bluuebunny/crossref_metadata_2025_split huggingface dataset:
What Longevity Predictors Should Be Allowed for When Valuing Pension Scheme Liabilities?
Authors: Madrigal A. M. , Matthews F. E. , Patel D. D. , Gaches A. T. , Baxter S. D. 
Published: March 2011

AbstractData held within administration records of occupational pension schemes yield a rich source of information on mortality rates and the statistical predictors (covariates) of longevity. In this paper we provide, for the first time, a multivariable analysis of post-retirement mortality using the detailed information held within occupational pension scheme records.Using the extensive dataset of over one million living pensioners and dependants and 530,000 historic deaths collected by Club Vita, we investigate the importance of factors including gender, affluence and lifestyle on the observed period life expectancy of individuals. We describe one approach to constructing a multivariable model for pensioner baseline mortality, showing how such factors explain a variation in observed period life expectancy in excess of ten years. The relative importance of each factor on mortality is analysed and we describe the interactions between these factors and age, answering questions such as whether the impact of a healthy lifestyle or affluence attenuates with age. Further, we highlight the importance of the choice of affluence measure in analysing mortality, and show that the salary at retirement is a better predictor of longevity than the pension amount for male pensioners.The results of this paper are directly relevant to any pensions actuary advising on an appropriate baseline assumption (i.e. current mortality rates) for use with occupational pension schemes.
A Review of Strain Analysis Using Electron Backscatter Diffraction
Authors: Wright Stuart I. , Nowell Matthew M. , Field David P. 
Published: March 2011

AbstractSince the automation of the electron backscatter diffraction (EBSD) technique, EBSD systems have become commonplace in microscopy facilities within materials science and geology research laboratories around the world. The acceptance of the technique is primarily due to the capability of EBSD to aid the research scientist in understanding the crystallographic aspects of microstructure. There has been considerable interest in using EBSD to quantify strain at the submicron scale. To apply EBSD to the characterization of strain, it is important to understand what is practically possible and the underlying assumptions and limitations. This work reviews the current state of technology in terms of strain analysis using EBSD. First, the effects of both elastic and plastic strain on individual EBSD patterns will be considered. Second, the use of EBSD maps for characterizing plastic strain will be explored. Both the potential of the technique and its limitations will be discussed along with the sensitivity of various calculation and mapping parameters.
LOOP GROUPS, STRING CLASSES AND EQUIVARIANT COHOMOLOGY
Authors: VOZZO RAYMOND F. 
Published: March 2011

AbstractWe give a classifying theory for LG-bundles, where LG is the loop group of a compact Lie group G, and present a calculation for the string class of the universal LG-bundle. We show that this class is in fact an equivariant cohomology class and give an equivariant differential form representing it. We then use the caloron correspondence to define (higher) characteristic classes for LG-bundles and to prove a result for characteristic classes for based loop groups for the free loop group. These classes have a natural interpretation in equivariant cohomology and we give equivariant differential form representatives for the universal case in all odd dimensions.
PCR-based analysis of microbial communities during the EuroGeoMars campaign at Mars Desert Research Station, Utah
Authors: Thiel Cora S. , Ehrenfreund Pascale , Foing Bernard , Pletser Vladimir , Ullrich Oliver 
Published: March 2011

