bluuebunny/crossref_metadata_2025 huggingface dataset:
Political Parties and Corruption: Reflections on the Italian Case
Authors: della Porta Donatella
Published: September 2011

Political corruption can be considered as a means by which money influences politics. In the classic studies the causes of corruption have usually been identified in the characteristics of the principal actor in the political system: the party. Samuel Huntington, in particular, has linked the development of corruption to party weakness during phases of growing political participation. Corruption spreads in those specific paths to modernization in which popular participation in political decision-making is not immediately accompanied by a strengthening of those institutions, such as political parties, which should filter and direct collective demands: ‘the weaker and less accepted the political parties, the greater the likelihood of corruption’.
Confinement of ‘improved H-modes’ in the all-tungsten ASDEX Upgrade with nitrogen seeding
Authors: Schweinzer J. , Sips A.C.C. , Tardini G. , Schneider P.A. , Fischer R. , Fuchs J.C. , Gruber O. , Hobirk J. , Kallenbach A. , McDermott R.M. , Neu R. , Pütterich T. , Rathgeber S.K. , Stober J. , Vicente J.
Published: September 2011

In ASDEX Upgrade the compatibility of improved H-modes with an all-W wall has been demonstrated. Under boronized conditions light impurities and the radiated power fraction in the divertor were reduced, requiring N seeding to cool the divertor plasma. The impurity seeding does not only protect the divertor tiles but also considerably improves the performance of improved H-mode discharges by up to 25%. The energy confinement increases to H
98-factors up to 1.3 and thereby exceeds the best values in the carbon-dominated AUG at the same density and collisionality. This improvement is due to higher edge temperatures rather than to peaking of the electron density profile. Higher temperatures are reached at the pedestal top leading, via profile stiffness, to an increase in the total plasma pressure. There is no change to
in the plasma core. The dilution at the plasma edge by nitrogen seems to play an important role since it allows higher ion temperatures at the same edge ion pressure as in the unseeded case. The dilution of the core plasma remains moderate.
Structural gene (prME) chimeras of St Louis encephalitis virus and West Nile virus exhibit altered in vitro cytopathic and growth phenotypes
Authors: Maharaj Payal D. , Anishchenko Michael , Langevin Stanley A. , Fang Ying , Reisen William K. , Brault Aaron C.
Published: September 2011

Despite utilizing the same avian hosts and mosquito vectors, St Louis encephalitis virus (SLEV) and West Nile virus (WNV) display dissimilar vector-infectivity and vertebrate-pathogenic phenotypes. SLEV exhibits a low oral infection threshold for Culex mosquito vectors and is avirulent in avian hosts, producing low-magnitude viraemias. In contrast, WNV is less orally infective to mosquitoes and elicits high-magnitude viraemias in a wide range of avian species. In order to identify the genetic determinants of these different phenotypes and to assess the utility of mosquito and vertebrate cell lines for recapitulating in vivo differences observed between these viruses, reciprocal WNV and SLEV pre-membrane and envelope protein (prME) chimeric viruses were generated and growth of these mutant viruses was characterized in mammalian (Vero), avian (duck) and mosquito [Aedes (C6/36) and Culex (CT)] cells. In both vertebrate lines, WNV grew to 100-fold higher titres than SLEV, and growth and cytopathogenicity phenotypes, determined by chimeric phenotypes, were modulated by genetic elements outside the prME gene region. Both chimeras exhibited distinctive growth patterns from those of SLEV in C6/36 cells, indicating the role of both structural and non-structural gene regions for growth in this cell line. In contrast, growth of chimeric viruses was indistinguishable from that of virus containing homologous prME genes in CT cells, indicating that structural genetic elements could specifically dictate growth differences of these viruses in relevant vectors. These data provide genetic insight into divergent enzootic maintenance strategies that could also be useful for the assessment of emergence mechanisms of closely related flaviviruses.
Intrabronchial inoculation of cynomolgus macaques with cowpox virus
Authors: Smith Alvin L. , St Claire Marisa , Yellayi Srikanth , Bollinger Laura , Jahrling Peter B. , Paragas Jason , Blaney Joseph E. , Johnson Reed F.
Published: September 2011

The public health threat of orthopoxviruses from bioterrorist attacks has prompted researchers to develop suitable animal models for increasing our understanding of viral pathogenesis and evaluation of medical countermeasures (MCMs) in compliance with the FDA Animal Efficacy Rule. We present an accessible intrabronchial cowpox virus (CPXV) model that can be evaluated under biosafety level-2 laboratory conditions. In this dose-ranging study, utilizing cynomolgus macaques, signs of typical orthopoxvirus disease were observed with the lymphoid organs, liver, skin (generally mild) and respiratory tract as target tissues. Clinical and histopathological evaluation suggests that intrabronchial CPXV recapitulated many of the features of monkeypox and variola virus, the causative agent of smallpox, infections in cynomolgus macaque models. These similarities suggest that CPXV infection in non-human primates should be pursued further as an alternative model of smallpox. Further development of the CPXV primate model, unimpeded by select agent and biocontainment restrictions, should facilitate the development of MCMs for smallpox.
JC virus granule cell neuronopathy is associated with VP1 C terminus mutants
Authors: Dang Xin , Vidal Jose E. , Penalva de Oliveira Augusto C. , Simpson David M. , Morgello Susan , Hecht Jonathan H. , Ngo Long H. , Koralnik Igor J.
Published: September 2011

