Impacts of fault-sill interactions on sill emplacement in the Vøring Basin, Norwegian North Sea

Pre-existing faults may facilitate subsurface magma transport and sill trangression in sedimentary basins. Although widely recognized, interaction between faults and intrusion networks in sedimentary basins remains poorly imaged by seismic reflection data. To understand how sills interact with pre-existing faults in sedimentary basins, we use high-resolution 3-D seismic reflection data from the Naglfar Dome, Vøring Basin to examine the seismic expression of sills, interpret fault geometries and displacement patterns, and characterize sill-fault interactions. The sills are expressed as tuned reflection packages, meaning they are below ∼<50 ± 5 m thick, with saucer-shaped, transgressive, and strata-concordant morphologies that range in area from 6 km2 to 180 km2. The interconnected sills form a sill-complex, which was emplaced during the Eocene and cross-cuts three main stratigraphic intervals (i.e. the Nise, Tang, and Brygge Formations). Faults are of Early Paleocene to Early Eocene age, tectonic in origin and dominated by normal faults that are up to 28 km long. Fault and sill interactions define a spectrum, which we sub-divide into five categories (i.e. Type 1a, 1b, 2, 3 and 4); the two main end-member fault-sill relationships documented here are (a) sills stepping up stratigraphy short distances via faults and (b) those with inclined limbs intruded along fault planes. Whilst interactions between the faults and the sills are common, quantitative displacement analysis reveals fault displacement did not influence where sills exploited faults. In the study, the intricate interaction of fault and magmatic sills and its broader implications to structural compartmentalization and outcrop-scale studies in many magma-rich continental margins are demonstrated

ProtQuant: a tool for the label-free quantification of MudPIT proteomics data

<p>Abstract</p> <p>Background</p> <p>Effective and economical methods for quantitative analysis of high throughput mass spectrometry data are essential to meet the goals of directly identifying, characterizing, and quantifying proteins from a particular cell state. Multidimensional Protein Identification Technology (MudPIT) is a common approach used in protein identification. Two types of methods are used to detect differential protein expression in MudPIT experiments: those involving stable isotope labelling and the so-called label-free methods. Label-free methods are based on the relationship between protein abundance and sampling statistics such as peptide count, spectral count, probabilistic peptide identification scores, and sum of peptide Sequest XCorr scores (ΣXCorr). Although a number of label-free methods for protein quantification have been described in the literature, there are few publicly available tools that implement these methods. We describe ProtQuant, a Java-based tool for label-free protein quantification that uses the previously published ΣXCorr method for quantification and includes an improved method for handling missing data.</p> <p>Results</p> <p><it>ProtQuant </it>was designed for ease of use and portability for the bench scientist. It implements the ΣXCorr method for label free protein quantification from MudPIT datasets. <it>ProtQuant </it>has a graphical user interface, accepts multiple file formats, is not limited by the size of the input files, and can process any number of replicates and any number of treatments. In addition,<it>ProtQuant </it>implements a new method for dealing with missing values for peptide scores used for quantification. The new algorithm, called ΣXCorr*, uses "below threshold" peptide scores to provide meaningful non-zero values for missing data points. We demonstrate that ΣXCorr* produces an average reduction in false positive identifications of differential expression of 25% compared to ΣXCorr.</p> <p>Conclusion</p> <p><it>ProtQuant </it>is a tool for protein quantification built for multi-platform use with an intuitive user interface. <it>ProtQuant </it>efficiently and uniquely performs label-free quantification of protein datasets produced with Sequest and provides the user with facilities for data management and analysis. Importantly, <it>ProtQuant </it>is available as a self-installing executable for the Windows environment used by many bench scientists.</p

Identification of Giardia lamblia DHHC Proteins and the Role of Protein S-palmitoylation in the Encystation Process

Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.Fil: Merino, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Zamponi, Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Vranych, Cecilia Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Touz, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Ropolo, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin

Errors in the measurement of voltage-activated ion channels in cell-attached patch-clamp recordings

