Development of a single tube 640-plex genotyping method for detection of nucleic acid variations on microarrays

Detection of DNA sequence variation is critical to biomedical applications, including disease genetic identification, diagnosis and treatment, drug discovery and forensic analysis. Here, we describe an arrayed primer extension-based genotyping method (APEX-2) that allows multiplex (640-plex) DNA amplification and detection of single nucleotide polymorphisms (SNPs) and mutations on microarrays via four-color single-base primer extension. The founding principle of APEX-2 multiplex PCR requires two oligonucleotides per SNP/mutation to generate amplicons containing the position of interest. The same oligonucleotides are then subsequently used as immobilized single-base extension primers on a microarray. The method described here is ideal for SNP or mutation detection analysis, molecular diagnostics and forensic analysis. This robust genetic test has minimal requirements: two primers, two spots on the microarray and a low cost four-color detection system for the targeted site; and provides an advantageous alternative to high-density platforms and low-density detection systems

Identifying, Analysing and Comparing Organisational Cultures in the Game Development Industry : A comparative case study on the two Blizzards from 1997-2005.

Organisational culture is a long debated research field, one that is greatly influential in modern day workspace, possibly deeply affecting organisational performance. This thesis is a case study on Blizzard entertainment from 1997 to 2005, where Blizzard North and Blizzard South, two organisations, existed and worked on some of the company’s most influential games. The authors analysed and inspected the unique culture of each of the organisation, intending to understand the effect of organisational culture on video game development. The analysis is conducted utilising multiple organisational cultural theories and models. Both of the studios' organisational culture is explored in this study and the study aims to show the effect of these organisational cultures in the game development process. The importance of this research lies in studying the connection between organisational culture and the gaming development process. This research is for an audience which takes interest in starting their own company or working in one, people who want to understand how companies work and people who are interested to see different behaviours in different situations. The key findings of this study are about how organisational culture affects different aspects of game development such as design, approaches and relationships between peers

Identifying, Analysing and Comparing Organisational Cultures in the Game Development Industry : A comparative case study on the two Blizzards from 1997-2005.

Organisational culture is a long debated research field, one that is greatly influential in modern day workspace, possibly deeply affecting organisational performance. This thesis is a case study on Blizzard entertainment from 1997 to 2005, where Blizzard North and Blizzard South, two organisations, existed and worked on some of the company’s most influential games. The authors analysed and inspected the unique culture of each of the organisation, intending to understand the effect of organisational culture on video game development. The analysis is conducted utilising multiple organisational cultural theories and models. Both of the studios' organisational culture is explored in this study and the study aims to show the effect of these organisational cultures in the game development process. The importance of this research lies in studying the connection between organisational culture and the gaming development process. This research is for an audience which takes interest in starting their own company or working in one, people who want to understand how companies work and people who are interested to see different behaviours in different situations. The key findings of this study are about how organisational culture affects different aspects of game development such as design, approaches and relationships between peers

Stability of nanoparticle production by atmospheric-pressure spark ablation

The stability of nanoparticle (NP) production by atmospheric-pressure spark ablation was studied and found to depend on the composition of the electrodes and the carrier gas (here N2 or Ar). For materials that do not react with N2, such as Pd and Ni, NP production was rather stable regardless of the carrier gas employed. In contrast, for materials that can easily produce nitride species (e.g., Al and Mg), both the concentration and size of the resulting NPs exhibited noticeable fluctuations, when ablating them in N2, which are more pronounced when the electrical energy input to the system is low. The variation in concentration and particle size is attributed to the formation of a metal-nitride region on the face of the electrodes where the sparks hit, as a result of its reaction with the carrier gas, altering the electrical and thermal conductivity, and consequently the ablatability of the electrode at that region. This explanation was corroborated by offline analysis of the face surface of the electrodes, showing two chemically distinct regions: one with high content of N and one without. In addition, the concentration of the Al and Mg NPs produced in N2 decreased gradually over time until it reached a plateau after several hours. When using Ar, the fluctuation and decreasing trend in NP production, and consequently the formation of nitride compounds on the face surface of the electrodes, were negligible, providing an effective solution for stable ablation of materials that can easily react with N2.ChemE/Materials for Energy Conversion and StorageAtmospheric Remote Sensin

Low-temperature water-gas shift on Pt/Ce0.8La0.2O2−δ–CNT: The effect of Ce0.8La0.2O2−δ/CNT ratio