AbstractThe search for evidence of past or present life on Mars will require the detection of markers that indicate the presence of life. Because deoxyribonucleic acid (DNA) is found in all known living organisms, it is considered to be a ‘biosignature’ of life. The main function of DNA is the long-term storage of genetic information, which is passed on from generation to generation as hereditary material. The Polymerase Chain Reaction (PCR) is a revolutionary technique which allows a single fragment or a small number of fragments of a DNA molecule to be amplified millions of times, making it possible to detect minimal traces of DNA. The compactness of the contemporary PCR instruments makes routine sample analysis possible with a minimum amount of laboratory space. Furthermore the technique is effective, robust and straightforward. Our goal was to establish a routine for the detection of DNA from micro-organisms using the PCR technique during the EuroGeoMars simulation campaign. This took place at the Mars Society's Mars Desert Research Station (MDRS) in Utah in February 2009 (organized with the support of the International Lunar Exploration Working Group (ILEWG), NASA Ames and the European Space Research and Technology Centre (ESTEC)). During the MDRS simulation, we showed that it is possible to establish a minimal molecular biology lab in the habitat for the immediate on-site analysis of samples by PCR after sample collection. Soil and water samples were taken at different locations and soil depths. The sample analysis was started immediately after the crew returned to the habitat laboratory. DNA was isolated from micro-organisms and used as a template for PCR analysis of the highly conserved ribosomal DNA to identify representatives of the different groups of micro-organisms (bacteria, archaea and eukarya). The PCR products were visualized by agarose gel electrophoresis and documented by transillumination and digital imaging. The microbial diversity in the collected samples was analysed with respect to sampling depth and the presence or absence of vegetation. For the first time, we have demonstrated that it is possible to perform direct on-site DNA analysis by PCR at MDRS, a simulated planetary habitat in an extreme environment that serves as a model for preparation and optimization of techniques to be used for future Mars exploration.
New X-ray absorption fine structure measurement system under atmospheric pressure in the soft X-ray region at SAGA Light Source
Authors: Okajima Toshihiro , Ohtani Ryota 
Published: March 2011

A new X-ray absorption fine structure (XAFS) measurement system under atmospheric pressure in the soft X-ray region has been installed at the beamline BL11 of Saga Light Source (SAGA-LS) in Japan. XAFS spectra in the lower photon energy region of about 2–4 keV could be newly obtained at the beamline. The system was applied to obtain sulphur K-edge XAFS spectra of solid and oily specimens using fluorescence yield and electron yield modes. The spectra were successfully collected. We anticipate that this new system will have various applications in environmental and biochemical research.
Erratum: Aerobic denitrification in permeable Wadden Sea sediments
Authors: Gao Hang , Schreiber Frank , Collins Gavin , Jensen Marlene M , Kostka Joel E , Lavik Gaute , de Beer Dirk , Zhou Huai-yang , Kuypers Marcel M M 
Published: March 2011

Abstract
Correction to: The ISME Journal (2010) 4, 417–426; doi:10.1038/ismej.2009.127 Since the publication of this paper, the authors have noticed an error in the list of co-authors and affiliations. The correct list of co-authors and affiliations is shown below. Hang Gao1,2,3, Frank Schreiber1, Gavin Collins1,4, Marlene M Jensen1,5, Olivera Svitlica1, Joel E Kostka1,6, Gaute Lavik1, Dirk de Beer1, Huai-yang Zhou2,7 and Marcel MM Kuypers1
Translocation, switching and gating: potential roles for ATP in long-range communication on DNA by Type III restriction endonucleases
Authors: Szczelkun Mark D. 
Published: March 2011

To cleave DNA, the Type III RM (restriction–modification) enzymes must communicate the relative orientation of two recognition sequences, which may be separated by many thousands of base pairs. This long-range interaction requires ATP hydrolysis by a helicase domain, and both active (DNA translocation) and passive (DNA sliding) modes of motion along DNA have been proposed. Potential roles for ATP binding and hydrolysis by the helicase domains are discussed, with a focus on bipartite ATPases that act as molecular switches.
Ferritin heavy chain‐mediated iron homoeostasis regulates expression of IL‐10 in Chlamydia trachomatis‐infected HeLa cells
Authors: Vardhan Harsh , Gupta Rishein , Jha Rajneesh , Bhengraj Apurb Rashmi , Mittal Aruna 
Published: March 2011

