I Ceric ammonium nitrate-mediated oxidative cleavages of hemiacetals II Synthesis of beta-proline derivatives through the tandem chain extension-imine capture reaction

A novel ceric ammonium nitrate-mediated oxidative cleavage of hemiacetals generated through the use of the zinc carbenoid-mediated tandem chain extension-aldol reaction was developed. This chemistry has been applied towards the formation of a class of natural products, phaseolinic acids, in two steps from a commercially available beta-keto ester, methyl 4-methoxyacetoacetate. The tandem chain extension-imine capture reaction has also been developed to provide access to beta-proline derivatives. Two activated imines were studied and provided access to different diastereomers, making the chemistry versatile. beta-Keto esters, beta-keto amides, and beta-keto imides were subjected to the tandem chain extension-imine capture reaction conditions and proved to be reasonably successful in most cases. beta-Keto esters were efficient in the synthesis of free --NH beta-proline derivatives in three steps and beta-keto imides were efficient in the synthesis of Boc-protected beta-proline derivatives in just two steps. The zinc carbenoid-mediated chain extension imine capture reaction has developed into a flexible route in obtaining different diastereomers of protected and unprotected beta-proline derivatives in minimal steps from commercially available starting materials

Key generic curriculum factors affecting grade twelve learner performance : a multiple case study of South African secondary schools

