bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Diverse Non‐covalent Interactions Associated with Protein Acetylation
Authors: Xu Lingjia , Zhang Zhengyong , Kong Jilie
Published: December 2011

Protein acetylation has early emerged as a major posttranslational modification for histones and was recently found to be involved in a variety of biological events such as enzymatic activation and signal transduction. Traditional notion about the physicochemical effects associated with protein acetylation is mainly because of its presence capable of neutralizing positively charged protein system, while diverse non‐covalent interactions arising from the acetylation are largely ignored and have never been investigated systematically. In the current work, we perform a comprehensive examination of the geometrical profile and energetic landscape of such acetylation‐related non‐covalent interactions in protein context by using a combination of high‐levelab initiocalculations, crystal structure survey, and hybrid mechanical/molecular mechanical analysis, on the basis of small model complexes and real protein systems. It is all coming together to suggest that the formation of complicated non‐covalent networks around the acetylated site of protein is fundamentally important for stabilizing local structure, improving systemic rigidity, and even conducting more sophisticated biological functions such as switching enzymatic activity.
The Value of Knowledge
Authors: Olsson Erik J
Published: December 2011

A problem occupying much contemporary epistemology is that of explaining why knowledge is more valuable than mere true belief. This paper provides an overview of this debate, starting with historical figures and early work. The contemporary debate in mainstream epistemology is then surveyed and some recent developments that deserve special attention are highlighted, including mounting doubts about the prospects for virtue epistemology to solve the value problem as well as renewed interest in classical and reliabilist‐externalist responses.
Joseph Raz’s Theory of Authority
Authors: Ehrenberg Kenneth
Published: December 2011

Joseph Raz’s theory of authority has become influential among moral, political, and legal philosophers. This article will provide an overview and accessible explanation of the theory, guiding those coming to it for the first time as to its theoretical ambitions within the wider issues of authority, and through its intricacies. I first situate the theory among philosophical examinations of authority, and then explain the theory itself in detail.
The Philosophy of Comics
Authors: Meskin Aaron
Published: December 2011

Comics have been around since the 19th century, but it is only just recently that they have begun to receive philosophical attention as an art form in their own right. This essay begins by exploring the reasons for their comparative neglect by philosophers of art and then provides an overview of extant work on the philosophy of comics. The primary issues discussed are the definition of comics, the ontology of comics, the relationship between comics and other art forms, the relationship between text and image in comics, and the connection between comics and cartooning.
Three species of the subfamily Campopleginae (Hymenoptera: Ichneumonidae) new to Korea
Authors: CHOI Jin‐Kyung , JEONG Jong‐Chul , LEE Jong‐Wook
Published: December 2011

We report three species that are new to Korea, Dusona falcator (Fabricius, 1775), Phobocampe yasumatsuiUchida, 1954 and Venturia longipropodeum (Uchida, 1942). Among them, the genus Venturia is recorded for the first time in Korea. Descriptions and photographs of diagnostic characteristics are provided.
New approaches for treating staphylococcal biofilm infections
Authors: Kiedrowski Megan R. , Horswill Alexander R.
Published: December 2011

Bacteria of the genus Staphylococcus are a prominent cause of acute and chronic infections. The ability of the staphylococci to establish biofilms has been linked to the persistence of chronic infections, which has drawn considerable interest from researchers over the past decade. Biofilms can be defined as sessile communities of surface‐attached cells encased in an extracellular matrix, and treatment of bacteria in this mode of growth is challenging due to the resistance of biofilm structures to both antimicrobials and host defenses. In this review of the literature, we introduce Staphylococcus aureus and Staphylococcus epidermidis biofilms and summarize current antibiotic treatment approaches for staphylococcal biofilm infections. We also review recent studies on alternative strategies for preventing biofilm formation and dispersing established biofilms, including matrix‐degrading enzymes, small‐molecule approaches, and manipulation of natural staphylococcal disassembly mechanisms. While research on staphylococcal biofilm development is still in its early stages, new discoveries in the field hold promise for improved therapies that target staphylococcal biofilm infections.
Draft consensus guidelines for diagnosis and treatment of Shwachman‐Diamond syndrome
Authors: Dror Yigal , Donadieu Jean , Koglmeier Jutta , Dodge John , Toiviainen‐Salo Sanna , Makitie Outi , Kerr Elizabeth , Zeidler Cornelia , Shimamura Akiko , Shah Neil , Cipolli Marco , Kuijpers Taco , Durie Peter , Rommens Johanna , Siderius Liesbeth , Liu Johnson M.
Published: December 2011

Shwachman‐Diamond syndrome (SDS) is an autosomal recessive disorder characterized by pancreatic exocrine insufficiency and bone marrow failure, often associated with neurodevelopmental and skeletal abnormalities. Mutations in the SBDS gene have been shown to cause SDS. The purpose of this document is to provide draft guidelines for diagnosis, evaluation of organ and system abnormalities, and treatment of hematologic, pancreatic, dietary, dental, skeletal, and neurodevelopmental complications. New recommendations regarding diagnosis and management are presented, reflecting advances in understanding the genetic basis and clinical manifestations of the disease based on the consensus of experienced clinicians from Canada, Europe, and the United States. Whenever possible, evidence‐based conclusions are made, but as with other rare diseases, the data on SDS are often anecdotal. The authors welcome comments from readers.
Prognostic factors for survival in a Chinese population presenting with advanced non‐small cell lung cancer with an emphasis on smoking status: A regional, single‐institution, retrospective analysis of 4552 patients
Authors: Hu Qiong , Li Bing , Garfield David , Ren Shengxiang , Li Aiwu , Chen Xiaoxia , Zhou CaiCun
Published: December 2011

