bluuebunny/crossref_metadata_2025 huggingface dataset:
Point-Counterpoint: It Is Time To Use Treponema-Specific Antibody Screening Tests for Diagnosis of Syphilis
Authors: Loeffelholz Michael J. , Binnicker Matthew J.
Published: November 2011

Assays that detect treponema-specific antibodies, which are either automated or can be done as point-of-care tests, have been developed, some of which are FDA approved. These assays have the advantage of being easily performed and demonstrate high sensitivity, both key features of an infectious disease screening test. As a result, many high-volume clinical laboratories have begun to offer a reverse syphilis testing algorithm where a treponema-specific test is used for screening, followed by a nontreponemal test (i.e., rapid plasma reagin [RPR]) to assess disease activity and treatment status. Concerns about physicians being able to understand and apply this new testing algorithm have been expressed (8). In this point-counterpoint, Michael Loeffelholz of the University of Texas Medical Branch at Galveston explains why his laboratory has adopted this reverse algorithmic approach. Matthew Binnicker of the Mayo Clinic, Rochester, MN, explains why the reverse algorithm may not be suitable for all clinical laboratories and every clinical situation.
Enhanced Growth of Influenza Vaccine Seed Viruses in Vero Cells Mediated by Broadening the Optimal pH Range for Virus Membrane Fusion
Authors: Murakami Shin , Horimoto Taisuke , Ito Mutsumi , Takano Ryo , Katsura Hiroaki , Shimojima Masayuki , Kawaoka Yoshihiro
Published: November 2011

Vaccination is one of the most effective preventive measures to combat influenza. Prospectively, cell culture-based influenza vaccines play an important role for robust vaccine production in both normal settings and urgent situations, such as during the 2009 pandemic. African green monkey Vero cells are recommended by the World Health Organization as a safe substrate for influenza vaccine production for human use. However, the growth of influenza vaccine seed viruses is occasionally suboptimal in Vero cells, which places limitations on their usefulness for enhanced vaccine production. Here, we present a strategy for the development of vaccine seed viruses with enhanced growth in Vero cells by changing an amino acid residue in the stem region of the HA2 subunit of the hemagglutinin (HA) molecule. This mutation optimized the pH for HA-mediated membrane fusion in Vero cells and enhanced virus growth 100 to 1,000 times in the cell line, providing a promising strategy for cell culture-based influenza vaccines.
A Role for the Internal Repeat of the Kaposi's Sarcoma-Associated Herpesvirus Latent Nuclear Antigen in the Persistence of an Episomal Viral Genome
Authors: Alkharsah Khaled R. , Schulz Thomas F.
Published: November 2011

The latent nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus (KSHV) is required for the replication and partitioning of latent viral genomes. It contains an extended internal repeat (IR) region whose function is only incompletely understood. We constructed KSHV genomes lacking either LANA (KSHV-ΔLANA) or the IR region of LANA (KSHV-LANAΔ329-931). Although still capable of replicating a plasmid containing a latent origin of replication, LANAΔ329-931 does not support the establishment of stable cell lines containing a KSHV genome. These findings suggest a role for the LANA IR in KSHV episomal maintenance without its being required for replication.
Adaptation of a Duck Influenza A Virus in Quail
Authors: Yamada Shinya , Shinya Kyoko , Takada Ayato , Ito Toshihiro , Suzuki Takashi , Suzuki Yasuo , Le Quynh Mai , Ebina Masahito , Kasai Noriyuki , Kida Hiroshi , Horimoto Taisuke , Rivailler Pierre , Chen Li Mei , Donis Ruben O. , Kawaoka Yoshihiro
Published: November 2011

Quail are thought to serve as intermediate hosts of influenza A viruses between aquatic birds and terrestrial birds, such as chickens, due to their high susceptibility to aquatic-bird viruses, which then adapt to replicate efficiently in their new hosts. However, does replication of aquatic-bird influenza viruses in quail similarly result in their efficient replication in humans? Using sialic acid-galactose linkage-specific lectins, we found both avian (sialic acid-α2-3-galactose [Siaα2-3Gal] linkages on sialyloligosaccharides)- and human (Siaα2-6Gal)-type receptors on the tracheal cells of quail, consistent with previous reports. We also passaged a duck H3N2 virus in quail 19 times. Sequence analysis revealed that eight mutations accumulated in hemagglutinin (HA) during these passages. Interestingly, many of the altered HA amino acids found in the adapted virus are present in human seasonal viruses, but not in duck viruses. We also found that stepwise stalk deletion of neuraminidase occurred during passages, resulting in reduced neuraminidase function. Despite some hemagglutinin mutations near the receptor binding pocket, appreciable changes in receptor specificity were not detected. However, reverse-genetics-generated viruses that possessed the hemagglutinin and neuraminidase of the quail-passaged virus replicated significantly better than the virus possessing the parent HA and neuraminidase in normal human bronchial epithelial cells, whereas no significant difference in replication between the two viruses was observed in duck cells. Further, the quail-passaged but not the original duck virus replicated in human bronchial epithelial cells. These data indicate that quail can serve as intermediate hosts for aquatic-bird influenza viruses to be transmitted to humans.
Epigenetic Regulation of the Latency-Associated Region of Marek's Disease Virus in Tumor-Derived T-Cell Lines and Primary Lymphoma
Authors: Brown Andrew C. , Nair Venugopal , Allday Martin J.
Published: November 2011

