bluuebunny/crossref_metadata_2025 huggingface dataset:
Renewable Hydrogen From the Zn/ZnO Solar Thermochemical Cycle: A Cost and Policy Analysis
Authors: Haltiwanger Julia F. , Davidson Jane H. , Wilson Elizabeth J.
Published: October 2010

Flexible energy carriers are a crucial element of our energy portfolio. In a future in which a significant fraction of our energy comes from renewable sources, renewably produced fuels will be vital. The zinc/zinc-oxide thermochemical redox cycle is one approach for producing hydrogen using solar energy. This paper explores the level of carbon taxation necessary to make the cycle competitive with hydrogen production via methane reforming. In addition, the time frame for economic viability is assessed through the use of experience curves under minimal input, midrange, and aggressive incentive policy scenarios. Prior work projects that hydrogen produced by the zinc/zinc-oxide cycle will cost between $5.02/kg and $14.75/kg, compared with $2.40–3.60/kg for steam methane reforming. Overcoming this cost difference would require a carbon tax of ($119–987)/tCO2, which is significantly higher than is likely to be implemented in most countries. For the technology to become cost competitive, incentive policies that lead to early implementation of solar hydrogen plants will be necessary to allow the experience effect to draw down the price. Under such policies, a learning curve analysis suggests that hydrogen produced via the Zn/ZnO cycle could become economically viable between 2032 and 2069, depending on how aggressively the policies encourage the emerging technology. Thus, the Zn/ZnO cycle has the potential to be economically viable by midcentury if incentive policies—such as direct financial support, purchase guarantees, low interest rate loans, and tax breaks—are used to support initial projects.
Calibration and Validation of the Dynamic Wake Meandering Model for Implementation in an Aeroelastic Code
Authors: Madsen H. Aa. , Larsen G. C. , Larsen T. J. , Troldborg N. , Mikkelsen R.
Published: October 2010

As the major part of new wind turbines are installed in clusters or wind farms, there is a strong need for reliable and accurate tools for predicting the increased loadings due to wake operation and the associated reduced power production. The dynamic wake meandering (DWM) model has been developed on this background, and the basic physical mechanisms in the wake—i.e., the velocity deficit, the meandering of the deficit, and the added turbulence—are modeled as simply as possible in order to make fast computations. In the present paper, the DWM model is presented in a version suitable for full integration in an aeroelastic model. Calibration and validation of the different parts of the model is carried out by comparisons with actuator disk and actuator line (ACL) computations as well as with inflow measurements on a full-scale 2 MW turbine. It is shown that the load generating part of the increased turbulence in the wake is due almost exclusively to meandering of the velocity deficit, which causes “apparent” turbulence when measuring the flow in a fixed point in the wake. Added turbulence, originating mainly from breakdown of tip vortices and from the shear of the velocity deficit, has only a minor contribution to the total turbulence and with a small length scale in the range of 10–25% of the ambient turbulence length scale. Comparisons of the calibrated DWM model with ACL results for different downstream positions and ambient turbulence levels show good correlation for both wake deficits and turbulence levels. Finally, added turbulence characteristics are compared with correlation results from literature.
Experimental Simulation of Solar Flash Desalination
Authors: Abutayeh Mohammad , Goswami D. Yogi
Published: October 2010

Experimental simulations of a sustainable desalination process have been carried out using a pilot unit. Experiments were conducted at analogous conditions to simplify design evaluation but with different values of the controlling variables to enhance analysis and modeling. The proposed desalination process, which employs solar heating and passive vacuum generation, has been theoretically simulated in earlier work. It entails flowing seawater through a condenser to preheat it and then through a heater before flashing it in a vacuumed evaporator connected to the condenser where the flashed hot vapor is condensed by the incoming cold seawater forming fresh water. All experiments were run for the same period of time starting at the same initial vacuum. Experiments were carried out at different seawater flow rates and different flash temperatures. In addition, each experiment was duplicated three times to validate its outcome. Flashing seawater at higher temperatures increases vaporization and fresh water production rate. In addition, the accumulating noncondensable gases that are slowly eroding the vacuum will decrease the overall vaporization with time, which reduces the production rate of fresh water.
Deformation Measurements and Material Property Estimation of Mouse Carotid Artery Using a Microstructure-Based Constitutive Model
Authors: Ning Jinfeng , Xu Shaowen , Wang Ying , Lessner Susan M. , Sutton Michael A. , Anderson Kevin , Bischoff Jeffrey E.
Published: October 2010

A series of pressurization and tensile loading experiments on mouse carotid arteries is performed with deformation measurements acquired during each experiment using three-dimensional digital image correlation. Using a combination of finite element analysis and a microstructure-based constitutive model to describe the response of biological tissue, the measured surface strains during pressurization, and the average axial strains during tensile loading, an inverse procedure is used to identify the optimal constitutive parameters for the mouse carotid artery. The results demonstrate that surface strain measurements can be combined with computational methods to identify material properties in a vascular tissue. Additional computational studies using the optimal material parameters for the mouse carotid artery are discussed with emphasis on the significance of the qualitative trends observed.
Characterization of electrodeposited Ni–Fe–SiC alloys for microelectromechanical applications
Authors: Zheng Xiaohu , Chen Xing , Gu Feng , Liu YuanWei , Lee Dong-Weon
Published: October 2010

