Synthesis and biological evaluations of NO-donating oxa- and aza-pentacycloundecane derivatives as potential neuroprotective candidates

In order to utilize the neuroprotective properties of polycyclic cage compounds, and explore the NO-donating ability of nitrophenyl groups, an array of compounds was synthesized where the different nitrophenyl groups were appended on oxa and aza-bridged cage derivatives. Biological evaluations of the compounds were done for cytotoxicity, neuroprotective abilities, the inhibition of N-methyl-D-aspartate (NMDA)-mediated Ca2+ influx, the inhibition of voltage-mediated Ca2+ influx, and S-nitrosylation abilities. All of the compounds showed low toxicity. With a few exceptions, most of the compounds displayed good neuroprotection and showed inhibitory activity for NMDA-mediated and voltage-gated calcium influx, ranging from high (>70%) to low (20–39%) inhibition. In the S-nitrosylation assay, the compounds with the nitro moiety as the NO-donating group exhibited low to good nitrosylation potency compared to the positive controls. From the biological evaluation of the tested compounds, it was not possible to obtain a simple correlation that could explain the results across all of the biological study domains. This can be ascribed to the independent processes evaluated in the different assays, which reiterate that neuroprotection is a result of multifactorial biochemical mechanisms and interactions. However, these results signify the important aspects of the pentacylcoundecylamine neuroprotectants across different biological study realms.IS

Global unmet needs in cardiac surgery

More than 6 billion people live outside industrialized countries and have insufficient access to cardiac surgery. Given the recently confirmed high prevailing mortality for rheumatic heart disease in many of these countries together with increasing numbers of patients needing interventions for lifestyle diseases due to an accelerating epidemiological transition, a significant need for cardiac surgery could be assumed. Yet, need estimates were largely based on extrapolated screening studies while true service levels remained unknown. A multi-author effort representing 16 high-, middle-, and low-income countries was undertaken to narrow the need assessment for cardiac surgery including rheumatic and lifestyle cardiac diseases as well as congenital heart disease on the basis of existing data deduction. Actual levels of cardiac surgery were determined in each of these countries on the basis of questionnaires, national databases, or annual reports of national societies. Need estimates range from 200 operations per million in low-income countries that are nonendemic for rheumatic heart disease to >1,000 operations per million in high-income countries representing the end of the epidemiological transition. Actually provided levels of cardiac surgery range from 0.5 per million in the assessed low- and lower-middle income countries (average 107 ± 113 per million; representing a population of 1.6 billion) to 500 in the upper-middle-income countries (average 270 ± 163 per million representing a population of 1.9 billion). By combining need estimates with the assessment of de facto provided levels of cardiac surgery, it emerged that a significant degree of underdelivery of often lifesaving open heart surgery does not only prevail in low-income countries but is also disturbingly high in middle-income countries

Archive of Darkness:William Kentridge's Black Box/Chambre Noire

Situating itself in histories of cinema and installation art, William Kentridge's Black Box/Chambre Noire (2005) raises questions about screens, exhibition space, site-specificity and spectatorship. Through his timely intervention in a debate on Germany’s colonial past, Kentridge’s postcolonial art has contributed to the recognition and remembrance of a forgotten, colonial genocide. This article argues that, by transposing his signature technique of drawings for projection onto a new set of media, Kentridge explores how and what we can know through cinematic projection in the white cube. In particular, his metaphor of the illuminated shadow enables him to animate archival fragments as shadows and silhouettes. By creating a multi-directional archive, Black Box enables an affective engagement with the spectres of colonialism and provides a forum for the calibration of moral questions around reparation, reconciliation and forgiveness