Meq is the major Marek's disease virus (MDV)-encoded oncoprotein and is essential for T-cell lymphomagenesis. Meq and several noncoding RNAs, including three microRNA (MiR) clusters, are expressed from the repeats of the MDV genome during latent infection of T cells. To investigate the state of the chromatin in this and flanking regions, we carried out chromatin immunoprecipitation (ChIP) analysis of covalent histone modifications and associated bound proteins. T-cell lines and a lymphoma were compared. The chromatin around the promoters for
Meq
and the noncoding RNAs in both cell lines and the lymphoma were associated with H3K9 acetylation and H3K4 trimethylation, which are marks of transcriptionally active chromatin. These correlated with bound Meq–c-Jun heterodimers. The only binding site for Meq homodimers is located at the lytic origin of replication (OriLyt), next to the lytic gene
pp38
. This region lacked active marks and was associated with repressive histone modifications (H3K27 and H3K9 trimethylation). DNA CpG methylation was investigated using methylated DNA precipitation (MeDP). In cell lines, DNA methylation was abundant across the repeats but noticeably reduced or absent around the active promoters. In primary tumors, CpG methylation occurred less than 2 months after infection, focused within the
ICP4
gene. These data suggest that nonrandom
de novo
DNA methylation occurs early in lymphomagenesis. In addition, the histone data indicate a role for Meq in the epigenetic regulation of the MDV genome repeats in transformed T cells and suggest that the OriLyt region and the
Meq/
MiR region might be separated by chromatin boundary elements, and preliminary data on CTCF binding are consistent with this.
Genetic Mapping of a Highly Variable Norovirus GII.4 Blockade Epitope: Potential Role in Escape from Human Herd Immunity
Authors: Debbink Kari , Donaldson Eric F. , Lindesmith Lisa C. , Baric Ralph S.
Published: November 2011

Noroviruses account for 96% of viral gastroenteritis cases worldwide, with GII.4 strains responsible >80% of norovirus outbreaks. Histo-blood group antigens (HBGAs) are norovirus binding ligands, and antigenic and preferential HBGA binding profiles vary over time as new GII.4 strains emerge. The capsid P2 subdomain facilitates HBGA binding, contains neutralizing antibody epitopes, and likely evolves in response to herd immunity. To identify amino acids regulating HBGA binding and antigenic differences over time, we created chimeric virus-like particles (VLPs) between the GII.4-1987 and GII.4-2006 strains by exchanging amino acids in putative epitopes and characterized their antigenic and HBGA binding profiles using anti-GII.4-1987 and -2006 mouse monoclonal antibodies (MAbs) and polyclonal sera, 1988 outbreak human sera, and synthetic HBGAs. The exchange of amino acids 393 to 395 between GII.4-1987 and GII.4-2006 resulted in altered synthetic HBGA binding compared to parental strains. Introduction of GII.4-1987 residues 294, 297 to 298, 368, and 372 (epitope A) into GII.4-2006 resulted in reactivity with three anti-GII.4-1987 MAbs and reduced reactivity with four anti-GII.4-2006 MAbs. The three anti-GII.4-1987 MAbs also blocked chimeric VLP-HBGA interaction, while an anti-GII.4-2006 blocking antibody did not, indicating that epitope A amino acids comprise a potential neutralizing epitope for GII.4-1987 and GII.4-2006. We also tested GII.4-1987-immunized mouse polyclonal sera and 1988 outbreak human sera for the ability to block chimeric VLP-HBGA interaction and found that epitope A amino acids contribute significantly to the GII.4-1987 blockade response. Our data provide insights that help explain the emergence of new GII.4 epidemic strains over time, may aid development of norovirus therapeutics, and may help predict the emergence of future epidemic strains.
The Highly Conserved Arginine Residues at Positions 76 through 78 of Influenza A Virus Matrix Protein M1 Play an Important Role in Viral Replication by Affecting the Intracellular Localization of M1
Authors: Das Subash C. , Watanabe Shinji , Hatta Masato , Noda Takeshi , Neumann Gabrielle , Ozawa Makoto , Kawaoka Yoshihiro
Published: November 2011

Influenza A virus matrix protein (M1) plays an important role in virus assembly and budding. Besides a well-characterized basic amino acid-rich nuclear localization signal region at positions 101 to 105, M1 contains another basic amino acid stretch at positions 76–78 that is highly conserved among influenza A and B viruses, suggesting the importance of this stretch. To understand the role of these residues in virus replication, we mutated them to either lysine (K), alanine (A), or aspartic acid (D). We could generate viruses possessing either single or combination substitutions with K or single substitution with A at any of these positions, but not those with double substitutions with A or a single substitution with D. Viruses with the single substitution with A exhibited slower growth and had lower nucleoprotein/M1 quantitative ratio in virions compared to the wild-type virus. In cells infected with a virus possessing the single substitution with A at position 77 or 78 (R77A or R78A, respectively), the mutated M1 localized in patches at the cell periphery where nucleoprotein and hemagglutinin colocalized more often than the wild-type did. Transmission electron microscopy showed that virus possessing M1 R77A or R78A, but not the wild-type virus, was present in vesicular structures, indicating a defect in virus assembly and/or budding. The M1 mutations that did not support virus generation exhibited an aberrant M1 intracellular localization and affected protein incorporation into virus-like particles. These results indicate that the basic amino acid stretch of M1 plays a critical role in influenza virus replication.
Codelivery of the Chemokine CCL3 by an Adenovirus-Based Vaccine Improves Protection from Retrovirus Infection
Authors: Lietz Ruth , Bayer Wibke , Ontikatze Teona , Johrden Lena , Tenbusch Matthias , Storcksdieck genannt Bonsmann Michael , Überla Klaus , Dittmer Ulf , Wildner Oliver
Published: November 2011

