Sense of humour and adolescents’ cognitive flexibility

Objective: There is a lack of research on humour among adolescents in South Africa. This article examines cognitive flexibility and humour. The objective was to investigate the roles of gender and language as possible moderating variables in the relationship between adolescents’ cognitive flexibility and sense of humour. Design: A correlational research design was used in which pupils were asked to complete the Multidimensional Sense of Humor Scale to assess their sense of humour. In order to determine the cognitive flexibility of the sample group, Martin and Rubin’s Cognitive Flexibility Scale was applied. Setting and subjects: The initial sample comprised 1 203 adolescents (Grade 11 and 12 pupils) randomly selected from the Eastern Cape, Gauteng and Mpumalanga. Of these, a final 392 adolescents qualified after eliminating criteria had been applied.Results: No significant correlations were found between the total group or for the two genders. Significant positive correlations were found between cognitive flexibility and two of the scores for humour (creating and expressing humour), as well as for the total score for Afrikaans-speaking participants. Significant negative correlations were found between cognitive flexibility and all five of the scores for humour for the Nguni language speakers. Conclusion: This study recommends that culturally sensitive measuring instruments should be developed.Keywords: sense of humour, cognitive flexibility, adolescents, psychological well-being, language, gende

Paleomagnetism of a lateritic paleoweathering horizon and overlying Paleoproterozoic red beds from South Africa: Implications for the Kaapvaal apparent polar wander path and a confirmation of atmospheric oxygen enrichment

The Olifantshoek Group in southern Africa contains Paleoproterozoic red beds that are exceptionally well preserved, lying unconformably atop a regionally extensive lateritic paleoweathering profile. We studied the basal unit of this succession, known as the Gamagara or Mapedi Formation, and the lateritized substrate (so-called “Drakenstein” or “Wolhaarkop” paleosol) on which it developed. Two ancient magnetic components are observed. One (INT), usually with a distributed unblocking spectrum between 300° and 600°C but occasionally persisting to >675°C, is directed shallowly southward or northward. A mesoscale fold test at South Sishen Mine indicates that this component was acquired during deformation; similarity of the direction to previous results suggests that it was acquired at ∼1240 Ma, during early Namaqua orogenesis. Combining our INT results with existing data from the Namaqua eastern zone (NEZ), we calculate the NEZ pole at (44.9°N, 021.5°E, K = 23.2, A_95 = 12.8°, Q = 5). The most stable component from our data set (HIG), always persisting as a nonzero endpoint to demagnetization at >665°–680°C, is observed in 32 samples from South Sishen and Beeshoek Mines. Directed moderately east-downward (Sishen) or west-upward (Beeshoek), this component predates the mesoscale fold at Sishen. More importantly, a conglomerate test at Beeshoek indicates that HIG was acquired prior to Paleoproterozoic deposition of the Gamagara/Mapedi Formation. The concordance between directions from the paleoweathering zone and immediately overlying red beds indicates that HIG is a primary magnetic remanence for the basal Gamagara/Mapedi (BGM) Formation. The dual-polarity BGM paleomagnetic pole (02.2°N, 081.9°E, dp = 7.2°, dm = 11.5°, Q = 6) lies neatly between previous Kaapvaal poles with ages of ∼2220 (Ongeluk lavas) and 2060 Ma (Bushveld complex). Our data thus support recent correlations of the Gamagara/Mapedi Formation with pre-Bushveld sediments of the Pretoria Group. A pre-Bushveld age for BGM is also consistent with its substantial distance from a new, albeit less reliable, paleomagnetic pole from the ∼1930-Ma Hartley lavas, higher within the Olifantshoek succession (12.5°N, 332.8°E, K = 18.6, A95 = 16.0°, Q = 3). Our conglomerate test at Beeshoek confirms previous allegations that the intense hematitization observed in the Drakenstein-Wolhaarkop paleosol occurred during Paleoproterozoic weathering under a highly oxygenated atmosphere