Aerodynamic development of a contra-rotating shrouded rotor system for a UAV

Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Unmanned aerial vehicles with vertical take-off and landing capabilities have received extensive attention worldwide in the last decade. Their low detectability, high manoeuvrability in confined spaces, and their capability for out-of-sight operations make them practical solutions for an array of military and civilian missions. The main advantage of shrouded rotors in hover and low speed conditions is the decreased blade tip induced drag when the tip gap is small enough. A well-designed shroud augments the rotor thrust in hover and low axial flight conditions. It also provides noise reduction and safety. A contra-rotating rotor system eliminates the need for separate anti-torque devices, thus producing a smaller footprint and a more compact vehicle. In this study a more efficient coaxial rotor for the ducted coaxial rotor system as published by (Lee 2010) was developed. The first phase of the design process consisted of the selection and numerical analysis of the best suited parent airfoils for the rotors by using XFOIL and XFLR 5. The second phase dealt with the design of a counter-rotating rotor system for the existing cambered shroud as published by (Lee, 2010), using the DFDC-070ES2a two dimensional code, specifically written for ducted rotor optimization. The final phase of the study dealt with the Computational Fluid Dynamic (CFD) verification of the design in ANSYS-CFX 15.07. A comparison between the CFX predictions of the newly designed rotor system and the reference design indicates a 33% improvement in hover thrust at the design power input.AFRIKAANSE OPSOMMING: Onbemande lugvaartuie met vertikale opstyg en landings vermoëns het uitgebreide aandag wêreldwyd in die laaste dekade geniet. Hul lae waarneembaarheid, hoë beweegbaarheid in beperkte ruimtes, en hul vermoë om buite-sig operasies uit te voer maak dat hulle praktiese oplossings vir 'n verskeidenheid van militêre en burgerlike missies is. Die grootste voordeel van gehulde rotors in hangvlug en lae spoed omstandighede is die afname in die lem punt sleepkrag wanneer die lem punt gaping klein genoeg is. 'n Goed ontwerpde omhulsel dra by tot die rotor stukrag in hangvlug en lae aksiale vlug omstandighede. Dit bied ook geraasreduksie en veiligheid. 'n Kontra-roterende rotorstelsel skakel die vereiste van afsonderlike anti-wringkrag toestelle uit, wat lei tot 'n kleiner voetspoor en 'n meer kompakte voertuig. In hierdie studie is 'n meer doeltreffende koaksiale rotor vir die gehulde koaksiale rotor stelsel soos gepubliseer deur (Lee 2010) ontwikkel. Die eerste fase van die ontwerp-proses het bestaan uit die seleksie en numeriese analise van die mees geskikte lemprofiele vir die rotors deur die gebruik van XFOIL en XFLR 5. Fase twee het die ontwerp van 'n teen-roterende rotor stelsel vir die bestaande omhulsel soos gebruik in (Lee, 2010) se publikasie behels. Die ontwerp is met behulp van DFDC-070ES2a, ‘n twee dimensionele kode wat spesifiek vir gehul-rotor optimering geskryf is, gedoen. Die verifikasie van die nuwe ontwerp is in die finale fase met behulp van die berekeings vloeidinamika sagteware, ANSYS-CFX 15.07 gedoen. ‘n Vergelyking tussen die CFX prestasie voorspelling vir die nuwe rotorstelsel en die gepubliseerde data van (Lee, 2010) toon ‘n 33% toename in hangvlug stukrag by die ontwerpsdrywing

The development of an implementation framework for green retrofitting of existing buildings in South Africa