Processing and presentation of vaccine antigens by professional antigen-presenting cells (APCs) is of great importance for the efficient induction of protective immunity. We analyzed whether the efficacy of an adenovirus-based retroviral vaccine can be enhanced by coadministration of adenovirus-encoded chemokines that attract and stimulate APCs. In the Friend retrovirus (FV) mouse model we coexpressed CCL3, CCL20, CCL21, or CXCL14 from adenoviral vectors, together with FV Gag and Env antigens, and then analyzed immune responses and protection from pathogenic FV infection. Although most tested chemokines did not improve protection against FV challenge, mice that received adenoviral vectors encoding CCL3 together with FV antigens showed significantly better control over viral loads and FV-induced disease than mice immunized with the viral antigens only. Improved protection correlated with enhanced virus-specific CD4+T cell responses and higher neutralizing antibody titers. To apply these results to an HIV vaccine, mice were immunized with adenoviral vectors encoding the HIV antigens Env and Gag-Pol and coadministered vectors encoding CCL3. Again, this combination vaccine induced higher virus-specific antibody titers and CD4+T cell responses than did the HIV antigens alone. These results indicate that coexpression of the chemokine CCL3 by adenovirus-based vectors may be a promising tool to improve antiretroviral vaccination strategies.
Varicella-Zoster Virus Inhibition of the NF-κB Pathway during Infection of Human Dendritic Cells: Role for Open Reading Frame 61 as a Modulator of NF-κB Activity
Authors: Sloan Elizabeth , Henriquez Rodney , Kinchington Paul R. , Slobedman Barry , Abendroth Allison
Published: November 2011

Dendritic cells (DC) are antigen-presenting cells essential for initiating primary immune responses and therefore an ideal target for viral immune evasion. Varicella-zoster virus (VZV) can productively infect immature human DCs and impair their function as immune effectors by inhibiting their maturation, as evidenced by the expression modulation of functionally important cell surface immune molecules CD80, CD86, CD83, and major histocompatibility complex I. The NF-κB pathway largely regulates the expression of these immune molecules, and therefore we sought to determine whether VZV infection of DCs modulates the NF-κB pathway. Nuclear localization of NF-κB p50 and p65 indicates pathway activation; however, immunofluorescence studies revealed cytoplasmic retention of these NF-κB subunits in VZV-infected DCs. Western blotting revealed phosphorylation of the inhibitor of κBα (IκBα) in VZV-infected DCs, indicating that the pathway is active at this point. We conclude that VZV infection of DC inhibits the NF-κB pathway following protein phosphorylation but before the translocation of NF-κB subunits into the nucleus. An NF-κB reporter assay identified VZV open reading frame 61 (ORF61) as an inhibitor of tumor necrosis factor alpha-induced NF-κB reporter activity. Mutational analysis of ORF61 identified the E3 ubiquitin ligase domain as a region required for NF-κB pathway inhibition. In summary, we provide evidence that VZV inhibits the NF-κB signaling pathway in human DCs and that the E3 ubiquitin ligase domain of ORF61 is required to modulate this pathway. Thus, this work identifies a mechanism by which VZV modulates host immune function.
Transmissible Gastroenteritis Coronavirus RNA-Dependent RNA Polymerase and Nonstructural Proteins 2, 3, and 8 Are Incorporated into Viral Particles
Authors: Nogales Aitor , Márquez-Jurado Silvia , Galán Carmen , Enjuanes Luis , Almazán Fernando
Published: November 2011

Coronavirus replication and transcription are processes mediated by a protein complex, with the RNA-dependent RNA polymerase (RdRp) as a main component. Proteomic analysis of highly purified transmissible gastroenteritis virus showed the RdRp to be a component of the viral particles. This finding was confirmed by Western blotting, immunofluorescence, and immunoelectron microscopy analyses. Interestingly, the replicase nonstructural proteins 2, 3, and 8 colocalized with the RdRp in the viral factories and were also incorporated into the virions.
Exercise prescription: a case for standardised reporting
Authors: Slade Susan Carolyn , Keating Jennifer Lyn
Published: November 2011

Background

Structured, regular exercise is recommended to improve health outcomes. Exercise takes many forms and varies in type, intensity, duration and frequency. The authors used the example of exercise for chronic health conditions to examine how exercise programmes are described and summarised in systematic reviews.

Methods

Two independent reviewers conducted a review of exercise reporting practices using the evidence of exercise effects for chronic conditions as the source material. Inclusion criteria: systematic reviews that summarised the effects of exercise programmes for adults with chronic health conditions. Exclusion criteria: reviews of studies of children and adolescent populations, and non-English publications.