The polyomavirus JC (JCV) infects glial cells and causes progressive multifocal leukoencephalopathy (PML). We described a novel JCV-variant with a 10 bp deletion in the C terminus of the VP1 capsid protein, JCVGCN1. This mutant was associated with lytic infection of cerebellar granule cell neurons and cerebellar atrophy in an human immunodeficiency virus/PML patient. This condition, also observed independently from PML, was named JCV granule cell neuronopathy (JCV GCN). We characterized JCV mutations in cerebrospinal fluid (CSF) of four other JCV GCN patients, and reviewed the literature on 10 reported cases. The strain from one patient harboured the identical GCN1-deletion, while the other patients had novel mutations in the same area, named JCVGCN2–4, causing variable changes in VP1 structure. One patient also had wild-type JCV in the CSF. To study the mechanisms leading to JCV GCN, we compared viral replication kinetics from JCVGCN1 with the prototype JCVMad1, the PML isolate JCVHWM and the prototype JCVMad1D engineered with the GCN1-deletion. While all strains replicated at low levels in the medulloblastoma cell line DAOY from a cerebellar neuronal tumour, JCVMad1 replicated better in astroglial SVG cells than JCVMad1D or JCVGCN1 and all strains replicated at higher levels in COS-7 kidney cells, suggesting that the GCN1-deletion confers a disadvantage for viral growth in central nervous system white matter. The GCN1-deletion remained stable after 100 days in culture and VP1 protein was produced in all cell lines, indicating that JCVGCN1 is replication-competent in vitro. These data highlight an important and previously overlooked aspect of JCV-pathogenesis. Detection of GCN-type JCV strains in CSF may help clinicians diagnose JCV GCN.
Molecular and Biochemical Basis for Stress-Induced Accumulation of Free and Boundp-Coumaraldehyde in Cucumber
Authors: Varbanova Marina , Porter Katie , Lu Fachuang , Ralph John , Hammerschmidt Ray , Jones A. Daniel , Day Brad
Published: September 2011

To elucidate the genetic and biochemical regulation of elicitor-induced p-coumaraldehyde accumulation in plants, we undertook a multifaceted approach to characterize the metabolic flux through the phenylpropanoid pathway via the characterization and chemical analysis of the metabolites in the p-coumaryl, coniferyl, and sinapyl alcohol branches of this pathway. Here, we report the identification and characterization of four cinnamyl alcohol dehydrogenases (CADs) from cucumber (Cucumis sativus) with low activity toward p-coumaraldehyde yet exhibiting significant activity toward other phenylpropanoid hydroxycinnamaldehydes. As part of this analysis, we identified and characterized the activity of a hydroxycinnamoyl-coenzyme A:shikimate hydroxycinnamoyl transferase (HCT) capable of utilizing shikimate and p-coumaroyl-coenzyme A to generate p-coumaroyl shikimate. Following pectinase treatment of cucumber, we observed the rapid accumulation of p-coumaraldehyde, likely the result of low aldehyde reductase activity (i.e. alcohol dehydrogenase in the reverse reaction) of CsCAD enzymes on p-coumaraldehyde. In parallel, we noted a concomitant reduction in the activity of CsHCT. Taken together, our findings support the hypothesis that the up-regulation of the phenylpropanoid pathway upon abiotic stress greatly enhances the overall p-coumaryl alcohol branch of the pathway. The data presented here point to a role for CsHCT (as well as, presumably, p-coumarate 3-hydroxylase) as a control point in the regulation of the coniferyl and sinapyl alcohol branches of this pathway. This mechanism represents a potentially evolutionarily conserved process to efficiently and quickly respond to biotic and abiotic stresses in cucurbit plants, resulting in the rapid lignification of affected tissues.
Natural selection. I. Variable environments and uncertain returns on investment*
Authors: FRANK S. A.
Published: September 2011

Many studies have analysed how variability in reproductive success affects fitness. However, each study tends to focus on a particular problem, leaving unclear the overall structure of variability in populations. This fractured conceptual framework often causes particular applications to be incomplete or improperly analysed. In this article, I present a concise introduction to the two key aspects of the theory. First, all measures of fitness ultimately arise from the relative comparison of the reproductive success of individuals or genotypes with the average reproductive success in the population. That relative measure creates a diminishing relation between reproductive success and fitness. Diminishing returns reduce fitness in proportion to variability in reproductive success. The relative measurement of success also induces a frequency dependence that favours rare types. Second, variability in populations has a hierarchical structure. Variable success in different traits of an individual affects that individual's variation in reproduction. Correlation between different individuals’ reproduction affects variation in the aggregate success of particular alleles across the population. One must consider the hierarchical structure of variability in relation to different consequences of temporal, spatial and developmental variability. Although a complete analysis of variability has many separate parts, this simple framework allows one to see the structure of the whole and to place particular problems in their proper relation to the general theory. The biological understanding of relative success and the hierarchical structure of variability in populations may also contribute to a deeper economic theory of returns under uncertainty.
“No Hints, No Forecasts, No Previews”: An Empirical Analysis of Supreme Court Nominee Candor from Harlan to Kagan
Authors: Farganis Dion , Wedeking Justin
Published: September 2011