Background:  Lung cancer ranks as the top of cancer‐related mortality in the world. Approximately 85–90% of all lung cancer cases are non‐small cell lung cancer (NSCLC). For advanced NSCLC patients, the five‐year survival rate is less than 5%. Previous studies have attempted to determine prognostic factors, such as smoking status, gender, ethnicity, age, and histological type. However, the results are controversial and conflict. In this study, we investigated prognostic factors in a Chinese population presenting with advanced NSCLC.

Methods:  Medical records of patients with advanced NSCLC (AJCC Stage IIIB/IV) who received treatment at our institution were reviewed. Kaplan‐Meier method and Cox Proportional Hazards model were performed in both univariate and multivariate analyses.

Results:  A total of 4552 patients were entered. Among them, 1320 (29.0%) were female, 2408 non‐smokers (52.9%), and all had Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) = 0/1. Univariate analysis suggested that female gender (P < 0.001), adenocarcinoma histology (P < 0.001), age <70 (P < 0.001), and non‐smoker status (P < 0.001) were associated with better survival. However, multivariate analysis demonstrated that age (hazard ratio [HR]= 1.173, 95% confidence interval [CI]: 1.085–1.268, P < 0.001), smoking status (vs. non‐smokers, HR = 1.212, 95% CI: 1.123–1.308, P < 0.001), and histological type (non‐adenocarcinoma vs. adenocarcinoma, HR = 1.104, 95% CI: 1.031–1.181, P = 0.004), but not gender, were independent prognostic factors.

Conclusions:  Smoking status, age, and histological type are independent prognostic factors in Chinese NSCLC patients presenting with advanced disease. Non‐smoking status is associated with better overall survival in Chinese NSCLC patients.
REGIONAL BUSINESS CYCLE PHASES IN TAIWAN
Authors: LIU DE‐CHIH
Published: December 2011

This paper uses both univariate and multivariate Markov‐switching models to explore the characteristics of the regional business cycle phases in Taiwan. In particular, this paper provides novel evidence regarding the “turning‐point identification” puzzle in Taiwan that to date has not been fully resolved. We find that the regime‐switching behaviour of the common regional business cycle is consistent (or even precedes recession) with the business cycle expansion and contraction indicators used by the Council for Economic Planning and Development. This finding suggests that the common regional business cycle identifies the turning point after the 1990s. This finding also suggests that the employment growth index would be a great indicator for monitoring the business cycle in Taiwan.
SMALL TRADE FLOWS AND PREFERENCE UTILISATION: THE CASE OF THE EUROPEAN UNION
Authors: NILSSON LARS
Published: December 2011

A significant number of preference eligible goods are imported into the European Union (EU) from developing countries at relatively low values. In 2008, more than 90% of the number of preferential import flows (at eight‐digit level) represented together about 5% of the value of EU preferential imports from developing countries. While the overall utilisation of EU trade preferences is high, preference utilisation rates of these low‐value imports are markedly lower. This fact is unobserved in the aggregate figures, and thus rarely noticed. This paper examines the extent and the importance of this phenomenon. It attempts to identify exporting countries and products that are particularly affected, and relate these findings to the preferential margin offered on the EU market as well as to the requirements of rules of origin.
The mediators of minority ethnic underperformance in final medical school examinations
Authors: Woolf Katherine , McManus I. Chris , Potts Henry W. W. , Dacre Jane
Published: December 2011

Background.  UK‐trained medical students and doctors from minority ethnic groups underperform academically. It is unclear why this problem exists, which makes it difficult to know how to address it.

Aim.  To investigate whether demographic and psychological factors mediate the relationship between ethnicity and final examination scores.

Sample.  Two consecutive cohorts of Year 5 (final year) UCL Medical School students (n= 703; 51% minority ethnic). A total of 587 (83%) had previously completed a questionnaire in Year 3.

Methods.  Participants were administered a questionnaire in 2005 and 2006 that included a short version of the NEO‐PI‐R, the Study Process Questionnaire, and the General Health Questionnaire (GHQ) as well as socio‐demographic measures. Participants were then followed up to final year (2007–2010). White and minority ethnic students’ questionnaire responses and final examination grades were compared using univariate tests. The effect of ethnicity on final year grades after taking into account the questionnaire variables was calculated using hierarchical multiple linear regression.

Results.  Univariate ethnic differences were found on age, personality, learning styles, living at home, first language, parental factors, and prior education. Minority ethnic students had lower final exam scores, were more likely to fail, and less likely to achieve a merit or distinction in finals. Multivariate analyses showed ethnicity predicted final exam scores even after taking into account questionnaire factors.