Patch-clamp recording techniques have revolutionized understanding of the function and sub-cellular location of ion channels in excitable cells. The cell-attached patch-clamp configuration represents the method of choice to describe the endogenous properties of voltage-activated ion channels in the axonal, somatic and dendritic membrane of neurons, without disturbance of the intracellular milieu. Here, we directly examine the errors associated with cell-attached patch-clamp measurement of ensemble ion channel activity. We find for a number of classes of voltage-activated channels, recorded from the soma and dendrites of neurons in acute brain-slices and isolated cells, that the amplitude and kinetics of ensemble ion channel activity recorded in cell-attached patches is significantly distorted by transmembrane voltage changes generated by the flow of current through the activated ion channels. We outline simple error–correction procedures that allow a more accurate description of the density and properties of voltage-activated channels to be incorporated into computational models of neurons

Lack of awareness of erectile dysfunction in many men with risk factors for erectile dysfunction

<p>Abstract</p> <p>Background</p> <p>Men with erectile dysfunction often have concurrent medical conditions. Conversely, men with these conditions may also have underlying erectile dysfunction. The prevalence of unrecognized erectile dysfunction in men with comorbidities commonly associated with erectile dysfunction was determined in men invited to participate in a double-blind, randomized, placebo-controlled trial of sildenafil citrate.</p> <p>Methods</p> <p>Men ≥30 years old presenting with ≥1 erectile dysfunction risk factor (controlled hypertension, hypercholesterolemia, smoking, metabolic syndrome, stable coronary artery disease, diabetes, depression, lower urinary tract symptoms, obesity [body mass index ≥30 kg/m²] or waist circumference ≥40 inches), and not previously diagnosed with erectile dysfunction were evaluated. The screening question, "Do you have erectile dysfunction?," with responses of "no," "yes," and "unsure," and the Erectile Function domain of the International Index of Erectile Function (IIEF-EF) were administered.</p> <p>Results</p> <p>Of 1084 men screened, 1053 answered the screening question and also had IIEF-EF scores. IIEF-EF scores indicating erectile dysfunction occurred in 71% (744/1053), of whom 54% (399/744) had moderate or severe erectile dysfunction. Of 139 answering "yes," 526 answering "unsure," and 388 answering "no," 96%, 90%, and 36%, respectively, had some degree of erectile dysfunction. The mean±SD (range) number of risk factors was 2.9 ± 1.7 (3-8) in the "yes" group, 3.2 ± 1.7 (3-9) in the "unsure" group, and 2.6 ± 1.5 (2-8) in the "no" group.</p> <p>Conclusion</p> <p>Although awareness of having erectile dysfunction was low, most men with risk factors had IIEF-EF scores indicating erectile dysfunction. Erectile dysfunction should be suspected and assessed in men with risk factors, regardless of their apparent level of awareness of erectile dysfunction.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier NCT00343200.</p

Phenotypic Variation and Bistable Switching in Bacteria

Microbial research generally focuses on clonal populations. However, bacterial cells with identical genotypes frequently display different phenotypes under identical conditions. This microbial cell individuality is receiving increasing attention in the literature because of its impact on cellular differentiation, survival under selective conditions, and the interaction of pathogens with their hosts. It is becoming clear that stochasticity in gene expression in conjunction with the architecture of the gene network that underlies the cellular processes can generate phenotypic variation. An important regulatory mechanism is the so-called positive feedback, in which a system reinforces its own response, for instance by stimulating the production of an activator. Bistability is an interesting and relevant phenomenon, in which two distinct subpopulations of cells showing discrete levels of gene expression coexist in a single culture. In this chapter, we address techniques and approaches used to establish phenotypic variation, and relate three well-characterized examples of bistability to the molecular mechanisms that govern these processes, with a focus on positive feedback.

Coincident Activity of Converging Pathways Enables Simultaneous Long-Term Potentiation and Long-Term Depression in Hippocampal CA1 Network In Vivo

Memory is believed to depend on activity-dependent changes in the strength of synapses, e.g. long-term potentiation (LTP) and long-term depression (LTD), which can be determined by the sequence of coincident pre- and postsynaptic activity, respectively. It remains unclear, however, whether and how coincident activity of converging efferent pathways can enable LTP and LTD in the pathways simultaneously. Here, we report that, in pentobarbital-anesthetized rats, stimulation (600 pulses, 5 Hz) to Schaffer preceding to commissural pathway within a 40-ms timing window induced similar magnitudes of LTP in both pathways onto synapses of CA1 neurons, with varied LTP magnitudes after reversal of the stimulation sequence. In contrast, in urethane-anesthetized or freely-moving rats, the stimulation to Schaffer preceding to commissural pathway induced Schaffer LTP and commissural LTD simultaneously within a 40-ms timing window, without affecting synaptic efficacy in the reversed stimulation sequence. Coincident activity of Schaffer pathways confirmed the above findings under pentobarbital and urethane anesthesia. Thus, coincident activity of converging afferent pathways tends to switch the pathways to be LTP only or LTP/LTD depending on the activity states of the hippocampus. This network rule strengthens the view that activity-dependent synaptic plasticity may well contribute to memory process of the hippocampal network with flexibility or stability from one state to another

