Abstract The widespread use of HMDE for multi-ionic analysis is mainly explained by the following factors: excellent reproducibility, due to the electrode surface ease of renewal, for preventing hysteresis; wide Ec; ability to forming amalgams with many redox-active metal ions; and (sub)nanomolar detection limits, which have unique capabilities for multi-metal determination. In this research, selectivity and sensitivity for Pb, Cd and Zn simultaneous determination, by DPAdSV, using HMDE as WE and CCA as a ligand, were tested. This method is based on the deposition of CCA-metals on Hg electrodes. The instrumental and chemical parameters that could improve measurements were obtained under optimal conditions, including: CCA concentration (0.05 mmol/L), pH (7), Edep (-0.3 V) tdep (60 s), AB concentration (0.5 mol/L), scan rate (150 mV/s), pulse height (80 mV), Hg drop size (4 mm2) and linearity (Ip vs concentration), which was in the range from 5 to 170, 5 to 140 and 5 to 190 M, for Pb, Cd and Zn, respectively). The LOD (S/N = 3) values were 0.05, 0.03 and 0.05 µg/L for Pb, Cd and Zn, respectively. The repeatability and intermediate precisions were tested as RSD of 0.44, 1.21 and 1.23% for Pb, Cd and Zn, respectively. The recovery values were 98, 99 and 101% for Pb, Cd and Zn, respectively. As result, the DPAdSV method with CCA ligands was successfully applied for heavy metals determination in the seawater of a former bauxite mining area.

Higher education institutions recognize the importance of committing, assimilating, and applying education for sustainable development (ESD) into their curriculum to realize the Sustainable Development Goals. The intention of such a commitment assists in creating a culture of students who are actively engaged. Committed to the notion of teaching and teacher education for social change, in this article, I discuss my conceptualization of service-learning through my experience in higher education. Service-learning has been defined as a mode of "experiential education that integrates meaningful community service into the curriculum" (Nives 2015, 1). My perception is that by adopting service-learning for pre-service commerce teachers, there will be a shift in how social justice issues (Frederick, Cave, and Perencevich 2010) can be infused as a meaningful community service approach within the curriculum. In undertaking such steps, I highlight the nuances of power in these programs in this article. Service-learning is adopted through constructive and cooperative strategies to address the engagement questions that underpin the modules. In the academic and method module, these approaches allow pre-service students to be aware and reflect on their prior encounters and experiences of social justice issues, such as poverty, to mention but one. Drawing on both Dewey and Gwele, this article highlights the lecturer's experience of assisting students to deliberate service-learning and participate as democratic citizens. In this article, I unpack my notions of service-learning as a subjective experience of the processes and product of service-learning as a didactic approach. This article introduces a platform to re-think and reconnoitre service-learning in higher education through this complex story. The discussion and recommendations of engineering and reengineering the concept, process, and urgency of incorporating service-learning in Higher Education curricula are discussed, and recommendations for future research are made.

Abstract The aim of this study was to analyze the similarities between the Karawang local superior varieties and several national superior varieties based on chromosome analysis or allele size. Analysis were carried out in the laboratory of the Biogen Research Institute in 2021. There were 9 genotypes analyzed, consisting of 8 national superior varieties, namely NS Karawang, Argomulyo, Grobogan, Anjasmoro, Devon-1, Detap-1, Dena-1 and Dena-2 and 1 Karawang local soybean genotypes. The results of the analysis show that Karawang local soybean has a difference with the national superior variety. The similarity of local soybeans from Karawang to NS Karawang with varieties Agromulyo and Grobogan is 68%, with soybean varieties Anjasmoro and Devon-1 is 71%, while with soybeans Detap-1, Dena-1 and Dena-2 is 76%.

Resumo O objetivo deste estudo foi analisar as semelhanças entre as variedades superiores locais de Karawang e diversas variedades superiores nacionais, com base na análise cromossômica ou no tamanho do alelo. As análises foram realizadas no laboratório do Biogen Research Institute em 2021. Foram analisados 9 genótipos, constituídos por 8 variedades superiores nacionais, nomeadamente NS Karawang, Argomulyo, Grobogan, Anjasmoro, Devon-1, Detap-1, Dena-1 e Genótipos locais de soja Dena-2 e 1 Karawang. Os resultados da análise mostram que a soja local Karawang apresenta uma diferença em relação à variedade superior nacional. A similaridade da soja local de Karawang a NS Karawang com as variedades Agromulyo e Grobogan é de 68%, com as variedades de soja Anjasmoro e Devon-1 é de 71%, enquanto com a soja Detap-1, Dena-1 e Dena-2 é de 76%.