AbstractChlamydia trachomatis is the leading cause of sexually transmitted infection worldwide, in which disease outcome is determined by the balance between pro‐ and anti‐inflammatory host immune responses. Iron plays important roles in regulation and enhancement of various pro‐ and anti‐inflammatory cytokines. Earlier studies have established essentiality of iron in C. trachomatis infection; however, there is lack of study wherein modulatory effect of iron regulated protein [FHC (ferritin heavy chain)] in regulation of anti‐inflammatory cytokine IL (interleukin)‐10 has been investigated. In this study, immunoblotting results showed the up‐regulation of FHC in C. trachomatis‐infected HeLa cells in comparison with mock (in vitro control). Further secretory IL‐10 level was significantly increased (P<0.001) or decreased (P<0.001) in response to iron supplementation [FAC (ferric ammonium citrate)] and depletion [DFO (deferoxamine)], respectively. However, in C. trachomatis‐infected HeLa cells, levels of IL‐10 remain higher, irrespective of availability of iron in comparison with their respective control. These results showed that secretion of IL‐10 and expressions of FHC have concordance. Further, to understand interdependence of IL‐10 and iron homoeostasis (regulation), the levels of IL‐10 were compared with iron‐responsive GFP (green fluorescent protein) expression in HeLa‐229 cells. The mean fluorescent intensities of GFP were in accordance with levels of IL‐10 in C. trachomatis‐infected cells. These results showed the association of secreted IL‐10, FHC and iron homoeostasis in C. trachomatis‐infected HeLa‐229 cells. This study provides insight into host–Chlamydia interaction at the crossroad of iron metabolism and immune responses and may help in realizing the potential of iron homoeostasis modulators in treatment of chronic chlamydial infection.
Histamine promotes the expression of receptors TLR2 and TLR4 and amplifies sensitivity to lipopolysaccharide and lipoteichoic acid treatment in human gingival fibroblasts
Authors: Gutiérrez‐Venegas Gloria , Cruz‐Arrieta Sandra , Villeda‐Navarro Mónica , Méndez‐Mejía José Antonio 
Published: March 2011

AbstractThe vasoactive hydrophilic amine histamine is the most important molecule released by mast cells. However, histamine's role in activating intracellular responses in HGFs (human gingival fibroblasts) has not been evaluated to date. In the present study, we investigated the effect of histamine and of Gram‐negative [LPS (lipopolysaccharide)] and Gram‐positive [LTA (lipoteichoic acid)] bacterial components on the modulation of the inflammatory response of HGFs. We incubated HGFs with histamine to determine whether this hydrophilic amine regulates overexpression of TLR2 (Toll‐like receptor 2) and TLR4, which recognize LTA and LPS respectively. Our experiments demonstrated that histamine increases transcription and translation of TLR2 and TLR4. Incubation with LTA or LPS in the presence of histamine markedly increased expression of COX2 (cyclo‐oxygenase 2) and synthesis of prostaglandin E2. These results suggest that histamine plays an important role in modulating the innate immune response, and likewise, that LTA and LPS regulate the adaptive immune response. The present study provides information about the regulation and expression of molecules that promote chronic inflammatory processes leading to the emergence of periodontitis and the consequent loss of the dental organ.
Modelling Early-type Stars in Eclipsing Binaries of Open Clusters: A New Method for Age Determination from the Ratio of Radii
Authors: Yıldız M. 
Published: March 2011

AbstractBinary systems, in particular eclipsing binaries, are essential sources of knowledge of the fundamental properties of stars. The ages of binaries, members of open clusters, are constrained by their own fundamental properties and by those of the hosting cluster. The ages of eleven open clusters are here found by constructing models for the components of twelve eclipsing binaries. The difference between the ages we find and the ages of the clusters derived from isochrone fitting is up to 40%. For the binary system V497 Cep in NGC 7160, the difference is about 100%. Binary systems whose primary component is about to complete its main-sequence lifetime, such as V453 Cyg and V906 Sco, are the most suitable systems for age determination. Using model results for these stars, we derive an expression for sensitive and uncomplicated relative age determination of binary systems (age divided by the main-sequence lifetime of the primary star). The expression is given as a logarithm of radii ratio divided by a logarithm of mass ratio. Two advantages of this expression are that: (i) it is nearly independent of the assumed chemical composition of the models because of the appearance of the ratio of radii; and (ii) the ratios of radii and masses are observationally much more precise than their absolute values. We also derive another expression using luminosities rather than radii and compare results.
Astrophysical Supercomputing with GPUs: Critical Decisions for Early Adopters
Authors: Fluke Christopher J. , Barnes David G. , Barsdell Benjamin R. , Hassan Amr H. 
Published: March 2011

