Financial health and sense of coherence

Orientation: This article reports on a quantitative-relational study addressing the impact of sense of coherence (SOC), which is a psychological-wellness construct, on the financial-health profile of employees in an insurance company. Research purpose: The objective of the study was to explore the relationship between psychological wellness as operationalised in the SOC construct and in financial health. Motivation for the study: Financial pressure can be a major stressor in the workplace, affecting employees’ ability to function optimally. The debt crisis in South Africa is therefore necessitating employers to invest in the financial health of their employees. In light of the National Credit Act 34 of 2005, employers should, in fact, provide debt counselling to employees struggling with financial problems. In the South African context, however, studies investigating the potential influence of psychological-wellness constructs on financial health are lacking. Research design, approach and method: A cross-sectional survey design was applied and a quantitative-relational approach followed. From the 1 100 employees in a financial insurance company, 435 completed questionnaires were received. Main findings: The empirical results indicated a significant relationship between the variables, confirming that a stronger SOC impacts positively on employees’ financial health. A stronger SOC therefore relates positively to more effective debt management and retirement planning. Practical/managerial implications: The findings emphasised the importance of debt management and retirement planning being addressed and integrated into employee-assistance strategies and programmes. Contribution/value-add: This study is a significant step in addressing financial health from a psychological perspective

Photometric Redshift Calibration Requirements for WFIRST Weak-lensing Cosmology: Predictions from CANDELS

In order for the Wide-Field Infrared Survey Telescope (WFIRST) and other stage IV dark energy experiments (e.g., Large Synoptic Survey Telescope, LSST; and Euclid) to infer cosmological parameters not limited by systematic errors, accurate redshift measurements are needed. This accuracy can be met by using spectroscopic subsamples to calibrate the photometric redshifts for the full sample. In this work, we find the minimal number of spectra required for the WFIRST weak-lensing redshift calibration by employing the Self-Organizing Map (SOM) spectroscopic sampling technique. We use galaxies from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) to build the LSST+WFIRST lensing analog sample of ~36,000 objects and to train the LSST+WFIRST SOM. We find that 26% of the WFIRST lensing sample consists of sources fainter than the Euclid depth in the optical, 91% of which live in color cells already occupied by brighter galaxies. We demonstrate the similarity between faint and bright galaxies as well as the feasibility of redshift measurements at different brightness levels. Our results suggest that the spectroscopic sample acquired for calibration to the Euclid depth is sufficient for calibrating the majority of the WFIRST color space. For the spectroscopic sample to fully represent the synthetic color space of WFIRST, we recommend obtaining additional spectroscopy of ~0.2–1.2k new sources in cells occupied by mostly faint galaxies. We argue that either the small area of the CANDELS fields and the small overall sample size or the large photometric errors might be the reason for no/fewer bright galaxies mapped to these cells. Acquiring the spectra of these sources will confirm the above findings and will enable the comprehensive calibration of the WFIRST color–redshift relation

Primordial non-Gaussianity: local curvature method and statistical significance of constraints on f_NL from WMAP data

We test the consistency of estimates of the non-linear coupling constant f_{NL} using non-Gaussian CMB maps generated by the method described in (Liguori, Matarrese and Moscardini 2003). This procedure to obtain non-Gaussian maps differs significantly from the method used in previous works on estimation of f_{NL}. Nevertheless, using spherical wavelets, we find results in very good agreement with (Mukherjee and Wang 2004), showing that the two ways of generating primordial non-Gaussian maps give equivalent results. Moreover, we introduce a new method for estimating the non-linear coupling constant from CMB observations by using the local curvature of the temperature fluctuation field. We present both Bayesian credible regions (assuming a flat prior) and proper (frequentist) confidence intervals on f_{NL}, and discuss the relation between the two approaches. The Bayesian approach tends to yield lower error bars than the frequentist approach, suggesting that a careful analysis of the different interpretations is needed. Using this method, we estimate f_{NL}=-10^{+270}_{-260} at the 2\sigma level (Bayesian) and f_{NL}=-10^{+310}_{-270} (frequentist). Moreover, we find that the wavelet and the local curvature approaches, which provide similar error bars, yield approximately uncorrelated estimates of f_{NL} and therefore, as advocated in (Cabella et al. 2004), the estimates may be combined to reduce the error bars. In this way, we obtain f_{NL}=-5\pm 85 and f_{NL}=-5\pm 175 at the 1\sigma and 2\sigma level respectively using the frequentist approach.Comment: Accepted for publication in MNRAS. Improved limits on f_{NL} and covariance matrix derivatio

Planck intermediate results. XII: Diffuse Galactic components in the Gould Belt system

Peer reviewe

Development of a constitutive luciferase reporter line for comparable evaluation of antiplasmodial drugs on all life cycle stages of Plasmodium falciparum

The vision of a malaria-free world is threatened by antimalarial drug resistance. For malaria elimination to be achieved, drug combinations should have dual action: cure infection and block transmission of the Plasmodium parasite between the human host and mosquito vector. Furthermore, such dual action drugs should lower the risk of resistance development and prolong the therapeutic lifespan of antimalarials. New antimalarial drugs need to comply to a set guideline from the Medicines for Malaria Venture with regards to the types of molecules [target candidate profiles (TCP)] and the combination of medicines being developed. Therefore, knowing a compound’s activity towards a specific stage of the parasite, in other words its TCP, is important for drug development. However, due to the parasite’s complex life cycle, each stage of the parasite currently requires a different biochemical platform to assay compounds for activity against that particular life cycle state. This does introduce assay readout variability and complicates standardisation of drug assays. This study, therefore, aimed to generate a constitutive luciferase-expressing P. falciparum line that can be used to develop a single assay platform for all life cycle stages of the parasite. By using gene expression profiling, we identified several constitutively expressed genes throughout the life cycle of P. falciparum. The promoters of these genes were used to generate transgenic lines in which a robust luciferase reporter is strongly expressed under control of these promoters. Two transgenic lines were successfully generated and allowed luciferase expression under control of promoters for histone H3 and nuclear assembly protein (NF54H3 and NF54nap). Whilst NF54H3 could be used to effectively determine antiplasmodial activity for compounds towards the asexual stages, this line was compromised to the extent that it was not able to produce gametocytes. By contrast, NF54nap produced both asexual parasites and gametocytes and was used to evaluate drug activity for both these stages on a single luciferase reporter assay platform. As a result, the line generated here enables a single platform to delineate the TCP of compounds and identify novel compounds that are active against multiple stages or that show selective activity towards a specific stage of the parasite. This data contributes to a novel avenue in antimalarial drug discovery, thereby supporting malaria elimination strategies.Dissertation (MSc (Biotechnology))--University of Pretoria, 2020.BiochemistryMSc (Biotechnology)Unrestricte