150 research outputs found

    NGAL (Lcn2) monomer is associated with tubulointerstitial damage in chronic kidney disease

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    The type and the extent of tissue damage inform the prognosis of chronic kidney disease (CKD), but kidney biopsy is not a routine test. Urinary tests that correlate with specific histological findings might serve as surrogates for the kidney biopsy. We used immunoblots and ARCHITECT-NGAL assays to define the immunoreactivity of urinary neutrophil gelatinase–associated lipocalin (NGAL) in CKD, and we used mass spectroscopy to identify associated proteins. We analyzed kidney biopsies to determine whether specific pathological characteristics associated with the monomeric NGAL species. Advanced CKD urine contained the NGAL monomer as well as novel complexes of NGAL. When these species were separated, we found a significant correlation between the NGAL monomer and glomerular filtration rate (r=-0.53, P<0.001), interstitial fibrosis (mild vs. severe disease; mean 54 vs. 167μg uNGAL/g Cr, P<0.01), and tubular atrophy (mild vs. severe disease; mean 54 vs. 164μg uNGAL/g Cr, P<0.01). Monospecific assays of the NGAL monomer demonstrated a correlation with histology that typifies progressive, severe CKD

    Oral Microbiome Profiles: 16S rRNA Pyrosequencing and Microarray Assay Comparison

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    The human oral microbiome is potentially related to diverse health conditions and high-throughput technology provides the possibility of surveying microbial community structure at high resolution. We compared two oral microbiome survey methods: broad-based microbiome identification by 16S rRNA gene sequencing and targeted characterization of microbes by custom DNA microarray.Oral wash samples were collected from 20 individuals at Memorial Sloan-Kettering Cancer Center. 16S rRNA gene survey was performed by 454 pyrosequencing of the V3–V5 region (450 bp). Targeted identification by DNA microarray was carried out with the Human Oral Microbe Identification Microarray (HOMIM). Correlations and relative abundance were compared at phylum and genus level, between 16S rRNA sequence read ratio and HOMIM hybridization intensity.; Correlation = 0.70–0.84).Microbiome community profiles assessed by 16S rRNA pyrosequencing and HOMIM were highly correlated at the phylum level and, when comparing the more commonly detected taxa, also at the genus level. Both methods are currently suitable for high-throughput epidemiologic investigations relating identified and more common oral microbial taxa to disease risk; yet, pyrosequencing may provide a broader spectrum of taxa identification, a distinct sequence-read record, and greater detection sensitivity

    ViralORFeome: an integrated database to generate a versatile collection of viral ORFs

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    Large collections of protein-encoding open reading frames (ORFs) established in a versatile recombination-based cloning system have been instrumental to study protein functions in high-throughput assays. Such ‘ORFeome’ resources have been developed for several organisms but in virology, plasmid collections covering a significant fraction of the virosphere are still needed. In this perspective, we present ViralORFeome 1.0 (http://www.viralorfeome.com), an open-access database and management system that provides an integrated set of bioinformatic tools to clone viral ORFs in the Gateway® system. ViralORFeome provides a convenient interface to navigate through virus genome sequences, to design ORF-specific cloning primers, to validate the sequence of generated constructs and to browse established collections of virus ORFs. Most importantly, ViralORFeome has been designed to manage all possible variants or mutants of a given ORF so that the cloning procedure can be applied to any emerging virus strain. A subset of plasmid constructs generated with ViralORFeome platform has been tested with success for heterologous protein expression in different expression systems at proteome scale. ViralORFeome should provide our community with a framework to establish a large collection of virus ORF clones, an instrumental resource to determine functions, activities and binding partners of viral proteins

    The Art of Research: A Divergent/Convergent Framework and Opportunities for Science-Based Approaches

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    Applying science to the current art of producing engineering and research knowledge has proven difficult, in large part because of its seeming complexity. We posit that the microscopic processes underlying research are not so complex, but instead are iterative and interacting cycles of divergent (generation of ideas) and convergent (testing and selecting of ideas) thinking processes. This reductionist framework coherently organizes a wide range of previously disparate microscopic mechanisms which inhibit these processes. We give examples of such inhibitory mechanisms and discuss how deeper scientific understanding of these mechanisms might lead to dis-inhibitory interventions for individuals, networks and institutional levels

