bluuebunny/crossref_metadata_2025 huggingface dataset:
Vitamin D Rescues Impaired Mycobacterium tuberculosis-Mediated Tumor Necrosis Factor Release in Macrophages of HIV-Seropositive Individuals through an Enhanced Toll-Like Receptor Signaling PathwayIn Vitro
Authors: Anandaiah Asha , Sinha Sanjeev , Bole Medhavi , Sharma Surendra K. , Kumar Narendra , Luthra Kalpana , Li Xin , Zhou Xiuqin , Nelson Benjamin , Han Xinbing , Tachado Souvenir D. , Patel Naimish R. , Koziel Henry
Published: October 2012

Mycobacterium tuberculosisdisease represents an enormous global health problem, with exceptionally high morbidity and mortality in HIV-seropositive (HIV+) persons. Alveolar macrophages from HIV+persons demonstrate specific and targeted impairment of critical host cell responses, including impairedM. tuberculosis-mediated tumor necrosis factor (TNF) release and macrophage apoptosis. Vitamin D may promote anti-M. tuberculosisresponses through upregulation of macrophage NO, NADPH oxidase, cathelicidin, and autophagy mechanisms, but whether vitamin D promotes anti-M. tuberculosismechanisms in HIV+macrophages is not known. In the current study, human macrophages exposed toM. tuberculosisdemonstrated robust release of TNF, IκB degradation, and NF-κB nuclear translocation, and these responses were independent of vitamin D pretreatment. In marked contrast, HIV+U1 human macrophages exposed toM. tuberculosisdemonstrated very low TNF release and no significant IκB degradation or NF-κB nuclear translocation, whereas vitamin D pretreatment restored these critical responses. The vitamin D-mediated restored responses were dependent in part on macrophage CD14 expression. Importantly, similar response patterns were observed with clinically relevant human alveolar macrophages from healthy individuals and asymptomatic HIV+persons at high clinical risk ofM. tuberculosisinfection. Taken together with the observation that local bronchoalveolar lavage fluid (BALF) levels of vitamin D are severely deficient in HIV+persons, the data from this study demonstrate that exogenous vitamin D can selectively rescue impaired critical innate immune responsesin vitroin alveolar macrophages from HIV+persons at risk forM. tuberculosisdisease, supporting a potential role for exogenous vitamin D as a therapeutic adjuvant inM. tuberculosisinfection in HIV+persons.
Effects of Treatment on IgE Responses against Parasite Allergen-Like Proteins and Immunity to Reinfection in Childhood Schistosome and Hookworm Coinfections
Authors: Pinot de Moira Angela , Jones Frances M. , Wilson Shona , Tukahebwa Edridah , Fitzsimmons Colin M. , Mwatha Joseph K. , Bethony Jeffrey M. , Kabatereine Narcis B. , Dunne David W.
Published: October 2012

Naturally occurring human immunity to both schistosomiasis and hookworm infection has been associated with IgE responses against parasite allergen-like proteins. Since the two helminths frequently coinfect the same individuals, there is growing advocacy for their concurrent treatment. However, both helminths are known to exert strong immunomodulatory effects; therefore, coinfected individuals could have immune responses different from those characteristically seen in monoinfected individuals. In this study, we measured changes in IgE, IgG1, and IgG4 responses to schistosome and hookworm antigens, including the allergen-like proteinsSchistosoma mansonitegumental-allergen-like 1 protein (SmTAL1), SmTAL2, andNecator americanus Ancylostoma-secreted protein-2 (Na-ASP-2), following concurrent treatment of schoolchildren coinfected withSchistosoma mansoniand hookworm. Antibody responses to schistosome egg (soluble egg antigen and SmTAL2) or somatic adult hookworm (AHW) antigens either decreased after treatment or were unchanged, whereas those to schistosome worm antigens (soluble worm antigen and SmTAL1) increased. The observed different effects of treatment likely reflect the different modes of drug action and sites of infection for these two helminths. Importantly, there was no evidence that the simultaneous treatment of coinfected children with praziquantel and albendazole affected schistosome- and hookworm-specific humoral responses differently from those characteristic of populations in which only one organism is endemic; schistosome- and hookworm-specific responses were not associated, and there was no evidence for cross-regulation. Posttreatment increases in the levels of IgE to schistosome worm antigens were associated with lowerSchistosoma mansonireinfection intensity, while no associations between humoral responses to AHW antigen and protection from hookworm reinfection were observed in this sample of school-aged children.
Phosphoethanolamine Residues on the Lipid A Moiety of Neisseria gonorrhoeae Lipooligosaccharide Modulate Binding of Complement Inhibitors and Resistance to Complement Killing
Authors: Lewis Lisa A. , Shafer William M. , Dutta Ray Tathagat , Ram Sanjay , Rice Peter A.
Published: October 2012