Job satisfaction amongst teachers at special needs schools

The aim of this study was to establish the level of job satisfaction amongst teachers at special schools. Teachers in special schools need to cope with curriculum changes, the administrative duties that come with these changes, and the learners with their diverse needs. Learners with special needs require a specific educational programme and also schools that cater for the needs of learners with emotional, social, neurological or physical problems. The research group consisted of 101 teachers working at six different special schools situated in various parts of the Bloemfontein area, two in the Mangaung area, and four were situated in suburban areas. The group consisted of English- and Afrikaans-speaking teachers of both genders and from different race groups. The data for this study were compiled by means of a short biographical questionnaire and the Minnesota Satisfaction Questionnaire. The results indicated that the teachers experienced an average level of job satisfaction. In addition to this finding, differences were also found in the levels of job satisfaction between different races, but not between genders.Keywords: job satisfaction; Minnesota Satisfaction Questionnaire; South African education; special school

Lime pretreatment of sugar beet pulp and evaluation of synergy between ArfA, ManA and XynA from Clostridium cellulovorans on the pretreated substrate

Sugar beet pulp (SBP) is a waste product from the sugar beet industry and could be used as a potential biomass feedstock for second generation biofuel technology. Pretreatment of SBP with ‘slake lime’ (calcium hydroxide) was investigated using a 23 factorial design and the factors examined included lime loading, temperature and time. The pretreatment was evaluated for its ability to enhance enzymatic degradation using a combination of three hemicellulases, namely ArfA (an arabinofuranosidase), ManA (an endo-mannanase) and XynA (an endo-xylanase) from C. cellulovorans to determine the conditions under which optimal activity was facilitated. Optimal pretreatment conditions were found to be 0.4 g lime/g SBP, with 36 h digestion at 40 °C. The synergistic interactions between ArfA, ManA and XynA from C. cellulovorans were subsequently investigated on the pretreated SBP. The highest degree of synergy was observed at a protein ratio of 75% ArfA to 25% ManA, with a specific activity of 2.9 U/g protein. However, the highest activity was observed at 4.2 U/g protein at 100% ArfA. This study demonstrated that lime treatment enhanced enzymatic hydrolysis of SBP. The ArfA was the most effective hemicellulase for release of sugars from pretreated SBP, but the synergy with the ManA indicated that low levels of mannan in SBP were probably masking the access of the ArfA to its substrate. XynA displayed no synergy with the other two hemicellulases, indicating that the xylan in the SBP was not hampering the access of ArfA or ManA to their substrates and was not closely associated with the mannan and arabinan in the SBP

Synergy between EngE, XynA and ManA from Clostridium cellulovorans on corn stalk, grass and pineapple pulp substrates

The synergistic interaction between various hemi/cellulolytic enzymes has become more important in order to achieve effective and optimal degradation of complex lignocellulose substrates for biofuel production. This study investigated the synergistic effect of three enzymes endoglucanase (EngE), mannanase (ManA) and xylanase (XynA) on the degradation of corn stalk, grass, and pineapple fruit pulp and determined the optimal degree of synergy between combinations of these enzymes. It was established that EngE was essential for degradation of all of the substrates, while the hemicellulases were able to contribute in a synergistic fashion to increase the activity on these substrates. Maximum specific activity and degree of synergy on the corn stalk and grass was found with EngE:XynA in a ratio of 75:25%, with a specific activity of 41.1 U/mg protein and a degree of synergy of 6.3 for corn stalk, and 44.1 U/mg protein and 3.4 for grass, respectively. The pineapple fruit pulp was optimally digested using a ManA:EngE combination in a 50:50% ratio; the specific activity and degree of synergy achieved were 52.4 U/mg protein and 2.7, respectively. This study highlights the importance of hemicellulases for the synergistic degradation of complex lignocellulose. The inclusion of a mannanase in an enzyme consortium for biomass degradation should be examined further as this study suggests that it may play an important, although mostly overlooked, role in the synergistic saccharification of lignocellulose

Identification of Antimycobacterial Natural Products from a Library of Marine Invertebrate Extracts