Conclusions.  Ethnic differences in the final year performance of two cohorts of UCL medical students were not due to differences in psychological or demographic factors, which suggests alternative explanations are responsible for the ethnic attainment gap in medicine.
Active Control of Sound Radiated by a Submarine Hull in Axisymmetric Vibration Using Inertial Actuators
Authors: Caresta Mauro , Kessissoglou Nicole
Published: December 2011

This paper investigates the use of inertial actuators to reduce the sound radiated by a submarine hull under excitation from the propeller. The axial forces from the propeller are tonal at the blade passing frequency. The hull is modeled as a fluid-loaded cylindrical shell with ring stiffeners and equally spaced bulkheads. The cylinder is closed at each end by circular plates and conical end caps. The forces from the propeller are transmitted to the hull by a rigid foundation connected to the propeller shaft. Inertial actuators are used as the structural control inputs. The actuators are arranged in circumferential arrays and attached to the internal end plates of the hull. Two active control techniques corresponding to active vibration control and discrete structural acoustic sensing are implemented to attenuate the structural and acoustic responses of the submarine. In the latter technique, error information on the radiated sound fields is provided by a discrete structural acoustic sensor. An acoustic transfer function is defined to estimate the far field sound pressure from a single point measurement on the hull. The inertial actuators are shown to provide control forces with a magnitude large enough to reduce the sound due to hull vibration.
Onset of Self-Excited Oscillations of Traveling Wave Thermo-Acoustic-Piezoelectric Energy Harvester Using Root-Locus Analysis
Authors: Aldraihem O. , Baz A.
Published: December 2011

The onset of self-excited oscillations is developed theoretically for a traveling wave thermo-acoustic-piezoelectric (TAP) energy harvester. The harvester is intended for converting thermal energy, such as solar or waste heat energy, directly into electrical energy without the need for any moving components. The thermal energy is utilized to generate a steep temperature gradient along a porous regenerator. At a specific threshold of the temperature gradient, self-sustained acoustic waves are generated inside an acoustic resonator. The resulting pressure fluctuations excite a piezoelectric diaphragm, placed at the end of the resonator, which converts the acoustic energy directly into electrical energy. The pressure pulsations are amplified by using an acoustic feedback loop which introduces appropriate phasing that make the pulsations take the form of traveling waves. Such traveling waves render the engine to be inherently reversible and thus highly efficient. The behavior of this class of harvesters is modeled using the lumped-parameter approach. The developed model is a multifield model which combines the descriptions of the acoustic resonator, feedback loop, and the regenerator with the characteristics of the piezoelectric diaphragm. A new method is proposed here to analyze the onset of self-sustained oscillations of the traveling wave engine using the classical control theory. The predictions of the developed models are validated against published results. Such models present invaluable tools for the design of efficient TAP energy harvesters and engines.
Numerical Investigation of Heat Transfer in Rectangular Microchannels Under H2 Boundary Condition During Developing and Fully Developed Laminar Flow
Authors: Dharaiya V. V. , Kandlikar S. G.
Published: December 2011

Study of fluid flow characteristics at microscale is gaining importance with shrinking device sizes. Better understanding of fluid flow and heat transfer in microchannels will have important implications in electronic chip cooling, heat exchangers, MEMS, and microfluidic devices. Due to short lengths employed in microchannels, entrance header effects can be significant and need to be investigated. In this work, three dimensional model of microchannels, with aspect ratios (α = a/b) ranging from 0.1 to 10, are numerically simulated using CFD software tool fluent. Heat transfer effects in the entrance region of microchannel are presented by plotting average Nusselt number as a function of nondimensional axial length x*. The numerical simulations with both circumferential and axial uniform heat flux (H2) boundary conditions are validated for existing data set for four wall heat flux case. Large numerical data sets are generated in this work for rectangular cross-sectional microchannels with heating on three walls, two opposing walls, one wall, and two adjacent walls under H2 boundary condition. This information can provide better understanding and insight into the transport processes in the microchannels. Although the results are seen as relevant in microscale applications, they are applicable to any sized channels. Based on the numerical results obtained for the whole range, generalized correlations for Nusselt numbers as a function of channel aspect ratio are presented for all the cases. The predicted correlations for Nusselt numbers can be very useful resource for the design and optimization of microchannel heat sinks and other microfluidic devices.
Scattering of S0 and A0 Lamb Modes in a Plate With Multiple Damage
Authors: Qing-tian Deng , Zhi-chun Yang
Published: December 2011

A study of scattering characteristics of S0 and A0 Lamb modes in an infinite isotropic plate with multiple damage is presented in this paper. Both plate theory and the wave function expansion method are utilized to derive the scattered wave field of a single damage. By using the addition theorems of Bessel functions, a complex scattering wave field of multiple damage is investigated. Measurements agreed well between theoretical results and FE simulations. Numerical results of a plate with two damage are graphically presented by considering S0 and A0 modes as an incoming Lamb wave. Effects of geometric properties of damage on the scattering wave field are discussed.
Solutions of Delayed Partial Differential Equations With Space-Time Varying Coefficients
Authors: Deshmukh Venkatesh
Published: December 2011

