Selective monoamine-oxidase inhibition in man : a biochemical and pharmacological study

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A New Method for the Asteroseismic Determination of the Evolutionary State of Red-Giant Stars

Determining the ages of red-giant stars is a key problem in stellar astrophysics. One of the difficulties in this determination is to know the evolutionary state of the individual stars -- i.e. have they started to burn Helium in their cores? That is the topic of this paper. Asteroseismic data provide a route to achieving this information. What we present here is an highly autonomous way of determining the evolutionary state from an analysis of the power spectrum of the light curve. The method is fast and efficient and can provide results for a large number of stars. It uses the structure of the dipole-mode oscillations, which have a mixed character in red-giant stars, to determine some measures that are used in the categorisation. It does not require that all the individual components of any given mode be separately characterised. Some 6604 red giant stars have been classified. Of these 3566 are determined to be on the red-giant branch, 2077 are red-clump and 439 are secondary-clump stars. We do not specifically identify the low metallicity, horizontal-branch stars. The difference between red-clump and secondary-clump stars is dependent on the manner in which Helium burning is first initiated. We discuss that the way the boundary between these classifications is set may lead to mis-categorisation in a small number of stars. The remaining 522 stars were not classified either because they lacked sufficient power in the dipole modes (so-called depressed dipole modes) or because of conflicting values in the parameters.Comment: Accepted for publication in MNRAS. There will be an online table associated with the publicatio

Thinning of the Sun's magnetic layer: the peculiar solar minimum could have been predicted

The solar magnetic activity cycle causes changes in the Sun on timescales that are relevant to human lifetimes. The minimum in solar activity that preceded the current solar cycle (cycle 24) was deeper and quieter than any other recent minimum. Using data from the Birmingham Solar-Oscillations Network (BiSON), we show that the structure of the solar sub-surface layers during the descending phase of the preceding cycle (cycle 23) was very different from that during cycle 22. This leads us to believe that a detailed examination of the data would have led to the prediction that the cycle-24 minimum would be out of the ordinary. The behavior of the oscillation frequencies allows us to infer that changes in the Sun that affected the oscillation frequencies in cycle 23 were localized mainly to layers above about 0.996Rsun, depths shallower than about 3000 km. In cycle 22, on the other hand, the changes must have also occurred in the deeper-lying layers.Comment: To appear in Ap

On the asymptotic acoustic-mode phase in red-giant stars and its dependence on evolutionary state

Asteroseismic investigations based on the wealth of data now available,in particular from the CoRoT and Kepler missions, require a good understanding of the relation between the observed quantities and the properties of the underlying stellar structure. Kallinger et al. 2012 found a relation between their determination of the asymptotic phase of radial oscillations in evolved stars and the evolutionary state, separating ascending-branch red giants from helium-burning stars in the `red clump'. Here we provide a detailed analysis of this relation, which is found to derive from differences between these two classes of stars in the thermodynamic state of the convective envelope. There is potential for distinguishing red giants and clump stars based on the phase determined from observations that are too short to allow distinction based on determination of the period spacing for mixed modes. The analysis of the phase may also point to a better understanding of the potential for using the helium-ionization-induced acoustic glitch to determine the helium abundance in the envelopes of these stars.Comment: MNRAS, in the pres

Knowledge-based automation and new workforce implementation at a financial institution

Abstract : Intelligent Automation (IA) entails advanced knowledge-based technologies associated with the so-called Fourth Industrial Revolution (4IR). In this study, the phrase “IA journey” refers to the processes of knowledge-based automation and new workforce implementation. The study’s unit of analysis is not as much the IA journey itself, rather it is an analysis of what constitutes a balanced approach to IA implementation and adoption within an organisation. For example, employees’ feelings of uncertainty during an organisation’s IA journey could cause an imbalance in staff morale and resistance from employees to adapt to the changes. Therefore, the main research question of this study is: What are the components of a balanced approach to knowledge-based automation and new workforce implementation of a financial institution? The research question aligns to the world of service delivery that is changing at an alarming rate, with customers expecting fast, personalised, digital service. The landscape for financial institutions is changing, for example, traditional competitors are taking steps to meet customer demands and non-traditional competitors are entering the market place, threatening the existence of traditional financial institutions, commonly referred to as banks. The literature reveals that the evolution of Internet usage and the influence of social media and smart phones have increased the significance of technology and digital service in the financial services industry. Adoptions of these technologies is vital if traditional banks want to remain relevant in the market where financial technologies companies (Fintechs), and small, digitally nimble start-ups can provide the quick, personalised service that customers expect. Already many financial institutions have started to investigate the opportunities that technologies such as IA and chatbots provide. The potential of chatbot technology to improve customer experience and reduce operational costs make it an attractive option for organisations to consider. Literature reveals that the cost of implementation of this technology is a fraction of the cost of legacy system re-writes. The ability of this technology to integrate with existing systems and improve turnaround time and service to customers makes the IA journey a favourable choice. The IA journey of one South African Financial Institution (SAFI) formed the focus of this study. Research was conducted within the SAFI into the application of this technology across the organisation to understand the impact that the changes experienced had on the employees of the organisation. Understanding how these changes impact employees helps in determining the best ways to manage the changes in order to develop a balanced approach to implementation and adaption of IA within an organisation. The empirical study followed a qualitative research design, featuring qualitative data collection and analysis techniques. Secondary data were collected and displayed in order to show case v hoe IA project were implemented into the organisation. The philosophical paradigm that suited a study of this nature was interpretivism as the research was socially constructed in its aim to understand the adoption processes of the organisation implementing an IA programme. The research followed an inductive approach as the study’s conceptual framework was developed based on data collected and conclusions drawn through the analysis of this data. The study involved the collection of data through the use of interviews conducted across junior and senior management levels within the business units impacted by the changes associated with the IA journey. The aim of these interviews was to gain an understanding of employees’ perceptions of the IA journey across the organisation as well as understand the experiences of those involved in the IA programme. Secondary data was also collected from five SAFI use cases, which provided a rich source for quantitative data. The presentation of results regarding the outcomes of use cases implemented across the organisation is in accordance to the University of Johannesburg Code of Academic and Research Ethics. The research findings informed the development of a conceptual framework, which can be used to encourage a balanced approach towards IA implementation and adoption throughout an organisation that is experiencing major changes. This study reveals that employees’ fears of the changes need to be identified and managed early in order to avoid resistance to the changes and negative perceptions of the technology being created. The conceptual framework identifies the components that a financial institution can use in its balanced approach to increase adoption and reduce fears. Moreover, the study revealed the need for organisations to invest in technologies of the future and the benefits that this technology can have for the organisation. Customer experience and expectations form a vital part of any organisation and the lessons learnt in the value this technology can provide in creating a great customer experience are invaluable. The study revealed that there is a difference between digitisation and automation and that knowledge-based automation technology plays a key role in enabling a digital customer experience...M.Phil. (Information Management