Loss of phosphoethanolamine (PEA) from the lipid A of gonococcal strain FA19 results in increased sensitivity to killing by the classical pathway of complement. Here we demonstrate that loss of PEA from lipid A diminishes binding of the complement regulatory protein C4b binding protein (C4BP) to the FA19 porin B (PorB), providing a molecular basis to explain the susceptibility of anlptAnull strain of FA19 to killing by normal human serum (NHS). Loss of PEA from lipid A in three additional gonococcal strains that expressed diverse PorB molecules also resulted in decreased C4BP binding, increased deposition of C4b, and increased susceptibility to killing by NHS. Complementation oflptAnull strains withlptArestored C4BP binding, decreased C4b deposition, and increased resistance to killing by NHS. These effects of lipid A PEA on C4BP binding to gonococcal PorB and serum resistance were simulated when gonococcal PorB was expressed in a meningococcal background. Loss of PEA from lipid A also affected binding of the alternative pathway regulator factor H (fH) to PorB of some strains. For instance, PorB molecules oflptAnull mutants of strains 252 and 1291 bound less fH than those of their parent strains when lipooligosaccharide (LOS) was sialylated, whereas PorB molecules oflptAnull mutants of strains FA1090 and 273 retained the ability to bind fH when LOS was sialylated. These data indicate that replacement of lipid A with PEA alters binding of C4BP and fH to PorB and contributes to the ability of gonococci to resist complement-mediated killing.
Anaplasma phagocytophilum Asp14 Is an Invasin That Interacts with Mammalian Host Cells via Its C Terminus To Facilitate Infection
Authors: Kahlon Amandeep , Ojogun Nore , Ragland Stephanie A. , Seidman David , Troese Matthew J. , Ottens Andrew K. , Mastronunzio Juliana E. , Truchan Hilary K. , Walker Naomi J. , Borjesson Dori L. , Fikrig Erol , Carlyon Jason A.
Published: October 2012

Anaplasma phagocytophilum
, a member of the family
Anaplasmataceae
, is the tick-transmitted obligate intracellular bacterium that causes human granulocytic anaplasmosis. The life cycle of
A. phagocytophilum
is biphasic, transitioning between the noninfectious reticulate cell (RC) and infectious dense-cored (DC) forms. We analyzed the bacterium's DC surface proteome by selective biotinylation of surface proteins, NeutrAvidin affinity purification, and mass spectrometry. Transcriptional profiling of selected outer membrane protein candidates over the course of infection revealed that
aph_0248
(designated
asp14
[14-kDa
A. phagocytophilum
surface protein]) expression was upregulated the most during
A. phagocytophilum
cellular invasion.
asp14
transcription was induced during transmission feeding of
A. phagocytophilum
-infected ticks on mice and was upregulated when the bacterium engaged its receptor, P-selectin glycoprotein ligand 1. Asp14 localized to the
A. phagocytophilum
surface and was expressed during
in vivo
infection. Treating DC organisms with Asp14 antiserum or preincubating mammalian host cells with glutathione
S
-transferase (GST)–Asp14 significantly inhibited infection of host cells. Moreover, preincubating host cells with GST-tagged forms of both Asp14 and outer membrane protein A, another
A. phagocytophilum
invasin, pronouncedly reduced infection relative to treatment with either protein alone. The Asp14 domain that is sufficient for cellular adherence and invasion lies within the C-terminal 12 to 24 amino acids and is conserved among other
Anaplasma
and
Ehrlichia
species. These results identify Asp14 as an
A. phagocytophilum
surface protein that is critical for infection, delineate its invasion domain, and demonstrate the potential of targeting Asp14 in concert with OmpA for protecting against infection by
A. phagocytophilum
and other
Anaplasmataceae
pathogens.
Extremely Drug-Resistant Salmonella enterica Serovar Senftenberg Infections in Patients in Zambia
Authors: Hendriksen Rene S. , Joensen Katrine Grimstrup , Lukwesa-Musyani Chileshe , Kalondaa Annie , Leekitcharoenphon Pimlapas , Nakazwe Ruth , Aarestrup Frank M. , Hasman Henrik , Mwansa James C. L.
Published: October 2012

Two cases of extremely drug-resistant
Salmonella enterica
serovar Senftenberg isolated from patients in Zambia were investigated by utilizing MIC determinations and whole-genome sequencing. The isolates were resistant to, and harbored genes toward, nine drug classes, including fluoroquinolones and extended-spectrum cephalosporins, contained two plasmid replicons, and differed by 93 single-nucleotide polymorphisms.
A Case of Q Fever Prosthetic Joint Infection and Description of an Assay for Detection of Coxiella burnetii
Authors: Tande Aaron J. , Cunningham Scott A. , Raoult Didier , Sim Franklin H. , Berbari Elie F. , Patel Robin
Published: October 2012

We present the first published case of
Coxiella burnetii
prosthetic joint infection. Diagnosis was established with PCR and culture of periprosthetic tissue and synovial fluid (and serology). A novel PCR assay is described herein. Q fever should be considered in patients with prosthetic joint infection without an identified pathogen.
Cleavage of the Junin Virus Nucleoprotein Serves a Decoy Function To Inhibit the Induction of Apoptosis during Infection
Authors: Wolff Svenja , Becker Stephan , Groseth Allison
Published: October 2012

The regulation of apoptosis during infection is an important factor for host survival and, in some cases, also for the virus life cycle. At the same time, mechanisms to prevent the induction of apoptosis have been observed in numerous viral pathogens, but until now the role of apoptosis during arenavirus infection has not been investigated. Junin virus (JUNV) belongs to the New World arenavirus serogroup of the
Arenaviridae
and is the causative agent of Argentine hemorrhagic fever. We have demonstrated that infection with JUNV in cell culture does not induce apoptosis but leads to cleavage of the nucleoprotein (NP) into discrete products resembling caspase cleavage events. Similar specific NP degradation patterns were also observed in NP-transfected cell lines, and a closer examination of the sequence of NP showed several putative caspase cleavage motifs. Point mutations that abolished these cleavage motifs were consistent with the loss of certain cleavage products. Consistent with these data, further studies showed that treatment with a caspase inhibitor also reduced NP cleavage, indicating that the observed cleavage events were occurring as a result of caspase activity with NP as a substrate. Finally, we showed that expression of NP suppresses the cleavage of caspase 3 in cells treated with an apoptosis activator. Based on these findings, we propose that NP functions as a decoy substrate for caspase cleavage in order to inhibit the induction of apoptosis in JUNV-infected cells.
The Tale of the Long Tail: the Cytoplasmic Domain of HIV-1 gp41
Authors: Postler Thomas S. , Desrosiers Ronald C.
Published: October 2012