Hybrid materials of (100 − x) wt% Ce0.8La0.2O2−δ–x wt% CNT composition (x = 0, 7.5, 20.5, 32.5, 44.1 and 100) were synthesized using the urea-assisted co-precipitation method and used as supports of 0.5 wt% Pt toward the low-temperature WGS (LT-WGS) reaction. The main focus of this work was to provide fundamental understanding of the effect of Ce0.8La0.2O2−δ/CNT ratio on the LT-WGS catalytic activity of such materials. It was found that the material containing 44.1 wt% CNT presented the best catalytic activity (kinetic rate and CO conversion), result that is correlated with the following parameters: (i) Pt-CO bond strength (TPD-CO), (ii) extent of dispersion of the Ce0.8La0.2O2−δ phase in the hybrid support system and, thus of the Pt phase; the larger dispersion of the Ce0.8La0.2O2−δ phase had a direct impact on its reducibility ability (labile oxygen species), (iii) concentration of surface Ce3+ species (XPS), indication for an increased concentration of oxygen vacant sites, (iv) PtH bond strength (H2-TPD studies), and (v) concentration of active carbon-containing intermediates, “C-pool” formed around each Pt nanoparticle (SSITKA studies). WGS kinetic studies at 300 °C revealed that the reaction order with respect to CO was 0.17 and 0.13 for the catalysts containing 20.5 and 44.1 wt% CNT, respectively, while the reaction order with respect to H2O was 1.40 for the latter CNT loading. Oxidation of CNTs over the catalyst containing 44.1 wt% of CNTs occurred at temperatures larger than 400 °C, result of practical importance for the LT-WGS reaction. The proposed WGS reaction mechanism over the present catalytic materials is that of “redox” in parallel with the “associative with –OH group regeneration” mechanism.The European Regional Development Fund, the Republic of Cyprus and the Research Promotion Foundation of Cyprus are gratefully acknowledged for their financial support through the project TECHNOLOGY/0308(BE)/05.Peer Reviewe

Water-gas shift reaction on Pt/Ce1- xTixO 2-δ: The effect of Ce/Ti ratio

Pt nanoparticles (1.2–2.0 nm size) supported on Ce1–xTixO2−δ (x = 0, 0.2, 0.5, 0.8, and 1.0) carriers synthesized by the citrate sol–gel method were tested toward the water–gas shift (WGS) reaction in the 200–350 °C range. A deep insight into the effect of two structural parameters, the chemical composition of support (Ce/Ti atom ratio), and the Pt particle size on the catalytic performance of Pt-loaded catalysts was realized after employing in situ X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM) and HAADF/STEM, scanning electron microscopy (SEM), in situ Raman and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopies under different gas atmospheres, H2 temperature-programmed reduction (H2-TPR), and temperature-programmed desorption (NH3-TPD and CO2-TPD) techniques. The 0.5 wt % Pt/Ce0.8Ti0.2O2−δ solid (dPt = 1.7 nm) was found to be by far the best catalyst among all the other solids investigated. In particular, at 250 °C the CO conversion over Pt/Ce0.8Ti0.2O2−δ was increased by a factor of 2.5 and 1.9 compared to Pt/TiO2 and Pt/CeO2, respectively. The catalytic superiority of the Pt/Ce0.8Ti0.2O2−δ solid is the result of the support’s (i) robust morphology preserved during the WGS reaction, (ii) moderate acidity and basicity, and (iii) better reducibility at lower temperatures and the significant reduction of “coking” on the Pt surface and of carbonate accumulation on the Ce0.8Ti0.2O2−δ support. Several of these properties largely influenced the reactivity of sites (k, s–1) at the Pt–support interface. In particular, the specific WGS reaction rate at 200 °C expressed per length of the Pt–support interface (μmol CO cm–1 s–1) was found to be 2.2 and 4.6 times larger on Pt supported on Ce0.8Ti0.2O2−δ (Ti4+-doped CeO2) compared to TiO2 and CeO2 alone, respectively.The European Regional Development Fund, the Republic of Cyprus, the Research Promotion Foundation of Cyprus, and the Research Committee of the University of Cyprus are gratefully acknowledged for their financial support through the project TEXNO/0308(BE)/05. S.B. acknowledges financial support from the COST Action CM1104.Peer Reviewe

Tuning atomic-scale mixing of nanoparticles produced by atmospheric-pressure spark ablation

Nanoparticles (NPs) mixed at the atomic scale have been synthesized by atmospheric-pressure spark ablation using pairs of Pd and Hf electrodes. Gravimetric analysis of the electrodes showed that the fraction of each material in the resulting mixed NPs can be varied from ca. 15-85 at% to 85-15 at% by employing different combinations of electrode polarities and thicknesses. These results were also qualitatively corroborated by microscopy and elemental analysis of the produced NPs. When using pairs of electrodes having the same diameter, the material from the one at negative polarity was represented at a substantially higher fraction in the mixed NPs regardless of whether a pair of thin or thick electrodes were employed. This can be attributed to the higher ablation rate of the electrodes at the negative polarity, as already known from earlier experiments. When using electrodes of different diameters, the fraction of the element from the thinner electrode was always higher. This is because thinner electrodes are ablated more effectively due to, at least in part, the increased importance of the associated heat losses compared to its thicker counterpart. In those cases, the polarity of the electrodes had a significantly smaller effect. Overall, our results demonstrate, for the first time, that spark ablation can be used to control atomic scale mixing and thus produce alloyed NPs with compositions that can be tuned to a good extent by simply using different combinations of electrode diameters and polarities. This expands the capabilities of the technique for producing mixed nanoparticle building blocks of well-defined composition that are highly desired for a wide range of applications.ChemE/Materials for Energy Conversion and StorageAtmospheric Remote Sensin