Results

Seventy-three reviews were included. Data on sample size, number of included trials, interventions, comparisons, programme characteristics, exercise components, author conclusions and recommendations were extracted. Seventy-one per cent of reviews reported being unable to adequately describe the exercise programmes, because the required information was not reported in included trials. Using key exercise descriptors from the included reviews, the authors developed criteria for reporting to a level that enables replication.

Conclusions

All included reviews recommended better and standardised reporting. Incomplete exercise programme descriptions limit confidence in the accurate replication of effective interventions and limits critical appraisal of interventions when conflicting outcomes are reported. The evaluation and implementation of physical activity and exercise research would be facilitated if exercise programmes are comprehensively described. The authors propose that systematic reviews/meta-analysis and clinical application of the outcomes of exercise therapy research would be enhanced if authors used an exercise reporting grid that includes a detailed description of the programme components.
Parenteral methotrexate for patients with Crohn's disease: how to develop a high-quality and safe self-administration service: Figure 1
Authors: Coltart Iona , Blackmore Laura , Caisley Jane , Harris Adam
Published: November 2011

Parenteral methotrexate is recommended for patients with Crohn's disease who have failed treatment with thiopurines. There is no good evidence for the use of oral methotrexate, yet patients frequently receive this due to the difficulties associated with prescribing and administering an unlicensed, cytotoxic drug.

We present our experience of developing a local service to provide our patients with the option to self-administer parenteral methotrexate in a safe and structured manner at home.
Incidence of severe work-related injuries among young adult workers in Brazil: analysis of compensation data
Authors: Sousa Santana Vilma , Villaveces Andrés , Bangdwala Shrikant L , W Runyan Carol , Albuquerque Oliveira Paulo Rogerio
Published: November 2011

Objectives

To obtain national estimates of the annual cumulative incidence and incidence density of severe non-fatal injuries using compensation benefits data from the Brazilian National Social Security Institute (INSS), and to describe their sociodemographic distribution among workers aged under 25 years.

Methods

Data are records of health-related compensation benefits from the Ministry of Social Insurance's information system of compensation benefits of the INSS recorded in 2006. Injuries were cases classified under chapter XIX, ICD-10. The assessment of their relation with work was made by INSS's occupational physician experts. The study population comprised young workers aged 16–24 years.

Results

59 381 workers received compensation benefits for injuries in the study year. Among them 14 491 (24.4%) were work related, 12 501 (86.3%) were male and 1990 were female workers (13.7%). The annual cumulative incidence rate of work-related injuries (ACI–WI) was 2.9×1000 workers, higher among men (4.2×1000) than women (1.0×1000). The incidence density rate (IDR–WI) was 0.7/1000 full-time equivalent (FTE), higher for men (0.97/1000 FTE) than women (0.24/1000 FTE). Both morbidity measures were higher in the younger group (16–19 years), and inversely related to wage, especially for women in the younger group. Logging, extraction, food/beverage and construction industries had higher ACI–WI and IDR–WI for adolescents and young adult workers of both sex groups.

Conclusions

These findings suggest that the Brazilian labour laws limiting young adult workers in hazardous settings need to be expanded, adding occupations in other extractive industries and certain types of work in the food/beverage manufacturing industries. Social inequalities associated with sex need to be examined further with more detailed data.
Lysyl oxidase regulates MMTV promoter: indirect evidence of histone H1 involvement
Authors: Oleggini Roberta , Di Donato Armando
Published: November 2011

Lysyl oxidase (LOX) is the enzyme that facilitates the cross-linking of collagen and elastin, although other functions for this enzyme have been indicated. Of these other functions, we describe herein the ability of LOX to regulate several gene promoters, like collagen III, elastin, and cyclin D1. We have previously demonstrated a specific binding between LOX and histone H1, in vitro. Therefore, we investigated whether LOX would affect the mouse mammary tumor virus (MMTV) promoter and its glucocorticoid regulation, which depends on the phophorylation status of histone H1. Our results show that the over-expression of recombinant human LOX was able to trigger MMTV activity, both in the presence and absence of glucocorticoids. Moreover, we demonstrated that histone H1 from cells expressing recombinant LOX contained isodesmosine and desmosine, indicating specific lysyl-oxidase-dependent lysine modifications. Finally, we were able to co-immunoprecipitate the exogenous LOX and histone H1 from the LOX transfected cells. The data are compatible with a decreased positive charge of histone H1, owing to deamination by LOX of its lysine residues. This event would favor H1 detachment from the target DNA, and consequent opening of the MMTV promoter structure to the activating transcription factors. The presented data, therefore, suggest a possible histone-H1-dependent mechanism for the modulation of MMTV promoter by LOX.
Electrochemical and spectroelectrochemical behavior of planar binuclear naphthalocyanines
Authors: Trashin Stanislav A. , Dubinina Tatiana V. , Fionov Aleksander V. , Tomilova Larisa G.
Published: November 2011