A constructive algorithm using Chebyshev spectral collocation is proposed for computing trustworthy approximate solutions of linear and weakly nonlinear delayed partial differential equations or initial boundary value problems, with continuous and bounded coefficients. The boundary conditions are assumed to be Dirichlet. The solution of linear problems is obtained at Chebyshev grid points in space and a given interval of time. The algorithm is then extended to systems with weak nonlinearities using perturbation series, which yields nonhomogeneous initial boundary value problems without delay. The proposed methodology is illustrated using examples of linear and weakly nonlinear heat and wave equations with bounded continuous space-time varying coefficients.
Experimental Primer Seating-Stamping Tool Study in Small Caliber Cartridge Production
Authors: Russell Kevin , Reinhardt Lyonel
Published: December 2011

In an effort to produce a more secure assembly fit between the primer and the cartridge case in 5.56 mm combat ammunition, variants of the conventional case stamping tool were developed and incorporated in the small caliber ammunition manufacturing process (or SCAMP). The challenge is to develop a tool that provides a secure cartridge case-primer assembly fit while maximizing tool life. Two concept tool designs were realized—a concept four-prong triangular stamping tool and a concept four-prong wave stamping tool. This work compares the results of SCAMP trials using a concept four-prong triangular stamping tool, a concept four-prong wave stamping tool and the conventional circular stamping tool. Comparison data include cartridge case material movement after stamping, stamping tool stress distribution, stamping tool life, and stamping forces required to achieve the objective primer seating depths. Although the SCAMP trials are still ongoing, the findings to date show that the wave stamping tool has consistently met the design challenges of improved cartridge case-primer assembly fit and maximized tool life and is currently the leading candidate for implementation in SCAMP.
Materials Design of All-Cellulose Composite Using Microstructure Based Finite Element Analysis
Authors: Li Dongsheng , Sun Xin , Khaleel Mohammed A.
Published: December 2011

A microstructure-based finite element analysis model was developed to predict the effective elastic property of cellulose nanowhisker reinforced all-cellulose composite. Analysis was based on the microstructure synthesized with assumption on volume fraction, size, and orientation distribution of cellulose nanowhiskers. Simulation results demonstrated some interesting discovery: With the increase of aspect ratio, the effective elastic modulus increases in isotropic microstructure. The elastic property anisotropy increases with the aspect ratio and anisotropy of nanowhisker orientation. Simulation results from microstructure-based finite element analysis agree well with experimental results, comparing with other homogenization methods: upper bound, lower bound, and self-consistent models. Capturing the anisotropic elastic property, the microstructure-based finite element analysis demonstrated the capability in guiding materials design to improve effective properties.
Effects of atomic layer deposited thin films on dye sensitized solar cell performance
Authors: Campbell Jonathan A. , deBorniol Mervyn , Mozer Attila J. , Evans Peter J. , Burford Robert P. , Triani Gerry
Published: December 2011

The application of thin titania films by atomic layer deposition on top of a low temperature nanoparticulate TiO2 electrode was found to enhance the performance of dye sensitized solar cells. Dynamic measurements of photoinduced charge extraction showed that the atomic layer deposited top coat increased the electron lifetime at the same electron density. This was attributed to an increased electron trap concentration, which resulted in slower charge transport and increased charge carrier lifetimes.
Carbon monoxide detection sensitivity of ZnO nanorod-gated AlGaN/GaN high electron mobility transistors in different temperature environments
Authors: Lo Chien-Fong , Liu Lu , Chu Byung-Hwan , Ren Fan , Pearton Stephen J. , Doré Sylvain , Hsu Chien-Hsing , Kim Jihyun , Dabiran Amir M. , Chow Peter P.
Published: December 2011

The effect of ambient temperature on the detection sensitivity of carbon monoxide (CO) using ZnO nanorod-gated AlGaN/GaN high electron mobility transistor (HEMT) sensors was studied over a range of temperatures from 25 to 400 °C. An increase of the HEMT drain current was observed for exposure to the CO-containing ambients, due to chemisorbed oxygen on the ZnO surface reacting with CO to form CO2 and releasing electrons to the oxide surface, increasing the counter charges in the two-dimensional electron gas channel of the HEMT. By increasing the detection temperature from 25 °C to 150 °C, the CO detection sensitivity, ΔI/I, and detection limit were significantly improved from 0.23% to 7.5% and from 100 ppm to ∼30 ppm, respectively. However, the sensitivity of the CO detection was degraded by the decrease of mobility and saturation drain current of HEMT at temperatures higher than 200 °C.
Jumping hoops
Authors: Yang Eunjin , Kim Ho-Young
Published: December 2011

We investigate the dynamics of an elastic hoop as a model of the jumps of small insects. During a jump the initial elastic strain energy is converted to translational, gravitational, and vibrational energy, and is dissipated by interaction with the floor and the ambient air. We show that the strain energy is initially divided into translational, vibrational, and dissipation energies with a ratio that is constant regardless of the dimension, initial deflection, and the properties of a hoop. This novel result enables us to accurately predict the maximum jump height of a hoop with known initial conditions and drag coefficient without resorting to a numerical computation. Our model reduces the optimization of the hoop geometry for maximizing the jump height to a simple algebraic problem.
Magnetic damping: Integrating experimental and theoretical analysis
Authors: Onorato Pasquale , De Ambrosis Anna
Published: December 2011