Ni–Fe–SiC alloy is a promising material for the fabrication of microactuators. In this article, the electrolytic codeposition technique is used to deposit the Ni–Fe–SiC composite onto stainless-steel substrates, where nickel becomes alloyed with iron as the binder phase, and SiC becomes alloyed as dispersed particles. Analysis of the morphology indicates that the deposited SiC nanoparticles are compact, with the orientation of the deposited crystal planes indexed as (111), (200), (220), (311), and (222). The resistivity of the deposited SiC nanoparticles is about 30×10−8 Ω m. When the loading of Fe (wt %) ranges from 10% to 50% in the deposit, the electrodeposit shows a strong paramagnetism with a lowest value of coercivity of 2.75×10−2 A/m. In addition, the remanence shows a monotonic decrease with an increasing iron content in the deposit. It is demonstrated that the electroformed Ni–Fe–SiC alloy has better electromagnetic properties and a higher corrosion resistance (with a corrosion rate of 0.17 mg/dm2 h 2M HCl) than the electroformed Ni–Fe alloy (with a corrosion rate of 0.23 mg/dm2 h).
Why Testing Improves Memory: Mediator Effectiveness Hypothesis
Authors: Pyc Mary A. , Rawson Katherine A.
Published: October 2010

Testing not only evaluates the state of memory, but also improves memory more than restudy.
Granulosa Cell Ligand NPPC and Its Receptor NPR2 Maintain Meiotic Arrest in Mouse Oocytes
Authors: Zhang Meijia , Su You-Qiang , Sugiura Koji , Xia Guoliang , Eppig John J.
Published: October 2010

Arresting Meiosis

In mammals, meiotic maturation of oocytes must be coordinated precisely with ovulation to produce a developmentally competent egg at the right time for fertilization. How is coordination achieved? Follicular granulosa cells prevent precocious resumption of meiosis in oocytes, maintaining meiotic arrest until the pre-ovulatory hormone surge. Granulosa cells produce cyclic guanosine monophosphate, which is delivered to oocytes and arrests meiotic progression by inhibiting oocyte cyclic adenosine monophosphate degradation. How cGMP production is regulated is unclear. Now,

Zhang
et al.

(p.
366
) report that NPPC (natriuretic peptide precursor type C), produced by mural granulosa cells, and its receptor NPR2, a guanylyl cyclase expressed by cumulus cells, together promote cGMP production by cumulus cells and are thus essential for maintaining meiotic arrest in mouse oocytes.
Salmonella
Pathogenesis and Processing of Secreted Effectors by Caspase-3
Authors: Srikanth C. V. , Wall Daniel M. , Maldonado-Contreras Ana , Shi Hai Ning , Zhou Daoguo , Demma Zachary , Mumy Karen L. , McCormick Beth A.
Published: October 2010

Salmonella
Stealth Bomber

Salmonella
secretes a virulence factor, SipA, which helps it to invade epithelial cells of the gut. During invasion, the host cell is triggered into synthesizing and secreting the apoptotic enzyme caspase-3.

Srikanth
et al.

(p.
390
) now show that instead of being extinguished as the host cell collapses into programmed cell death, during the early stages of infection,
Salmonella
diverts the host enzyme to its own use. The SipA protein has amino acid motifs that are recognized by caspase-3, which cleaves the bacterial protein into active virulence effectors: one stimulates actin polymerization to help cell entry and the other induces inflammation. If the caspase motif contains a single-point mutation, then virulence is lost in mouse models of infection. Conversely, caspase-deficient mice suffer less from
Salmonella
-induced gastroenteritis.
The Benefits of Multilingualism
Authors: Diamond Jared
Published: October 2010

Bilingual rearing of children, instead of confusing them, may bring lifelong advantages.
Temperature as a Universal Resetting Cue for Mammalian Circadian Oscillators
Authors: Buhr Ethan D. , Yoo Seung-Hee , Takahashi Joseph S.
Published: October 2010

Time and Temperature

Daily cycles in environmental temperature are an important cue for many organisms to synchronize their endogenous circadian clock. However, mammals do not respond to this cue. Studying mouse tissue,

Buhr
et al.

(p.
379
; see the Perspective by

Edery

) find that this resistance to temperature is a feature specific to the suprachiasmatic nucleus (SCN), a region of the mammalian brain that functions as the body's master clock. In contrast, the clocks in peripheral tissues (for example, lung, liver) are fully capable of resetting in response to temperature changes and do so by a mechanism involving the heat shock pathway. The SCN drives daily rhythms in body temperature, and SCN-driven changes in temperature may synchronize the body's peripheral clocks. Without its intrinsic resistance to temperature, the SCN could be subject to disruptive feedback effects.
Discovery of a Frank-Kasper σ Phase in Sphere-Forming Block Copolymer Melts
Authors: Lee Sangwoo , Bluemle Michael J. , Bates Frank S.
Published: October 2010

Block Copolymer Assembly

Despite their structural simplicity, block copolymers can assemble into complex and often surprising structures.

Lee
et al.

(p.
349
; see the Perspective by

Peterca and Percec

) demonstrate the formation of a new ordered phase in a diblock copolymer and a tetrablock copolymer formed from frustrated self-assembled spherical microdomains. Remarkably, this structure contains tetragonal unit cells with 30 spheres per lattice site and is related to dodecagonal quasicrystals. This structure was first described by Frank and Kasper as a sigma phase 50 years ago and is seen in some metal alloys.
Ecosystem Services for 2020
Authors: Perrings C. , Naeem S. , Ahrestani F. , Bunker D. E. , Burkill P. , Canziani G. , Elmqvist T. , Ferrati R. , Fuhrman J. , Jaksic F. , Kawabata Z. , Kinzig A. , Mace G. M. , Milano F. , Mooney H. , Prieur-Richard A.-H. , Tschirhart J. , Weisser W.
Published: October 2010

The Convention on Biological Diversity's 2020 targets are an improvement over the 2010 target, but they could be strengthened.
Temperatures to Communicate By
Authors: Edery Isaac
Published: October 2010