Criticism of Supreme Court confirmation hearings has intensified considerably over the past two decades. In particular, there is a growing sense that nominees are now less forthcoming and that the hearings have suffered as a result. In this article, we challenge that conventional wisdom. Based on a comprehensive content analysis of every question and answer in all of the modern confirmation hearings—nearly 11,000 in total—we find only a mild decline in the candor of recent nominees. Moreover, we find that senators ask more probing questions than in the past, and that nominees are now more explicit about their reasons when they choose not to respond—two factors that may be fueling the perception that evasiveness has increased in recent years. We close with a discussion of the normative implications of our findings as well as an outline for future research into this issue.
Turnout and Party Registration among Criminal Offenders in the 2008 General Election
Authors: Burch Traci
Published: September 2011

This paper estimates the voter registration, turnout, and party registration in the 2008 general election for men with felony convictions in Florida, Georgia, Michigan, Missouri, and North Carolina. The findings indicate that turnout among felons is much lower than previous research has shown. Ex-felon turnout in 2008 varied by state, averaging 22.2 percent. People captured and convicted for their first offense after the election voted at similarly low rates. Also contrary to the expectations of previous literature, the ex-felon population does not seem overwhelmingly Democratic. In North Carolina and Florida, two states for which the data are available, party registration varies by race. Among registered black male ex-felons, 71.7 percent in North Carolina and 84.2 percent in Florida are registered Democrats. Among whites, however, only 35.3 percent and 36.4 percent of ex-felons are registered Democrats in North Carolina and Florida, respectively.
PREBIOTIC DI‐D‐FRUCTOSE DIANHYDRIDE‐ENRICHED CARAMELS: DEVELOPMENT OF BATCH PROCESS (1 L) AND OPTIMIZATION OF OPERATING CONDITIONS
Authors: IDRI IMANE , HAVET JEAN‐LOUIS , GARCIA FERNANDEZ JOSÉ MANUEL , PORTE CATHERINE
Published: September 2011

An experimental design was used to scale up the synthesis of caramels enriched in di‐D‐fructose dianhydride. The scale‐up from 100 mL to 1 L is particularly difficult because the mixture is a viscous paste. Using the Doehlert design for three factors, a model of difructose dianhydrides (DFAs) yield in relation to operating conditions was established. By considering only the significant coefficients, a second model was rewritten. The second model was verified and validated. F‐test was calculated (3.3) and was satisfactory (probability of adjustment is 25%). In a 100‐mL flask, the optimum DFAs yield was 30%. The determination of an optimum in a 1‐L reactor was 50% with better rheological conditions (a lower proportion of resin and a higher proportion of water).

PRACTICAL APPLICATIONS

DFAs have prebiotic properties and are intended to be used as food additives. The possibility of producing them by caramelization allows one to consider the addition of these healthy caramels to different food matrices. The synthesis used at 100‐mL scale presented the advantage of satisfying yields but the inconvenience of strong rheological constraints. This work shows that the passage at the larger scale is possible while increasing performance and decreasing the viscosity of the medium. This step is fundamental in the industrial extrapolation process.
Compositional Effect of Thin Electrode Functional Layers on the Performance of Solid Oxide Fuel Cells
Authors: Park Hyeon-Cheol , Dogan Fatih
Published: September 2011

Anode supported solid oxide fuel cells (SOFC) were fabricated by addition of various metal oxides such as Fe2O3, Co3O4 and TiO2 to thin anode functional layers between the electrolyte (yttria-stabilized zirconia, YSZ) and electrode materials (anode support: YSZ-NiO). Effect of the additives on the power density and impedance spectra of SOFC was studied. It was found that addition of Co3O4 to anode functional layer was most effective towards improvement of power densities and reduction of the total ohmic resistance as well as the area specific resistance of the cells, while addition of TiO2 to anode functional layer resulted in lower power densities. Possible mechanisms on the relationship between the additives in electrode functional layers and the cell performance were briefly discussed.
Mass Transport Characteristics of Cathodes in a Phosphoric Acid Polybenzimidazole Membrane Fuel Cell
Authors: Mamlouk M. , Scott K.
Published: September 2011

A study of the effect of electrode parameters on the mass transport characteristics of cathodes used for oxygen reduction in a phosphoric acid loaded polybenzimidazole membrane fuel cell is reported. Mass transport characteristics were determined using chrono-amperometry to measure the dynamic response of electrodes. Mass transfer behavior was analyzed using equations for diffusion in finite lengths of thin film electrolytes covering the catalyst surface area. Electrode structure parameters were measured using SEM images of the cross section of the membrane electrode assemblies. Electrode mass transfer parameters were determined for cathodes using different catalyst Pt loadings and using cathodes which were heat treated to modify micro-structure and hydrophobicity. Analysis of data showed that the dynamic current response was not controlled simply by mass transport by diffusion of oxygen through an electrolyte film covering the catalysts surface, but by an interfacial mass transport at the gas (vapor)/electrolyte film interface. Electrodes which exhibited the better oxygen mass transfer and solubility characteristics also produced better cell voltage versus current density performance in fuel cell studies.
Impacts of the Cretaceous Terrestrial Revolution and KPg Extinction on Mammal Diversification
Authors: Meredith Robert W. , Janečka Jan E. , Gatesy John , Ryder Oliver A. , Fisher Colleen A. , Teeling Emma C. , Goodbla Alisha , Eizirik Eduardo , Simão Taiz L. L. , Stadler Tanja , Rabosky Daniel L. , Honeycutt Rodney L. , Flynn John J. , Ingram Colleen M. , Steiner Cynthia , Williams Tiffani L. , Robinson Terence J. , Burk-Herrick Angela , Westerman Michael , Ayoub Nadia A. , Springer Mark S. , Murphy William J.
Published: September 2011

Molecular phylogenetic analysis, calibrated with fossils, resolves the time frame of the mammalian radiation.
A tool for measuring workers' sitting time by domain: the Workforce Sitting Questionnaire
Authors: Chau Josephine Y , van der Ploeg Hidde P , Dunn Scott , Kurko John , Bauman Adrian E
Published: September 2011

Background

Sitting time is an emerging health risk, and many working adults spend large amounts of time sitting each day. It is important to have reliable and accurate measurement tools to assess sitting time in different contexts.