We discuss a sequence of experiments aimed at exploring electromagnetic induction phenomena and energy dissipation due to magnetic friction forces. We analyze the motion of a moving conductor as it passes between the poles of a permanent magnet. Motion and current-voltage sensors allow real time measurements of the position, velocity, and induced voltage. The analysis and interpretation of the results helps students construct and verify the theoretical model describing magnetic damping.
Particle filtering for passive fathometer tracking
Authors: Michalopoulou Zoi-Heleni , Yardim Caglar , Gerstoft Peter
Published: December 2011

Seabed interface depths and fathometer amplitudes are tracked for an unknown and changing number of sub-bottom reflectors. This is achieved by incorporating conventional and adaptive fathometer processors into sequential Monte Carlo methods for a moving vertical line array. Sediment layering information and time-varying fathometer response amplitudes are tracked by using a multiple model particle filter with an uncertain number of reflectors. Results are compared to a classical particle filter where the number of reflectors is considered to be known. Reflector tracking is demonstrated for both conventional and adaptive processing applied to the drifting array data from the Boundary 2003 experiment. The layering information is successfully tracked by the multiple model particle filter even for noisy fathometer outputs.
Lessons from a Science Education Portal
Authors: Micklos David , Lauter Susan , Nisselle Amy
Published: December 2011

Doing your best on the Web requires attending to search engines, answering hard questions, and making cybertools accessible to a broad audience.
Response to Comment on “Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology”
Authors: Schmitz Lars , Motani Ryosuke
Published: December 2011

Hall
et al
. claim that it is not yet possible to infer the diel activity patterns of fossil archosaurs with high confidence. We demonstrate here that this assertion is founded on unscreened data, untenable assumptions, and inappropriate methods. Our approach follows ecomorphological and phylogenetic principles in a probabilistic framework, resulting in statistically well-supported reconstructions of diel activity patterns in Mesozoic archosaurs.
Global Seabird Response to Forage Fish Depletion—One-Third for the Birds
Authors: Cury Philippe M. , Boyd Ian L. , Bonhommeau Sylvain , Anker-Nilssen Tycho , Crawford Robert J. M. , Furness Robert W. , Mills James A. , Murphy Eugene J. , Österblom Henrik , Paleczny Michelle , Piatt John F. , Roux Jean-Paul , Shannon Lynne , Sydeman William J.
Published: December 2011

One-third of maximum fish biomass must be available for seabirds to sustain high breeding success.
Earth's Redox History
Authors: Hayes John M.
Published: December 2011

About 2 billion years ago, Earth's carbon cycle was severely disrupted by a period of intense oxidation of organic material.
Snapshots From the Meeting
Authors: Kerr Richard A.
Published: December 2011

Snapshots from the meeting include a report that studies suggesting that the world's energy needs could be met by biofuels are far too optimistic and a spot on the floor of the eastern tropical Pacific where oceanographers can track the changing pressure of the overlying water accurately enough to gauge the changing mass of the world ocean.
HIV Treatment as Prevention
Authors: Cohen Jon
Published: December 2011

Science
has chosen the finding that antiretroviral drugs reduce the risk of heterosexual transmission of HIV as its Breakthrough of the Year.
New Sensitive Competitive Enzyme-Linked Immunosorbent Assay Using a Monoclonal Antibody against Nonstructural Protein 1 of West Nile Virus NY99
Authors: Hirota Jiro , Shimoji Yoshihiro , Shimizu Shinya
Published: December 2011

An anti-West Nile virus (anti-WNV) monoclonal antibody, SHW-7A11, was developed for competitive enzyme-linked immunosorbent assays (c-ELISAs). SHW-7A11 reacted with nonstructural protein 1 in Western blot analysis. SHW-7A11 was relatively specific for the WNV strain NY99 and recognized Kunjin and Eg101 strains in indirect ELISAs. Two c-ELISAs were developed for sera diluted 10 and 100 times and named c-ELISA10 and c-ELISA100, respectively. Both c-ELISAs detected antibodies against WNV NY99 and Kunjin strains. Little cross-reactivity was observed for antibodies against Japanese encephalitis virus and St. Louis encephalitis virus in these assays. Using the cutoff point for the St. Louis encephalitis virus, all WNV-infected chickens were found to be positive on day 21 after infection in both c-ELISAs. On the other hand, all infected chickens were found to be positive on day 35 after infection in a virus neutralization test. Our newly developed SHW-7A11-based c-ELISA can detect WNV infection with sera diluted 10 to 100 times. Therefore, this c-ELISA can be used for WNV serosurveillance of chickens and wild birds.
Effects of Different Adjuvants in the Context of Intramuscular and Intranasal Routes on Humoral and Cellular Immune Responses Induced by Detergent-Split A/H3N2 Influenza Vaccines in Mice
Authors: Baz Mariana , Samant Mukesh , Zekki Hakima , Tribout-Jover Pascale , Plante Martin , Lanteigne Anne-Marie , Hamelin Marie-Eve , Mallett Corey , Papadopoulou Barbara , Boivin Guy
Published: December 2011