Water–Gas Shift Reaction on Pt/Ce_1–<i>x</i>Ti_<i>x</i>O_2−δ: The Effect of Ce/Ti Ratio

Pt nanoparticles (1.2–2.0 nm size) supported on Ce_1–<i>x</i>Ti_<i>x</i>O_2−δ (<i>x</i> = 0, 0.2, 0.5, 0.8, and 1.0) carriers synthesized by the citrate sol–gel method were tested toward the water–gas shift (WGS) reaction in the 200–350 °C range. A deep insight into the effect of two structural parameters, the chemical composition of support (Ce/Ti atom ratio), and the Pt particle size on the catalytic performance of Pt-loaded catalysts was realized after employing in situ X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM) and HAADF/STEM, scanning electron microscopy (SEM), in situ Raman and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopies under different gas atmospheres, H₂ temperature-programmed reduction (H₂-TPR), and temperature-programmed desorption (NH₃-TPD and CO₂-TPD) techniques. The 0.5 wt % Pt/Ce_0.8Ti_0.2O_2−δ solid (<i>d</i>_Pt = 1.7 nm) was found to be by far the best catalyst among all the other solids investigated. In particular, at 250 °C the CO conversion over Pt/Ce_0.8Ti_0.2O_2−δ was increased by a factor of 2.5 and 1.9 compared to Pt/TiO₂ and Pt/CeO₂, respectively. The catalytic superiority of the Pt/Ce_0.8Ti_0.2O_2−δ solid is the result of the support’s (i) robust morphology preserved during the WGS reaction, (ii) moderate acidity and basicity, and (iii) better reducibility at lower temperatures and the significant reduction of “coking” on the Pt surface and of carbonate accumulation on the Ce_0.8Ti_0.2O_2−δ support. Several of these properties largely influenced the reactivity of sites (<i>k</i>, s^–1) at the Pt–support interface. In particular, the specific WGS reaction rate at 200 °C expressed per length of the Pt–support interface (μmol CO cm^–1 s^–1) was found to be 2.2 and 4.6 times larger on Pt supported on Ce_0.8Ti_0.2O_2−δ (Ti⁴⁺-doped CeO₂) compared to TiO₂ and CeO₂ alone, respectively

Structural and Redox Properties of Ce_1–<i>x</i>Zr_<i>x</i>O_2−δ and Ce_0.8Zr_0.15RE_0.05O_2−δ (RE: La, Nd, Pr, Y) Solids Studied by High Temperature <i>in Situ</i> Raman Spectroscopy

<i>In situ</i> Raman spectroscopy at temperatures up to 450 °C is used to probe the structural and redox properties of Ce_1–<i>x</i>Zr_<i>x</i>O_2−δ solids (<i>x</i> = 0–0.8) prepared by the citrate sol–gel and coprecipitation with urea methods. The anionic sublattice structure of the solids is dependent on the preparation route. The composition effects exhibited by the Raman spectra are adequate for characterizing the phases present and/or eventual phase segregations. For <i>x</i> = 0.5 the pseudocubic <i>t</i>″ phase occurs for the solid prepared by the citrate sol–gel method, while phase segregation (cubic, tetragonal) is evidenced for the corresponding material prepared by the coprecipitation with urea method. A larger extent of defects and interstitial O atoms is evidenced for the materials prepared by the citrate sol–gel method. The well-known “defect” (“D”) band around 600 cm^–1 for CeO₂ as well as for Ce_1–<i>x</i>Zr_<i>x</i>O_2−δ consists of at least two components: “D1” above 600 cm^–1 and “D2” below 600 cm^–1. Doping of Ce_0.8Zr_0.2O_2−δ with rare earth cations (La³⁺, Nd³⁺, Y³⁺, Pr³⁺) results in strengthening of the “D2” band that, however, is found to be insensitive under reducing conditions of flowing 5% H₂/He at 450 °C. A novel approach based on sequential <i>in situ</i> Raman spectra under alternating oxidizing (20% O₂/He) and reducing (5% H₂/He) gas atmospheres showed that the “D1” band is selectively attenuated under reducing conditions at 450 °C and is therefore assigned to a metal–oxygen vibrational mode involving interstitial oxygen atoms that can be delivered under suitable conditions. A reversible temperature-dependent evolution of the anionic sublattice structures of Ce_1–<i>x</i>Zr_<i>x</i>O_2−δ solids is evidenced by <i>in situ</i> Raman spectroscopy. The results are corroborated by powder XRD and oxygen storage capacity measurements, and observed structure/function relationships are discussed. It is shown that at low temperatures (e.g., 450 °C) the function of oxygen release and refill is based on a mechanism involving oxygen atoms in interstitial sites rather than on defects induced by hetrovalent M⁴⁺→ RE³⁺ doping, the latter improving the pertinent function at high (e.g., >600 °C) temperatures