Objective

To validate the Workforce Sitting Questionnaire (WSQ), an adapted measure of total and domain-specific sitting time based on work and non-workdays for use in working adults.

Methods

A convenience sample (N=95, 63.2% women) was recruited from two workplaces and by word-of-mouth in Sydney, Australia. Participants completed the WSQ, which asked about sitting time (1) while travelling to and from places; (2) while at work; (3) while watching TV; (4) while using a computer at home; and (5) while doing other leisure activities on work and non-workdays on two occasions, 7 days apart. Participants also wore an accelerometer for the 7 days between test and retest. They recorded the times they wore the accelerometer, the days they worked and their work times in a logbook. Analyses determined test–retest reliability with intraclass correlation coefficients (ICCs) and assessed criterion validity against accelerometers using Spearman's r and Bland–Altman plots.

Results

Measuring total sitting time based on a workday, non-workday and on average had fair to excellent test–retest reliability (ICC=0.46–0.90) and had sufficient criterion validity against accelerometry in women (r=0.22–0.46) and men (r=0.18–0.29). Measuring domain-specific sitting at work on a workday was also reliable (ICC=0.63) and valid (r=0.45).

Conclusions

The WSQ has acceptable measurement properties for measuring sitting time at work on a workday and for assessing total sitting time based on work and non-workdays. This questionnaire would be suitable for use in research investigating the relationships between sitting time and health in working populations.
Organisational characteristics associated with the use of daily interruption of sedation in US hospitals: a national study
Authors: Miller Melissa A , Krein Sarah L , Saint Sanjay , Kahn Jeremy M , Iwashyna Theodore J
Published: September 2011

Objective

Daily interruption of sedation (DIS) has multiple proven benefits, but implementation is erratic. Past research on sedative interruption utilisation focused on individual clinicians, ignoring the role of organisations in shaping practice. The authors test the hypothesis that specific hospital organisational characteristics are associated with routine use of DIS.

Design and setting

National, mailed survey to a stratified random sample of US hospitals in 2009. Respondents were the lead infection control professionals at each institution.

Methods

Survey items enquired about DIS use, institutional structure, and organisational culture. Multivariable analysis was used to evaluate the independent association of these factors with DIS use.

Results

A total of 386 hospitals formed our final analytic sample; the response rate was 69.4%. Hospitals ranged in size from 25 to 1359 beds. 26% of hospitals were associated with a medical school. Almost 80% reported regular use of DIS for ventilated patients. While 75.4% of hospitals reported having leadership focus on safety culture, only 42.7% reported that their staff were receptive to changes in practice. In a multivariable logistic regression model, structural characteristics such as size and academic affiliation were not associated with use of DIS. However, leadership emphasis on safety culture (p=0.04), staff receptivity to change (p=0.02) and involvement in an infection prevention collaborative (p=0.04) were significantly associated with regular DIS use.

Conclusions

Several elements of hospital organisational culture were associated with regular use of DIS in US hospitals. These findings emphasise the importance of combining specific administrative approaches with strategies to encourage receptivity to change among bedside clinicians in order to successfully implement complex evidence-based practices in the intensive care setting.
An analysis of outcomes of emergency physician/department-based thrombolysis for stroke
Authors: Volans A P
Published: September 2011

Background

Stroke thrombolysis is strongly supported as an effective therapy for selected cases of early stroke. The absence of 24 h stroke specialists in district general hospitals (DGHs) has led to the suggestion that regional hyper-acute stroke centres should be developed. This paper describes a cooperative model that uses the skills already present in a DGH to deliver a thrombolysis service initiated in the emergency department by the emergency physicians, and describes the outcomes of that service in comparison with the SITS-MOST trial.

Method

The outcomes of all stroke patients thrombolysed at Scarborough DGH from 2004 to January 2009 were reviewed. Outcome was defined using a three-part scale. Data at Scarborough DGH were compared with data from the SITS-MOST European-wide study of stroke thrombolysis.

Results

Data were available for 98 of 110 patients thrombolysed during the study period. Fifty (51%) had a good outcome, seven (8%) had partial resolution of their symptoms, and 41 (42%) showed no improvement or deterioration. These outcomes were comparable to those in the European database.

