1,303 research outputs found

    The Challenges of Business Analytics: Successes and Failures

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    The successful use of business analytics is an important element of a company’s success. Business analytics enables analysts and managers to engage in an IT-driven sense-making process in which they use the data and analysis as a means to understand the phenomena that the data represent . Not all organizations apply business analytics successfully to decision making. When used correctly, the actionable intelligence gained from a business analytics program can be utilized to improve strategic decision making. Conversely, an organization that does not utilize business analytics information appropriately will not experience optimal decision making; failing to realize the full potential of a data analytics program. This paper examines some organizations that implemented data analytics programs; both successfully and unsuccessfully, and discuss the implications for each organization. Based on the lesson learned, we present ways to implement a successful business analytics program

    Some results on homoclinic and heteroclinic connections in planar systems

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    Consider a family of planar systems depending on two parameters (n,b)(n,b) and having at most one limit cycle. Assume that the limit cycle disappears at some homoclinic (or heteroclinic) connection when Φ(n,b)=0.\Phi(n,b)=0. We present a method that allows to obtain a sequence of explicit algebraic lower and upper bounds for the bifurcation set Φ(n,b)=0.{\Phi(n,b)=0}. The method is applied to two quadratic families, one of them is the well-known Bogdanov-Takens system. One of the results that we obtain for this system is the bifurcation curve for small values of nn, given by b=57n1/2+72/2401n30024/45294865n3/22352961656/11108339166925n2+O(n5/2)b=\frac5 7 n^{1/2}+{72/2401}n- {30024/45294865}n^{3/2}- {2352961656/11108339166925} n^2+O(n^{5/2}). We obtain the new three terms from purely algebraic calculations, without evaluating Melnikov functions

    Direct correlation of crystal structure and optical properties in wurtzite/zinc-blende GaAs nanowire heterostructures

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    A novel method for the direct correlation at the nanoscale of structural and optical properties of single GaAs nanowires is reported. Nanowires consisting of 100% wurtzite and nanowires presenting zinc-blende/wurtzite polytypism are investigated by photoluminescence spectroscopy and transmission electron microscopy. The photoluminescence of wurtzite GaAs is consistent with a band gap of 1.5 eV. In the polytypic nanowires, it is shown that the regions that are predominantly composed of either zinc-blende or wurtzite phase show photoluminescence emission close to the bulk GaAs band gap, while regions composed of a nonperiodic superlattice of wurtzite and zinc-blende phases exhibit a redshift of the photoluminescence spectra as low as 1.455 eV. The dimensions of the quantum heterostructures are correlated with the light emission, allowing us to determine the band alignment between these two crystalline phases. Our first-principles electronic structure calculations within density functional theory, employing a hybrid-exchange functional, predict band offsets and effective masses in good agreement with experimental results

    Prostate cancer support groups: Canada-based specialists\u27 perspectives

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    To understand prostate cancer (PCa) specialists’ views about prostate cancer support groups (PCSGs), a volunteer sample of Canada-based PCa specialists ( n = 150), including urologists ( n = 100), radiation oncologists ( n = 40), and medical oncologists ( n = 10) were surveyed. The 56-item questionnaire used in this study included six sets of attitudinal items to measure prostate cancer specialists’ beliefs about positive and negative influences of PCSGs, reasons for attending PCSGs, the attributes of effective PCSGs, and the value of face-to-face and web-based PCSGs. In addition, an open-ended question was included to invite additional input from participants. Results showed that PCSGs were positively valued, particularly for information sharing, education and psychosocial support. Inclusivity, privacy, and accessibility were identified as potential barriers, and recommendations were made for better marketing PCSGs to increase engagement. Findings suggest prostate cancer specialists highly valued the role and potential benefits of face-to-face PCSGs. Information provision and an educational role were perceived as key benefits. Some concerns were expressed about the ability of web-based PCSGs to effectively engage and educate men who experience prostate cancer

    A MOF-Based Spatial-Separation Layer to Enable a Uniform Favorable Microenvironment for Electrochemical CO2 Reduction

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    Regulating the local microenvironment of active sites to increase their specific CO2 concentration and pH gradient, is a promising approach to optimize the electrochemical CO2 reduction reaction (eCO2RR). However, currently reported morphological strategies display an uncertainty to the compatibility and distribution between catalytic sites and their microenvironment. Here, a uniform spatial-separation metal-organic framework (MOF) layer between active sites and bulk electrolyte is proposed, which enables each active site to locate in a similarly favorable microenvironment. Zinc oxide (ZnO) nanorods (NR), a representative electrocatalyst for eCO2RR, is covered with a Zeolitic imidazolate framework-8 (ZIF-8) thin layer to serve as a model system. The prepared ZnO NR@ZIF-8 exhibits an enhanced Faradaic efficiency toward CO at a wide range of potentials and reaches a maximum FE of CO (85%) at −1.05 V versus reversible hydrogen electrode, which is one of the best records till date. Moreover, the hydrophobic ZIF-8 layer protects ZnO against self-reduction. Such performance benefits from the porous ZIF-8 shell with high CO2 affinity, realizing efficient CO2 access and retaining an increased local pH near ZnO active sites