Improving Grade 12 learner performance is a critical issue because only a few learners are able to go to university. Grade 8 learners lack the required subject content knowledge to be in secondary school. The aim of this study was to identify key generic curriculum factors affecting Grade 12 learner performance. The aim was addressed by conducting the relevant literature study and an empirical investigation. In various studies, the implementation of the Curriculum and Assessment Policy Statement (CAPS) has been associated with tremendous challenges, including content congestion, workload, too much paperwork, too much assessment and limited time. There are ongoing expressions of uncertainty about the type of learners the CAPS is producing. Many of these learners do not understand English, cannot read or write, do not care about their education, are not doing their homework and are ill-disciplined. Against this backdrop of uncertainty, this study offers a critical reflection of key curriculum factors affecting learners’ performance. This multiple case study was undertaken using semi-structured individual interviews with 12 Heads of Departments, which were conducted to explore their perceptions and experiences regarding the CAPS. Six focus group interviews with teachers were also conducted to provide an in-depth understanding of their views. The findings of the study offer a deeper understanding of the key generic curriculum factors affecting learner performance which require a special intervention at foundation phase to ensure that primary school learners are prepared for Grade 12. It is envisaged that the research findings will assist the Department of Basic Education with decisions relating to improving learners’ performance. The study recommends that involving as many experienced teachers as possible in the curriculum design will have a positive impact on learner performance. It is recommended that the Department of Basic Education should reduce the number of subjects at secondary school level; align time allocated to complete the syllabus with the Annual Teaching Plan; replace School-Based Assessments with tests; conduct an exit examination at the end of every phase; identify one prescribed textbook for each subject; encourage top performing students to become teachers; and make teaching a high-status profession. Experienced teachers should be given an opportunity to design the curriculum because they understand the challenges facing the education system. The Department of Basic Education should minimise changes to the curriculum because the teachers work better with what they know. iv The study concluded that the first 30 minutes of each day should be an English period to enhance reading skills; learners should be given an opportunity to choose subjects from Grade 8 not from Grade 10; the pass rate should be raised to 50% for all the subjects; Life Orientation should be done only up to Grade 7; more Further Education and Training colleges should be opened so that learners can be directed accordingly if they cannot cope in a mainstream school; progression and adjustment of marks should be stopped; more teacher training colleges should be opened; more and better resources at all under-resourced schools must be provided; each school should have a full-time psychologist on staff; and learners should be motivated regularly by educated or successful community members.Dit is noodsaaklik om die prestasie van Graad 12-leerlinge te verbeter aangesien weinig van hulle aan ʼn universiteit verder kan studeer. Graad 8-leerders beskik nie oor die vakkennis wat op hoërskool van hulle verwag word nie. Die oogmerk van hierdie studie was om vas te stel watter betekenisvolle generiese kurrikulumfaktore die prestasie van Graad 12-leerders bepaal. ʼn Literatuurstudie en empiriese ondersoek is met die oog hierop gedoen. Volgens verskeie studies bring die implementering van die Kurrikulum- en Assesseringsbeleidsverklaring (KABV) geweldige uitdagings mee waaronder die vertering van lesinhoud, ʼn groot werklas, te veel papierwerk, te veel assessering en te min tyd. Bedenkinge word gereeld uitgespreek oor die soort leerder wat die KABV tot gevolg het. Talle leerders verstaan nie Engels nie, kan nie lees of skryf nie, is nie oor hulle eie opvoeding besorg nie, doen nie hulle huiswerk nie, en is ongehoorsaam. Hierdie studie besin krities oor die betekenisvolle kurrikulumfaktore wat leerders se prestasie beïnvloed. In hierdie meervoudige gevallestudie is halfgestruktureerde onderhoude met 12 departementshoofde gevoer. Hulle perspepsie en ervaring van die KABV is in die onderhoude verken. Ses fokusgroeponderhoude is met onderwysers gevoer om hulle siening daarvan te verkry. Die bevindings van die studie bied ʼn grondige insig in die betekenisvolle generiese kurrikulumfaktore wat leerderprestasie beïnvloed. Dit vereis ingryping in die grondslagfase om laerskoolleerders vir hoërskool en uiteindelik Graad 12 gereed te kry. Op grond van hierdie bevindings kan die Departement van Basiese Onderwys veranderings aanbring wat die prestasie van leerders kan verbeter. Die studie beveel aan dat soveel ervare onderwysers as moontlik by die kurrikulumontwerp betrek word. Dit sal leerdersprestasie verbeter. Daar word voorts aanbeveel dat die Departement van Basiese Onderwys die aantal hoërskoolvakke verminder; die tydperk waarin die sillabus afgehandel word, met die jaarlikse onderrigplan in ooreenstemming bring; vii skoolassessering met toetse vervang; leerders aan die einde van elke fase ʼn uitgangseksamen laat skryf; een handboek vir elke vak voorskryf; skrander studente aanmoedig om onderwysers te word; en die aansien van die onderwysberoep verhoog. Ervare onderwysers moet aan die opstel van die kurrikulum meewerk omdat hulle die struikelblokke in die onderwysstelsel die beste begryp. Die Departement van Basiese Onderwys moet minder aan die kurrikulum torring aangesien onderwysers beter werk met dinge wat hulle ken. Die slotsom waartoe in hierdie studie gekom word, is dat die eerste 30 minute van elke skooldag ʼn Engelse periode moet wees waarin leerders hulle leesvaardighede verbeter. Leerders moet reeds in Graad 8 vakke kan kies, nie eers in Graad 10 nie. Die slaagpunt moet in alle vakke 50% wees. Lewensoriëntering moet slegs tot Graad 7 aangebied word. Leerders wat nie in ʼn hoofstroomskool die mas opkom nie, moet aan kolleges vir verdere onderwys en opleiding verder kan leer. Punte moenie opgeskuif word nie. Meer onderwyseropleidingskolleges moet geopen word. Skole met beperkte hulpbronne moet van meer en beter hulpmiddels voorsien word. ʼn Voltydse sielkundige moet by elke skool aangestel word, en suksesvolle en opgevoede gemeenskapslede moet leerders gereeld motiveer.Kaonafatšo ya mašomelo a Kreite ya 12 ke ntlha ya bohlokwa ka ge baithuti ba mmalwa ba kgona go ya yunibesithi. Baithuti ba Kreiti ya 8 ba hloka tsebo ya diteng tša thuto yeo e nyakwaga ke baithuti ba dikolo tše di phagamego. Nepo ya thuto ye ke go hlaola dintlhakakaretšo tša kharikhulamo ya go ama mašomelo a moithuti wa Kreite ya 12. Maikemišetšo a a rarollotšwe ka go dira thuto ya dingwalwa le dinyakišišo tša thuto. Ka go dithuto tša go fapana, phethagatšo ya Setatamente sa Pholisi ya Kharikhulamo le Tekolo (CAPS) e amana le mathata a magolo,a go akaretša pitlagano, tšhomišo ye ntši ya pampiri, tekolo ye ntši, le nako ye nnyane. Go na le ditšweletšo tše dintši tša go se kgotsofale ka ga mohuta wa baithuti bao CAPS e ba tšweletšago. Bontši bja baithuti ba ga ba kwešiše Seisemane; ga ba kgone go bala goba go ngwala; ga ba na taba le thuto ya bona; ba ba dire mošomo wa bona wa gae; ga ba na mekgwa ye mebotse. Ke ka lebaka la tšweletšo ye ya go se be le nnete, thuto ye e tšweletša taetšo ya bohlokwa ka ga dintlha tša bohlokwa tša kharikhulamo tšeo di amago mašomelo a baithuti. Thutophatišišo ye e swanetše go dirwa go šomišwa ditherišano tša go hlangwa gannyane le Dihlogo tše 12 tša Dikgoro. Dipoledišano tše tša mošomo di dirilwe go lemoga mmono wa bona le boitemogelo bja CAPS. Dipoledišano le dihlopha tše tshela tša barutiši di dirilwe go hwetša kwešišo ya go tsenelela ya mmono wa bona. Dipoelo tša thuto di fana ka kwešišo ya go tsenelela ya dintlha tša motheo tša kharikhulamo tšeo di amago mašomelo a baithuti le go nyaka thušo ya go ikgetha ka go thuto ya motheo go netefatša go re baithuti ba thuto ya phoraemari a loketše sekolo se se phagamego le Kreite ya 12. Go lebeletšwe gore dipoelo tša diphatišišo di tla thuša Kgoro ya Thuto ya Motheo go dira diphetho tša go tliša kaonafalo ka go mašomelo a baithuti. Thuto e hlohleletša go re ka ge barutiši ba bantši ba maitemogelo ba tšee karolo ka go tlhamo ya kharikhulamo ka ge se se tla ba le seabe sa maleba go mašomelo a baithuti. Go dirwa tšhišinyo ya go re Kgoro ya Thuto ya Motheo e swanetše go fokotša palo ya dithutwana x maemong a sekolo se se phagamego; lekanyetša nako yeo e filwego go phetha dithuto go ya ka leano la go ruta la ngwaga; go tlošwe ditekolo tšeo di dirwago sekolong go dirwe melekwana; go dirwe hlahlobo ya go tšwa mafelelong a sekgao se sengwe le se sengwe; go hlaolwe puku ye tee yeo e kgwethilwego go thuto ye nngwe le ye nngwe; go hlohleletša baithuti bao ba šomago gabotse go re ba be barutiši; le go dira gore barutiši e be mošomo wa maemo a godimo. Barutiši ba maitemogelo ba swanetše go fiwa sebaka sa go hlama kharikhulamo ka gobane ba kwešiša mathata a tshepedišo ya thuto. Kgoro ya thuto ya Motheo e swanetše go fokotša diphetogo ka go kharikhulamo ka gobane barutiši ba šoma gabotse ka tšeo ba di tsebago. Thuto ye e rumile ka go re metsotso ye 30 ya mathomo ya letšatši le lengwe le lelengwe e swanetše go ba thuto ya Seisemane go kgontšha bokgoni bja go bala; baithuti a swanetše go fiwa sebaka sa go kgetha dithuto go tloga ka go Kreite ya 8 e sego ka go Kreite ya 10; kelo ya katlego e swanetše go phagamišwa go ya go diperesente tše 50 go dithuto ka moka; Life Orientation e swanetše go rutwa fela go fihla go Kreiti ya 7; go swanetše go bulwe dikholetšhe tša tlaleletšo tša thuto le tlhahlo go baithuti bao ba sa kgonego go kgotlelela go sekolo sa setlwaedi; tšwelopele le tlaleletšo ya meputso e swanetše go emišwa; go swanetše go bulwe dikholetšhe tše dingwe tša barutiši; methopo ye mentši ya kaone go dikolo ka moka tšeo di se nago methopo ya go lekana e swanetš go fiwa; sekolo se sengwe le se sengwe se swanetše go ba le rasaekholotši wa sa ruri gare ga bašomi; le baithuti ba swanetše go hlohleletšwa kgafetšakgafetša ke maloko a setšhaba ao a rutegilego goba go atlega.Curriculum and Instructional StudiesPh. D. (Education (Curriculum Studies)

