2,4-Dioxa-λ6-thia­tetra­cyclo­[5.3.1.15,9.01,5]dodecane-3,3-dione

The crystal structure of the title compound, C9H12O4S, was determined in order to investigate the effect of the eclipsed O atoms on the bond length of the vicinal quaternary C atoms. The two quaternary C atoms of the noradamantane skeleton and the two O atoms to which they are connected all located essentially in the same plane (maximum deviation = 0.01 Å), resulting in an eclipsed conformation of the C—O bonds. The C—C bond of the quaternary C atoms is 1.581 (3) Å, considerably longer than the other C—C bonds of the mol­ecule due to the stretch of the cage structure

Digital natives and digital immigrants revisited: a case of CALL

The aim of the paper is to examine the uses of CALL among students and teachers in Cyprus private secondary education. The notions of digital native and digital immigrant are revisited as part of the framework set for understanding the current situation in CALL exploitation and future potential within and beyond the classroom walls. A survey investigation is conducted for the collection of the data. Results indicate that a third category of users emerges, the ‘inbetweeners’ who may have a key role to play in CALL integration

Velké matky: ženská síla ve vybraných románech Toni Morrisonové.

81 Résumé Tato práce uvádí, že mateřství, jak je znázorněno v románech Toni Morrisonové Šalamounova píseň (Song of Solomon), Milovaná (Beloved) a Milosrdenství (A Mercy) je prostor pro posílení postavení žen. Jeho emancipační potenciál je nastaven proti kontextu otroctví a patriarchátu popsané v příbězích a ukazuje, jak matky jsou schopné odolávat represivním strukturám a zajistit svým dětem blaho. Otroctví potrhalo rodinné vazby a způsobilo rozdělení rodin, oddělením rodičů od svých dětí. V románech, které jsou předmětem této práce je obnovy rodinných vazeb docíleno na základě imaginárního přepisování dějin. Některé z postav matek, jako je například postava Sethe v románu Beloved (Milovaná), znovu prožívají bolestnou rodinnou minulost a musí se vypořádat s jejími traumatizujícími účinky, aby mohly jít dále. Jiné z postav, jako je například postava Pilate v románu Song of Solomon (Šalomounova píseň), se vrací ke své minulosti a fungují jako prostředníci mezi dřívějšími a novými členy komunity. Přepisování historie je pro afroamerické spisovatele a lidi, kteří v minulosti zažili otrokářské praktiky, zcela zásadní k tomu, aby se mohli vypořádat s odkazem minulosti. Mateřství je definováno v několika stále se opakujících vzorech. Toni Morrisonová popisuje fyzické aspekty mateřství z pohledu matky a používá...81 Abstract This thesis argues that motherhood as depicted in Toni Morrison's novels Song of Solomon, Beloved and A Mercy is a site of female empowerment. Its emancipating potential is set against the context of slavery and patriarchy found in the narratives and shows how mothers are able to resist oppressive structures and secure their children's well-being. Slavery practices severed family ties and caused its dismemberment by separating parents from their children. In the novels under study the recovery of those ties happens in an imaginative re-writing of history. Mother figures, such as Beloved's Sethe, come to terms with the re-embodiment of a painful familial past and deal with its traumatizing effects to be able to renounce it and move on. Others like Song of Solomon's Pilate cling to their past and act as mediators between the community's history and its descendants. A re-writing of history is urgent for African American writers and peoples who share slavery pasts, and who thus need to deal with their lasting legacies in the present. Motherhood is thus identified in several recurring patterns. Toni Morrison describes physical aspects of mothering from the point of view of the mother and uses the female body as a life-giving source that cancels the objectification of female slave bodies....Department of Anglophone Literatures and CulturesÚstav anglofonních literatur a kulturFaculty of ArtsFilozofická fakult

The effects of temperature distortion on aerodynamics and low engine order forced response in axial turbines

