Selfevidensie in die natuurwetenskap

Die hoofpunte van Aristoteles se wetenskapsleer kan saamgevat word in die vorm van ’n definisie van „deduktiewe wetenskap”

Laboratory and observational study of the interrelation of the carbonaceous component of interstellar dust and solar system materials

By studying the chemical and isotopic composition of interstellar ice and dust, one gains insight into the composition and chemical evolution of the solid bodies in the solar nebula and the nature of the material subsequently brought into the inner part of the solar system by comets and meteorites. It is now possible to spectroscopically probe the composition of interstellar ice and dust in the mid-infrared, the spectral range which is most diagnostic of fundamental molecular vibrations. We can compare these spectra of various astronomical objects (including the diffuse and dense interstellar medium, comets, and the icy outer planets and their satellites) with the spectra of analogs we produce in the laboratory under conditions which mimic those in these different objects. In this way one can determine the composition and abundances of the major constituents of the various ices and place general constraints on the types of organics coating the grains in the diffuse interstellar medium. In particular we have shown the ices in the dense clouds contain H2O, CH3OH, CO, perhaps some NH3 and H2CO, we well as nitriles and ketones or esters. Furthermore, by studying the photochemistry of these ice analogs in the laboratory, one gains insight into the chemistry which takes place in interstellar/precometary ices. Chemical and spectroscopic studies of photolyzed analogs (including deuterated species) are now underway. The results of some of these studies will be presented and implications for the evolution of the biogenic elements in interstellar dust and comets will be discussed

Clinical findings and genetic screening for copy number variation mutations in a cohort of South African patients with Parkinson’s disease

Background. Parkinson’s disease (PD), with a prevalence of up to 4% in Western countries, appears to be less common in Africa, possibly in part because of genetic factors. African studies investigating the genetic causation of PD are limited.Objective. To describe the clinical and genetic findings in a group of black South African patients with PD.Methods. All black African patients with PD from a tertiary hospital neurology clinic were examined. Symptoms were scored according to the Unified Parkinson’s Disease Rating Scale (UPDRS), and patients were classified according to motor features. Genomic DNA was extracted and multiplex ligation-dependent probe amplification was used for detection of copy number variation (CNV) mutations in the known PD-causing genes.Results. Sixteen patients were identified (ages 56 - 82 years). Three had a family history of PD. Classification into motor subtypes showed 44% mixed, 31% akinetic-rigid, and 25% tremor-dominant subtypes. UPDRS scores ranged from 7 to 88, with dementia in 20%. No patient had G2019S LRRK2 and A30P SNCA mutations, and all except one had no CNV mutations in the known PD-causing genes. A female patient (age of onset 50 years, no family history) had a parkin gene heterozygous deletion of exon 4. She had hyperreflexia, bilateral Hoffmann’s reflexes, normal plantar responses and no dystonia.Conclusion. This group of black African patients showed similar characteristics to patients in Western studies, possibly with a higher proportion having tremor dominant disease. Genetic analysis showed one parkin gene mutation. The limited knowledge on PD-causing genes and mutations in black populations warrants further studies involving next-generation sequencing approaches

Increasing Emotional Intelligence through Training: Current Status and Future Directions

Emotional intelligence consists of adaptive emotional functioning involving inter-related competencies relating to perception, understanding, utilising and managing emotions in the self and others. Researchers in diverse fields have studied emotional intelligence and found the construct to be associated with a variety of intrapersonal and interpersonal factors such as mental health, relationship satisfaction, and work performance. This article reviews research investigating the impact of training in emotional-intelligence skills. The results indicate that it is possible to increase emotional intelligence and that such training has the potential to lead to other positive outcomes. The paper offers suggestions about how future research, from diverse disciplines,can uncover what types of training most effectively increase emotional intelligence and produce related beneficial outcomes

Spontaneous Raman scattering for simultaneous measurements of in-cylinder species

A technique for multi-species mole fraction measurement in internal combustion engines is described. The technique is based on the spontaneous Raman scattering. It can simultaneously provide the mole fractions of several species of N-2, O-2, H2O, CO2 and fuel. Using the system, simultaneous measurement of air/fuel ratio and burnt residual gas are carried out during the mixture process in a Controlled Auto Ignition (CAI) combustion engine. The accuracy and consistency of the measured results were confirmed by the measured air fuel ratio using an exhaust gas analyzer and independently calculated mole fraction values. Measurement of species mole fractions during combustion process has also been demonstrated. It shows that the SRS can provide valuable data on this process in a CAI combustion engine

Safe nights out: Workers’ perspectives on tackling violence against women and girls

Existing research focused on workers within the night-timeeconomy (NTE) is limited. In this unique study, research was conducted with workers from a wide range of professions and occupations. The study garnered important insights into NTE workers’ understanding and experience of violence against women and girls (VAWG). Workers observed a strong relationship between alcohol consumption and VAWG and were knowledgeable about spiking, perceiving this practice to be growing. Strong protocols were in place to support women when spiking was alleged. The understanding of VAWG was, in contrast, broad but inconsistent. NTE workers provide myriad ways to support and protect women who are out at night. However, responses to potential incidents of VAWG are shaped by intuition, rather than being rooted in formal knowledge and institutional protocols. The decision to intervene is usually based on NTE workers’ levels of experience, confidence, and subjective perception of risk – described as ‘going with your gut’. There were, however, some good examples of where formal training had been provided and found to be useful. Specifically,there was evidence that many of the initiatives established as part of the Safer Streets project were making a difference. Respondents valued the training that they had received (such as zero-tolerance), and they recognised the important role that Street Pastors provide. Nevertheless, several training gaps were identified. Specifically, workers reported that they wanted to be better equipped to identify potential perpetrators of crime and would welcome advice on how to enhance personal and customer safety. NTE workers would also benefit from knowing more about the location and value of safe havens. The study showed that while many venues offer support to customers, there is some inconsistency in the way that safety measures are advertised and enacted

Molecular and mass spectroscopic analysis of isotopically labeled organic residues

Experimental studies aimed at understanding the evolution of complex organic molecules on interstellar grains were performed. The photolysis of frozen gas mixtures of various compositions containing H2O, CO, NH3, and CH4 was studied. These species were chosen because of their astrophysical importance as deducted from observational as well as theoretical studies of ice mantles on interstellar grains. These ultraviolet photolyzed ices were warmed up in order to produce refractory organic molecules like the ones formed in molecular clouds when the icy mantles are being irradiated and warmed up either by a nearby stellar source or impulsive heating. The laboratory studies give estimates of the efficiency of production of such organic material under interstellar conditions. It is shown that the gradual carbonization of organic mantles in the diffuse cloud phase leads to higher and higher visual absorptivity - yellow residues become brown in the laboratory. The obtained results can be applied to explaining the organic components of comets and their relevance to the origin of life