Tuberculosis (TB) remains a public health crisis, requiring the urgent identification of new anti-mycobacterial drugs. We screened several organic and aqueous marine invertebrate extracts for their in vitro inhibitory activity against the causative organism, Mycobacterium tuberculosis. Here, we report the results obtained for 54 marine invertebrate extracts. The chemical components of two of the extracts were dereplicated, using 1H NMR and HR-LCMS with GNPS molecular networking, and these extracts were further subjected to an activity-guided isolation process to purify the bioactive components. Hyrtios reticulatus yielded heteronemin 1 and Jaspis splendens was found to produce the bengamide class of compounds, of which bengamides P 2 and Q 3 were isolated, while a new derivative, bengamide S 5, was putatively identified and its structure predicted, based on the similarity of its MS/MS fragmentation pattern to those of other bengamides. The isolated bioactive metabolites and semi-pure fractions exhibited M. tuberculosis growth inhibitory activity, in the rang

Comparing outcomes between enhanced recovery after surgery and traditional protocols in total knee arthroplasty : a retrospective cohort study

BACKGROUND : Knee replacement surgery was traditionally associated with prolonged recovery and rehabilitation programmes in hospital. Enhanced recovery after surgery (ERAS) protocols have been shown to be cost effective while not compromising patient safety or functional outcome. Despite this proven efficacy, ERAS has not been widely adopted in South African orthopaedic practices. The aim of this study is to determine if it is possible to practise these guidelines in South Africa so as to decrease the length of stay (LOS) without an increase in complication rate or compromise in functional outcome. METHODS : Included in the study were 119 patients undergoing elective total knee arthroplasty between 2013 and 2017. They were divided into two cohorts. The first group was treated with a traditional protocol and included 59 patients. The second group was treated with ERAS and included 60 patients, following implementation of the ERAS protocol in 2015. The functional outcome was assessed using the Oxford Knee Score (OKS). The 30-day readmission rate was used to assess safety of early discharge. LOS and patient demographics were also collected to compare the cohorts. RESULTS : There was no clinically significant difference between the cohorts with regards to OKS or readmission rate. Two sample t-tests were used to compare these parameters. The mean OKS for the traditional group was 59.1 (SD 2.4), and for the ERAS group, 58.7 (SD 5.0) (p = 0.73). The readmission rate was 8.5% in the traditional group and 10% in the ERAS group (p = 1.00). The LOS was significantly decreased in the ERAS group, with a mean of 2.3 days (SD 1.8) compared to 5.0 (SD 2.2) in the traditional group (p < 0.001). CONCLUSION : ERAS protocols used in the South African context in elective total knee arthroplasty significantly decrease the LOS without compromising patient safety or functional outcome.http://journal.saoa.org.zadm2022Orthopaedic Surger

A novel approach for engineering efficient nanofluids by radiolysis

This contribution reports for the first time the possibility of using radiolysis to engineer stable efficient nanofluids which exhibit an enhanced thermal conductivity. The validation was confirmed on Ag-H2O and Ag-C2H6O2 nanofluids fabricated via g-radiolysis within the mild dose range of 0.95 × 103–2.45 × 103 Gray. The enhanced thermal conductivity of Ag-H2O and Ag-C2H6O2 nanofluids, was found to be g-radiations dose dependent. In the latter case of Ag-C2H6O2 nanofluid, the relative enhancement in the temperature range of 25–50 °C was found to be 8.89%, 11.54%, 18.69%, 23.57% and 18.45% for D1 = 0.95 × 103 Gray, D2 = 1.2 × 103 Gray, D3 = 1.54 × 103 Gray, D4 = 1.80 × 103 Gray and D5 = 2.45 × 103 Gray respectively. Yet not optimized, an enhancement of the effective thermal conductivity as much as 23.57% relatively to pure C2H6O2 was observed in stable Ag-C2H6O2 nanofluids. Equivalent results were obtained with Ag-H2O

Assessment of potential anti-cancer stem cell activity of marine algal compounds using an in vitro mammosphere assay:

The cancer stem cell (CSC) theory proposes that tumours arise from and are sustained by a subpopulation of cells with both cancer and stem cell properties. One of the key hallmarks of CSCs is the ability to grow anchorage-independently under serum-free culture conditions resulting in the formation of tumourspheres. It has further been reported that these cells are resistant to traditional chemotherapeutic agents