In South Africa, the school textbook remains a powerful source of content knowledge to both teachers and learners. Such knowledge is often engaged uncritically by textbook users. As such, the worldviews and value systems in the knowledge selected for consumption remain embedded and are likely to do powerful ideological work. In this article, we present an account of the ideological orientations of knowledge in a corpus of school economics textbooks. We engage the tenets of critical discourse analysis to examine the representations of the construct "poverty" as a taught topic in the Further Education and Training Economics curriculum. Using Thompson's legitimation as a strategy and form-function analysis as specific analytical tools, we unearth the subtext of curriculum content in a selection of Grade 12 Economics textbooks. The study reveals how power and domination are normalised through a strategy of economic legitimation, thereby offering a "legitimate" rationale for the existence of poverty in the world. The article concludes with implications for curriculum and a humanising pedagogy, and a call for embracing critical knowledge on poverty in the South African curriculum.

BACKGROUND: The impacts of disturbance history on the floristics of Northern Coastal Forest (NCF; South Africa) are unknown. OBJECTIVES: This study compared the floristics of three remnant patches of NCF (in KwaZulu-Natal) with contrasting disturbance histories: a primary forest with low levels of disturbance (Hawaan), a primary forest with high levels of disturbance (Umdoni) and a secondary forest (Twinstreams) that was rehabilitated with presently low disturbance levels. METHOD: Transects and quadrats were used to assess species composition and diversity at each site. RESULTS: Collectively, 688 species, 400 genera and 113 families were found, but only 21.95% of the species were shared by the three forests. The most speciose families were Fabaceae > Asteraceae > Rubiaceae. The species richness was highest at the disturbed primary forest and notably lower at the primary forest. Diversity indices exhibited a similar trend. Cluster analyses and ordinations indicated that the secondary forest was intermediate between the two primary forests, with the disturbed primary forest and secondary forest being more similar. CONCLUSION: The disturbed and secondary forests maintained a NCF floristic affinity. The dissimilarity between Hawaan and other forests is most likely the product of differing disturbance histories and rehabilitation efforts. The findings suggested that NCF patches are likely to be different in richness, but not in structure and affinity. Anthropogenic related pressures and disturbance appear to be major causes of floristic differences amongst patches. This leads to higher levels of richness by accommodating opportunistic, atypical and alien species, and possibly the creation of novel NCF types.

BACKGROUND: Tropical and subtropical Africa is predicted to experience a rise in temperature. The effects of rising temperatures on temperate grasslands have been studied using open-top chambers (OTCs) but reports for tropical/subtropical grasslands are scarce. This study used OTCs to investigate the effects of elevated temperatures on a threatened subtropical grassland type, namely KwaZulu-Natal Sandstone Sourveld (KZNSS). OBJECTIVES: To assess the effects of OTCs on selected abiotic parameters and plant productivity within KZNSS. METHODS: Five OTC and control plots were randomly distributed at the same altitude within a patch of KZNSS. Air and soil temperature, relative humidity (RH), soil moisture content and light intensity were monitored in all plots in spring, summer, autumn and winter. Biomass production and plant density were measured in each season, for each life form (graminoid, forb and shrub), separately and combined RESULTS: The OTCs resulted in a rise in average, maximum and minimum day and night, air and soil temperatures. This increase, the degree of which differed across seasons, was accompanied by a decline in RH and soil moisture content. Elevated temperatures led to a significant increase in combined, graminoid and shrub above-ground productivity (AGP) and a decrease in forb density, but in certain seasons only. Below-ground biomass production was unaffected by elevated temperatures. CONCLUSIONS: OTCs can simulate realistic increases of air temperature in subtropical grasslands. Graminoids and shrubs appear to benefit from elevated temperatures whilst forbs decrease in abundance, possibly through competition and/or direct physiological effects.

BACKGROUND: KwaZulu-Natal Sandstone Sourveld (KZNSS) is an endangered subtropical grassland type, of which a large proportion occurs within the eThekwini Municipal Area (EMA). OBJECTIVES: Examining the flora of KZNSS will allow a more fundamental understanding of the potential variability across remnant patches of this vegetation type, increasing the ability to accurately delimit KZNSS from adjacent similar vegetation types. METHOD: Floristic data were collected using quadrats and transects for three recognised KZNSS sites (Giba Gorge Environmental Precinct (GGEP), Inanda Mountain (IM) and Springside Nature Reserve (SSNR)), all within the EMA. Alpha diversity (Shannon's exponential and Simpson's inverse indices) and beta diversity measures were calculated and compared across all sites. An unweighted pair group method with arithmetic mean (UPGMA) analysis using the Jaccard index and a non-parametric multidimensional scaling (NMDS) ordination were used to assess similarity amongst quadrats across the three sites. RESULTS: One hundred and thirty-one plant species were found to occur in GGEP, 95 in IM and 121 in SSNR. However, of the total 193 species found to occur collectively (i.e. quadrat and transect data combined) across the three sites, only 50 species were common to all these sites. The results of the alpha and beta diversity analyses revealed significant floristic variability both within and across the KZNSS sites sampled, with Shannon's exponential index being highest in SSNR, followed by GGEP and lowest in IM. The lack of controlled access and unregulated burning regimes appear to have clearly affected the flora at the IM site in terms of species richness and increased evenness, as well as the relatively greater presence of introduced alien species and lower abundances of taxa of conservation concern. The pristine GGEP site had the highest number of species in total, with species being less evenly spread across the site, as well as the highest number of taxa conservation and low abundances of alien species. The main separations in the ordination results can be attributed to quadrat sampling performed pre- and post-burn. CONCLUSION: The floristic distinction of IM from GGEP and SSNR is attributed here to the intermediate disturbance effect of fire in grasslands which can lead to species loss if burning is too frequent. The implications of these findings are discussed in the context of the delimitation, classification and management of KZNSS.