    Engineering the Interfacial Microenvironment via Surface Hydroxylation to Realize the Global Optimization of Electrochemical CO Reduction

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    The adsorption and activation of CO on the electrode interface is a prerequisite and key step for electrocatalytic CO reduction reaction (eCO RR). Regulating the interfacial microenvironment to promote the adsorption and activation of CO is thus of great significance to optimize overall conversion efficiency. Herein, a CO-philic hydroxyl coordinated ZnO (ZnO-OH) catalyst is fabricated, for the first time, via a facile MOF-assisted method. In comparison to the commercial ZnO, the as-prepared ZnO-OH exhibits much higher selectivity toward CO at lower applied potential, reaching a Faradaic efficiency of 85% at −0.95 V versus RHE. To the best of our knowledge, such selectivity is one of the best records in ZnO-based catalysts reported till date. Density functional theory calculations reveal that the coordinated surficial −OH groups are not only favorable to interact with CO molecules but also function in synergy to decrease the energy barrier of the rate-determining step and maintain a higher charge density of potential active sites as well as inhibit undesired hydrogen evolution reaction. Our results indicate that engineering the interfacial microenvironment through the introduction of CO-philic groups is a promising way to achieve the global optimization of eCO RR via promoting adsorption and activation of CO

    Dehydration entropy drives liquid-liquid phase separation by molecular crowding

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    Liquid-liquid phase separation occurs in cells and can be induced in artificial systems, but the mechanism of the effect of molecular crowders is unclear. Here dehydration entropy-driven phase separation of model charged polymers lacking any chemical complexity or hydrophobicity is shown to be enhanced by polyethylene glycol. Complex coacervation driven liquid-liquid phase separation (LLPS) of biopolymers has been attracting attention as a novel phase in living cells. Studies of LLPS in this context are typically of proteins harboring chemical and structural complexity, leaving unclear which properties are fundamental to complex coacervation versus protein-specific. This study focuses on the role of polyethylene glycol (PEG)-a widely used molecular crowder-in LLPS. Significantly, entropy-driven LLPS is recapitulated with charged polymers lacking hydrophobicity and sequence complexity, and its propensity dramatically enhanced by PEG. Experimental and field-theoretic simulation results are consistent with PEG driving LLPS by dehydration of polymers, and show that PEG exerts its effect without partitioning into the dense coacervate phase. It is then up to biology to impose additional variations of functional significance to the LLPS of biological systems.11Ysciescopu

    Exposure to environmentally persistent free radicals during gestation lowers energy expenditure and impairs skeletal muscle mitochondrial function in adult mice

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    © 2016 the American Physiological Society. We have investigated the effects of in utero exposure to environmentally persistent free radicals (EPFRs) on growth, metabolism, energy utilization, and skeletal muscle mitochondria in a mouse model of diet-induced obesity. Pregnant mice were treated with laboratory-generated, combustion derived particular matter (MCP230). The adult offspring were placed on a high-fat diet for 12 wk, after which we observed a 9.8% increase in their body weight. The increase in body size observed in the MCP230-exposed mice was not associated with increases in food intake but was associated with a reduction in physical activity and lower energy expenditure. The reduced energy expenditure in mice indirectly exposed to MCP230 was associated with reductions in skeletal muscle mitochondrial DNA copy number, lower mRNA levels of electron transport genes, and reduced citrate synthase activity. Upregulation of key genes involved in ameliorating oxidative stress was also observed in the muscle of MCP230-exposed mice. These findings suggest that gestational exposure to MCP230 leads to a reduction in energy expenditure at least in part through alterations to mitochondrial metabolism in the skeletal muscle

    Improvement of carbon dioxide electroreduction by crystal surface modification of ZIF-8

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    Metal-organic frameworks (MOFs) possess high CO adsorption properties and are considered to be a promising candidate for the electrochemical carbon dioxide reduction reaction (eCORR). However, their insufficient selectivity and current density constrain their further exploration in the eCORR. In this work, by introducing a very small proportion of 2,5-dihydroxyterephthalic acid (DOBDC) into ZIF-8, a surface modified ZIF-8-5% catalyst was synthesized by a post-modification method, exhibiting enhanced selectivity (from 56% to 79%) and current density (from −4 mA cm to −10 mA m) compared to ZIF-8. Density functional theory (DFT) calculations further demonstrate that the boosted eCORR performance on ZIF-8-5% could be attributed to the improved formation of the *COOH intermediate stemming from successful DOBDC surface modification. This work opens a new path for improving the catalytic properties of MOFs via their surface modification
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