Conclusion

Stroke thrombolysis can be effectively delivered in a non-specialist (a non-hyper-acute stroke centre) DGH in the UK. An audit of cases completed describes complications seen.
Scalar–tensor theories of gravity: validity of the cosmic no-hair conjecture
Authors: Mukerji Sudeshna , Mazumder Nairwita , Biswas Ritabrata , Chakraborty Subenoy
Published: September 2011

This paper deals with the cosmic no-hair conjecture for anisotropic Bianchi models in the scalar–tensor theory of gravity. Herein, we have considered both the Jordan frame and the Einstein frame to describe the scalar–tensor theory of gravity and examine the conjecture. In the Jordan frame, one should restrict both the coupling function of the scalar field and the coupling parameter, in addition to the usual energy conditions for the matter field, to maintain the validity of the cosmic no-hair conjecture, while in the Einstein frame, the restrictions are purely on the energy conditions.
Quantum ion–acoustic shock waves in warm dissipative electron–positron–ion plasmas with relativistic ions
Authors: Pakzad Hamid Reza
Published: September 2011

Propagation of nonlinear quantum ion–acoustic shock waves in dense quantum plasma, whose constituents are electrons, positrons, and positive ions, is investigated using a quantum hydrodynamical model. Moreover, it is assumed that ion velocity is weakly relativistic. Also, we consider the effects of kinematic viscosity among the plasma constituents. By using reductive perturbation method, the Korteweg – de Vries – Burger equation is derived. The effects of relativistic ions, ion temperature, and the quantum Bohm potential on the shock waves are reported in this paper.
Tipping time of a holonomic quantum cylinder
Authors: Shegelski Mark R.A. , Stoker Jamie Sanchez-Fortun , Kellett Ian
Published: September 2011

The classical and quantum mechanical Hamiltonians for a cylinder subject to holonomic constraints are derived. The quantum mechanical Hamiltonian is simplified and cast into a dimensionless form. The tipping time of a quantum mechanical cylinder subject to gravity is calculated. Numerical solutions for an appropriate initial wave function are obtained. We find that the tipping time is given by 〈t〉tip = t0C1 exp [C2(r/r0)9], where t0 is the time scale, C1 and C2 are constants of order unity, r is the radius of the cylinder, and r0 is the length scale for the tipping. We compare our results with those found in previous works.
Effect of resveratrol derivative BTM-0512 on high glucose-induced dysfunction of endothelial cells: role of SIRT1
Authors: Yuan Qiong , Chen Lei , Xiang Da-Xiong , Li Yuan-Jian , Hu Chang-Ping
Published: September 2011

Hyperglycemia impairs the function of endothelial cells. Sirtuin 1 (SIRT1) is involved in regulating the function of endothelial cells. Resveratrol, a polyphenol found in many plant species, exerts protective effects on endothelial cells through activation of SIRT1. The aims of this work were to explore whether BTM-0512, a novel derivative of resveratrol, is able to exert beneficial effects on high glucose-induced dysfunction of endothelial cells through regulation of SIRT1. We found that high glucose significantly impaired the function of endothelial cells as shown by reduced tube formation, cell migration, and cell adhesion concomitantly with downregulation of mRNA expression of SIRT1 and vascular endothelial growth factor as well as increased tumor necrosis factor-α release and reactive oxygen species production. These effects of high glucose were inhibited by pretreatment with BTM-0512. The beneficial effects of BTM-0512 on high glucose-induced cell dysfunction were abolished by splitomicin, a specific inhibitor of SIRT1. The regulatory effects of BTM-0512 on high glucose-induced changes in vascular endothelial growth factor mRNA expression and tumor necrosis factor-α release were also abolished by splitomicin. The results suggest that BTM-0512 exerts beneficial effects on high glucose-induced endothelial cell dysfunction through regulation of the SIRT1 – reactive oxygen species – vascular endothelial growth factor – tumor necrosis factor-α pathway.
Specific loss of Toll-like receptor 2 on bone marrow derived cells decreases atherosclerosis in LDL receptor null mice*The senior author, Stewart C. Whitman, passed away on 19 February 2010. The manuscript has been communicated by Ross W. Milne (e-mail: rmilne@ottawaheart.ca) and Yves L. Marcel (e-mail: ylmarcel@ottawaheart.ca), University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y 4W7, Canada.
Authors: Hasu Mirela , Thabet Mohamed , Tam Nancy , Whitman Stewart C.
Published: September 2011

Innate immunity and, notably, Toll-like receptors (TLR), have an important role in atherogenesis. We have tested the hypothesis that the selective loss of TLR-2 by cells of bone marrow (BM) origin will protect low-density receptor-deficient (Ldlr −/−) mice from both early- and late-stage atherosclerosis. BM cells from Tlr2+/+ and Tlr2−/− littermates were used to reconstitute lethally irradiated Ldlr−/− mice. Following a recovery period, mice were placed either on a diet containing 21% saturated fat – 0.15% cholesterol for 8 weeks to study early-stage atherosclerosis, or on a diet richer in cholesterol (1.5%) for 16 weeks to study late-stage atherosclerosis. Donor cell Tlr2 genotype did not alter serum cholesterol levels or lipoprotein profiles in recipient animals. After 8 weeks on the 0.15% cholesterol diet, deficiency of TLR-2 expression on cells of BM origin reduced atherosclerosis in the aortic root and the aortic arch in both genders of mice. In contrast, the BM recipients who received the 1.5% cholesterol diet for 16 weeks showed much larger lesions in the aortic root, and TLR-2 deficiency in BM cells failed to provide protection. Thus, TLR-2 expression in BM-derived cells contributes primarily to early stage atherosclerosis.
POWER SERIES SOLUTIONS OF SINGULAR LINEAR SYSTEMS
Authors: HAN JEN-YIN , LIN CHIN-YUAN
Published: September 2011

By using exponential functions, a fundamental set of power series solutions for singular linear systems of the first kind is explicitly computed.
In the Virtual Extension
Authors: CACM Staff
Published: September 2011