Envelope glycoproteins (Env) of lentiviruses typically possess unusually long cytoplasmic domains, often 150 amino acids or longer. It is becoming increasingly clear that these sequences contribute a diverse array of functional activities to the life cycle of their viruses. The cytoplasmic domain of gp41 (gp41CD) is required for replication of human immunodeficiency virus type 1 (HIV-1) in most but not all cell types, whereas it is largely dispensable for replication of simian immunodeficiency virus (SIV). Functionally, gp41CD has been shown to regulate rapid clathrin-mediated endocytosis of Env. The resultant low levels of Env expression at the cell surface likely serve as an immune avoidance mechanism to limit accessibility to the humoral immune response. Intracellular trafficking of Env is also regulated by gp41CD through interactions with a variety of cellular proteins. Furthermore, gp41CD has been implicated in the incorporation of Env into virions through an interaction with the virally encoded matrix protein. Most recently, the gp41CDs of HIV-1 and SIV were shown to activate the key cellular-transcription factor NF-κB via the serine/threonine kinase TAK1. Less well understood are the cytotoxicity- and apoptosis-inducing activities of gp41CD as well as potential roles in modulating the actin cytoskeleton and overcoming host cell restrictions. In this review, we summarize what is currently known about the cytoplasmic domains of HIV-1 and SIV and attempt to integrate the wealth of information in terms of defined functional activities.
Induction of Stress Granule-Like Structures in Vesicular Stomatitis Virus-Infected Cells
Authors: Dinh Phat X. , Beura Lalit K. , Das Phani B. , Panda Debasis , Das Anshuman , Pattnaik Asit K.
Published: October 2012

Previous studies from our laboratory revealed that cellular poly(C) binding protein 2 (PCBP2) downregulates vesicular stomatitis virus (VSV) gene expression. We show here that VSV infection induces the formation of granular structures in the cytoplasm containing cellular RNA-binding proteins, including PCBP2, T-cell-restricted intracellular antigen 1 (TIA1), and TIA1-related protein (TIAR). Depletion of TIA1 via small interfering RNAs (siRNAs), but not depletion of TIAR, results in enhanced VSV growth and gene expression. The VSV-induced granules appear to be similar to the stress granules (SGs) generated in cells triggered by heat shock or oxidative stress but do not contain some of the
bona fide
SG markers, such as eukaryotic initiation factor 3 (eIF3) or eIF4A, or the processing body (PB) markers, such as mRNA-decapping enzyme 1A (DCP1a), and thus may not represent canonical SGs or PBs. Our results revealed that the VSV-induced granules, called SG-like structures here, contain the viral replicative proteins and RNAs. The formation and maintenance of the SG-like structures required viral replication and ongoing protein synthesis, but an intact cytoskeletal network was not necessary. These results suggest that cells respond to VSV infection by aggregating the antiviral proteins, such as PCBP2 and TIA1, to form SG-like structures. The functional significance of these SG-like structures in VSV-infected cells is currently under investigation.
Shame! Self-stigmatisation as an obstacle to sick doctors returning to work: a qualitative study
Authors: Henderson Max , Brooks Samantha K , del Busso Lilliana , Chalder Trudie , Harvey Samuel B , Hotopf Matthew , Madan Ira , Hatch Stephani
Published: October 2012

Objective

To explore the views of sick doctors on the obstacles preventing them returning to work.

Design

Qualitative study.

Setting

Single participating centre recruiting doctors from all over the UK.

Participants

Doctors who had been away from work for at least 6 months with physical or mental health problems, drug or alcohol problems, General Medical Council involvement or any combination of these, were eligible. Eligible doctors were recruited in conjunction with the Royal Medical Benevolent Fund, the General Medical Council and the Practitioner Health Programme. These organisations approached 77 doctors; 19 participated. Each doctor completed an in-depth semistructured interview. We used a constant comparison method to identify and agree on the coding of the data and the identification of a number of central themes.

Results

The doctors described that being away from work left them isolated and sad. Many experienced negative reactions from their family and some deliberately concealed their problems. Doctors described a lack of support from colleagues and feared a negative response when returning to work. Self-stigmatisation was central to the participants’ accounts; several described themselves as failures and appeared to have internalised the negative views of others.

