147 research outputs found

    Employability skills: Profiling data scientists in the digital labour market

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    In the current scenario, data scientists are expected to make sense of vast stores of big data, which are becoming increasingly complex and heterogeneous in nature. In the context of today's rapid technological development and its application in a growing array of fields, this role is evolving simultaneously. The present study provides an insight into the current expectations of employers seeking to hire individuals with this job title. It is argued that gaining a better understanding of data scientists’ employability criteria and the evolution of this professional role is crucial. The focus is placed on the desired prerequisites articulated through job advertisements, thus deriving relevant means for furthering theory and practice. It was achieved by harvesting relevant data from job advertisements published on US employment websites, which currently attract the US market's highest recruitment traffic. The key contribution of this study is to have identified means of systematically mapping skills, experience, and qualifications sought by employers for their data scientists, thus providing a data-driven pathway for employability and avoiding skills gaps and mismatches in a profession that is pivotal in the Industry 4.0

    Generation of OH radicals at palladium oxide nanoparticle modified electrodes, and scavenging by fluorescent probes and antioxidants

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    The reduction of palladium oxide nanoparticles in the presence of hydrogen peroxide or dissolved oxygen gives rise to a catalytic reduction current dependent on the hydrogen peroxide concentration or the oxygen concentration. Using terephthalic acid as an OH radical scavenger yielding the fluorescent 2-hydroxyterephthalic acid, we demonstrate that the catalytic current stems from the freshly exposed palladium metal re-oxidation by OH radicals. A kinetic model is presented to account for these catalytic reactions. We also demonstrate that the measurement of the catalytic reduction current in the presence of antioxidant molecules can be used to measure the OH scavenging properties of antioxidants

    Antioxidant Redox Sensors Based on DNA Modified Carbon Screen-Printed Electrodes

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    Antioxidant redox sensors based on DNA modified carbon screen-printed electrodes were developed. The carbon ink was doped with TiO2 nanoparticles, onto which double- strand DNA was adsorbed. A redox mediator, namely, tris- 2,2′-bipyridine ruthenium(II) [Ru(bpy)32+] was electro- oxidized on the electrode surface to subsequently oxidize both the adsorbed ds-DNA and the antioxidants in solu- tion. The resulting oxidation damage of the adsorbed ds- DNA was then detected by square wave voltammetry in a second solution containing only Ru(bpy)3Cl2 at a low con- centration (μM). A kinetic model was developed to study the protecting role of antioxidants in aqueous solutions. The electrochemical sensor has been applied to evaluate the redox antioxidant capacity of different molecules

    Hydrovoltaic cells. Part II: Thermogalvanic cells and numerical simulations of thermal diffusion potentials

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    When two electrolyte solutions of different temperature are placed in contact, a thermal diffusion potential (TDP) is established. The phenomenon is studied numerically using finite element simulations of the temperature distribution within a hydrodynamic cell. Experimentally, the hydrovoltaic flow cell is used to demonstrate how a temperature difference can induce redox reactions at electrodes placed in the two liquids in order to extract a current continuously in an external circuit resulting in a power-generating unit. When the concentration of the redox couple introduced in the solution is moderated, it is shown that the TDP is not negligible, even if the main driving force is due to the temperature effect on the standard potential of the couple present. The numerical model may also be applied in more general situations involving thermal effects in microsystems

    Antioxidant Sensors Based on DNA-Modified Electrodes

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    TiO2/ITO modified electrodes were developed to quantitatively photooxidize adsorbed ds-DNA and to study the effect of antioxidants as ds-DNA protecting agents. TiO2 films are used for efficient ds-DNA immobilization, for ds- DNA oxidation through photogenerated hydroxyl radicals, and as electrodes for amperometric sensing. The films, prepared by a sol-gel process, are deposited on ITO glass electrodes. Damages occurring after ds-DNA oxidation by ROS are detected by adding MB as an intercalant probe and by monitoring the electrochemical reduction current of the intercalated redox probe. The MB electrochemical signal is found to be sensitive enough to monitor ds-DNA structure changes, and the electrochemical sensor has been applied to the evaluation of the antioxidant properties of glutathione and gallic acid

    Biomarkers of oxidative stress and its association with the urinary reducing capacity in bus maintenance workers

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    <p>Abstract</p> <p>Background</p> <p>Exposure to particles (PM) induces adverse health effects (cancer, cardiovascular and pulmonary diseases). A key-role in these adverse effects seems to be played by oxidative stress, which is an excess of reactive oxygen species relative to the amount of reducing species (including antioxidants), the first line of defense against reactive oxygen species. The aim of this study was to document the oxidative stress caused by exposure to respirable particles <it>in vivo</it>, and to test whether exposed workers presented changes in their urinary levels for reducing species.</p> <p>Methods</p> <p>Bus depot workers (n = 32) exposed to particles and pollutants (respirable PM<sub>4</sub>, organic and elemental carbon, particulate metal content, polycyclic aromatic hydrocarbons, NO<sub>x</sub>, O<sub>3</sub>) were surveyed over two consecutive days. We collected urine samples before and after each shift, and quantified an oxidative stress biomarker (8-hydroxy-2'-deoxyguanosine), the reducing capacity and a biomarker of PAH exposure (1-hydroxypyrene). We used a linear mixed model to test for associations between the oxidative stress status of the workers and their particle exposure as well as with their urinary level of reducing species.</p> <p>Results</p> <p>Workers were exposed to low levels of respirable PM<sub>4 </sub>(range 25-71 μg/m<sup>3</sup>). However, urinary levels of 8-hydroxy-2'-deoxyguanosine increased significantly within each shift and between both days for non-smokers. The between-day increase was significantly correlated (p < 0.001) with the concentrations of organic carbon, NO<sub>x</sub>, and the particulate copper content. The within-shift increase in 8OHdG was highly correlated to an increase of the urinary reducing capacity (Spearman ρ = 0.59, p < 0.0001).</p> <p>Conclusions</p> <p>These findings confirm that exposure to components associated to respirable particulate matter causes a systemic oxidative stress, as measured with the urinary 8OHdG. The strong association observed between urinary 8OHdG with the reducing capacity is suggestive of protective or other mechanisms, including circadian effects. Additional investigations should be performed to understand these observations.</p