To ensure the timely publication of articles,
Communications
created the Virtual Extension (VE) to expand the page limitations of the print edition by bringing readers the same high-quality articles in an online-only format. VE articles undergo the same rigorous review process as those in the print edition and are accepted for publication on merit. The following synopses are from articles now available in their entirety to ACM members via the Digital Library.
Improving brain-computer interfaces
Authors: Kroeker Kirk L.
Published: September 2011

Researchers are demonstrating advances in restorative BCI systems that are giving paralyzed individuals more effective ways to communicate, move, and interact with their environment.
Living in a digital world
Authors: Greengard Samuel
Published: September 2011

Technology has created new opportunities to connect and interact. Yet, researchers are increasingly concerned that heavy technology usage is changing people's behavior in less than desirable ways.
Success at 16
Authors: Krakovsky Marina
Published: September 2011

A high school student wins first prize from ACM for developing a faster keyboard layout.
The platform leader's dilemma
Authors: Cusumano Michael A.
Published: September 2011

Studying the lessons learned from past and present platform leaders.
Modernizing the Danish democratic process
Authors: Schürmann Carsten
Published: September 2011

Examining the socio-technological issues involved in Denmark's decision to pursue the legalization of electronic elections.
From blitzkrieg to bitskrieg
Authors: Arquilla John
Published: September 2011

Expect more cyberwarfare on the conventional battlefield and less against civilian infrastructure…assuming containment is possible.
Unsupervised learning of hierarchical representations with convolutional deep belief networks
Authors: Lee Honglak , Grosse Roger , Ranganath Rajesh , Ng Andrew Y.
Published: September 2011

There has been much interest in unsupervised learning of hierarchical generative models such as deep belief networks (DBNs); however, scaling such models to full-sized, high-dimensional images remains a difficult problem. To address this problem, we present the
convolutional deep belief network
, a hierarchical generative model that scales to realistic image sizes. This model is translation-invariant and supports efficient bottom-up and top-down probabilistic inference. Key to our approach is
probabilistic max-pooling
, a novel technique that shrinks the representations of higher layers in a probabilistically sound way. Our experiments show that the algorithm learns useful high-level visual features, such as object parts, from unlabeled images of objects and natural scenes. We demonstrate excellent performance on several visual recognition tasks and show that our model can perform hierarchical (bottom-up and top-down) inference over full-sized images.
Future Tense: A person of influence
Authors: Baluja Shumeet
Published: September 2011

Future Tense, one of the revolving features on this page, presents stories and essays from the intersection of computational science and technological speculation, their boundaries limited only by our ability to imagine what will and could be.

Inferred connections map our past and predict our future.
Angiotensin II-NADPH oxidase-derived superoxide mediates diabetes-attenuated cell excitability of aortic baroreceptor neurons
Authors: Li Yu-Long , Zheng Hong
Published: September 2011

Overactivation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels is involved in diabetes-depressed excitability of aortic baroreceptor neurons in nodose ganglia. This involvement links to the autonomic dysfunction associated with high morbidity and mortality in diabetic patients. The present study examined the effects of an angiotensin II type I receptor (AT1R) antagonist (losartan), a NADPH oxidase inhibitor (apocynin), and a superoxide dismutase mimetic (tempol) on the enhanced HCN currents and attenuated cell excitability in diabetic nodose neurons. In sham and streptozotocin-induced type 1 diabetic rats, HCN currents and cell excitability of aortic baroreceptor neurons were recorded by the whole cell patch-clamp technique. The angiotensin II level in nodose ganglia from diabetic rats was higher than that from sham rats (101.6 ± 4.8 vs. 38.9 ± 4.2 pg/mg protein, P < 0.05). Single-cell RT-PCR, Western blot, immunofluorescence staining, and chemiluminescence data showed that mRNA and protein expression of AT1R, protein expression of NADPH oxidase components, and superoxide production in nodose neurons were increased in diabetic rats compared with those from sham rats. HCN current density was higher and cell excitability was lower in aortic baroreceptor neurons from diabetic rats than that from sham rats. Losartan (1 μM), apocynin (100 μM), and tempol (1 mM) normalized the enhanced HCN current density and increased the cell excitability in the aortic baroreceptor neurons of diabetic rats. These findings suggest that endogenous angiotensin II-NADPH oxidase-superoxide signaling contributes to the enhanced HCN currents and the depressed cell excitation in the aortic baroreceptor neurons of diabetic rats.
Ion channnels and transporters in cancer. 5. Ion channels in control of cancer and cell apoptosis
Authors: Lehen'kyi V'yacheslav , Shapovalov George , Skryma Roman , Prevarskaya Natalia
Published: September 2011

Ion channels contribute to virtually all basic cellular processes, including such crucial ones for maintaining tissue homeostasis as proliferation, differentiation, and apoptosis. The involvement of ion channels in regulation of programmed cell death, or apoptosis, has been known for at least three decades based on observation that classical blockers of ion channels can influence cell death rates, prolonging or shortening cell survival. Identification of the central role of these channels in regulation of cell cycle and apoptosis as well as the recent discovery that the expression of ion channels is not limited solely to the plasma membrane, but may also include membranes of internal compartments, has led researchers to appreciate the pivotal role of ion channels plays in development of cancer. This review focuses on the aspects of programmed cell death influenced by various ion channels and how dysfunctions and misregulations of these channels may affect the development and progression of different cancers.
Hippocampal functional hyperemia mediated by NMDA receptor/NO signaling in rats during mild exercise
Authors: Nishijima Takeshi , Okamoto Masahiro , Matsui Takashi , Kita Ichiro , Soya Hideaki
Published: September 2011