The challenges of implementing the Curriculum and Assessment Policy Statement in accounting

South African schools have experienced several curriculum changes over the past few years. In this article we report on the findings regarding the challenges experienced by heads of department (HODs) with the implementation of the Curriculum and Assessment Policy Statement (CAPS) in accounting. A qualitative approach, modelled on the interpretative perspective, was used to explore these challenges, namely: medium of instruction; time allocated to complete the syllabus; poor subject content foundation; progression of learners; and the integration of economic and  management sciences (EMS). Open-ended individual interviews with 12 HODs were used as a data-collection technique. The findings indicate that  the time allocated in the annual teaching plan (ATP) for accounting may have a negative impact on effective teaching and learning and learner  performance. It has also been noted that EMS teachers are not sufficiently competent to teach financial literacy, which may affect learners’ subject  choices prior to Grade 10. Grade 8 and 9 learners lack exposure to accounting due to subject integration and learner progression. Furthermore,  accounting textbooks do not prepare learners for school-based assessments (SBAs) or examinations. Recommendations include that subject choice  should occur in Grade 8, rather than Grade 10, and that a secondary school improvement programme (SSIP) should start from Grade 10, and not  Grade 12

Dysregulation of microtubule stability impairs morphofunctional connectivity in primary neuronal networks

Functionally related neurons assemble into connected networks that process and transmit electrochemical information. To do this in a coordinated manner, the number and strength of synaptic connections is tightly regulated. Synapse function relies on the microtubule (MT) cytoskeleton, the dynamics of which are in turn controlled by a plethora of MT-associated proteins, including the MT-stabilizing protein Tau. Although mutations in the Tau-encodingMAPT gene underlie a set of neurodegenerative disorders, termed tauopathies, the exact contribution of MT dynamics and the perturbation thereof to neuronal network connectivity has not yet been scrutinized. Therefore, we investigated the impact of targeted perturbations of MT stability on morphological (e.g., neurite- and synapse density) and functional (e.g., synchronous calcium bursting) correlates of connectivity in networks of primary hippocampal neurons. We found that treatment with MT-stabilizing or -destabilizing compounds impaired morphofunctional connectivity in a reversible manner. We also discovered that overexpression of MAPT induced significant connectivity defects, which were accompanied by alterations in MT dynamics and increased resistance to pharmacological MT depolymerization. Overexpression of a MAPT variant harboring the P301L point mutation in the MT-binding domain did far less, directly linking neuronal connectivity with Tau's MT binding affinity. Our results show that MT stability is a vulnerable node in tauopathies and that its precise pharmacological tuning may positively affect neuronal network connectivity. However, a critical balance in MT turnover causes it to be a difficult therapeutic target with a narrow operating window