The electrochemical and spectroelectrochemical behavior of two planar binuclear naphthalocyanines containing benzene and naphthalene π-conjugated bridges was investigated for the first time. Their intense absorption in the near infrared region was observed even in a low polar solvent such as o-dichlorobenzene after electrochemical reduction at a potential of -0.4 V vs. SCE, which was not enough to reduce the complexes into their first reduction state. These data and EPR studies allow us to conclude that the electrochemically generated form is the true neutral form of the synthesized compounds whereas the suppression of the near-infrared bands is a result of the presence of their cation radicals as one-electron oxidized forms.
The microstructural and rheological evolution of shear zones
Authors: Austin Nicholas J.
Published: November 2011

Evidence of localized strain is ubiquitous in deformed lithospheric rocks. Recent advances in laboratory deformation techniques, including the use of torsion experiments, have enabled the coupling of microstructural and rheological evolution to be investigated in experiments run to strains approaching those reached in many natural shear zones. Further, the increased use of electron backscatter diffraction to quantify crystallographic preferred orientation (CPO) has significantly increased understanding of CPO formation and evolution. Combined, these laboratory and field observations support the assertion that a rock's microstructure is strongly linked to its rheology. However, complete quantification of the coupling between microstructure and rheology is complicated by the fact that rocks have inherently complex microstructures. This paper reviews recent work focused on quantifying the rates of microstructural evolution and the attainment of steady state for two key microstructural parameters: grain size and crystallographic preferred orientation. Theoretical considerations, laboratory measurements and field observations suggest that a full description of all relevant microstructural parameters, and the appropriate evolution equations for these parameters, may be needed to link microstructural and rheological evolution and therefore to quantify the bulk rheology of the lithosphere.
Torsion experiments on coarse-grained dunite: implications for microstructural evolution when diffusion creep is suppressed
Authors: Skemer Philip , Sundberg Marshall , Hirth Greg , Cooper Reid
Published: November 2011

Large strain deformation experiments in torsion were conducted on a coarse-grained natural dunite with a pre-existing lattice preferred orientation (LPO). Experiments were conducted at conditions where deformation by diffusion creep is initially negligible. Microstructural evolution was studied as a function of strain. We observe that the pre-existing LPO persists to a shear strain of at least 0.5. At larger strains, this LPO is transformed. Relict deformed grains exhibit LPO with [100] crystallographic axes at high angles to the shear plane. Unlike previous experimental studies, these axes do not readily rotate into the shear plane with increasing strain. Partial dynamic recrystallization occurs in samples deformed to moderate strains (
γ
>0.5). Recrystallized material forms bands that mostly transect grain interiors. The negligible rate of diffusion creep along relict grain boundaries, as well as the limited nature of dynamic recrystallization, may account for the relatively large strains required to observe evolution of microstructures. Our data support hypotheses based on natural samples that microstructures may preserve evidence of complex deformation histories. Relationships between LPO, seismic anisotropy and deformation kinematics may not always be straightforward.
Slip-system and EBSD analysis on compressively deformed fine-grained polycrystalline olivine
Authors: Farla R. J. M. , Gerald J. D. Fitz , Kokkonen H. , Halfpenny A. , Faul U. H. , Jackson I.
Published: November 2011

A slip-system analysis was performed on two synthetic compressively deformed olivine aggregates, derived from experimental solution–gelation (sol–gel) and natural San Carlos precursors to determine how dislocation density relates to Schmid factor for slip in olivine. Individual grain orientations were measured with electron backscatter diffraction. Using decorated dislocations, grain populations were separated into subsets of high versus low dislocation density. Analysis of preferred orientations and distributions of Schmid factors suggests that there is only weak correlation between Schmid factor and dislocation density, slip on (010)[100] in San Carlos grains but (001)[100] in sol–gel material, with multiple slip or stress heterogeneity in both.
Characterization of microstructures and interpretation of flow mechanisms in naturally deformed, fine-grained anhydrite by means of EBSD analysis
Authors: Hildyard Rebecca C. , Prior David J. , Mariani Elisabetta , Faulkner Daniel R.
Published: November 2011

Anhydrite-rich layers within foreland fold and thrust belts are frequently observed to be the weakest horizon of the sequence. Characterizing the microstructure of anhydrite is therefore important for interpreting the larger-scale deformation history of these rocks. Two microstructures from naturally deformed, fine-grained (<15 µm mean grain size) anhydrite samples from the Triassic Evaporites of the Umbria–Marche Apennines, Italy were analysed using electron backscatter diffraction (EBSD). Microstructural observations, misorientation analysis and crystallographic preferred orientation (CPO) determination were carried out on these samples. Both samples have a CPO characterized by alignment of 〈001〉 and distribution of 〈100〉 and 〈010〉 on a great circle normal to this. This anhydrite 〈001〉 ‘fibre texture’ has not been described before. Microstructure A is characterized by a moderate to weak CPO and a weak shape preferred orientation at 55° to 70° from the trace of the 〈001〉 maximum. Low-angle boundaries are revealed by misorientation analysis. A change in grain size from
c
. 10 to
c
. 7 µm corresponds to reduction in strength of CPO and reduction in the number of low-angle grain boundaries. Microstructure B is characterized by a very strong CPO. The orientation of the CPO changes between different microstructural domains. The 〈001〉 maximum is always perpendicular to the trace of a strong grain elongation and high-angle grain boundaries have misorientations close to 〈001〉, suggesting that the CPO is geometrically controlled: anhydrite grains are platy with 〈001〉 short axes. The origin of the CPO is therefore unclear but it need not relate to dislocation creep deformation. Whether or not CPO relates to dislocation creep, both samples have a high number of lower-angle grain boundaries and internal grain distortions with 〈010〉 and 〈001〉 misorientation axes. These are indicative of dislocation activity and the data are best explained by slip on either (100)[010] (dominant) and (001)[100] or a combination of these. Neither of these slip systems has been recognized before. Both microstructures are interpreted to have undergone dynamic recrystallization, and the weakening of the CPO with decreasing grain size in microstructure A is suggested to be indicative of a grain-boundary sliding mechanism becoming active. Comparison with experimental data shows that creep mechanisms involving dislocations at the observed grain sizes require the differential stress magnitudes driving deformation to be greater than
c
. 100 MPa.
Grain growth and the lifetime of diffusion creep deformation
Authors: Pearce Mark A. , Wheeler John
Published: November 2011