Temperature changes synchronize circadian clocks in organs that can't sense light-dark cycles.
Germany's Energy Research Plan
Authors: Schavan Annette
Published: October 2010

Last month, German Chancellor Angela Merkel approved a long-term strategy to push renewable energies as a reliable, economical, and environmentally sound pillar of sustainable economic growth. The “Energiekonzept” (Energy Concept) foresees an end to the country's dependence on fossil fuels and defines key milestones to achieve by 2050, including the reduction of greenhouse gas emissions by 80% (compared to 1990 levels), the modernization and insulation of buildings, and a decrease in electricity consumption by 25%. Innovations must contribute substantially to meet these objectives, and so energy research is an explicit part of the Energiekonzept. By spring 2011, the German government will present a detailed new Energy Research Program that outlines important research tasks to support these new goals.
Can the Census Go Digital?
Authors: Kean Sam
Published: October 2010

Technology seems like an obvious remedy for soaring costs and privacy concerns. But demographers say the cure to what ails the U.S. census isn't nearly that simple.
Soap or Census?
Authors: Kean Sam
Published: October 2010

Will people really out themselves for discounts on cleansers and other products? The answer seems to be yes.
Nanoparticle Trojan Horses Gallop From the Lab Into the Clinic
Authors: Service Robert F.
Published: October 2010

Experimental cancer treatments are aiming to deliver toxic medicines to cells inside packages that protect normal tissues and evade the body's immune system.
Strategies for Translational Research in the United Kingdom
Authors: Soderquest Katrina , Lord Graham M.
Published: October 2010

The United Kingdom has made a substantial investment in translational research, resulting in a well-developed infrastructure designed to advance clinical medicine.
Network Dynamics to Evaluate Performance of an Academic Institution
Authors: Hughes Michael E. , Peeler John , Hogenesch John B.
Published: October 2010

Creation of a network of research collaborations allows assessment of a Clinical and Translational Science Award recipient.
New Cause for Diabetic Nephropathy
Authors: Buettner Christoph
Published: October 2010

The deletion of the insulin receptor only in kidney podocytes induces diabetic nephropathy in mice.
Prevalence of Antibodies to Four Human Coronaviruses Is Lower in Nasal Secretions than in Serum
Authors: Gorse Geoffrey J. , Patel Gira B. , Vitale Joseph N. , O'Connor Theresa Z.
Published: October 2010

Little is known about the prevalence of mucosal antibodies induced by infection with human coronaviruses (HCoV), including HCoV-229E and -OC43 and recently described strains (HCoV-NL63 and -HKU1). By enzyme-linked immunosorbent assay, we measured anti-HCoV IgG antibodies in serum and IgA antibodies in nasal wash specimens collected at seven U.S. sites from 105 adults aged 50 years and older (mean age, 67 ± 9 years) with chronic obstructive pulmonary disease. Most patients (95 [90%]) had at least one more chronic disease. More patients had serum antibody to each HCoV strain (104 [99%] had antibody to HCoV-229E, 105 [100%] had antibody to HCoV-OC43, 103 [98%] had antibody to HCoV-NL63, and 96 [91%] had antibody to HCoV-HKU1) than had antibody to each HCoV strain in nasal wash specimens (12 [11%] had antibody to HCoV-229E, 22 [22%] had antibody to HCoV-OC43, 8 [8%] had antibody to HCoV-NL63, and 31 [31%] had antibody to HCoV-HKU1), respectively (
P
< 0.0001). The proportions of subjects with IgA antibodies in nasal wash specimens and the geometric mean IgA antibody titers were statistically higher for HCoV-OC43 and -HKU1 than for HCoV-229E and -NL63. A higher proportion of patients with heart disease than not had IgA antibodies to HCoV-NL63 (6 [16%] versus 2 [3%];
P
= 0.014). Correlations were highest for serum antibody titers between group I strains (HCoV-229E and -NL63 [
r
= 0.443;
P
< 0.0001]) and between group II strains (HCoV-OC43 and -HKU1 [
r
= 0.603;
P
< 0.0001]) and not statistically significant between HCoV-NL63 and -OC43 and between HCoV-NL63 and -HKU1. Patients likely had experienced infections with more than one HCoV strain, and IgG antibodies to these HCoV strains in serum were more likely to be detected than IgA antibodies to these HCoV strains in nasal wash specimens.
Equine Neonates Have Attenuated Humoral and Cell-Mediated Immune Responses to a Killed Adjuvanted Vaccine Compared to Adult Horses
Authors: Ryan Clare , Giguère Steeve
Published: October 2010

The objectives of this study were to compare relative vaccine-specific serum immunoglobulin concentrations, vaccine-specific lymphoproliferative responses, and cytokine profiles of proliferating lymphocytes between 3-day-old foals, 3-month-old foals, and adult horses after vaccination with a killed adjuvanted vaccine. Horses were vaccinated intramuscularly twice at 3-week intervals with a vaccine containing antigens from bovine viral respiratory pathogens to avoid interference from maternal antibody. Both groups of foals and adult horses responded to the vaccine with a significant increase in vaccine-specific IgGa and IgG(T) concentrations. In contrast, only adult horses and 3-month-old foals mounted significant vaccine-specific total IgG, IgGb, and IgM responses. Vaccine-specific concentrations of IgM and IgG(T) were significantly different between all groups, with the highest concentrations occurring in adult horses, followed by 3-month-old foals and, finally, 3-day-old foals. Only the adult horses mounted significant vaccine-specific lymphoproliferative responses. Baseline gamma interferon (IFN-γ) and interleukin-4 (IL-4) concentrations were significantly lower in 3-day-old foals than in adult horses. Vaccination resulted in a significant decrease in IFN-γ concentrations in adult horses and a significant decrease in IL-4 concentrations in 3-day-old foals. After vaccination, the ratio of IFN-γ/IL-4 in both groups of foals was significantly higher than that in adult horses. The results of this study indicate that the humoral and lymphoproliferative immune responses to this killed adjuvanted vaccine are modest in newborn foals. Although immune responses improve with age, 3-month-old foals do not respond with the same magnitude as adult horses.
Evaluation of Molecular Assays for Rapid Detection of Methicillin-Resistant
Staphylococcus aureus
Authors: Malhotra-Kumar Surbhi , Van Heirstraeten Liesbet , Lee Andie , Abrahantes José Cortinas , Lammens Christine , Vanhommerig Evelyn , Molenberghs Geert , Aerts Marc , Harbarth Stephan , Goossens Herman
Published: October 2010