AbstractGeneral-purpose computing on graphics processing units (GPGPU) is dramatically changing the landscape of high performance computing in astronomy. In this paper, we identify and investigate several key decision areas, with a goal of simplifying the early adoption of GPGPU in astronomy. We consider the merits of OpenCL as an open standard in order to reduce risks associated with coding in a native, vendor-specific programming environment, and present a GPU programming philosophy based on using brute force solutions. We assert that effective use of new GPU-based supercomputing facilities will require a change in approach from astronomers. This will likely include improved programming training, an increased need for software development best practice through the use of profiling and related optimisation tools, and a greater reliance on third-party code libraries. As with any new technology, those willing to take the risks and make the investment of time and effort to become early adopters of GPGPU in astronomy, stand to reap great benefits.
Nucleosynthesis in the Stellar Systems ω Centauri and M22
Authors: Da Costa G. S. , Marino A. F. 
Published: March 2011

AbstractThe stellar system ω Centauri (ω Cen) is well known for the large range in elemental abundances among its member stars. Recent work has indicated that the globular cluster M22 (NGC 6656) also possesses an internal abundance range, albeit substantially smallerthan that in ω Cen. Here we compare, as a function of [Fe/H], element-to-iron ratios in the two systems for a number of different elements using data from abundance analyses of red giant branch stars. It appears that the nucleosynthetic enrichment processes were very similar in these two systems despite the substantial difference in total mass.
What Is a Galaxy? Cast Your Vote Here
Authors: Forbes Duncan A. , Kroupa Pavel 
Published: March 2011

AbstractAlthough originally classified as galaxies, Ultra-Compact Dwarfs (UCDs) have many properties in common with globular star clusters. The debate on the origin and nature of UCDs, and the recently discovered ultra-faint dwarf spheroidal (dSph) galaxies which contain very few stars, has motivated us to as the question ‘What is a galaxy?’ Our aim here is to promote further discussion of how to define a galaxy and, in particular, what separates it from a star cluster. Like most previous definitions, we adopt the requirement of gravitationally bound stellar system as a minimum. In order to distinguish a dwarf galaxy from a globular cluster, we discuss other possible requirements, such as a minimum size, a long two-body relaxation time a satellite system, the presence of complex stellar populations and non-baryonic dark matter. We briefly mention the implications of the adoption of each of these definitions. Some special cases of objects with a ambiguous nature are also discussed. Finally, we give our favoured criteria, and in the spirit of ‘collective wisdom’, invite readers to vote on their prefered definition of a galaxy via a dedicated website.
Eastern Equatorial Pacific productivity and related-CO
2
changes since the last glacial period
Authors: Calvo Eva , Pelejero Carles , Pena Leopoldo D. , Cacho Isabel , Logan Graham A. 
Published: March 2011

Understanding oceanic processes, both physical and biological, that control atmospheric CO
2
is vital for predicting their influence during the past and into the future. The Eastern Equatorial Pacific (EEP) is thought to have exerted a strong control over glacial/interglacial CO
2
variations through its link to circulation and nutrient-related changes in the Southern Ocean, the primary region of the world oceans where CO
2
-enriched deep water is upwelled to the surface ocean and comes into contact with the atmosphere. Here we present a multiproxy record of surface ocean productivity, dust inputs, and thermocline conditions for the EEP over the last 40,000 y. This allows us to detect changes in phytoplankton productivity and composition associated with increases in equatorial upwelling intensity and influence of Si-rich waters of sub-Antarctic origin. Our evidence indicates that diatoms outcompeted coccolithophores at times when the influence of Si-rich Southern Ocean intermediate waters was greatest. This shift from calcareous to noncalcareous phytoplankton would cause a lowering in atmospheric CO
2
through a reduced carbonate pump, as hypothesized by the Silicic Acid Leakage Hypothesis. However, this change does not seem to have been crucial in controlling atmospheric CO
2
, as it took place during the deglaciation, when atmospheric CO
2
concentrations had already started to rise. Instead, the concomitant intensification of Antarctic upwelling brought large quantities of deep CO
2
-rich waters to the ocean surface. This process very likely dominated any biologically mediated CO
2
sequestration and probably accounts for most of the deglacial rise in atmospheric CO
2
.
Natural immune boosting in pertussis dynamics and the potential for long-term vaccine failure
Authors: Lavine Jennie S. , King Aaron A. , Bjørnstad Ottar N. 
Published: March 2011