Conclusions

Self-stigmatising views, which possibly emerge from the belief that ‘doctors are invincible’, represent a major obstacle to doctors returning to work. From medical school onwards cultural change is necessary to allow doctors to recognise their vulnerabilities so they can more easily generate strategies to manage if they become unwell.
Field study of wrinkles in a geomembrane at a composite liner test site
Authors: Rowe R. Kerry , Chappel M.J. , Brachman R.W.I. , Take W.A.
Published: October 2012

The variation in length of the longest hydraulic features (connected wrinkles) formed in an exposed black high-density polyethylene (HDPE) geomembrane liner observed at different times of the day and in different seasons over multiple years is presented for both a 3% base slope and 3H:1V side slope at the Queen’s University Experimental Liner Test Site (latitude of 44°34′N and longitude 76°39′W). The longest wrinkle observed on the 0.15 ha base was about 1500 m. The longest wrinkle observed on the 0.17 ha slope was about 2000 m. The length of connected wrinkles is shown to be primarily related to solar radiation, although the soil and ambient temperature played a role in maintaining wrinkles in the afternoon as solar radiation decreased. Wrinkles of less than 20 m connected length were observed for geomembrane surface temperatures of less than 30 °C and solar radiation of less than 600 W/m2. Wrinkles exceeding 500 m in connected length were observed for geomembrane temperatures between about 30 and 62 °C and solar radiation between 600 and 1100 W/m2. The vast majority (about 85%) of wrinkle heights were between 0.04 and 0.08 m with the average wrinkle height being 0.06 m and a maximum wrinkle height of about 0.18 m. The manually measured wrinkle widths around noon (when there was the greatest number of wrinkles) ranged between about 0.20 and 0.43 m, but most of the wrinkles were between 0.23 and 0.36 m with a mean of 0.29 m (standard deviation 0.05 m). The data from this study suggest that a reasonable estimate of mean wrinkle width would be about 0.2 to 0.3 m. The size of the area constraining the geomembrane is shown to affect the connected wrinkle length. Calculations of leakage for the wrinkle lengths and widths observed are reported to be consistent with what has been reported for landfills in North America.
JACOBI ELLIPTIC MONOPOLE–ANTIMONOPOLE PAIR SOLUTIONS
Authors: TEH ROSY , TAN PEI-YEN , WONG KHAI-MING
Published: October 2012

We present new classical generalized Jacobi elliptic one monopole–antimonopole pair (MAP) solutions of the SU(2) Yang–Mills–Higgs theory with the Higgs field in the adjoint representation. These generalized 1-MAP solutions are solved with θ-winding number m = 1 and ϕ-winding number n = 1, 2, 3,…,6. Similar to the generalized Jacobi elliptic one monopole solutions, these generalized 1-MAP solutions are solved by generalizing the large distance behavior of the solutions to the Jacobi elliptic functions and solving the second order equations of motion numerically when the Higgs potential is vanishing (λ = 0) and nonvanishing (λ = 1). These generalized 1-MAP solutions possess total energies that are comparable to the total energy of the 1-MAP solution with winding number m = 1. However these total energies are significantly lower than the total energy of the 1-MAP solution with winding number m = 2. All these new generalized solutions are regular numerical finite energy non-BPS solutions of the Yang–Mills–Higgs field theory.
D-TERM DYNAMICAL SUPERSYMMETRY BREAKING GENERATING SPLIT ${\mathcal N} = 2$ GAUGINO MASSES OF MIXED MAJORANA–DIRAC TYPE
Authors: ITOYAMA H. , MARU NOBUHITO
Published: October 2012

Under a few mild assumptions, [Formula: see text] supersymmetry (SUSY) in four dimensions is shown to be spontaneously broken in a metastable vacuum in a self-consistent Hartree–Fock approximation of Bardeen–Cooper–Schrieffer/Nambu–Jona-Lasinio (BCS/NJL) type to the leading order, in the gauge theory specified by the gauge kinetic function and the superpotential of adjoint chiral superfields, in particular, that possess [Formula: see text] extended SUSY spontaneously broken to [Formula: see text] at tree level. We derive an explicit form of the gap equation, showing the existence of a nontrivial solution. The [Formula: see text] gauginos in the observable sector receive mixed Majorana–Dirac masses and are split due to both the nonvanishing 〈D0〉 and 〈F0〉 induced with 〈D0〉. It is argued that proper physical applications and assessment of the range of the validity of our framework are made possible by rendering the approximation into [Formula: see text] expansion.
INVESTIGATION OF OPTICAL PROPERTIES OF CdSexTe1-x NANOPARTICLES (NPs) SYNTHESIZED BY THERMOCHEMICAL METHOD
Authors: BAHARI H. S. , IRANIZAD E.-SAIEVAR , MOLAEI M.
Published: October 2012

CdSe x Te 1-x nanoparticles (NPs) have been synthesized by a thermochemical method in aqueous medium in presence of TGA as capping agent. XRD analysis demonstrated hexagonal phase CdSe x Te 1-x NPs. The size of these samples was found to be about 2.5 nm. UV-vis and photoluminescence (PL) spectra indicated a nonlinear relationship between band gap and composition related to bowing effect. Bowing constant was obtained at about b = 0.55 eV.
STRUCTURES OUT OF CHAOS IN BARRED-SPIRAL GALAXIES
Authors: PATSIS P. A.
Published: October 2012

We review the dynamical mechanisms we have found to support the morphological features in barred-spiral galaxies based on chaotic motions of stars in their gravitational fields. These morphological features are the spiral arms, that emerge out of the ends of the bar, but also shape the bar itself. The potentials used have been estimated directly from near-infrared images of barred-spiral galaxies. In this paper, we present the results from the study of the dynamics of the potentials of the galaxies NGC 4314, NGC 1300 and NGC 3359. The main unknown parameter in our models is the pattern speed of the system Ωp. By varying Ωp, we have investigated several cases trying to match the results of our modeling with available photometrical and kinematical data. We found realistic models with stars on spirals in chaotic motion, while their bars are built by stars usually on regular orbits. However, we also encountered cases, where a major part of trajectories of the stars even in the bar is chaotic as well. Finally, we examined the gas dynamics of barred-spiral systems, and found that the presence of gas reinforces the intensity of the "chaotic" spiral arms.
ON A NOVEL CLASS OF INTEGRABLE ODEs RELATED TO THE PAINLEVÉ EQUATIONS
Authors: FOKAS ATHANASSIOS S. , YANG DI
Published: October 2012