Influenza A/H3N2 viruses have caused the most severe epidemics since 1968 despite current immunization programs with inactivated vaccines. We undertook a side-by-side preclinical evaluation of different adjuvants (Alum, AS03, and Protollin) and routes of administration (intramuscular [i.m.] and intranasal [i.n.]) for assessing their effect on the immunogenicity and cross-reactivity of inactivated split vaccines (A/H3N2/New York/55/2004). Humoral and T cell-mediated immune responses against the homologous virus and a heterologous drifted strain (A/H3N2/Wisconsin/67/2005) were measured in BALB/c mice at 2, 6, and 19 weeks postboost. The AS03- and Alum-adjuvanted i.m. vaccines induced at least an 8-fold increase over the nonadjuvanted vaccine in functional antibody titers against both the homotypic and heterotypic strains and low IgG2a and high IgG1 levels, suggesting a mixed Th1/Th2 response with a Th2 trend. The Protollin-adjuvanted i.n. vaccine induced the lowest IgG1/IgG2a ratio, which is indicative of a mixed Th1/Th2-type profile with a Th1 trend. This adjuvanted vaccine was the only vaccine to stimulate a mucosal IgA response. Whatever the timing after the boost, both hemagglutination inhibition (HAI) and microneutralization (MN) titers were higher with the AS03-adjuvanted i.m. vaccine than with the protollin-adjuvanted i.n. vaccine. Finally, the Alum-adjuvanted i.m. vaccine and the lower-dose Protollin-adjuvanted i.n. vaccine elicited significantly higher CD4+Th1 and Th2 responses and more gamma interferon (IFN-γ)-producing CD8+T cells than the nonadjuvanted vaccine. Our data indicate that the adjuvanted vaccines tested in this study can elicit stronger, more persistent, and broader immune responses against A/H3N2 strains than nonadjuvanted inactivated influenza vaccines.
Development of Specific Sequence-Characterized Amplified Region Markers for Detecting Histoplasma capsulatum in Clinical and Environmental Samples
Authors: Frías De León María Guadalupe , Arenas López Gabina , Taylor Maria Lucia , Acosta Altamirano Gustavo , Reyes-Montes María del Rocío
Published: December 2011

Sequence-characterized amplified region (SCAR) markers, generated by randomly amplified polymorphic DNA (RAPD)-PCR, were developed to detect
Histoplasma capsulatum
selectively in clinical and environmental samples. A 1,200-bp RAPD-PCR-specific band produced with the 1281-1283 primers was cloned, sequenced, and used to design two SCAR markers, 1281-1283
220
and 1281-1283
230
. The specificity of these markers was confirmed by Southern hybridization. To evaluate the relevance of the SCAR markers for the diagnosis of histoplasmosis, another molecular marker (M antigen probe) was used for comparison. To validate 1281-1283
220
and 1281-1283
230
as new tools for the identification of
H. capsulatum
, the specificity and sensitivity of these markers were assessed for the detection of the pathogen in 36 clinical (17 humans, as well as 9 experimentally and 10 naturally infected nonhuman mammals) and 20 environmental (10 contaminated soil and 10 guano) samples. Although the two SCAR markers and the M antigen probe identified
H. capsulatum
isolates from different geographic origins in America, the 1281-1283
220
SCAR marker was the most specific and detected the pathogen in all samples tested. In contrast, the 1281-1283
230
SCAR marker and the M antigen probe also amplified DNA from
Aspergillus niger
and
Cryptococcus neoformans
, respectively. Both SCAR markers detected as little as 0.001 ng of
H. capsulatum
DNA, while the M antigen probe detected 0.5 ng of fungal DNA. The SCAR markers revealed the fungal presence better than the M antigen probe in contaminated soil and guano samples. Based on our results, the 1281-1283
220
marker can be used to detect and identify
H. capsulatum
in samples from different sources.
Identification of Host Genes Linked with the Survivability of Chickens Infected with Recombinant Viruses Possessing H5N1 Surface Antigens from a Highly Pathogenic Avian Influenza Virus
Authors: Uchida Yuko , Watanabe Chiaki , Takemae Nobuhiro , Hayashi Tsuyoshi , Oka Takehiko , Ito Toshihiro , Saito Takehiko
Published: December 2011

Seventeen recombinant viruses were generated by a reverse genetic technique to elucidate the pathogenicity of highly pathogenic avian influenza viruses (HPAIVs) in chickens. The recombinant viruses generated possessed hemagglutinin (HA) and neuraminidase (NA) genes from an HPAIV. Other segments were combinations of the genes from an HPAIV and two low-pathogenic avian influenza viruses (LPAIVs) derived from chicken (LP) and wild bird (WB). Exchange of whole internal genes from an HPAIV with those of an LPAIV resulted in a significant extension of the survival time following intranasal infection of the chickens with the recombinants. Survival analysis demonstrated that the exchange of a gene segment affected survivability of the chickens with statistical significance. The analysis revealed three groups of recombinants with various gene constellations that depended upon the survivability of the infected chickens. Recombinants where the PA gene was exchanged from LP to WB in the LP gene background, LP (W/PA), did not kill any chickens. LP (W/PA) replicated less efficiently both
in vitro
and
in vivo
, suggesting that the intrinsic replication ability of LP (W/PA) affects pathogenicity; however, such a correlation was not seen for the other recombinants. Microarray analysis of the infected chicken lungs indicated that the expression of 7 genes,
CD274
,
RNF19B
,
OASL
,
AC3HAV1
,
PLA2G6
,
GCH1
, and
USP18
, correlated with the survivability of the chickens infected (
P
< 0.01). Further analysis of the functions of these genes in chickens would aid in the understanding of host gene responses following fatal infections by HPAIVs.
Use and usefulness of guidelines for sickness certification: results from a national survey of all general practitioners in Sweden
Authors: Skånér Ylva , Nilsson Gunnar H , Arrelöv Britt , Lindholm Christina , Hinas Elin , Wilteus Anna Löfgren , Alexanderson Kristina
Published: December 2011

Objectives

Diagnoses-specific sickness certification guidelines were recently introduced in Sweden. The aim of this study was to investigate to which extent general practitioners (GPs) used these guidelines and how useful they found them, 1 year after introduction.