    A MHz X-ray diffraction set-up for dynamic compression experiments in the diamond anvil cell

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    An experimental platform for dynamic diamond anvil cell (dDAC) research has been developed at the High Energy Density (HED) Instrument at the European X-ray Free Electron Laser (European XFEL). Advantage was taken of the high repetition rate of the European XFEL (up to 4.5 MHz) to collect pulse-resolved MHz X-ray diffraction data from samples as they are dynamically compressed at intermediate strain rates (≤103 s−1), where up to 352 diffraction images can be collected from a single pulse train. The set-up employs piezo-driven dDACs capable of compressing samples in ≥340 µs, compatible with the maximum length of the pulse train (550 µs). Results from rapid compression experiments on a wide range of sample systems with different X-ray scattering powers are presented. A maximum compression rate of 87 TPa s−1 was observed during the fast compression of Au, while a strain rate of ∼1100 s−1 was achieved during the rapid compression of N2 at 23 TPa s−1

    Temporal Analysis of the Honey Bee Microbiome Reveals Four Novel Viruses and Seasonal Prevalence of Known Viruses, Nosema, and Crithidia

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    Honey bees (Apis mellifera) play a critical role in global food production as pollinators of numerous crops. Recently, honey bee populations in the United States, Canada, and Europe have suffered an unexplained increase in annual losses due to a phenomenon known as Colony Collapse Disorder (CCD). Epidemiological analysis of CCD is confounded by a relative dearth of bee pathogen field studies. To identify what constitutes an abnormal pathophysiological condition in a honey bee colony, it is critical to have characterized the spectrum of exogenous infectious agents in healthy hives over time. We conducted a prospective study of a large scale migratory bee keeping operation using high-frequency sampling paired with comprehensive molecular detection methods, including a custom microarray, qPCR, and ultra deep sequencing. We established seasonal incidence and abundance of known viruses, Nosema sp., Crithidia mellificae, and bacteria. Ultra deep sequence analysis further identified four novel RNA viruses, two of which were the most abundant observed components of the honey bee microbiome (∼1011 viruses per honey bee). Our results demonstrate episodic viral incidence and distinct pathogen patterns between summer and winter time-points. Peak infection of common honey bee viruses and Nosema occurred in the summer, whereas levels of the trypanosomatid Crithidia mellificae and Lake Sinai virus 2, a novel virus, peaked in January

    Isotopic techniques to measure N2O, N2 and their sources

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    GHG emissions are usually the result of several simultaneous processes. Furthermore, some gases such as N2 are very difficult to quantify and require special techniques. Therefore, in this chapter, the focus is on stable isotope methods. Both natural abundance techniques and enrichment techniques are used. Especially in the last decade, a number of methodological advances have been made. Thus, this chapter provides an overview and description of a number of current state-of-theart techniques, especially techniques using the stable isotope 15N. Basic principles and recent advances of the 15N gas flux method are presented to quantify N2 fluxes, but also the latest isotopologue and isotopomer methods to identify pathways for N2O production. The second part of the chapter is devoted to 15N tracing techniques, the theoretical background and recent methodological advances. A range of different methods is presented from analytical to numerical tools to identify and quantify pathway-specific N2O emissions. While this chapter is chiefly concerned with gaseous N emissions, a lot of the techniques can also be applied to other gases such as methane (CH4), as outlined in Sect. 5.3

    Application of Surface wave methods for seismic site characterization

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    Surface-wave dispersion analysis is widely used in geophysics to infer a shear wave velocity model of the subsoil for a wide variety of applications. A shear-wave velocity model is obtained from the solution of an inverse problem based on the surface wave dispersive propagation in vertically heterogeneous media. The analysis can be based either on active source measurements or on seismic noise recordings. This paper discusses the most typical choices for collection and interpretation of experimental data, providing a state of the art on the different steps involved in surface wave surveys. In particular, the different strategies for processing experimental data and to solve the inverse problem are presented, along with their advantages and disadvantages. Also, some issues related to the characteristics of passive surface wave data and their use in H/V spectral ratio technique are discussed as additional information to be used independently or in conjunction with dispersion analysis. Finally, some recommendations for the use of surface wave methods are presented, while also outlining future trends in the research of this topic
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