions of the successive ambassadors. Prominent policy issues during this period included the European Recovery Plan and the Berlin Crisis. It is contended that the Embassy reached the peak of its peacetime importance under US Ambassador Lewis Douglas from 1947-1950, and that its most important role was in policy liaison. This liaison function stemmed from the need to coordinate British and US policies in the developing Cold War, and helped to lay the foundations for the long-term 'special relationship'. The article provides fresh insights into Anglo-American diplomatic bonds in a formative period.
Meridional Density Gradients Do Not Control the Atlantic Overturning Circulation
Authors: de Boer Agatha M. , Gnanadesikan Anand , Edwards Neil R. , Watson Andrew J. 
Published: October 2009

Abstract
A wide body of modeling and theoretical scaling studies support the concept that changes to the Atlantic meridional overturning circulation (AMOC), whether forced by winds or buoyancy fluxes, can be understood in terms of a simple causative relation between the AMOC and an appropriately defined meridional density gradient (MDG). The MDG is supposed to translate directly into a meridional pressure gradient. Here two sets of experiments are performed using a modular ocean model coupled to an energy–moisture balance model in which the positive AMOC–MDG relation breaks down. In the first suite of seven model integrations it is found that increasing winds in the Southern Ocean cause an increase in overturning while the surface density difference between the equator and North Atlantic drops. In the second suite of eight model integrations the equation of state is manipulated so that the density is calculated at the model temperature plus an artificial increment ΔT that ranges from −3° to 9°C. (An increase in ΔT results in increased sensitivity of density to temperature gradients.) The AMOC in these model integrations drops as the MDG increases regardless of whether the density difference is computed at the surface or averaged over the upper ocean. Traditional scaling analysis can only produce this weaker AMOC if the scale depth decreases enough to compensate for the stronger MDG. Five estimates of the depth scale are evaluated and it is found that the changes in the AMOC can be derived from scaling analysis when using the depth of the maximum overturning circulation or estimates thereof but not from the pycnocline depth. These two depth scales are commonly assumed to be the same in theoretical models of the AMOC. It is suggested that the correlation between the MDG and AMOC breaks down in these model integrations because the depth and strength of the AMOC is influenced strongly by remote forcing such as Southern Ocean winds and Antarctic Bottom Water formation.
Comparison of Aura MLS Water Vapor Measurements with GFS and NAM Analyses in the Upper Troposphere–Lower Stratosphere
Authors: Van Thien Le , Gallus William A. , Olsen Mark A. , Livesey Nathaniel 
Published: October 2009

Abstract
Water vapor mixing ratios in the upper troposphere and lower stratosphere measured by the Aura Microwave Limb Sounder (MLS) version 2.2 instrument have been compared with Global Forecast System (GFS) analyses at five levels within the 300–100-hPa layer and North American Mesoscale (NAM) model analyses at six levels within the 300–50-hPa layer over the two years of 2005 and 2006 at four analysis times (e.g., 0000, 0600, 1200, and 1800 UTC). Probability density functions of the vapor mixing ratios suggest that both analyses are often moister than Aura MLS values, but NAM model analyses agree somewhat better with Aura MLS measurements than GFS model analyses over the same North American domain at the five common levels. Examining five subsets of the global GFS domain, the GFS model analysis is moister than Aura MLS estimates everywhere but at 150 and 100 hPa in all regions outside of the tropics. NAM model analysis water vapor mixing ratios exceeded the Aura MLS values at all levels from 250 to 150 hPa in all four seasons of both years and some seasons at 100 and 50 hPa. Moist biases in winter and spring of both years were similar at all levels, but these moist biases in summer and fall were smaller in 2005 than in 2006 at all levels. These differences may be due to the change in the NAM from using the Eta Model to using the Weather Research and Forecasting model (WRF) in June 2006.
Comments on “Structure and Evolution of a Possible U.S. Landfalling Tropical Storm in 2006”
Authors: Beven John L. , Avila Lixion A. , Blake Eric S. , Cobb Hugh D. , Pasch Richard J. 
Published: October 2009

Abstract
The Best Track Change Committee of the National Hurricane Center evaluates proposed changes to the Hurricane Database (HURDAT) in the Atlantic and eastern North Pacific basins. In the companion paper, Gruskin documents a possible tropical cyclone that affected portions of the eastern United States on 27–28 June 2006 and proposes that it be added to HURDAT. The committee reviewed the aircraft, radar, rawinsonde, satellite, and surface data available on this system and found it to be a challenging and complex system. A reconnaissance aircraft flying in the system in real time failed to find a closed circulation before landfall, and kinematic parameters suggest the system was more likely to have the structure of an open wave, with any surface circulation at best being poorly defined. Because of the lack of conclusive evidence regarding the existence of a closed surface circulation before landfall, the committee has decided not to add this system to HURDAT as a tropical cyclone.
Sirolimus-eluting stent placement for refractory renal artery in-stent restenosis: sustained patency and clinical benefit at 24 months
Authors: Lookstein Robert A , Talenfeld Adam D , Raju Roman , Vorchheimer David A , Olin Jeffrey W , Marin Michael L 
Published: October 2009