The diagnostic sensitivities of the BD GeneOhm and Cepheid Xpert assays were compared using culture on log-serial dilutions of well-characterized methicillin-resistant
Staphylococcus aureus
(MRSA) and non-MRSA strains and on nasal and groin swabs from patients with histories of MRSA carriage. The sensitivities of GeneOhm and Xpert were high at 10
3
-CFU/ml MRSA concentrations (92.3% and 96.3%, respectively) although decreased considerably (<35%) at a 1-log-lower concentration. Unexpectedly, both assays also detected select coagulase-negative staphylococci, which requires further evaluation.
Identification of a Novel T17 Genotype of
Acanthamoeba
from Environmental Isolates and T10 Genotype Causing Keratitis in Thailand
Authors: Nuprasert Warisa , Putaporntip Chaturong , Pariyakanok Lalida , Jongwutiwes Somchai
Published: October 2010

We analyzed the nuclear small-subunit rRNA genes of
Acanthamoeba
isolates from freshwater sources (
n
= 16) and from patients (
n
= 6) in Bangkok and surrounding areas. The T10 genotype from a keratitis patient and a novel T17 genotype from water samples were diagnosed for the first time in this study.
Pacemaker Lead Endocarditis Due to Multidrug-Resistant
Corynebacterium striatum
Detected with Sonication of the Device
Authors: Oliva Alessandra , Belvisi Valeria , Iannetta Marco , Andreoni Carolina , Mascellino Maria T. , Lichtner Miriam , Vullo Vincenzo , Mastroianni Claudio M.
Published: October 2010

Corynebacterium striatum
is a commensal of human skin and has been recently recognized as an emerging pathogen. A case of nosocomial pacemaker lead endocarditis due to a multidrug-resistant
C. striatum
strain is described, highlighting the role of sonication as a diagnostic tool in cardiac device infections.
Evaluation of Spectra VRE, a New Chromogenic Agar Medium Designed To Screen for Vancomycin-Resistant
Enterococcus faecalis
and
Enterococcus faecium
Authors: Peterson Jess F. , Doern Christopher D. , Kallstrom George , Riebe Katherine M. , Sander Tara , Dunne William Michael , Ledeboer Nathan A.
Published: October 2010

Spectra VRE (Remel, Lenexa, KS) is a chromogenic medium designed to recover and differentiate vancomycin-resistant
Enterococcus faecium
and
Enterococcus faecalis
(VRE). This medium was compared to bile esculin azide agar (BEAV) and was 98.2% sensitive and 99.3% specific compared to BEAV, which was 87.6% sensitive and 87.1% specific at 24 h.
Codon Optimization of Human Parvovirus B19 Capsid Genes Greatly Increases Their Expression in Nonpermissive Cells
Authors: Zhi Ning , Wan Zhihong , Liu Xiaohong , Wong Susan , Kim Dong Joo , Young Neal S. , Kajigaya Sachiko
Published: October 2010

Parvovirus B19 (B19V) is pathogenic for humans and has an extreme tropism for human erythroid progenitors. We report cell type-specific expression of the B19V capsid genes (
VP1
and
VP2
) and greatly increased B19V capsid protein production in nonpermissive cells by codon optimization. Codon usage limitation, rather than promoter type and the 3′ untranslated region of the capsid genes, appears to be a key factor in capsid protein production in nonpermissive cells. Moreover, B19 virus-like particles were successfully generated in nonpermissive cells by transient transfection of a plasmid carrying both codon-optimized
VP1
and
VP2
genes.
Fitness Disadvantage of Transitional Intermediates Contributes to Dynamic Change in the Infecting-Virus Population during Coreceptor Switch in R5 Simian/Human Immunodeficiency Virus-Infected Macaques
Authors: Shakirzyanova Madina , Ren Wuze , Zhuang Ke , Tasca Silvana , Cheng-Mayer Cecilia
Published: October 2010

Fitness disadvantage of the transitional intermediates compared to the initial R5 viruses has been suggested to constitute one of the blockades to coreceptor switching, explaining the late appearance of X4 viruses. Using a simian model for human immunodeficiency virus type 1 (HIV-1) coreceptor switching, we demonstrate in this study that similar molecular evolutionary pathways to coreceptor switch occur in more than one R5 simian/human immunodeficiency virus (SHIV)
SF162P3N
-infected macaque. In infected animals where multiple pathways for expansion or switch to CXCR4 coexist, fitness of the transitional intermediates in coreceptor usage efficiency influences their outgrowth and representation in the infecting virus population. Dualtropic and X4 viruses appear at different disease stages, but they have lower entry efficiency than the coexisting R5 strains, which may explain why they do not outcompete the R5 viruses. Similar observations were made in two infected macaques with coreceptor switch, providing
in vivo
evidence that fitness disadvantage is an obstacle to X4 emergence and expansion.
Nodavirus-Induced Membrane Rearrangement in Replication Complex Assembly Requires Replicase Protein A, RNA Templates, and Polymerase Activity
Authors: Kopek Benjamin G. , Settles Erik W. , Friesen Paul D. , Ahlquist Paul
Published: October 2010