A multidisciplinary approach to teacher education involves drawing from multiple pedagogies within disciplines, in particular the use of aesthetic methods of teaching, to redefine teaching through continuous reflection. This article reports on the process of pre-service students' interpretation of the sensory contemplation of aesthetic perceptiveness within their academic programmes at a higher education institution and explores how students internalised and applied these aesthetic qualities in their practice. Using a qualitative approach, the findings indicate the positive influence of aesthetically enjoyable and engaging teaching strategies, such as group or whole class discussions that infused technology, on pre-service students' understanding of content knowledge taught in lectures. Reports regarding pre-service students' application of these very strategies at schools during their school experience were positive in terms of their ability to reflect critically before, during and after the lesson, made possible by personal first-hand experiences with the selected strategy. It was found that pre-service teachers believe that for effective teaching to take place, as practitioners, they need to take 'full account of the multi-dimensional cultural world of the learner' and therefore it is recommended that they adopt a multi-dimensional approach that is inclusive of aesthetics in their practice.

Recent literature suggests that art and aesthetics are evident in ancient times, as well as in Islamic, Indian, Chinese, African and Western medieval traditions. However, literature on the incorporation of art and aesthetics into economic and management sciences and social sciences is not so readily available. Using a narrative exploratory study, this article reported on two lecturers' interpretation of the sensory contemplation or appreciation of aesthetic judgement within their academic programmes at a higher education institution. Stimulating creativity, passion and imagination is just part of an array of characteristics that prospective educators will need to develop in their teaching. Research has indicated that to become a reflective practitioner, educators should be able to assess and explore the success of their practices. It is this freedom to imagine, assess, explore and reflect continuously on new ways of doing things that leads ultimately to practical application. Teaching aesthetically also requires a strong grounding in pedagogical content knowledge, thereby allowing students to become transformers of society. The main thrust of this article was to determine how we develop and embody these qualities in ourselves and in the modules we teach. The results of the study indicated that whilst early socialisation processes did impact on how aesthetics was incorporated for one participant, culture did not play a very significant role for the other. The findings also indicated that students have a real appreciation of the incorporation of the aesthetic domain within the disciplines.

Die jongste literatuur toon dat kuns en estetika in antieke, Islamitiese, Indiese, Chinese, Afrika en Westerse Middeleeuse tradisies voorgekom het. Inligting oor die inkorporering van kuns en estetika in sosiale wetenskappe en ekonomiese en bestuurswetenskappe is egter nie so geredelik beskikbaar nie. Hierdie artikel doen verslag oor twee dosente se vertolking van die sensoriese beskouing of waardering van estetiese oordeel in die akademiese programme aan 'n hoëronderwysinstelling deur middel van 'n narratiewe, verkennende studie. Om kreatiwiteit, passie en verbeelding te stimuleer, is maar 'n paar van 'n reeks eienskappe wat voornemende opvoeders in hul onderrig moet ontwikkel. Navorsing het getoon dat om 'n nadenkende praktisyn te word, moet opvoeders in staat wees om die sukses van hul praktyke te assesseer en ondersoek. Dit is hierdie vryheid om voortdurend nuwe maniere om dinge te doen te bedink, assesseer, verken en daaroor na te dink wat uiteindelik tot die praktiese toepassing lei. Om esteties te onderrig, vereis ook grondige kennis van die pedagogiese inhoud ten einde studente in staat te stel om transformeerders van die samelewing te word. Die hoofdoel van hierdie artikel is om te bepaal hoe ons hierdie eienskappe kan ontwikkel en in onsself en die modules wat ons onderrig, kan vergestalt. Die bevindings van die studie dui daarop dat hoewel sosialiseringsprosesse 'n invloed het op hoe estetika vir een deelnemer geïnkorporeer is, kultuur nie 'n beduidende rol vir die ander gespeel het nie. Die bevindings dui ook aan dat studente opregte waardering het vir die inkorporering van die estetiese domein in die verskillende dissiplines.