Design

A cross-sectional questionnaire study. A comprehensive questionnaire about sickness certification practices in 2008 was sent to all physicians living and working in Sweden (n=36 898, response rate 60.6%). In all, 19.7% (n=4394) of the responders worked as GPs.

Setting

Primary healthcare in all Sweden.

Participants

The participating GPs who had consultations concerning sickness certification at least a few times a year (n=4278, 97%).

Main outcome measures

Descriptive statistics and prevalence ratios for the 11 questionnaire items about the use and usefulness of the sickness certification guidelines.

Results

A majority (76.2%) of the GPs reported that they used the guidelines. In addition, 65.4% and 43.5% of those GPs reported that the guidelines had facilitated their contacts with patients and social insurance officers, respectively. The guidelines also helped nearly one-third (31.5%) of the GPs to develop their competence and improve the quality of their management of sickness certification consultations (33.5%). About half experienced some problems when using the guidelines and 43.7% wanted better competence in using them. A larger proportion of non-specialists and of GPs with fewer sickness certification consultations had benefitted from the guidelines.

Conclusions

The national sickness certification guidelines implemented in Sweden were widely used by GPs already a year after introduction. Also, the GPs consider the guidelines useful in several respects, for example, in patient contacts and for competence development.
Oxytocin during labour and risk of severe postpartum haemorrhage: a population-based, cohort-nested case–control study
Authors: Belghiti Jérémie , Kayem Gilles , Dupont Corinne , Rudigoz René-Charles , Bouvier-Colle Marie-Hélène , Deneux-Tharaux Catherine
Published: December 2011

Objectives

Postpartum haemorrhage (PPH) is a major cause of maternal mortality and morbidity worldwide. Experimental studies support the hypothesis that oxytocin administration during labour, a common although not evidence-based practice, may increase the risk of atonic PPH. The clinical studies, however, are inconclusive. The objectives of this study was to investigate the association between the level of oxytocin exposure during labour and the risk of severe PPH and to explore whether the prophylactic use of oxytocin after birth modifies this association.

Design

Population-based, cohort-nested case–control study.

Setting

106 French hospitals from December 2004 through November 2006.

Participants

Women with term singleton vaginal deliveries, after an uncomplicated pregnancy. Cases were 1483 women with severe PPH, defined by peripartum change in haemoglobin of ≥4 g/dl or need for blood transfusion. Controls were 1758 women from a random sample of parturients without PPH.

Main outcome measures

The independent association between the level of oxytocin during labour and the risk of severe PPH was tested and quantified with ORs through two-level multivariable logistic regression modelling.

Results

Oxytocin was administered during labour to 73% of cases and 61% of controls (crude OR: 1.7, 95% CI 1.5 to 2.0). After adjustment for all potential confounders, oxytocin during labour was associated with a significantly higher risk of severe PPH (adjusted OR: 1.8, 95% CI 1.3 to 2.6) in women who did not receive prophylactic oxytocin after delivery; the OR for haemorrhage increased from 1 to 5 according to the level of oxytocin exposure. In women who had prophylactic oxytocin after delivery, this association was significant only for the highest exposure categories.

Conclusions

Oxytocin during labour appears to be an independent risk factor for severe PPH. The results emphasise the need for guidelines clarifying the evidence-based indications for this procedure and the minimal useful regimens.
An observational survey of child car safety practices in private pre-primary and primary schools in two local government areas of Lagos State, Nigeria
Authors: Olufunlayo T F , Odeyemi K A , Ogunnowo B E , Onajole A T , Oyediran M A
Published: December 2011

Objective

To describe child car safety practices among children aged 0–8 years. Eight schools from two local government areas (LGAs) were selected by simple random sampling. Passenger cars were observed for child seating position and restraint use at each selected school as children were being dropped off in the morning.

Results

Observed child restraint use was very low, as was the rate of appropriate restraint for age (10.8% and 4.2%, respectively, in Eti-Osa, and 7.0% and 1.8% in Ikeja). Child restraint use decreased with increasing age group from 25% in those below 1 year, to 12% in those aged 1–3 years, and 7.4% in those aged 4–8 years. A large proportion of restrained passengers were inappropriately restrained in a seatbelt alone. Front seating among observed child passengers was not as high as in studies from similar environments (9.4% and 17.5% in Eti-Osa and Ikeja, respectively). Factors associated with child restraint use were number of child passengers in car, and whether or not the driver wore a seatbelt. Seating position of the child was significantly associated with the relationship of the driver to the child, and driver's gender.