Extreme grain-size reduction due to cataclasis, neocrystallization or phase change results in a switch to diffusion creep and dramatic weakening in deforming rocks. Grain growth increases strength until dislocation creep becomes a significant deformation mechanism. We quantify the ‘lifetime’ of diffusion creep by substituting the normal grain growth law into the diffusion creep flow law to calculate the time taken for dislocation creep to become significant. Stress-temperature and strain-rate-temperature space is outlined where diffusion creep may accommodate significant strain: these regions have an upper temperature limit beyond which grain growth is fast enough to move the rock quickly into the dislocation creep field. For plagioclase the limit lies in the amphibolite facies. Rocks in a mantle upwelling experience grain-size reduction during phase changes. Pressure-dependent grain growth limits the deformation that can be accommodated by diffusion creep. This time limit and associated strain limit is independent of starting grain size with a small dependence on upwelling rate and plume width. In both these tectonic environments, second phases are likely to play a role in the maximum achievable grain size due to grain-boundary pinning. Hence we predict the minimum lifetimes of diffusion-creep-dominated deformation following extreme grain-size reduction.
Microstructures in deforming–reactive systems
Authors: Hobbs Bruce E. , Ord Alison
Published: November 2011

The inter-relationships between mineral reactions and deformation are explored with a view to understanding the development of certain mineral foliations and lineations. The following arguments are presented: (i) the processes involved during mineral reactions in deforming metamorphic rocks are described by coupled reaction–diffusion–deformation equations; (ii) these reactions can become unstable producing compositional patterning in both space (metamorphic differentiation) and time (compositional zoning); (iii) the patterns (foliations and mineral lineations) that result from coupled reaction–diffusion–deformation equations are described by surfaces that approximate minimal surfaces (surfaces of zero mean curvature) and an example of such geometry is given; and (iv) the foliations and mineral lineations that form by such processes are controlled by the evolution of the kinematics of the deformation history and not by the finite strain tensor.
Diffusion-creep modelling of fibrous pressure shadows II: influence of inclusion size and interface roughness
Authors: Berton J. R. , Durney D. W. , Wheeler J.
Published: November 2011

This paper extends previous work by us to gain a fuller appreciation of the physical factors that affect polycrystal diffusion-creep simulations of fibrous pressure-shadow growth around a pyrite inclusion. The earlier work dealt with the effect of diffusion ratio or diffusional conductance of the inclusion/matrix interface. The new work also examines the effects of inclusion geometry: a smaller inclusion of similar smoothness to the original, a regularly serrated inclusion the same size as the original and a coarse irregular inclusion of the same size. The results show: (1) significant enhancement of fibrous pressure-shadow growth and change of matrix strain pattern with decreased inclusion size, similar to an increase in diffusion ratio; (2) approach towards a maximum fibrous pressure-shadow growth at high diffusion ratios in the small-pyrite model; (3) little influence of the model serrations; (4) significant sliding on the interface at low diffusion ratios in all of the models; and (5) enhanced sliding in the irregular-pyrite model at low diffusion ratios. The results are qualitatively consistent with diffusion creep of a single grain interacting with a deforming medium. They demonstrate factors that may influence development of the natural structures under similar conditions in rocks.
Rock mechanics constraints on mid-crustal low-viscosity flow beneath Tibet
Authors: Rutter E. H. , Mecklenburgh J. , Brodie K. H.
Published: November 2011

It has been inferred from various types of geophysical data that the Tibetan middle and upper crust is detached from the underlying lower crust and mantle by a weak, mid-crustal zone involving partial melting at about 30–35 km depth. Previous modelling of the flow has used an arbitrary mid-crustal rheology to match the constraints imposed by the overall flow regime. Here we show that extrapolation of experimental rock mechanics data for solid-state flow of a quartz-dominated Tibetan middle and upper crust, plus flow of partially molten synthetic ‘granitoid’, are consistent with the geophysical constraints and provide an experimentally constrained basis for the modelling of crustal rheology involving partially molten rocks.
From crystal to crustal: petrofabric-derived seismic modelling of regional tectonics
Authors: Lloyd G. E. , Halliday J. M. , Butler R. W. H. , Casey M. , Kendall J.-M. , Wookey J. , Mainprice D.
Published: November 2011