Positive-strand RNA [(+)RNA] viruses invariably replicate their RNA genomes on modified intracellular membranes. In infected
Drosophila
cells, Flock House nodavirus (FHV) RNA replication complexes form on outer mitochondrial membranes inside ∼50-nm, virus-induced spherular invaginations similar to RNA replication-linked spherules induced by many (+)RNA viruses at various membranes. To better understand replication complex assembly, we studied the mechanisms of FHV spherule formation. FHV has two genomic RNAs; RNA1 encodes multifunctional RNA replication protein A and RNA interference suppressor protein B2, while RNA2 encodes the capsid proteins. Expressing genomic RNA1 without RNA2 induced mitochondrial spherules indistinguishable from those in FHV infection. RNA1 mutation showed that protein B2 was dispensable and that protein A was the only FHV protein required for spherule formation. However, expressing protein A alone only “zippered” together the surfaces of adjacent mitochondria, without inducing spherules. Thus, protein A is necessary but not sufficient for spherule formation. Coexpressing protein A plus a replication-competent FHV RNA template induced RNA replication in
trans
and membrane spherules. Moreover, spherules were not formed when replicatable FHV RNA templates were expressed with protein A bearing a single, polymerase-inactivating amino acid change or when wild-type protein A was expressed with a nonreplicatable FHV RNA template. Thus, unlike many (+)RNA viruses, the membrane-bounded compartments in which FHV RNA replication occurs are not induced solely by viral protein(s) but require viral RNA synthesis. In addition to replication complex assembly, the results have implications for nodavirus interaction with cell RNA silencing pathways and other aspects of virus control.
Quantitative and Qualitative RNA-Seq-Based Evaluation of Epstein-Barr Virus Transcription in Type I Latency Burkitt's Lymphoma Cells
Authors: Lin Zhen , Xu Guorong , Deng Nan , Taylor Christopher , Zhu Dongxiao , Flemington Erik K.
Published: October 2010

RNA-seq provides a rich source of transcriptome information with high qualitative and quantitative value. Here, we provide a pipeline for Epstein-Barr virus (EBV) transcriptome analysis using RNA-seq and we apply it to two type I latency cell lines, Mutu I and Akata. This analysis revealed substantial average expression levels of many lytic genes in predominantly latent cell populations. The lytic transcripts BHLF1 and LF3 were expressed at levels greater than those for 98% of all cellular polyadenylated transcripts. Exon junction mapping accurately identified the Qp-derived EBNA1 splicing pattern, lytic gene splicing, and a complex splicing pattern within the BamHI A region.
Structural Basis of Local, pH-Dependent Conformational Changes in Glycoprotein B from Herpes Simplex Virus Type 1
Authors: Stampfer Samuel D. , Lou Huan , Cohen Gary H. , Eisenberg Roselyn J. , Heldwein Ekaterina E.
Published: October 2010

Herpesviruses enter cells by membrane fusion either at the plasma membrane or in endosomes, depending on the cell type. Glycoprotein B (gB) is a conserved component of the multiprotein herpesvirus fusion machinery and functions as a fusion protein, with two internal fusion loops, FL1 and FL2. We determined the crystal structures of the ectodomains of two FL1 mutants of herpes simplex virus type 1 (HSV-1) gB to clarify whether their fusion-null phenotypes were due to global or local effects of the mutations on the structure of the gB ectodomain. Each mutant has a single point mutation of a hydrophobic residue in FL1 that eliminates the hydrophobic side chain. We found that neither mutation affected the conformation of FL1, although one mutation slightly altered the conformation of FL2, and we conclude that the fusion-null phenotype is due to the absence of a hydrophobic side chain at the mutated position. Because the ectodomains of the wild-type and the mutant forms of gB crystallized at both low and neutral pH, we were able to determine the effect of pH on gB conformation at the atomic level. For viruses that enter cells by endocytosis, the low pH of the endosome effects major conformational changes in their fusion proteins, thereby promoting fusion of the viral envelope with the endosomal membrane. We show here that upon exposure of gB to low pH, FL2 undergoes a major relocation, probably driven by protonation of a key histidine residue. Relocation of FL2, as well as additional small conformational changes in the gB ectodomain, helps explain previously noted changes in its antigenic and biochemical properties. However, no global pH-dependent changes in gB structure were detected in either the wild-type or the mutant forms of gB. Thus, low pH causes local conformational changes in gB that are very different from the large-scale fusogenic conformational changes in other viral fusion proteins. We propose that these conformational changes, albeit modest, play an important functional role during endocytic entry of HSV.
Genotypic and phenotypic characterisation of invasiveStreptococcus pneumoniaeisolates from Hungary, and coverage of the conjugate vaccines
Authors: Dobay Orsolya , Ungvári Ágnes , Kardos Szilvia , Kristóf Katalin , Hajdú Edit , Szabó Judit , Knausz Márta , Nagy Erzsébet , Rozgonyi Ferenc , Amyes Sebastian G B , Nagy Károly
Published: October 2010

Background and aims

The 7-valent conjugate pneumococcal vaccine (Prevenar) was introduced as a recommended (but not yet obligatory) vaccine in Hungary in April 2009 and there was a sharp increase in the number of children vaccinated. Hence there is an urgent need for in-depth epidemiological data on invasive pneumococci before vaccination becomes widespread. Such a study has never been done before in Hungary.