One of the authors recently introduced the concept of conjugate Hamiltonian systems: the solution of the equation h = H(p, q, t), where H is a given Hamiltonian containing t explicitly, yields the function t = T(p, q, h), which defines a new Hamiltonian system with Hamiltonian T and independent variable h. By employing this construction and by using the fact that the classical Painlevé equations are Hamiltonian systems, it is straightforward to associate with each Painlevé equation two new integrable ODEs. Here, we investigate the conjugate Painlevé II equations. In particular, for these novel integrable ODEs, we present a Lax pair formulation, as well as a class of implicit solutions. We also construct conjugate equations associated with Painlevé I and Painlevé IV equations.
PROBING THE LOCAL DYNAMICS OF PERIODIC ORBITS BY THE GENERALIZED ALIGNMENT INDEX (GALI) METHOD
Authors: MANOS T. , SKOKOS CH. , ANTONOPOULOS CH.
Published: October 2012

As originally formulated, the Generalized Alignment Index (GALI) method of chaos detection has so far been applied to distinguish quasiperiodic from chaotic motion in conservative nonlinear dynamical systems. In this paper, we extend its realm of applicability by using it to investigate the local dynamics of periodic orbits. We show theoretically and verify numerically that for stable periodic orbits, the GALIs tend to zero following particular power laws for Hamiltonian flows, while they fluctuate around nonzero values for symplectic maps. By comparison, the GALIs of unstable periodic orbits tend exponentially to zero, both for flows and maps. We also apply the GALIs for investigating the dynamics in the neighborhood of periodic orbits, and show that for chaotic solutions influenced by the homoclinic tangle of unstable periodic orbits, the GALIs can exhibit a remarkable oscillatory behavior during which their amplitudes change by many orders of magnitude. Finally, we use the GALI method to elucidate further the connection between the dynamics of Hamiltonian flows and symplectic maps. In particular, we show that, using the components of deviation vectors orthogonal to the direction of motion for the computation of GALIs, the indices of stable periodic orbits behave for flows as they do for maps.
EXACT TRAVELING WAVE SOLUTIONS AND THEIR BIFURCATIONS FOR THE GENERALIZED POCHHAMMER–CHREE EQUATIONS
Authors: LI JIBIN , CHEN GUANRONG
Published: October 2012

By using the method of dynamical systems to study the generalized Pochhammer–Chree equations, the dynamics of traveling wave solutions are characterized under different parameter conditions. Some exact parametric representations of the traveling wave solutions are obtained. Thus, many results reported in the literature can be completed.
FITTING A STEP FUNCTION TO A POINT SET WITH OUTLIERS BASED ON SIMPLICIAL THICKNESS DATA STRUCTURES
Authors: CHEN DANNY Z. , WANG HAITAO
Published: October 2012

Given a real ∊ > 0, an integer g ≥ 0 and a set of points in the plane, we study the problem of computing a piecewise linear functional curve with minimum number of line segments to approximate all points after removing g outliers such that the approximation error is at most ∊. We give an improved algorithm over the previous work. The algorithm is based on two dynamic data structures developed in this paper for the simplicial thickness queries, which are of independent interest. For a set S of simplices in the d-dimensional space ℝd(d ≥ 2 is a constant), the simplicial thickness of a point p is defined as the number of simplices in S that contain p. Given a set P of n points in ℝd, we develop two dynamic data structures to support the following operations. (1) Simplex insertion: Insert a simplex into S. (2) Simplex deletion: Delete a simplex from S. (3) Simplicial thickness query: Given a query simplex σ, compute the minimum simplicial thickness among all points in σ∩P. The first data structure is constructed in O(n1+δ) time, for any constant δ > 0, and can support each operation in O(n1-1/d) time; the second one is con-structed in O(n log n) time and can support each operation in O(n1-1/d( log n)O(1)) time. Both data structures use O(n). space. These data structures may find other applications as well.
SEARCHING POLYHEDRA BY ROTATING HALF-PLANES
Authors: VIGLIETTA GIOVANNI
Published: October 2012

THE SEARCHLIGHT SCHEDULING PROBLEM was first studied in 2-dimensional polygons, where the goal is for point guards in fixed positions to rotate searchlights to catch an evasive intruder. Here the problem is extended to 3-dimensional polyhedra, with the guards now boundary segments who rotate half-planes of illumination.