Thesis (MEng)--Stellenbosch University, 2017.ENGLISH ABSTRACT: In this study frameworks related to retrofitting were investigated in order to develop a holistic framework for the green retrofitting of existing buildings in South Africa. The developed framework consists of five phases: retrofit feasibility, pre-project planning, construction, post-retrofit activities, and finally operation and maintenance. The framework was validated by means of a case study. The time required by the organisation involved to obtain the necessary funds for constructing the retrofit far exceeds the available time of this study. Therefore only the first two phases of the developed frameworks, retrofit feasibility and pre-project planning, were validated. The framework was developed to be a generic representation for South African retrofit projects, and as with the maintenance phase, many aspects were selected and adapted for the South African context. One of the main barriers for green buildings in South Africa, identified from literature, is the high cost perception South Africans have regarding green buildings. In the case study it was demonstrated how internal resources and expertise of the organisation can be used to reduce the total retrofit cost. Combining a retrofit with maintenance actions can further reduce the additional amount needed to invest in a green retrofit. Fourteen retrofit features are suggested and grouped into seven smaller independent projects according to the types of skills that are required for each installation. This minimises the time, external expertise and resources needed for specific jobs. These sub-projects are generally not fixed to a pre-defined schedule and can be attempted at stages the organisation finds suitable.AFRIKAANSE OPSOMMING: In hierdie studie word raamwerke vir die aanpassing van geboue ondersoek met die doel om ’n holistiese raamwerk vir die groen aanpassing van bestaande geboue in Suid-Afrika te ontwikkel. Die raamwerk wat ontwikkel is bestaan uit vyf fases: die uitvoerbaarheid van die aanpassing, voorafbeplanning van die projek, konstruksie, post-aanpassingsaktiwiteite en laastens inwerkstelling en instandhouding. Die uitvoerbaarheid van die ontwikkelde raamwerk is deur middel van ’n gevalle studie getoets. Die tydperk wat die betrokke organisasie benodig om die nodige fondse vir die aanpassing te bekom is meer as die tyd wat beskikbaar is vir die studie. Daarom kon net die uitvoerbaarheid van die eerste twee fases van die ontwikkelde raamwerk, die uitvoerbaarheid van die aanpassing en die voorafbeplanning, getoets word. Die raamwerk is ontwikkel om verteenwoordigend te wees van Suid-Afrikaanse aanpassingsprojekte, en soos in die geval van die instandhoudingsfase, is baie aspekte gekies en aangepas met Suid-Afrikaanse toestande in gedagte. Een van die hoofstruikelblokke vir groen geboue in Suid-Afrika is, soos in literatuur geïdentifiseer, die persepsie van hoë koste. In die gevalle studie word daar gedemonstreer dat die interne bronne en kennis in die organisasie self gebruik kan word om die totale kostes verbonde aan die aanpassing te verminder. Die kombinering van die aanpassing met instandhoudingsaksies kan die addisionele bedrag wat benodig word vir belegging in die aanpassing, verder verminder. Veertien aspekte van aanpassing word voorgestel en in sewe kleiner onafhanklike subprojekte volgens die tipes vaardighede wat vir elke installasie benodig word, groepeer. Dit verminder die tyd, eksterne bedrewendheid en bronne wat vir spesifieke take bekom moet word. Daar is gewoonlik nie ’n voorafskedule verbonde aan hierdie subprojekte nie en dit kan uitgevoer word op stadiums wat vir die organisasie gerieflik is

SSUIT Smart Sustainable Urban Infrastructure Transitioning

Transformation towards smart sustainable cities requires transitioning and modernising urban infrastructure systems. This study builds upon previous work and recommendations to address the need for a holistic and comprehensive framework to guide the planning, development, and management of smart sustainable infrastructure transitions. Existing approaches and methods regarding city and infrastructure transitioning were reviewed to draw up an understanding of, the requirements for, and guidelines useful to the design of a conceptual framework. The framework was established through synthesis of the knowledge and insight gathered from the literature. A collective case study analysis was used to verify the theoretical framework and make adaptations to successfully address any shortcomings. The framework was then also subjected to a validation process testing the appropriateness of the framework’s design using a Delphi technique and industry experts. After adapting the framework based on the feedback from experts, all of them were certain the framework would hold up in practice. The framework is intended as a generic guideline useful to municipal managers, city planners, and project portfolio managers appointed to plan, direct, and manage the transition of an existing city towards a smart sustainable city

Global Unmet Needs in Cardiac Surgery

10.1016/j.gheart.2018.08.002GLOBAL HEART134293-30