The flow entering a high-pressure turbine in a gas turbine engine is characterised by a loss of symmetry due to temperature distortions in both radial and circumferential directions, known as hot streaks. In industrial simulations it is common practice to assume uniform inlet temperature conditions to simplify the aerodynamic analysis. However, hot streaks may have significant impact on the turbine aerodynamics with the redistribution of the hot fluid affecting the development of secondary flows with consequent effects on enhanced local heat transfer and aerodynamic losses. The loss of symmetry has also been linked to the excitation of low-order nodal diameter assembly modes of the downstream rotor blades leading to potential blade failure and thus, should be taken into account during the design process. In today’s carbon-constraint environment additional parameters arise as gas turbines are challenged to adapt to variations of the fuel composition driven by the need of efficient and lowCO2 power generation. Introducing syngas, a synthesis gas fuel that is used to power integrated gasification combined cycle (IGCC) power plants, is likely to affect the operating conditions of existing gas turbines leading to the requirement of re-design of components. With particular focus on the turbine hot flow path, the propagation mechanism of hot streaks throughout the turbine will be affected with consequent impact on the turbine aerodynamics and forced response excitation levels originating from the different hot flow patterns. Motivated by the lack of relevant studies, the current work provides a first step towards the evaluation of the effects of syngas on hot streaks aerodynamics and the induced forced response excitation levels. Using full annulus multi-bladerow unsteady 3D CFD simulations and applying combustor representative hot streak profiles in two different gas turbines, a complete analysis of the hot streaks migration is achieved, with respect to a number of geometric parameters such as the hot streaks shape and injection location in both spanwise and circumferential directions, the coolant configurations as well as the combined effects on the secondary flow development. The aerodynamic analysis indicated the propagation of the hot streaks up to the exit of the turbines under investigation with differences in characteristics depending on design parameters. With respect to the effect of fuel composition variations on the blades temperature levels and the flow pattern is observed between the natural gas and syngas turbine with the syngas showing a more concentrated wake shape. In effect of the syngas different flow pattern, differences are observed in the secondary flows with consequent interaction with the hot streaks. Contrast to initial expectations, the forced response analysis iii resulted slightly lower amplitude unsteady force of lower harmonics for syngas compared to natural gas; however, both fuels showed significant levels of the hot streak induced low engine order excitation compared to the burners and stator related blade passing frequency vibration

Multifunctional enzyme engineering by computational design for lignocellulosic valorization

Biomass- acting enzymes are vital components of biorefinery processes that aim to convert complex, lignocellulosic biomass into fuels, chemicals and materials and therefore, much effort has focused on the improvement of their characteristics (activity, stability, cost of production, etc) as well as on the discovery and development of novel enzymes. Metagenomic approaches revealed that in the Bacteroidetes phylum functionally related genes are often organized in characteristic clusters, known as Polysaccharide Utilization Loci (PUL) reflecting that biomass- acting enzymes act in synergy and that enzyme proximity is important to target complex substrates. In this study we designed a tailored made multifunctional enzyme, combining enzymes isolated from a xylan PUL (1). Computational simulations were performed to define and optimize engineered versions of a multi-domain GH10 endo- xylanase by replacing carbohydrate binding module (CBM) and grafting two new catalytic domains: either a GH43 xylosidase or a CE1 carbohydrate-esterase activities also present in the same PUL. The multifunctional enzymes were then experimentally assessed, demonstrating that chimeric GH10-GH43 had both activities and thus represents a powerful biological tool for hemicellulose deconstruction. Bastien, G., et al. (2013). Mining for hemicellulases in the fungus-growing termite Pseudacanthotermes militaris using functional metagenomics. Biotechnology for biofuels 6(1): 7

Aspects of environmental impacts of seawater desalination : Cyprus as a case study

Acknowledgements The authors are grateful to the European Commission for supporting the activities carried out in the framework of the H2020 European project ZERO BRINE (project under grant agreement No. 730390). The authors would equally like to thank the TOTAL Foundation (Project “Diversity of brown algae in the Eastern Mediterranean”) and the UK Natural Environment Research Council for their support to FCK (program Oceans 2025 – WP 4.5 and grants NE/D521522/1 and NE/J023094/1). This work also received support from the Marine Alliance for Science and Technology for Scotland pooling initiative. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. The authors would also like to thank representatives from competent authorities in Cyprus providing data, and specifically Nicoletta Kythreotou from the Department of Environment, George Ashikalis from the Transmission System Operator, Dr. DinosPoullis and Lia Georgiou from the Water Development Department.Peer reviewedPublisher PD

Prothymosin a and a prothymosin α-derived peptide enhance TH1-type immune responses against defined HER-2/neu epitopes