    Amperometric tape ion sensors for cadmium(II) ion analysis

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    This paper describes a novel tape platform ion sensing methodology specific to the detection of cadmium(II) ions in aqueous solution based on assisted ion transfer reactions across a polarized water | organic gel micro-interface. The tape ion sensors were constructed to incorporate the microwater | polyvinylchloride-2-nitrophenylethyl ether (PVC–NPOE) gel interfaces referred to as ionodes. The sensors have overall thicknesses less than 300μm300\mu m, allowing their packaging in a disposable tape format. The detection methodology is based on the selective assisted transfer of the cadmium ion in aqueous phase by ETH 1062 present in the PVC–NPOE gel layer and was first investigated using cyclic voltammetry. Quantitative analysis of cadmium(II) ions in aqueous solution using the tape sensors was then conducted under stop-flow conditions. Detection limits as low as 20 ppb (178 nM) for Cd(II) ions in very small volumes as low as a single 20ul droplet without any sample preconcentration was achieved in an analysis time of approximately 20 s, which could be easily employed for the direct measurement of Cd(II) ion levels in various field applications. The tape ion sensor can also be used in a flow-cell geometry to preconcentrate Cd(II) ions from aqueous samples and further improve the detection limit

    Reduced levels of two modifiers of epigenetic gene silencing, Dnmt3a and Trim28, cause increased phenotypic noise

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    Background: Inbred individuals reared in controlled environments display considerable variance in many complex traits but the underlying cause of this intangible variation has been an enigma. Here we show that two modifiers of epigenetic gene silencing play a critical role in the process.Results: Inbred mice heterozygous for a null mutation in DNA methyltransferase 3a (Dnmt3a) or tripartite motif protein 28 (Trim28) show greater coefficients of variance in body weight than their wild-type littermates. Trim28 mutants additionally develop metabolic syndrome and abnormal behavior with incomplete penetrance. Genome-wide gene expression analyses identified 284 significantly dysregulated genes in Trim28 heterozygote mutants compared to wild-type mice, with Mas1, which encodes a G-protein coupled receptor implicated in lipid metabolism, showing the greatest average change in expression (7.8-fold higher in mutants). This gene also showed highly variable expression between mutant individuals.Conclusions: These studies provide a molecular explanation of developmental noise in whole organisms and suggest that faithful epigenetic control of transcription is central to suppressing deleterious levels of phenotypic variation. These findings have broad implications for understanding the mechanisms underlying sporadic and complex disease in humans

    Mutants in the Mouse NuRD/Mi2 Component P66α Are Embryonic Lethal

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    The NuRD/Mi2 chromatin complex is involved in histone modifications and contains a large number of subunits, including the p66 protein. There are two mouse and human p66 paralogs, p66alpha and p66beta. The functions of these genes are not clear, in part because there are no mutants available, except in invertebrate model systems.We made loss of function mutants in the mouse p66alpha gene (mp66alpha, official name Gatad2a, MGI:2384585). We found that mp66alpha is essential for development, as mutant embryos die around day 10 of embryogenesis. The gene is not required for normal blastocyst development or for implantation. The phenotype of mutant embryos and the pattern of gene expression in mutants are consistent with a role of mp66alpha in gene silencing.mp66alpha is an essential gene, required for early mouse development. The lethal phenotype supports a role in execution of methylated DNA silencing

    A Large Scale shRNA Barcode Screen Identifies the Circadian Clock Component ARNTL as Putative Regulator of the p53 Tumor Suppressor Pathway

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    BACKGROUND: The p53 tumor suppressor gene is mutated in about half of human cancers, but the p53 pathway is thought to be functionally inactivated in the vast majority of cancer. Understanding how tumor cells can become insensitive to p53 activation is therefore of major importance. Using an RNAi-based genetic screen, we have identified three novel genes that regulate p53 function. RESULTS: We have screened the NKI shRNA library targeting 8,000 human genes to identify modulators of p53 function. Using the shRNA barcode technique we were able to quickly identify active shRNA vectors from a complex mixture. Validation of the screening results indicates that the shRNA barcode technique can reliable identify active shRNA vectors from a complex pool. Using this approach we have identified three genes, ARNTL, RBCK1 and TNIP1, previously unknown to regulate p53 function. Importantly, ARNTL (BMAL1) is an established component of the circadian regulatory network. The latter finding adds to recent observations that link circadian rhythm to the cell cycle and cancer. We show that cells having suppressed ARNTL are unable to arrest upon p53 activation associated with an inability to activate the p53 target gene p21(CIP1). CONCLUSIONS: We identified three new regulators of the p53 pathway through a functional genetic screen. The identification of the circadian core component ARNTL strengthens the link between circadian rhythm and cancer
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