Conclusion

The level of child restraint use observed in this study is unacceptably low. The relatively low prevalence of front seating while riding in cars should however be further reduced. The study recommends the enactment of specific country legislation on the use of child restraints, accompanied by multifaceted intervention programmes to improve the availability and use of child car safety seats and booster seats.
Free-base tetraarylporphyrin covalently linked to [60]fullerene through ethynylfluorene spacer
Authors: Echeverry Carlos A. , Tigreros Alexis , Ortiz Alejandro , Insuasty Braulio , Martín Nazario
Published: December 2011

The synthesis, structural and electronic characterization of novel electroactive systems based on porphyrin-fullerene in which the chromophores are linked by an ethynylfluorene spacer unit is reported. Sonogashira couplings have been used in short and efficient sequences to give access to these new molecules on a practical scale. The absorption studies, voltamperometric measurements and theoretical calculations at DFT level reveal the push-pull behavior for these systems.
Substituent effects on metallocorrole spectra: insights from chromium-oxo and molybdenum-oxo triarylcorroles
Authors: Johansen Inge , Norheim Hans-Kristian , Larsen Simon , Alemayehu Abraham B. , Conradie Jeanet , Ghosh Abhik
Published: December 2011

The Soret maxima of a number of metallotriarylcorroles shift sensitively in response to varying substituents on the meso-aryl groups. The effect is most pronounced for copper corroles but is not seen for silver and gold corroles. In the copper case, the effect has been attributed to a small HOMO–LUMO gap. Chromium-oxo corroles share a small HOMO–LUMO gap with copper corroles, as well as a substantially metal-based LUMO, yet the Soret maxima of chromium-oxo triarylcorroles do not shift in response to substitution on the meso-aryl groups. Molybdenum-oxo corroles are substituent-insensitive in the same sense. TDDFT calculations, focusing on chromium-oxo and molybednum-oxo triarylcorroles, are reported here in an attempt to explain the divergent spectroscopic behavior of different metallocorrole families.
Structural, electrochemical and photochemical investigation of the water-soluble tin(IV) tetrakis(2-N-hydroxyethyl-4-pyridinium)porphyrin photocatalyst
Authors: Olijve Luuk L. C. , How Ethan N. W. , Bhadbhade Mohan , Prasad Shiva , Colbran Stephen B. , Zhao Chuan , Thordarson Pall
Published: December 2011

The water-soluble tin(IV) tetrakis(2-N-hydroxyethyl-4-pyridinium)porphyrin 1 photocatalyst was synthesized in good yield and its structure determined by single crystal X-ray crystallography. Electrochemical measurements on tin(IV) porphyrin 1 reveal a range of complex redox processes that are highly dependent on the pH and electrode used. The cathodic processes at ca. -0.6 to -0.8 V were assigned to electrochemical processes on the pyridyl moiety following differential pulse voltammetry and spectroelectrochemical investigation into the electrochemical properties of tin(IV) porphyrin. Photocatalytic experiment on tin(IV) porphyrin 1 under anaerobic conditions using triethanolamine (TEAO) as a sacrifical donor reveal a phlorin species as the main product which rapidly disappears upon exposure to oxygen. These results suggest that tin(IV) porphyrin π-radical anion is perhaps not the species responsible for the apparent ability tin(IV) porphyrins to photocatalytically reduce various substrates, including water to hydrogen.
Alterations of calcium channels and cell excitability in intracardiac ganglion neurons from type 2 diabetic rats
Authors: Liu Jinxu , Tu Huiyin , Zheng Hong , Zhang Libin , Tran Thai P. , Muelleman Robert L. , Li Yu-Long
Published: December 2011

Clinical study has demonstrated that patients with type 2 diabetes with attenuated arterial baroreflex have higher mortality rate compared with those without arterial baroreflex dysfunction. As a final pathway for the neural control of the cardiac function, functional changes of intracardiac ganglion (ICG) neurons might be involved in the attenuated arterial baroreflex in the type 2 diabetes mellitus (T2DM). Therefore, we measured the ICG neuron excitability and Ca2+ channels in the sham and T2DM rats. T2DM was induced by a combination of both high-fat diet and low-dose streptozotocin (STZ, 30 mg/kg ip) injection. After 12–14 wk of the above treatment, the T2DM rats presented hyperglycemia, hyperlipidemia, and insulin resistance but no hyperinsulinemia, which closely mimicked the clinical features of the patients with T2DM. Data from immunofluorescence staining showed that L, N, P/Q, and R types of Ca2+ channels were expressed in the ICG neurons, but only protein expression of N-type Ca2+ channels was decreased in the ICG neurons from T2DM rats. Using whole cell patch-clamp technique, we found that T2DM significantly reduced the Ca2+ currents and cell excitability in the ICG neurons. ω-Conotoxin GVIA (a specific N-type Ca2+ channel blocker, 1 μM) lowered the Ca2+ currents and cell excitability toward the same level in sham and T2DM rats. These results indicate that the decreased N-type Ca2+ channels contribute to the suppressed ICG neuron excitability in T2DM rats. From this study, we think high-fat diet/STZ injection-induced T2DM might be an appropriate animal model to test the cellular and molecular mechanisms of cardiovascular autonomic dysfunction.