After carefully detailing the 3-dimensional model, several results are established. The first is a nearly direct extension of the planar one-way sweep strategy using what filling guards, a generalization that succeeds despite there being no well-defined we call notion in 3-dimensional space of planar "clockwise rotation." Next follow two results: every polyhedron with r > 0 reflex edges can be searched by at most r2 suitably placed boundary guards, whereas just r edguards suffice if the polyhedron is orthogonal. (Mini-mizing the number of guards to search a given polyhedron is easily seen to be NP-hard.) Finally we show that deciding whether a given set of boundary guards has a successful search schedule is strongly NP-hard. A number of peripheral results are proved en route to these central theorems, and several open problems remain for future work.
The Relationship between Underinvestment, Overinvestment and CEO's Compensation
Authors: Baxamusa Mufaddal
Published: October 2012

This research separates out the incentive and entrenchment effects of executive pay and uses it to test if the agency cost is that of underinvestment or overinvestment. I find that investments increase with dollar value of stock and options owned by the CEO but decrease with percentage of shares owned by the CEO. These results are robust to alternate measures of investments such as R&D, acquisitions, and change in assets. It appears that the positive relationship between investment and percentage of stocks owned by the CEO, as observed in the literature, is because of the omitted variable of dollar value of stock and options. I also find that the increases in dollar value of stock and options owned by the CEO reduces agency costs; while increases in percentage of stocks owned by the CEO increases entrenchment. These results are robust to endogeniety and a battery of relevant tests. This research concludes that, for the average firm, the agency cost is that of underinvestment, while the concerns about overinvestment are overstated.
Disciplinary Corporate Takeovers: Evidence for Australia
Authors: Dullard Stuart , Hawtrey Kim
Published: October 2012

This paper tests the relationship between takeovers and poor management performance, known as the market discipline hypothesis. We create a proprietary new Australian dataset for this study by individually researching company reports for executive retention data. We assess takeover targets for pre-bid managerial inefficiency and find evidence that Australian target companies exhibit negative abnormal returns prior to takeover. In particular, we find that disciplinary targets underperform their non-disciplinary counterparts. Our tests take into account the difference between friendly and hostile takeovers, and the industry sector in which the target firm operates.
Asymmetric Information and Market Decline: Evidence from the Chinese Market
Authors: Narayan Paresh Kumar , Zheng Xinwei
Published: October 2012

In this paper, we show that aggregate illiquidity is a priced risk factor on the Shanghai Stock Exchange (SHSE). We develop the relationship between the illiquidity factor, asymmetric information, and market decline. Our empirical results show that while the illiquidity factor is a source of asymmetric information on the SHSE, asymmetric information does not trigger market decline.
A HIGHER CHERN–WEIL DERIVATION OF AKSZ σ-MODELS
Authors: FIORENZA DOMENICO , ROGERS CHRISTOPHER L. , SCHREIBER URS
Published: October 2012

Chern–Weil theory provides for each invariant polynomial on a Lie algebra 𝔤 a map from 𝔤-connections to differential cocycles whose volume holonomy is the corresponding Chern–Simons theory action functional. Kotov and Strobl have observed that this naturally generalizes from Lie algebras to dg-manifolds and to dg-bundles and that the Chern–Simons action functional associated this way to an n-symplectic manifold is the action functional of the AKSZ σ-model whose target space is the given n-symplectic manifold (examples of this are the Poisson σ-model or the Courant σ-model, including ordinary Chern–Simons theory, or higher-dimensional Abelian Chern–Simons theory). Here we show how, within the framework of the higher Chern–Weil theory in smooth ∞-groupoids, this result can be naturally recovered and enhanced to a morphism of higher stacks, the same way as ordinary Chern–Simons theory is enhanced to a morphism from the stack of principal G-bundles with connections to the 3-stack of line 3-bundles with connections.
Meso–meso directly linked dipyrrolyl ligand dimer that shows the formation of metal-coordination polymers
Authors: Maeda Hiromitsu , Kobayashi Hiroaki , Akuta Ryo
Published: October 2012

A novel dipyrrolyl metal-coordination ligand dimer directly connected at the meso positions showed the formation of a ZnII -bridged coordination polymer and the spontaneous transformation to a meso–meso- and singly β–β-fused tetrapyrrolyl molecule in solution by C–C bond formation and concomitant proton migration.
Synthesis and photophysicochemical studies of non-metal 2,3,9,10,16,17,23,24-octacarboxyphthalocyanine
Authors: Kuznetsova Nina A. , Shevchenko Ekaterina N. , Makarov Dmitry A. , Slivka Ludmila K. , Solovyova Ludmila I. , Kaliya Oleg L. , Lukyanets Evgeny A.
Published: October 2012

A new method of preparation and the properties (solubility, aggregation, spectralluminescent properties, singlet oxygen and photobleaching quantum yields) of non-metal 2,3,9,10,16,17,23,24-octacarboxyphthalocyanine are reported. The influence of ionization state on photophysicochemical properties of this dye is also presented.
The Elementary Particle Physics Research in Singapore: the Past, the Present and the Future
Authors: Phua Kok Khoo
Published: October 2012

The discovery of the Higgs Boson (or more popularly known in media as God particle) in early July was hailed as one of the most significant scientific breakthrough in the 21st Century, stirring a sensation in the Science community and Media around the world. This discovery allows us to reassess our understanding of the importance of elementary particle physics or high energy physics, and how its study has to a certain extent influenced the direction of future development of scientific research as a whole. In this article, we want to take a look at how Singapore has fared in this area so far, and discuss some of the issues concerning the policies and directions of the research in the basic sciences in the Asia Pacific region.
Fifth ASTROD Symposium and Outlook of Direct Gravitational-Wave Detection
Authors: Arun K. G. , Iyer Bala R. , Ni Wei-Tou
Published: October 2012

From July 11 to July 13, 2012, Raman Research Institute (Bangalore, India) hosted the Fifth International ASTROD Symposium on Laser Astrodynamics, Space Test of Relativity and Gravitational-Wave Astronomy. About sixty persons attended the Symposium including 24 invited speakers, 15 professionals from various fields and 20 students (Fig. 1). The aim of this series of Symposia is to focus on various disciplines related to fundamental physics in space, to foster dialogues and to plan for the future. Previous ASTROD Symposia were held during September 21-23, 2001 (Beijing), June 2-3, 2005 (Bremen), July 14-16, 2006 (Beijing) and July 16-17, 2010 (Bremen).
Scientific Achievements of Prof. Chien Shiung Wu
Authors: Lu Tan
Published: October 2012