The Nanga Parbat Massif (NPM), Pakistan Himalaya, is an exhumed tract of Indian continental crust and represents an area of active crustal thickening and exhumation. While the most effective way to study the NPM at depth is through seismic imaging, interpretation depends upon knowledge of the seismic properties of the rocks. Gneissic, ‘mylonitic’ and cataclastic rocks emplaced at the surface were sampled as proxies for lithologies and fabrics currently accommodating deformation at depth. Mineral crystallographic preferred orientations (CPO) were measured via scanning electron microscope (SEM)/electron backscatter diffraction (EBSD), from which three-dimensional (3D) elastic constants, seismic velocities and anisotropies were predicted. Micas make the main contribution to sample anisotropy. Background gneisses have highest anisotropy (up to 10.4% shear-wave splitting, AVs) compared with samples exhibiting localized deformations (e.g. ‘mylonite’, 4.7% AVs; cataclasite, 1% AVs). Thus, mylonitic shear zones may be characterized by regions of low anisotropy compared to their wall rocks. CPO-derived sample elastic constants were used to construct seismic models of NPM tectonics, through which P-, S- and converted waves were ray-traced. Foliation orientation has dramatic effects on these waves. The seismic models suggest dominantly pure-shear tectonics for the NPM involving horizontal compression and vertical stretching, modified by localized ductile and brittle (‘simple’) shear deformations.
Obliteration of olivine crystallographic preferred orientation patterns in subduction-related antigorite-bearing mantle peridotite: an example from the Higashi–Akaishi body, SW Japan
Authors: Wallis S. R. , Kobayashi H. , Nishii A. , Mizukami T. , Seto Y.
Published: November 2011

Large parts of the mantle wedge near subduction boundaries are likely to be hydrated and contain antigorite. This mineral is acoustically highly anisotropic and potentially has a strong influence on seismic properties of the wedge. The Higashi–Akaishi body of SW Japan is an exhumed sliver of partially serpentinized forearc mantle, ideal for studying the effects of antigorite on the development of tectonic fabrics in the mantle. Samples with less than 1% antigorite show strong B-type olivine crystallographic preferred orientation (CPO) patterns. In contrast, samples with >10% antigorite deformed during the same tectonic event show much weaker olivine CPO patterns lacking the flow-normal
a
-axis concentration. These microstructural data suggest that the development of antigorite during deformation weakens olivine CPO due to phase boundary slip and associated rigid-body rotation of olivine grains. Antigorite and similar sheet silicates are likely to be present to some extent in the mantle wedge of all convergent margins. Our results suggest that even if this amount is only a few percent, strong olivine CPO is unlikely to develop and any pre-existing CPO is likely to be destroyed. Under these conditions, olivine CPO is unlikely to contribute significantly to seismic anisotropy in the mantle wedge.
Crystal fabric development and slip systems in a quartz mylonite: an approach via transmission electron microscopy and viscoplastic self-consistent modelling
Authors: Morales Luiz F. G. , Mainprice David , Lloyd Geoffrey E. , Law Richard D.
Published: November 2011

We have applied transmission electron microscopy (TEM) analyses coupled with viscoplastic self-consistent (VPSC) numerical modelling to identify the active slip systems and to better understand the crystal preferred orientation (CPO) development of the Torridon quartz mylonite (NW Scotland). TEM analyses showed evidence of activation of 1/3〈
a
〉{π′}, 1/3〈
a
〉{
z
} and possible 〈
a
〉(
c
) slip systems, as well as dislocation climb and dynamic recrystallization. All the CPOs generated by VPSC models share common characteristics with the Torridon quartz mylonite, but only Models 2 and 3 reproduce the [
c
]-axes maxima at low angle (<20°) to the foliation pole along the
YZ
plane, as observed in the mylonite. In Model 2, this concentration only occurs at γ≥2.6, whereas in Model 3 this maxima occurs at lower shear strains. The models that start with a previous preferred orientation acquire very strong CPOs after small-imposed strains, followed by the rapid rotation of the fabric in relation to the new imposed finite strain axes. The combined activation of 〈
a
〉{π′}, 〈
a
〉{
z
} and possibly 〈
a
〉(
c
) slip systems, as demonstrated by TEM analyses, suggests that the VPSC model that best predicts CPO development in the Torridon quartz mylonite is Model 2, where the critical resolved shear stress (CRSS) of 〈
a
〉{π/π′} is assumed to be slightly stronger than 〈
a
〉(
c
).
High-quality tactile paintings
Authors: Reichinger Andreas , Maierhofer Stefan , Purgathofer Werner
Published: November 2011

The aim of this work is to bring the cultural heritage of two-dimensional art closer to being accessible by blind and visually impaired people. We present a computer-assisted workflow for the creation of tactile representations of paintings, suitable to be used as a learning tool in the context of guided tours in museums or galleries. Starting from high-resolution images of original paintings, our process allows an artist to quickly design the desired form, and generate data suitable for rapid prototyping machines to produce the physical touch tools. Laser-cut
layered depth diagrams
convey not only the individual objects in the painting and their spatial layout, but also augment their depth relations. CNC-milled
textured reliefs
additionally render fine details like brush strokes and texture suitable for the sense of touch. Our methods mimic aspects of the visual sense, make sure that the haptic output is quite faithful to the original paintings, and do not require special manual abilities like sculpting skills.
Update on the CS Principles project
Authors: Astrachan Owen , Briggs Amy
Published: November 2011