Methods

144 pneumococcal isolates, obtained from invasive infections or pneumonia, were collected from eight Hungarian diagnostic laboratories between 2000 and 2008. After confirmation of species identity, their susceptibilities to nine antibiotics were determined by Etest and agar dilution method. The serotypes and pulsed-field gel electrophoresis genotypes of the strains were also determined.

Results

In this cohort, most of the isolates were from patients at the extreme of life. Only 1.4% of the strains were resistant to penicillin, but nearly 40% were resistant to erythromycin (mainly due to erm(B) gene). Higher incidences of resistance were found in the very young and very old. The most prevalent serotypes in the cohort in descending order were 14, 6A, 6, 6B, 23F, 3, 19F and 11A.

Conclusions

Results showed a similar but not identical profile to previously examined strains causing pulmonary infections in Hungary. The serotypes could be correlated to patient groups. Furthermore, there were examples of serotype switching in strains showing identical genotype but different serotype. The study also shows a good coverage by the conjugate vaccines over the invasive pneumococcal strains in Hungary based on the detected serotypes.
Human papillomavirus prevalence in invasive cervical carcinomas in Bulgaria
Authors: Todorova I , Ganchev G , Shikova E
Published: October 2010

Background

Although Bulgaria has one of the highest rates of cervical cancer incidence and mortality in the EU, data on HPV type distribution are limited.

Aim

To determine the prevalence of HPV types 16 and 18 in archival specimens from cervical cancer cases from Bulgaria.

Methods

A total of 145 formalin-fixed, paraffin-embedded tissue samples from women with histologically proven invasive squamous cell carcinoma of the uterine cervix were available for this study. Detection of HPV types 16 and 18 was based on two parallel PCRs from each sample using type-specific primers for these genotypes. The quality of the extracted DNA was evaluated by PCR using PC03/PC04 β-globin-specific primers. Sections from each block were H&E stained and assessed by the study pathologist to confirm the histological diagnosis.

Results

Of the 127 β-globin-positive squamous cell carcinoma cases, 98 (77.2%) were positive for HPV16 and/or HPV18 DNA. HPV16 was the more prevalent type and was found as a single infection in 86 (67.7%) cases. HPV type 18 as a single infection was detected in eight (6.3%) cases. Four specimens (3.2%) were double infected with HPV types 16 and 18.

Conclusions

HPV types 16 and 18 are important risk factors for cervical cancer in Bulgaria. These data are helpful for estimating the potential impact of HPV vaccines in Bulgaria and indicate that ∼77% of cervical cancer cases in the country are potentially preventable by vaccination with currently available prophylactic HPV16/18 vaccines.
Qualitative analysis of Camel Snus' website message board—users' product perceptions, insights and online interactions
Authors: Wackowski Olivia Ann , Lewis M Jane , Delnevo Cristine D
Published: October 2010

Background

In 2006, RJ Reynolds began test-marketing Camel Snus, a new smokeless tobacco (SLT) product. Promotion included use of a brand website, a relatively new marketing channel used by tobacco companies, which allowed visitors to learn about the product and discuss it with others on the website's message board. Our study aimed to examine early experiences with and perceptions of Camel Snus as described by board contributors and also to consider the use and benefits of the message board for both consumers and the company.

Methods

We conducted a qualitative analysis, coding each message in Atlas.Ti and analysing it for emerging themes and patterns. Messages were also coded for demographic information where evident, such as tobacco use status and geographical location. Descriptive data and illustrative quotes are presented.

Results

Board participants described being introduced to Camel Snus through free samples. Favourable evaluations were posted by current smokers who had never tried SLT before as well as current users of other SLT brands. Messages indicated both initiation of dual product use among smokers and product substitution. Participants used the board to advise each other on how to use the product, where to get more, suggest ways RJ Reynolds could improve the product and to encourage RJ Reynolds to release it nationally.

Discussion

Camel Snus has appeal for at least some smokers and SLT users. Camel Snus' website message board may have been a doubly beneficial marketing feature in both connecting product users and providing product feedback to the company during test-marketing.
A taxonomic assessment of the type series of Albertosaurus sarcophagus and the identity of Tyrannosauridae (Dinosauria, Coelurosauria) in the Albertosaurus bonebed from the Horseshoe Canyon Formation (Campanian–Maastrichtian, Late Cretaceous)This article is one of a series of papers published in this Special Issue on the theme Albertosaurus.
Authors: Carr Thomas D.
Published: October 2010

The type series of Albertosaurus sarcophagus , consisting of a type (CMN 5600) and a paratype (CMN 5601) is inadequately established, since it has not been demonstrated that the specimens represent the same taxon. This problem has arisen because the original diagnostic characters have a wider distribution among Tyrannosauridae or they are in error, and both specimens consist of incomplete and damaged skulls. The type series was studied to test for the presence of diagnostic characters in the type specimen and, if so, to provide a rationale for referring the paratype to the taxon. Of the bones shared between the skulls, only five could be compared. One character, the enlarged posterior pneumatic recess of the palatine, is shared between the two specimens; this condition differs from the situation seen in other tyrannosaurids. This character provided the rationale for assessing the identity of the specimens collected from the Albertosaurus bonebed, from which one palatine was collected that exhibits the diagnostic recess. Isolated cranial bones from the bonebed were compared with those preserved in the type series to evaluate their referral to A. sarcophagus ; additional characters shared between the type series and the specimens from the bonebed were identified in the maxilla, lacrimal, and palatine. This evidence supports the hypothesis that A. sarcophagus is the tyrannosaurid preserved in the bonebed. A hypothesis of the principal growth changes in the skull in A. sarcophagus, which includes the type series and bonebed material, is proposed.
The heterodonty ofAlbertosaurus sarcophagusandTyrannosaurus rex: biomechanical implications inferred through 3-D modelsThis article is one of a series of papers published in this Special Issue on the themeAlbertosaurus.
Authors: Reichel Miriam
Published: October 2010