Five years ago, we wrote two papers in memory of Prof. Chien Shiung Wu [1-2]. And now in memory of her 100th birthday, I am very happy to write this paper again. Indeed, she is a world top-class female experimental nuclear physicist. She is also known as the Chinese Madame Curie. As is well known, Madame (Marie) Curie was the first in discovering the radioactive substances, while C. S. Wu was the first in thoroughly studying β-decay, the most mysterious one among radioactivities. C. S. Wu did various experiments in proving the Fermi's theory of β-decay carefully and precisely, and even also improving it precisely and perfectly, and leading to the correct V-A form of the β-interaction and even leading to the electro-weak unification finally. Indeed, C. S. Wu known as Chinese Madame Curie is reasonable and admirable. As compared with Madame Curie, E. Segrè (1980) even said that C. S. Wu is more worldly, elegant, and witty [3].
First International Workshop on Web Science and Information Exchange in the Medical Web (MedEx 2010)
Authors: Denecke Kerstin , Dolog Peter
Published: October 2012

In April 2010, the First International Workshop on Web Science and Information Exchange in the Medical Web took place in Raleigh / North Carolina. This workshop was devoted to the technologies for dealing with social- and multi media data for medical information gathering and exchange. The workshop served as a forum for the confluence of new and multidisciplinary ideas that will help to drive research in the areas of medical web text and data mining.
HealthAchieve 2010
Authors: Padamadan D. J. , Closson Tom , Gabriele Joseph , Latam Janice , Pino Giuseppe
Published: October 2012

Here we summarize the
HealthAchieve
2010 event held November 8
th
-10
th
in Toronto, Canada.
HealthAchieve
is considered the definitive
Canadian healthcare delivery experience
conference. The insights garnered among attending delegates serves to expand the existing knowledge base and promote the need for research in healthcare to address respective enterprise gap deficiencies in delivery and quality.
HealthAchieve
2010, illuminated delegate awareness to decentralization trends; health promotion and wellbeing initiatives; optimal delivery approaches; chronic disease management, primary prevention, evidence-based best practices; and fundraising strategies. The conference encouraged learning, relationship building, knowledge sharing, and the strengthening of existing partnerships.
IEEE VisWeek Workshop on Visual Analytics in Health Care 2010
Authors: Gotz David , Sun Jimeng
Published: October 2012

Around the world, tremendous sums of money and time are being spent modernizing the health care ecosystem to improve outcomes and reduce cost. One of the critical hypotheses behind many of these efforts is that the collection of electronic data, such as longitudinal electronic health records (EHRs), will enable tools that provide actionable insights about a patient's condition required to make more intelligent medical decisions. This data-driven vision promises to improve care in facilities ranging from emergency rooms to general practitioner offices.
Pervasive healthcare
Authors: Maitland Julie , McGee-Lennon Marilyn , Mulvenna Maurice
Published: October 2012

This purpose of this article is to help the reader understand the research area of
pervasive healthcare
and pervasive healthcare computing. It defines the term, and discusses the 2011 conference on Pervasive Computing Technologies for Healthcare, held in Dublin, Ireland. In particular, it examines the workshops proposed for the conference, highlighting the current exploratory research on the fringe of the area of pervasive computing, before discussing the implications for mainstream healthcare.
Verification of Safety-critical Software
Authors: Andersen B. Scott , Romanski George
Published: October 2012

Avionics software has become a keystone in today’s aircraft design. Advances in avionics systems have reduced aircraft weight thereby reducing fuel consumption, enabled precision navigation, improved engine performance, and provided a host of other benefits. These advances have turned modern aircraft into flying data centers with computers controlling or monitoring many of the critical systems onboard. The software that runs these aircraft systems must be as safe as we can make it.
The World According to LINQ
Authors: Meijer Erik
Published: October 2012

Programmers building Web- and cloud-based applications wire together data from many different sources such as sensors, social networks, user interfaces, spreadsheets, and stock tickers. Most of this data does not fit in the closed and clean world of traditional relational databases. It is too big, unstructured, denormalized, and streaming in realtime. Presenting a unified programming model across all these disparate data models and query languages seems impossible at first. By focusing on the commonalities instead of the differences, however, most data sources will accept some form of computation to filter and transform collections of data.
Static bus schedule aware scratchpad allocation in multiprocessors
Authors: Chattopadhyay Sudipta , Roychoudhury Abhik
Published: October 2012

Compiler controlled memories or scratchpad memories offer more predictable program execution times than cache memories. Scratchpad memories are often employed in multi-processor system-on-chip (MPSoC) platforms which seek to meet the performance needs of embedded applications while limiting power consumption and timing unpredictability. Scratchpad allocation schemes optimize performance while ensuring predictable execution times (as compared to caches).