The Computer Science Principles project is a collaborative effort sponsored by the NSF and led by a group of Computer Science faculty working together with the College Board. Our goal is to design and teach a new introductory course in computer science that will attract a broader range of students to computer science. This course would serve as a new Advanced Placement (AP) course in addition to the current CS AP A.
SIGCSE speaker's fund program
Authors: Settle Amber
Published: November 2011

Since 2005, the SIGCSE Speaker's Fund Program has funded presentations at in-cooperation conferences. Speakers from previous SIGCSE conferences, including the Symposium, ITiCSE, and ICER, can be invited by the organizers of non-ACM conferences that have in-cooperation status with SIGCSE. The fund pays for up to $1000 of travel support for the speakers and is intended to disseminate outstanding presentations from SIGCSE conferences to other venues.
Cross-organizational service security
Authors: Miede Andre
Published: November 2011

Challenging market dynamics and the rise of complex value networks require organizations to adjust their processes rapidly in order to stay competitive. Because many organizational processes are directly supported or even enabled by Information Technology (IT), a process is only as flexible as its underlying technological representation. The Service-oriented Architecture paradigm (SOA) offers means on both a technological and organizational level for the flexible integration of internal and external IT systems. Thus, services are used to assemble processes through service compositions, as well as across enterprise boundaries. Such cross-organizational service-based workflows lead to a global SOA which is often referred to as the "Internet of Services".
Intelligent video processing using data mining techniques
Authors: Shirahama Kimiaki
Published: November 2011

Due to the rapidly increasing video data on the Web, much research effort has been devoted to develop video retrieval methods which can efficiently retrieve videos of interest. Considering the limited man-power, it is much expected to develop retrieval methods which use features automatically extracted from videos. However, since features only represent physical contents (e.g. color, edge, motion, etc.), retrieval methods require knowledge of how to use/integrate features for retrieving videos relevant to queries. To obtain such knowledge, this thesis concentrates on 'video data mining' where videos are analyzed using data mining techniques which extract previously unknown, interesting patterns in underlying data. Thereby, patterns for retrieving relevant shots to queries are extracted as explicit knowledge.
Semi-supervised learning for scalable and robust visual search
Authors: Wang Jun
Published: November 2011

Unlike textual document retrieval, searching of visual data is still far from satisfactory. There exist major gaps between the available solutions and practical needs in both accuracy and computational cost. This thesis aims at the development of robust and scalable solutions for visual search and retrieval. Specifically, we investigate two classes of approaches: graph-based semi-supervised learning and hashing techniques. The graph-based approaches are used to improve accuracy, while hashing approaches are used to improve efficiency and cope with large-scale applications. A common theme shared between these two subareas of our work is the focus on semi-supervised learning paradigm, in which a small set of labeled data is complemented with large unlabeled datasets.
Orai1 and Ca2+-independent phospholipase A2 are required for store-operated Icat-SOC current, Ca2+ entry, and proliferation of primary vascular smooth muscle cells
Authors: Yang Bo , Gwozdz Tomasz , Dutko-Gwozdz Joanna , Bolotina Victoria M.
Published: November 2011

Store-operated Ca2+ entry (SOCE) is important for multiple functions of vascular smooth muscle cells (SMC), which, depending of their phenotype, can resemble excitable and nonexcitable cells. Similar to nonexcitable cells, Orai1 was found to mediate Ca2+-selective (CRAC-like) current and SOCE in dedifferentiated cultured SMC and smooth muscle-derived cell lines. However, the role of Orai1 in cation-selective store-operated channels (cat-SOC), which are responsible for SOCE in primary SMC, remains unclear. Here we focus on primary SMC, and assess the role of Orai1 and Ca2+-independent phospholipase A2 (iPLA2β, or PLA2G6) in activation of cat-SOC current ( Icat-SOC), SOCE, and SMC proliferation. Using molecular, electrophysiological, imaging, and functional approaches, we demonstrate that molecular knockdown of either Orai1 or iPLA2β leads to similar inhibition of the whole cell cat-SOC current and SOCE in primary aortic SMC and results in significant reduction in DNA synthesis and impairment of SMC proliferation. This is the first demonstration that Orai1 and iPLA2β are equally important for cat-SOC, SOCE, and proliferation of primary aortic SMC.
More actors in ammonia absorption by the thick ascending limb
Authors: Houillier Pascal , Bourgeois Soline
Published: November 2011

This review will briefly summarize current knowledge on the basolateral ammonia transport mechanisms in the thick ascending limb (TAL) of the loop of Henle. This segment transports ammonia against a concentration gradient and is responsible for the accumulation of ammonia in the medullary interstitium, which, in turn, favors ammonia secretion across the collecting duct. Experimental data indicate that the sodium/hydrogen ion exchanger isoform 4 (NHE4; Scl9a4) is a sodium/ammonia exchanger and plays a major role in this process. Disruption of murine NHE4 leads to metabolic acidosis with inappropriate urinary ammonia excretion and decreases the ability of the TAL to absorb ammonia and to build the corticopapillary ammonia gradient. However, NHE4 does not account for the entirety of ammonia absorption by the TAL, indicating that, at least, one more transporter is involved.