Current studies have demonstrated that exercise increases regional cerebral blood flow (rCBF), an index of neuronal activity. However, neuronal regulation of the increased rCBF in the brain parenchyma is poorly understood. We developed a running model with rats for monitoring hippocampal cerebral blood flow (Hip-CBF) and found that mild treadmill running increases Hip-CBF in a tetrodotoxin-dependent manner, suggesting that functional hyperemia, an increase in rCBF in response to neuronal activation, occurs in the running rat's hippocampus (Nishijima T and Soya H. Neurosci Res 54: 186–191, 2006). To further support our hypothesis, it was important to discover the neurogenic pathways behind the increase in Hip-CBF that occurred during running. Here, we examine the possible role of N-methyl-d-aspartate (NMDA) receptor/nitric oxide (NO) signaling and group I metabotropic glutamate receptors in mediating the Hip-CBF increase. Hip-CBF during running was measured by laser-Doppler flowmetry. Intrahippocampal drug administration was performed by microdialysis. Mild treadmill running (10 m/min) increased Hip-CBF, which was remarkably attenuated by either NMDA receptor antagonists (1 mM MK-801) or NO synthase inhibitors (2 mM NG-nitro-l-arginine methyl ester). However, group I metabotropic glutamate receptor antagonists {1 mM 7-(hydroxyimino)cyclopropa[ b]chromen-1a-carboxylate ethyl ester + 1 mM 2-methyl-6-(phenylethynyl)pyridine hydrochloride} augmented the running-induced Hip-CBF increase. We also found that rCBF in the olfactory bulb was unchanged with running. These results strongly suggest that Hip-CBF during mild exercise is regulated locally under hippocampal neuronal activity, mediated mainly through NMDA receptor/NO signaling. Collectively, these results, together with our previous findings, support our hypothesis that mild exercise elicits neuronal activation, which then triggers functional hyperemia in the rat hippocampus.
Sphingosine Kinase Inhibitors and Cancer: Seeking the Golden Sword of Hercules
Authors: Pyne Susan , Bittman Robert , Pyne Nigel J.
Published: September 2011

There is considerable evidence that sphingosine kinases play a key role in cancer progression, which might involve positive selection of cancer cells that have been provided with a survival and growth advantage as a consequence of overexpression of the enzyme. Therefore, inhibitors of sphingosine kinase represent a novel class of compounds that have potential as anticancer agents. Poor inhibitor potency is a major issue that has precluded successful translation of these compounds into the clinic. However, recent discoveries have shown that sphingosine kinase 1 is an allosteric enzyme and that some inhibitors offer improved effectiveness by inducing proteasomal degradation of the enzyme or having nanomolar potency. Herein, we provide a perspective about these recent developments and highlight the importance of translating basic pharmacologic and biochemical findings on sphingosine kinase into new drug discovery programs for treatment of cancer. Cancer Res; 71(21); 6576–82. ©2011 AACR.
New Distributional Records and Conservation Implications for the Critically Endangered Greater Bamboo Lemur Prolemur simus
Authors: Rakotonirina Laingoniaina , Rajaonson Andry , Ratolojanahary Tianasoa , Rafalimandimby Jean , Fanomezantsoa Prosper , Ramahefasoa Bellarmin , Rasolofoharivelo Tovonanahary , Ravaloharimanitra Maholy , Ratsimbazafy Jonah , Dolch Rainer , King Tony
Published: September 2011

To improve our knowledge of the distribution of the critically endangered greater bamboo lemurProlemur simus,we surveyed 6 sites in eastern Madagascar. We found its characteristic feeding signs at 5 sites and made a direct sighting at one of these. One site represents a northern extension of 45 km of the known extant range of the species. Two sites are located in a forest corridor approximately halfway between the previously known southern and northern populations, therefore suggesting a broadly continuous distribution of the species within its range rather than the previously suspected distribution of two distinct populations separated by a distance of over 200 km. Our results illustrate the benefit of species-focussed surveys in determining the true distribution of endangered species, a realistic measure which is necessary in order to assess their current status and to prioritise long-term conservation interventions.
Evaluation of Different Fluoride Concentrations Supplemented with Trimetaphosphate on Enamel De- and Remineralization in vitro
Authors: Takeshita E.M. , Exterkate R.A.M. , Delbem A.C.B. , ten Cate J.M.
Published: September 2011

Trimetaphosphate (TMP) effects on demineralized bovine enamel were studied after 15 days of pH cycling. Treatments included 30 wt% (weight percent) dilutions of 0, 500, 1,500 or 3,000 µg F/g aqueous NaF solutions with or without 3% TMP. Treated specimens were assessed by transverse microradiography. With the exception of the 3,000 µg F/g case, 3% TMP addition provided significant additional overall remineralization compared with F alone. Mineral content profiles differed significantly between corresponding F and F + TMP groups. Fluoride alone resulted in more remineralization in the original demineralized zone, whereas F + TMP caused less demineralization in the underlying, originally sound enamel.
Pericyte-Derived Sphinogosine 1-Phosphate Induces the Expression of Adhesion Proteins and Modulates the Retinal Endothelial Cell Barrier
Authors: McGuire Paul G. , Rangasamy Sampathkumar , Maestas Joann , Das Arup
Published: September 2011

Objective—

The mechanisms that regulate the physical interaction of pericytes and endothelial cells and the effects of these interactions on interendothelial cell junctions are not well understood. We determined the extent to which vascular pericytes could regulate pericyte-endothelial adhesion and the consequences that this disruption might have on the function of the endothelial barrier.