Incidence of whooping cough, unlike many other childhood diseases for which there is an efficacious vaccine, has been increasing over the past twenty years despite high levels of vaccine coverage. Its reemergence has been particularly noticeable among teenagers and adults. Many hypotheses have been put forward to explain these two patterns, but parsimonious reconciliation of clinical data on the limited duration of immunity with both pre- and postvaccine era age-specific incidence remains a challenge. We consider the immunologically relevant, yet epidemiologically largely neglected, possibility that a primed immune system can respond to a lower dose of antigen than a naive one. We hypothesize that during the prevaccine era teenagers’ and adults’ primed immunity was frequently boosted by reexposure, so maintaining herd immunity in the face of potentially eroding individual immunity. In contrast, low pathogen circulation in the current era, except during epidemic outbreaks, allows immunity to be lost before reexposure occurs. We develop and analyze an age-structured model that encapsulates this hypothesis. We find that immune boosting must be more easily triggered than primary infection to account for age-incidence data. We make age-specific and dynamical predictions through bifurcation analysis and simulation. The boosting model proposed here parsimoniously captures four key features of pertussis data from highly vaccinated countries: (
i
) the shift in age-specific incidence, (
ii
) reemergence with high vaccine coverage, (
iii
) the possibility for cyclic dynamics in the pre- and postvaccine eras, and (
iv
) the apparent shift from susceptible-infectious-recovered (SIR)-like to susceptible-infectious-recovered-susceptible (SIRS)-like phenomenology of infection and immunity to
Bordetella pertussis
.
Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory
Authors: Marino Kristen A. , Hinnemann Berit , Carter Emily A. 
Published: March 2011

To maximize energy efficiency, gas turbine engines used in airplanes and for power generation operate at very high temperatures, even above the melting point of the metal alloys from which they are comprised. This feat is accomplished in part via the deposition of a multilayer, multicomponent thermal barrier coating (TBC), which lasts up to approximately 40,000 h before failing. Understanding failure mechanisms can aid in designing circumvention strategies. We review results of quantum mechanics calculations used to test hypotheses about impurities that harm TBCs and transition metal (TM) additives that render TBCs more robust. In particular, we discovered a number of roles that Pt and early TMs such as Hf and Y additives play in extending the lifetime of TBCs. Fundamental insight into the nature of the bonding created by such additives and its effect on high-temperature evolution of the TBCs led to design principles that can be used to create materials for even more efficient engines.
anota: analysis of differential translation in genome-wide studies
Authors: Larsson Ola , Sonenberg Nahum , Nadon Robert 
Published: March 2011

Abstract
Summary: Translational control of gene expression has emerged as a major mechanism that regulates many biological processes and shows dysregulation in human diseases including cancer. When studying differential translation, levels of both actively translating mRNAs and total cytosolic mRNAs are obtained where the latter is used to correct for a possible contribution of differential cytosolic mRNA levels to the observed differential levels of actively translated mRNAs. We have recently shown that analysis of partial variance (APV) corrects for cytosolic mRNA levels more effectively than the commonly applied log ratio approach. APV provides a high degree of specificity and sensitivity for detecting biologically meaningful translation changes, especially when combined with a variance shrinkage method for estimating random error. Here we describe the anota (analysis of translational activity) R-package which implements APV, allows scrutiny of associated statistical assumptions and provides biologically motivated filters for analysis of genome wide datasets. Although the package was developed for analysis of differential translation in polysome microarray or ribosome-profiling datasets, any high-dimensional data that result in paired controls, such as RNP immunoprecipitation-microarray (RIP-CHIP) datasets, can be successfully analyzed with anota.
Availability: The anota Bioconductor package, www.bioconductor.org.
Contact: ola.larsson@ki.se; robert.nadon@mcgill.ca