Background: Active cancer immunotherapies are beginning to yield clinical benefit, especially those using peptide-pulsed dendritic cells (DCs). Different adjuvants, including Toll-like receptor (TLR) agonists, commonly co-administered to cancer patients as part of a DC-based vaccine, are being widely tested in the clinical setting. However, endogenous DCs in tumor-bearing individuals are often dysfunctional, suggesting that ex vivo educated DCs might be superior inducers of anti-tumor immune responses. We have previously shown that prothymosin alpha (proTα) and its immunoreactive decapeptide proTα(100–109) induce the maturation of human DCs in vitro. The aim of this study was to investigate whether proTα- or proTα(100–109)-matured DCs are functionally competent and to provide preliminary evidence for the mode of action of these agents. Results: Monocyte-derived DCs matured in vitro with proTα or proTα(100–109) express co-stimulatory molecules and secrete pro-inflammatory cytokines. ProTα- and proTα(100–109)-matured DCs pulsed with HER-2/neu peptides induce TH1-type immune responses, prime autologous naïve CD8-positive (+) T cells to lyse targets expressing the HER-2/neu epitopes and to express a polyfunctional profile, and stimulate CD4+ T cell proliferation in an HER-2/neu peptide-dependent manner. DC maturation induced by proTα and proTα(100–109) is likely mediated via TLR-4, as 25 shown by assessing TLR-4 surface expression and the levels of the intracellular adaptor molecules TIRAP, MyD88 and TRIF. Conclusions: Our results suggest that proTα and proTα(100–109) induce both the maturation and the T cell stimulatory capacity of DCs. Although further studies are needed, evidence for a possible proTα and proTα(100–109) interaction with TLR-4 is provided. The initial hypothesis that proTα and the proTα-derived immunoactive decapeptide act as “alarmins”, provides a rationale for their eventual use as adjuvants in DC-based anti-cancer immunotherapy

The GH51 α-l-arabinofuranosidase from Paenibacillus sp. THS1 is multifunctional, hydrolyzing main-chain and side-chain glycosidic bonds in heteroxylans.

Background: Conceptually, multi functional enzymes are attractive because in the case of complex polymer hydrolysis having two or more activities defined by a single enzyme offers the possibility of synergy and reduced enzyme cocktail complexity. Nevertheless, multi functional enzymes are quite rare and are generally multi domain assemblies with each activity being defined by a separate protein module. However, a recent report described a GH51 arabinofuranosidase from Alicyclobacillus sp. A4 that displays both α l arabinofuranosidase and β d xylanase activities, which are defined by a single active site. Following on from this, we describe in detail another multi functional GH51 arabinofuranosidase and discuss the molecular basis of multifunctionality. Results: THSAbf is a GH51 α l arabinofuranosidase. Characterization revealed that THSAbf is active up to 75 °C, stable at 60 °C and active over a broad pH range (4–7). THSAbf preferentially releases para nitrophenyl from the l arabino furanoside ( k cat / K M = 1050 s − 1 mM − 1 ) and to some extent from d galactofuranoside and d xyloside. THSAbf is active on 4 O methylglucuronoxylans from birch and beechwood (10.8 and 14.4 U mg − 1 , respectively) and on sugar beet branched and linear arabinans (1.1 ± 0.24 and 1.8 ± 0.1 U mg − 1 ). Further investigation revealed that like the Alicyclo - bacillus sp. A4 α l arabinofuranosidase, THSAbf also displays endo xylanase activity, cleaving β 1,4 bonds in heteroxy lans. The optimum pH for THASAbf activity is substrate dependent, but ablation of the catalytic nucleophile caused a general loss of activity, indicating the involvement of a single active center. Combining the α l arabinofuranosidase with a GH11 endoxylanase did not procure synergy. The molecular modeling of THSAbf revealed a wide active site cleft and clues to explain multi functionality

Full Annulus Numerical Study of Hot Streaks Propagation in a Hydrogen-rich Syngas-Fired Heavy Duty Axial Turbine

This paper presents a study of the effect of fuel composition on hot streaks propagation in a high-pressure turbine using a full annulus unsteady computational fluid dynamics analysis of the first two stages. Hot streaks result from the inherent non-uniformities of temperature profiles at the exit of the combustion chamber. Variations in composition arise from current challenges requiring gas turbines to adapt to fuel variations driven by the need to reduce CO2 emissions through the use of synthetic hydrogen-rich fuels (syngas) typically generated from the gasification of coal or solid waste. Syngas containing 80% hydrogen has been used in this study in a heavy duty gas turbine modified to accommodate the low calorific value fuel. Calculations were conducted on the baseline gas turbine originally designed for natural gas for the comparative study. Applying combustor representative hot streak profiles, analyses were performed for different hot streak distributions and locations. Analysis of results focused on the segregation of cold and hot fluid patterns and the effects of hot streaks on secondary flows and temperature re-distributions up to the second turbine stage. The hot flow pattern is affected by the fuel composition, resulting in more concentrated thermal wake shapes for syngas when compared to the reference natural gas fuel. In effect, the interaction with the secondary flow leads to more intense flow turning of the pressure side leg of the horseshoe vortex in the first rotor passage. The higher temperature levels in the case of syngas, in combination with the effect of the enhanced secondary flow, result in higher radial spread of the hot fluid that tends to migrate towards the blade hub and tip with the effects being obvious further downstream the first turbine stage