Methods and Results—

Human retinal microvascular endothelial cells were cocultured with pericytes, and the effect on the monolayer resistance of endothelial cells and expression of the cell junction molecules N-cadherin and VE-cadherin were measured. The molecules responsible for the effect of pericytes or pericyte-conditioned media on the endothelial resistance and cell junction molecules were further analyzed. Our results indicate that pericytes increase the barrier properties of endothelial cell monolayers. This barrier function is maintained through the secretion of pericyte-derived sphingosine 1-phosphate. Sphingosine 1-phosphate aids in maintenance of microvascular stability by upregulating the expression of N-cadherin and VE-cadherin, and downregulating the expression of angiopoietin 2.

Conclusion—

Under normal circumstances, the retinal vascular pericytes maintain pericyte-endothelial contacts and vascular barrier function through the secretion of sphingosine 1-phosphate. Alteration of pericyte-derived sphingosine 1-phosphate production may be an important mechanism in the development of diseases characterized by vascular dysfunction and increased permeability.
Presence of Intracranial Artery Calcification Is Associated With Mortality and Vascular Events in Patients With Ischemic Stroke After Hospital Discharge
Authors: Bugnicourt Jean-Marc , Leclercq Claire , Chillon Jean-Marc , Diouf Momar , Deramond Hervé , Canaple Sandrine , Lamy Chantal , Massy Ziad A. , Godefroy Olivier
Published: September 2011

Background and Purpose—

Although intracranial artery calcification (IAC) has been reported to be a risk factor for ischemic stroke, the prognostic implications of IAC in stroke outcome are unknown. The purpose of this study was to determine the association between IAC and risk of vascular events and death in patients with stroke after hospital discharge.

Methods—

All patients with ischemic stroke over a 1-year period were included (n=302). IAC, assessed by multidetector CT, was defined as hyperdense foci (peak density >130 Hounsfield units) and assessed in the 7 major cerebral arteries. The IAC scores ranged from 0 (no calcification) to 7. Follow-up information on major clinical events (including fatal or nonfatal ischemic stroke, cardiac and peripheral artery events, and all-cause death) was obtained by means of a structured phone interview.

Results—

IAC was present in 260 patients (83%). With a mean follow-up of 773±223 days, 88 major clinical events occurred in 67 patients (22%): 45 new ischemic vascular events (ischemic stroke: n=22; cardiac event: n=15; peripheral artery event: n=8) and 43 deaths from any cause. Patients with the highest IAC scores had significantly higher rates of death and vascular events than those with the lowest IAC scores (log rank test,
P
=0.029). In the Cox proportional hazards regression model, the IAC score was significantly associated with major clinical events (hazard ratio, 1.34; 95% CI, 1.11–1.61;
P
=0.002).

Conclusions—

In patients with ischemic stroke, IAC detection may constitute a simple marker of a high risk of future major clinical events.
Carotid Intima-Media Thickness, Electrocardiographic Left Ventricular Hypertrophy, and Incidence of Intracerebral Hemorrhage
Authors: Folsom Aaron R. , Yatsuya Hiroshi , Psaty Bruce M. , Shahar Eyal , Longstreth W.T.
Published: September 2011

Background and Purpose—

Carotid intima-media thickness and electrocardiographic left ventricular hypertrophy are 2 subclinical cardiovascular disease measures associated with increased risk of total and ischemic strokes. Increased intima-media thickness and electrocardiographic left ventricular hypertrophy also may reflect end-organ hypertensive effects. Information is scant on the associations of these subclinical measures with intracerebral hemorrhage (ICH). We hypothesized that greater carotid intima-media thickness and the presence of electrocardiographic left ventricular hypertrophy would be independently associated with increased ICH incidence.

Methods—

Among 18 155 participants initially free of stroke in the Atherosclerosis Risk in Communities Study (ARIC) and the Cardiovascular Health Study (CHS), we assessed carotid intima-media thickness, carotid plaque, and electrocardiographic left ventricular hypertrophy. Over a median of 18 years of follow-up, 162 incident ICH events occurred.

Results—

After adjustment for other ICH risk factors, carotid intima-media thickness was associated positively with incidence of ICH in both ARIC and CHS. The risk was lowest in study-specific Quartile 1, elevated 1.6- to 2.6-fold in Quartiles 2 to 3, and elevated 2.5 to 3.7-fold in Quartile 4 (
P
<0.05 for both studies). In CHS, having a carotid plaque was associated with a 2-fold (95% CI, 1.1–3.4) greater ICH risk than having no plaque, but only 1.2-fold (95% CI, 0.76–2.0) greater ICH risk in ARIC. Electrocardiographic left ventricular hypertrophy carried a hazard ratio of ICH of 1.7 (95% CI, 0.77–3.7) in CHS and 2.8 (95% CI, 1.2–6.4) in ARIC.

Conclusions—

Our data suggest that people with carotid atherosclerosis and possibly left ventricular hypertrophy are at increased risk not only of ischemic stroke, but also of ICH.