Abstract Renal artery stenosis may cause or exacerbate hypertension and renal failure. Percutaneous transluminal renal artery stent placement, increasingly the first-line therapy for ostial atherosclerotic renal artery stenosis, can be complicated by in-stent restenosis weeks to months after the procedure. There is currently no consensus for the treatment of in-stent restenosis. Sirolimus-eluting stents have been shown to be effective to treat in-stent restenosis in the coronary circulation. We report a case of sustained 24-month patency after repair of recurrent renal artery in-stent restenosis with use of a sirolimus-eluting stent.
High-resolution 3D contrast-enhanced MRA with parallel imaging techniques before endovascular interventional treatment of arterial stenosis
Authors: Lin Jiang , Li Dan , Yan Fuhua 
Published: October 2009

Abstract This study aimed to evaluate the efficacy of high-resolution 3D contrast-enhanced magnetic resonance angiography (3D CE MRA) with parallel imaging techniques for the diagnosis of various arterial stenoses and its value for planning endovascular interventional treatment. Thirty-five patients underwent 3D CE MRA before endovascular interventional treatment. Numbers of patients were as follows: clinically documented renal artery stenosis ( n = 10), renal transplant artery stenosis ( n = 1), carotid artery stenosis ( n = 12), iliac artery stenosis ( n = 11) and femoro-popliteal artery stenosis ( n = 1). A total of 39 arterial segments were treated. The depiction of various arterial stenoses was evaluated. The degree and length of the stenoses were compared and analyzed between 3D CE MRA and digital subtraction angiography (DSA). The accuracy of MRA in depicting lesion characteristics (ulceration, eccentricity, post-stenotic dilatation) was reviewed. The overall value of 3D CE MRA in planning interventional treatment was determined. The quality of 3D CE MRA in the demonstration of various arterial stenoses was judged excellent or good. A strong correlation was noted between 3D CE MRA and DSA regarding severity and length of stenosis. The accuracy of 3D CE MRA in depicting lesion characteristics was good. 3D CE MRA overestimated three severe iliac artery stenoses. Except in these three segments, the value of 3D CE MRA analysis was judged high. 3D CE MRA was found to be better than DSA in revealing the distal reconstitution and occluded segment in cases of iliac artery stenosis. 3D CE MRA is accurate in demonstrating the relevant anatomy necessary to plan endovascular interventional treatment for patients with arterial stenosis.
Novel markers of peripheral arterial disease
Authors: Khawaja Farhan J , Kullo Iftikhar J 
Published: October 2009

Abstract Peripheral arterial disease (PAD), a relatively common manifestation of atherosclerotic vascular disease, is associated with significant morbidity and mortality. Although conventional risk factors contribute to the onset and progression of PAD, the role of ‘novel’ biomarkers in pathways of inflammation, thrombosis, lipoprotein metabolism, and oxidative stress in determining susceptibility to PAD is being increasingly recognized. Validation of novel risk factors for PAD may allow earlier detection, an improved understanding of disease etiology and progression, and the development of new therapies. In this review, we discuss available evidence for associations between novel circulating markers and several aspects of PAD including disease susceptibility, progression, functional limitation, and adverse outcomes.
The microtubule modulator RanBP10 plays a critical role in regulation of platelet discoid shape and degranulation
Authors: Kunert Stefan , Meyer Imke , Fleischhauer Silke , Wannack Martin , Fiedler Janine , Shivdasani Ramesh A. , Schulze Harald 
Published: October 2009

AbstractTerminally mature megakaryocytes undergo dramatic cellular reorganization to produce hundreds of virtually identical platelets. A hallmark feature of this process is the generation of an elaborate system of branched protrusions called proplatelets. We recently identified RanBP10 as a tubulin-binding protein that is concentrated along polymerized microtubules in mature megakaryocytes. RanBP10 depletion in vitro caused the disturbance of polymerized filaments. Here we study the function of RanBP10 in vivo by generating deficient mice using a gene-trap approach. Mutant mice show normal platelet counts, and fetal liver-derived megakaryocytes reveal only slightly reduced proplatelet formation. However, ultrastructural analysis unveiled a significantly increased geometric axis ratio for resting platelets, and many platelets exhibited disorders in microtubule filament numbers and localization. Mutant mice showed a markedly prolonged bleeding time. Granule release, a process that depends on internal contraction of the microtubule marginal coil, also was reduced. Flow cytometry analysis revealed reduced expression of CD62P and CD63 after PAR4-peptide stimulation. These data suggest that RanBP10 plays an essential role in hemostasis and in maintaining microtubule dynamics with respect to both platelet shape and function.