In this work, we develop a compile-time scratchpad allocation framework for multi-processor platforms, where the processors (virtually) share on-chip scratchpad space and external memory is accessed through a shared bus. Our allocation method considers the waiting time for bus access while deciding which memory blocks to load into the shared scratchpad memory space. Incorporating the bus schedule into our scratchpad allocation method leads to a global optimization of an application, as compared to employing local scratchpad allocation schemes in individual processors which locally optimize the per-processor execution time. We evaluate the efficacy, sensitivity and efficiency of our memory allocation scheme on two real-world embedded applications - an application controlling an Unmanned Aerial Vehicle (UAV), and a (fragment of) an in-orbit spacecraft software.
Synchronous programming of device drivers for global resource control in embedded operating systems
Authors: Berthier Nicolas , Maraninchi Florence , Mounier Laurent
Published: October 2012

In embedded systems, controlling a shared resource like the bus, or improving a property like power consumption, may be hard to achieve when programming device drivers individually. There is a need for global resource control, taking decisions based on a centralized view of the devices' states. In this paper, we study power consumption in sensor networks, where the nodes are small embedded systems powered by batteries. We concentrate on the hardware/software architecture of a node, where significant gains can be achieved by controlling the consumption modes of the various devices globally. The architecture we propose involves a simple adaptation of the application level, to communicate with the hardware via a control layer. The control layer itself is built from a set of simple automata: the drivers of the devices, whose states correspond to power consumption modes, and a controller that enforces global properties. All these automata are programmed using a synchronous language, whose compiler performs static scheduling and produces a single piece of C code. We explain the approach in details, demonstrate its use with either Contiki or a traditional multithreading operating system, and report on our experiments.
Dependence-based multi-level tracing and replay for wireless sensor networks debugging
Authors: Wang Man , Li Zhiyuan , Li Feng , Feng Xiaobing , Bagchi Saurabh , Lu Yung-Hsiang
Published: October 2012

Due to resource constraints and unreliable communication, wireless sensor network (WSN) programming and debugging remain to be a challenging task. Runtime errors must be constantly monitored, often by checking for violations of certain invariants. Once an error is detected, diagnosis must be performed to identify the origin of the error. Deterministic replay is an error diagnosis method which has long been proposed for distributed systems. However, one of the significant hurdles for applying deterministic replay on WSN is posed by the small program memory on typical sensor nodes. This paper proposes a dependence-based multi-level method for memory-efficient tracing and replay. In the interest of portability across different hardware platforms, the method is implemented as a source-level tracing and replaying tool. To further reduce the code size after tracing instrumentation, a cost model is used for making the decision on which functions to in-line. A prototype for the tool targets C programs is developed on top of the Open64 compiler and is tested using several TinyOS applications running on TelosB motes. Preliminary experimental results show that the test programs, which do not fit the program memory after straightforward instrumentation, can be successfully accommodated in memory using the new method such that the injected errors can be found.
Cache persistence analysis
Authors: Cullmann Christoph
Published: October 2012

To compute a worst-case execution time (WCET) estimate for a program, the architectural effects of the underlying hardware must be modeled. For modern processors this results in the need for a cache and pipeline analysis. The timing-relevant result of the cache analysis is the categorization of the accesses to cached memory. Categorizations that are obtainable by the well-known must and may cache analysis are always-hit, always-miss and not-classified. The cache persistence analysis tries to provide additional information for the not-classified case to limit the number of misses.

There exists a cache persistence analysis by Ferdinand and Wilhelm based on abstract interpretation computing these classifications. In this paper, we present a correctness issue with this analysis and a novel analysis that fixes it. For fully timing compositional architectures the persistence information is straightforward to use. We will focus on the application of the persistence analysis for state-of-the-art architectures that show timing anomalies. Such architectures do not allow to quantify the costs of a single cache hit or miss in isolation. To make the usage of the persistence information feasible, we integrate the novel persistence analysis together with a novel path analysis approach into the industrially used WCET analyzer aiT.
An instruction-scheduling-aware data partitioning technique for coarse-grained reconfigurable architectures
Authors: Jang Choonki , Kim Jungwon , Lee Jaejin , Kim Hee-Seok , Yoo Dong-Hoon , Kim Sukjin , Kim Hong-Seok , Ryu Soojung
Published: October 2012

In this paper, we propose a data partitioning technique for the memory subsystem that consists of a multi-ported scratchpad memory (SPM) unit and a single-ported data cache in coarse-grained reconfigurable arrays (CGRA) architecture. The embedded reconfigurable processor executes programs by switching between the Non-VLIW and VLIW modes depending on the type of the code region to achieve high performance. The VLIW mode exploits code regions with high ILP that require high memory bandwidth and the Non-VLIW mode exploits those with low ILP that require low memory latency. Our data partitioning technique between the SPM and the data cache is based on data interference graph reduction and profiling information. Given an SPM size, it finds the optimal data partitions by taking the VLIW instruction schedule into consideration. We evaluate our data partitioning technique for the CGRA architecture with three representative multimedia applications.
Pervasive computing technologies for healthcare
Authors: O'Grady Michael , O'Hare Gregory , O'Donoghue John
Published: October 2012

The conference series on Pervasive Computing Technologies for Healthcare is one of the leading fora for research dissemination in this space. In May 2011, the most recent event took place in Ireland. A brief overview of the conference is now presented.
Creating Languages in Racket
Authors: Flatt Matthew
Published: October 2012

Choosing the right tool for a simple job is easy: a screwdriver is usually the best option when you need to change the battery in a toy, and grep is the obvious choice to check for a word in a text document. For more complex tasks, the choice of tool is rarely so straightforward--all the more so for a programming task, where programmers have an unparalleled ability to construct their own tools. Programmers frequently solve programming problems by creating new tool programs, such as scripts that generate source code from tables of data.