The objective of this study is to analyze how different crown morphologies and different root lengths respond to stresses generated by the bite forces of Albertosaurus sarcophagus and Tyrannosaurus rex . Six well-preserved teeth of A. sarcophagus from the Albertosaurus bonebed in Dry Island Park (southern Alberta) were selected to study their biomechanics, and T. rex teeth were included for comparison. The three-dimensional (3-D) models were obtained through computerized tomography (CT) scanning and 3-D digitizing. Finite element analyses were performed in Strand7®. Bite forces for Albertosaurus and Tyrannosaurus were calculated based on cranial and jaw proportions. The results were viewed with the Tresca yield criterion. The ratios of shear stresses observed along the mesio-distal versus labio-lingual axes of all models allows the identification of similar stress distribution patterns in the upper and lower jaws of Albertosaurus and the upper jaws of Tyrannosaurus, with a higher amount of shear along the mesio-distal axis occurring in the mid-maxillary teeth. The dentary teeth of Tyrannosaurus, however, show a different stress distribution pattern, with a higher amount of shear occurring along the labio-lingual axis of the mid-dentary teeth. These differences in jaw mechanics suggest that the function of teeth in the lower jaw of Tyrannosaurus shifted a few positions to compensate different proportions in the dentary that cause the anterior dentary teeth to be aligned with the largest maxillary teeth in Tyrannosaurus. These results suggest that heterodonty in these groups is different and that tooth form and function are sensitive to jaw proportions.
On gregarious behavior inAlbertosaurusThis article is one of a series of papers published in this Special Issue on the themeAlbertosaurus.
Authors: Currie Philip J. , Eberth David A.
Published: October 2010

One century ago, a field party from the American Museum of Natural History discovered a bonebed in the Upper Cretaceous Horseshoe Canyon Formation of Alberta, Canada. Excavations by that museum, the Royal Tyrrell Museum of Palaeontology, and the University of Alberta have revealed the presence of at least a dozen individuals — represented by articulated partial skeletons, associated skeletons, and disarticulated isolated elements — of Albertosaurus sarcophagus . Tyrannosaurids dominate the bonebed assemblage, which also includes an adult Hypacrosaurus altispinus , two individuals of Albertonykus borealis , and numerous other, predominantly terrestrial, vertebrates. Skeletal morphology, phylogenetic inference, monodominant bonebeds, trackway sites, and ecological inferences support the notion that some non-avian theropods were gregarious animals. And specifically in the Albertosaurus bonebed, associated geologic and taphonomic evidence do not rule out a behavioural component in this catastrophic, mass-death assemblage.
Synthesis of metallocarbonyl substituted 1,2,3-triazole complexes via copper(I)-catalyzed azide–alkyne cycloaddition
Authors: Rudolf Bogna
Published: October 2010

(η5-C5H5)M(CO)x(η1-N-maleimidato) (M = Fe, x = 2; M = W, x = 3) complexes react with propargylamine and propargyl alcohol giving products from the Michael addition to the η1-N-maleimidato ligand. Metallocarbonyl compounds bearing a terminal alkyne group were reacted with organic azides affording corresponding 1,2,3-triazoles in high yields. One of these metallocarbonyl 1,2,3-triazoles (M = Fe, x = 2) was characterized by X-ray diffraction.
INVERSE AND SPONTANEOUS SUPERSYMMETRY BREAKING IN S1 × R3
Authors: OIKONOMOU V. K.
Published: October 2010

In this paper, we study the influence of hard-supersymmetry-breaking terms in an N = 1, d = 4 supersymmetric model, with S1 × R3 space–time topology. It is found that for some interaction terms and for certain values of the couplings, supersymmetry is unbroken for small lengths of the compact radius and spontaneously breaks as the radius increases. Also, for another class of interaction terms, when the radius is large, supersymmetry is unbroken and spontaneously breaks as the radius decreases. It is pointed out that the two phenomena have similarities to the theory of metastable vacua at finite temperature, as well as to the inverse symmetry breaking of continuous symmetries at finite temperature (where the role of the temperature is played by the radius of the compact dimension).
ASPECTS OF STRING PHENOMENOLOGY
Authors: ANTONIADIS I.
Published: October 2010

Lowering the string scale in the TeV region provides a theoretical framework for solving the mass hierarchy problem and unifying all interactions. The apparent weakness of gravity can then be accounted by the existence of large internal dimensions, in the submillimeter region, and transverse to a braneworld where our universe must be confined. I review the main properties of this scenario and its implications for observations at both particle colliders, and in nonaccelerator gravity experiments.
STRING CORRECTIONS TO QCD
Authors: LÜST DIETER
Published: October 2010

In this paper we are considering coorections to strong interactions which are due to colored string Regge excitations. In case of a low string scale within the TeV region these higher spin excitations of quarks and gluons will lead to spectacular, universal dijet signatures at the LHC, which are true for a large class of models in the string landscape.
STATUS OF SUPERSTRING AND M-THEORY
Authors: SCHWARZ JOHN H.
Published: October 2010