Do you get what you pay for? Sales incentives and implications for motivation and changes in turnover intention and work effort

This study investigated relations between pay-for-performance incentives designed to vary in instrumentality (annual pay-for-performance, quarterly pay-for-performance, and base pay level) and employee outcomes (self-reported work effort and turnover intention) in a longitudinal study spanning more than 2 years. After controlling for perceived instrumentality, merit pay increase, and the initial values of the dependent variables, the amount of base pay was positively related to work effort and negatively related to turnover intention, where both relationships were mediated by autonomous motivation. The amounts of quarterly and annual pay-for-performance were both positively related to controlled motivation, but were differently related to the dependent variables due to different relations with autonomous motivation

Iterative sorting reveals CD133+ and CD133- melanoma cells as phenotypically distinct populations

Background: The heterogeneity and tumourigenicity of metastatic melanoma is attributed to a cancer stem cell model, with CD133 considered to be a cancer stem cell marker in melanoma as well as other tumours, but its role has remained controversial. Methods: We iteratively sorted CD133+ and CD133- cells from 3 metastatic melanoma cell lines, and observed tumourigenicity and phenotypic characteristics over 7 generations of serial xeno-transplantation in NOD/SCID mice. Results: We demonstrate that iterative sorting is required to make highly pure populations of CD133+ and CD133- cells from metastatic melanoma, and that these two populations have distinct characteristics not related to the cancer stem cell phenotype. In vitro, gene set enrichment analysis indicated CD133+ cells were related to a proliferative phenotype, whereas CD133- cells were of an invasive phenotype. However, in vivo, serial transplantation of CD133+ and CD133- tumours over 7 generations showed that both populations were equally able to initiate and propagate tumours. Despite this, both populations remained phenotypically distinct, with CD133- cells only able to express CD133 in vivo and not in vitro. Loss of CD133 from the surface of a CD133+ cell was observed in vitro and in vivo, however CD133- cells derived from CD133+ retained the CD133+ phenotype, even in the presence of signals from the tumour microenvironment. Conclusion: We show for the first time the necessity of iterative sorting to isolate pure marker-positive and marker-negative populations for comparative studies, and present evidence that despite CD133+ and CD133- cells being equally tumourigenic, they display distinct phenotypic differences, suggesting CD133 may define a distinct lineage in melanoma

Soil mobility of surface applied polyaromatic hydrocarbons in response to simulated rainfall

Polyaromatic hydrocarbons (PAHs) are emitted from a variety of sources and can accumulate on and within surface soil layers. To investigate the level of potential risk posed by surface contaminated soils, vertical soil column experiments were conducted to assess the mobility, when leached with simulated rainwater, of six selected PAHs (naphthalene, phenanthrene, fluoranthene, pyrene, benzo(e)pyrene and benzo(ghi)perylene) with contrasting hydrophobic characteristics and molecular weights/sizes. The only PAH found in the leachate within the experimental period of 26 days was naphthalene. The lack of migration of the other applied PAHs were consistent with their low mobilities within the soil columns which generally parallelled their log Koc values. Thus only 2.3% of fluoranthene, 1.8% of pyrene, 0.2% of benzo(e)pyrene and 0.4% of benzo(ghi)perylene were translocated below the surface layer. The PAH distributions in the soil columns followed decreasing power relationships with 90% reductions in the starting levels being shown to occur within a maximum average depth of 0.94 cm compared to an average starting depth of 0.5 cm. A simple predictive model identifies the extensive time periods, in excess of 10 years, required to mobilise 50% of the benzo(e)pyrene and benzo(ghi)perylene from the surface soil layer. Although this reduces to between 2 and 7 years for fluoranthene and pyrene, it is concluded that the possibility of surface applied PAHs reaching and contaminating a groundwater aquifer is unlikely