BiSON data preparation: A correction for differential extinction and the weighted averaging of contemporaneous data

The Birmingham Solar Oscillations Network (BiSON) has provided high-quality high-cadence observations from as far back in time as 1978. These data must be calibrated from the raw observations into radial velocity and the quality of the calibration has a large impact on the signal-to-noise ratio of the final time series. The aim of this work is to maximise the potential science that can be performed with the BiSON data set by optimising the calibration procedure. To achieve better levels of signal-to-noise ratio we perform two key steps in the calibration process: we attempt a correction for terrestrial atmospheric differential extinction; and the resulting improvement in the calibration allows us to perform weighted averaging of contemporaneous data from different BiSON stations. The improvements listed produce significant improvement in the signal-to-noise ratio of the BiSON frequency-power spectrum across all frequency ranges. The reduction of noise in the power spectrum will allow future work to provide greater constraint on changes in the oscillation spectrum with solar activity. In addition, the analysis of the low-frequency region suggests we have achieved a noise level that may allow us to improve estimates of the upper limit of g-mode amplitudes.Comment: Accepted for publication in MNRAS; 10 pages, 7 figure

Changes in the Internal Organizational and Administrative Practices in the Elementary School from 1945 to 1950

This study is designed to show what changes have been made in the organization and the administration of the elementary school from 1945 to 1950, as revealed in the literature and to point out possible trends, or indices of trends during this period. The expression or indices of trends is used because it is difficult to point out trends in elementary education in a five-year period. The elementary school is not perfect, but that it is constantly changing in an effort to improve, is becoming more evident in the field of elementary education. This writer believes that democratic society never remains constant; we are always developing the elementary school, which has made notable progress during the last half century. Local and world conditions have their influence upon education which cause the internal changes in content and administration of the elementary curriculum. Changes are made in education to stimulate the program of the School, so that it will meet the growing needs of the children during their developmental period

Cyclic nitrones: oxidation studies and the synthesis of a heterocyclic nitrone

Part I: The synthesis of the heterocyclic nitrone, Δ³-dihydro-1,4-oxazine 4-oxide, by the oxidation of solutions of 4-hydroxymorpholine is described. The UV and IR spectra of the solutions were consistent with the structure proposed. Removal of the solvent gave linear polymers with the N-O-C repeating unit. Typical nitrone-reducing agents have been shown to be effective towards the heterocyclic nitrone. Arylhydrazines oxidised the heterocyclic nitrone with cleavage of the ether band, yielding glyoxal osazones. The same nitrone was very rapidly oxidised to 4-hydroxy-3-morpholone by ferric chloride. This cyclic hydroxamic acid underwent further oxidation at a slower rate, ultimately yielding diglycollic acid and nitrous oxide. 1,3-Cycloaddition products were formed when the heterocyclic nitrone was heated together with cyclohexene, with phenylisocyanate and with ethyl acrylate. All the products incorporated the fused bicyclic skeleton of morpholino-isoxazolidine and were each characterised by analysis, IR and p.m.r. spectra. Part 2: Cyclic aldonitrones and some related cyclic hydroxylamines have been shown to undergo oxidation by ferric chloride to cyclic hydroxamic acids. For example, the 2-unsubstituted 1-pyrroline 1-oxides gave l-hydroxy-2-pyrrolidones , and 1-piperideine 1-oxide gave 1-hydroxy-2-piperidone. The reaction could be followed titrimetrically or spectrophotometrically. The former involved the determination of the ferrous ion released, whereas the latter technique entailed observing the increase in the intensity of the colour of the solution