The first lecture gives a colloquium-level overview of string theory and M-theory. The second lecture surveys various attempts to construct a viable model of particle physics. A recently proposed approach, based on F-theory, is emphasized.
MODIFIED SCHEME OF CRYSTALLINE UNDULATOR
Authors: MKRTCHYAN A. R. , MKRTCHYAN A. H. , ASLANYAN H. A. , KHACHATURYAN G. K. , NASONOV N. N. , ZHUKOVA P. N. , KUBANKIN A. S.
Published: October 2010

The new scheme of crystalline undulator based on coherent bremsstrahlung from above barrier relativistic electrons interacting with a system of atomic strings periodically deformed by acoustic wave is proposed and studied in the work. The possibility to generate X-rays in the range of about 10 keV and more by electrons with energies of about 100 MeV is shown. Spectral-angular density of the emission being considered may be six times greater than ordinary CB.
MULTICAST CONGESTION CONTROL SRMSH APPROACH USING COMMUNICATING REAL-TIME STATE MACHINES
Authors: BONASTRE O. M. , NEVILLE S. , PALAU C. E.
Published: October 2010

New real-time applications frequently involve timing constraints related to accurate services from communication protocols. Concretely, real-time communication protocols utilize timers to implement these constraints between system event occurrences. In this context, the study of congestion control for Internet reliable multicast is at present an active research field related to real-time protocols. In this paper, the authors present an innovative real-time transport protocol named Scalable Reliable Multicast Stair Hybrid (SRMSH) as new hybrid multiple layer mechanism for multicast congestion control providing detection and recovery loss. This work is focused on formal specification of SRMSH approach using Communicating Real-Time State Machines as a formal method. Besides, SRMSH validation is presented within a formal proof framework in order to check the functional safety and liveness properties. As a result, authors outline a dynamical system framework in order to model behavior of their presented solution.
Cystathionine β-synthase and cystathionine γ-lyase double gene transfer ameliorate homocysteine-mediated mesangial inflammation through hydrogen sulfide generation
Authors: Sen Utpal , Givvimani Srikanth , Abe Oluwasegun A. , Lederer Eleanor D. , Tyagi Suresh C.
Published: October 2010

Elevated level of homocysteine (Hcy) induces chronic inflammation in vascular bed, including glomerulus, and promotes glomerulosclerosis. In this study we investigated in vitro mechanism of Hcy-mediated monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) induction and determined the regulatory role of hydrogen sulfide (H2S) to ameliorate inflammation. Mouse glomerular mesangial cells (MCs) were incubated with Hcy (75 μM) and supplemented with vehicle or with H2S (30 μM, in the form of NaHS). Inflammatory molecules MCP-1 and MIP-2 were measured by ELISA. Cellular capability to generate H2S was measured by colorimetric chemical method. To enhance endogenous production of H2S and better clearance of Hcy, cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) genes were delivered to the cells. Oxidative NAD(P)H p47 phox was measured by Western blot analysis and immunostaining. Phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH2-terminal kinase (JNK1/2) were measured by Western blot analysis. Our results demonstrated that Hcy upregulated inflammatory molecules MCP-1 and MIP-2, whereas endogenous production of H2S was attenuated. H2S treatment as well as CBS and CSE doubly cDNA overexpression markedly reduced Hcy-induced upregulation of MCP-1 and MIP-2. Hcy-induced upregulation of oxidative p47 phox was attenuated by H2S supplementation and CBS/CSE overexpression as well. In addition to that we also detected Hcy-induced MCP-1 and MIP-2 induction was through phosphorylation of ERK1/2 and JNK1/2. Either H2S supplementation or CBS and CSE doubly cDNA overexpression attenuated Hcy-induced phosphorylation of these two signaling molecules and diminished MCP-1 and MIP-2 expressions. Similar results were obtained by inhibition of ERK1/2 and JNK1/2 using pharmacological and small interferring RNA (siRNA) blockers. We conclude that H2S plays a regulatory role in Hcy-induced mesangial inflammation and that ERK1/2 and JNK1/2 are two signaling pathways involved this process.
BACE2 plays a role in the insulin receptor trafficking in pancreatic β-cells
Authors: Casas Silvia , Casini Paola , Piquer Sandra , Altirriba Jordi , Soty Maud , Cadavez Lisa , Gomis Ramon , Novials Anna
Published: October 2010

BACE1 (β-site amyloidogenic cleavage of precursor protein-cleaving enzyme 1) is a β-secretase protein that plays a central role in the production of the β-amyloid peptide in the brain and is thought to be involved in the Alzheimer's pathogenesis. In type 2 diabetes, amyloid deposition within the pancreatic islets is a pathophysiological hallmark, making crucial the study in the pancreas of BACE1 and its homologous BACE2 to understand the pathological mechanisms of this disease. The objectives of the present study were to characterize the localization of BACE proteins in human pancreas and determine their function. High levels of BACE enzymatic activity were detected in human pancreas. In normal human pancreas, BACE1 was observed in endocrine as well as in exocrine pancreas, whereas BACE2 expression was restricted to β-cells. Intracellular analysis using immunofluorescence showed colocalization of BACE1 with insulin and BACE2 with clathrin-coated vesicles of the plasma membrane in MIN6 cells. When BACE1 and -2 were pharmacologically inhibited, BACE1 localization was not altered, whereas BACE2 content in clathrin-coated vesicles was increased. Insulin internalization rate was reduced, insulin receptor β-subunit (IRβ) expression was decreased at the plasma membrane and increased in the Golgi apparatus, and a significant reduction in insulin gene expression was detected. Similar results were obtained after specific BACE2 silencing in MIN6 cells. All these data point to a role for BACE2 in the IRβ trafficking and insulin signaling. In conclusion, BACE2 is hereby presented as an important enzyme in β-cell function.