Alternative Conceptions about Simple Electric Circuits amongst High School FET Band Learners

Institute for Science and Technology Education (ISTE

Sprouty1 regulates reversible quiescence of a self-renewing adult muscle stem cell pool during regeneration.

Satellite cells are skeletal muscle stem cells capable of self-renewal and differentiation after transplantation, but whether they contribute to endogenous muscle fiber repair has been unclear. The transcription factor Pax7 marks satellite cells and is critical for establishing the adult satellite cell pool. By using a lineage tracing approach, we show that after injury, quiescent adult Pax7(+) cells enter the cell cycle; a subpopulation returns to quiescence to replenish the satellite cell compartment, while others contribute to muscle fiber formation. We demonstrate that Sprouty1 (Spry1), a receptor tyrosine kinase signaling inhibitor, is expressed in quiescent Pax7(+) satellite cells in uninjured muscle, downregulated in proliferating myogenic cells after injury, and reinduced as Pax7(+) cells re-enter quiescence. We show that Spry1 is required for the return to quiescence and homeostasis of the satellite cell pool during repair. Our results therefore define a role for Spry1 in adult muscle stem cell biology and tissue repair

Trichodinids (Ciliophora) of <i>Corydoras paleatus</i> (Siluriformes) and <i>Jenynsia multidentata</i> (Cyprinodontiformes) from Argentina, with description of <i>Trichodina corydori</i> n. sp. and <i>Trichodina jenynsii</i> n. sp

During surveys of parasites of the pepper cory Corydoras paleatus Jenyns, 1842 and sided-livebearer Jenynsia multidentata Jenyns, 1842 from Samborombón River, Argentina, Trichodina corydori n. sp., Trichodina cribbi Dove and O’Donoghue, 2005 and T. jenynsii n. sp. were morphologically studied. Taxonomic and morphometric data for these trichodinids based on dry silver nitrate-impregnated specimens are presented. Trichodina corydori is characterized by a prominent blade apophysis, the section connecting the blade and central part is short, and the adoral ciliary spiral makes a turn of 370-380°. Trichodina jenynsii is characterized by curved blades and prominentlyshaped denticle rays that are characteristically extremely long, tapering to thin sharp points in adult specimens. This study is the first formal report of these trichodinids from South America, and the description of two new species.Centro de Estudios Parasitológicos y de Vectore

Trichodinids (Ciliophora) of <i>Corydoras paleatus</i> (Siluriformes) and <i>Jenynsia multidentata</i> (Cyprinodontiformes) from Argentina, with description of <i>Trichodina corydori</i> n. sp. and <i>Trichodina jenynsii</i> n. sp

During surveys of parasites of the pepper cory Corydoras paleatus Jenyns, 1842 and sided-livebearer Jenynsia multidentata Jenyns, 1842 from Samborombón River, Argentina, Trichodina corydori n. sp., Trichodina cribbi Dove and O’Donoghue, 2005 and T. jenynsii n. sp. were morphologically studied. Taxonomic and morphometric data for these trichodinids based on dry silver nitrate-impregnated specimens are presented. Trichodina corydori is characterized by a prominent blade apophysis, the section connecting the blade and central part is short, and the adoral ciliary spiral makes a turn of 370-380°. Trichodina jenynsii is characterized by curved blades and prominentlyshaped denticle rays that are characteristically extremely long, tapering to thin sharp points in adult specimens. This study is the first formal report of these trichodinids from South America, and the description of two new species.Centro de Estudios Parasitológicos y de Vectore

Trichodinids (Ciliophora) of <i>Corydoras paleatus</i> (Siluriformes) and <i>Jenynsia multidentata</i> (Cyprinodontiformes) from Argentina, with description of <i>Trichodina corydori</i> n. sp. and <i>Trichodina jenynsii</i> n. sp

During surveys of parasites of the pepper cory Corydoras paleatus Jenyns, 1842 and sided-livebearer Jenynsia multidentata Jenyns, 1842 from Samborombón River, Argentina, Trichodina corydori n. sp., Trichodina cribbi Dove and O’Donoghue, 2005 and T. jenynsii n. sp. were morphologically studied. Taxonomic and morphometric data for these trichodinids based on dry silver nitrate-impregnated specimens are presented. Trichodina corydori is characterized by a prominent blade apophysis, the section connecting the blade and central part is short, and the adoral ciliary spiral makes a turn of 370-380°. Trichodina jenynsii is characterized by curved blades and prominentlyshaped denticle rays that are characteristically extremely long, tapering to thin sharp points in adult specimens. This study is the first formal report of these trichodinids from South America, and the description of two new species.Centro de Estudios Parasitológicos y de Vectore

Bydrae van Erich Mayer tot die vestiging van 'n estetiese bewussyn en die bevordering van 'n kunsidentiteit in Suid-Afrika tot aan die einde van die 1930's

Text in AfrikaansThis thesis entitled The contribution of Erich Mayer towards the establishment of an aesthetic consciousness and the promotion of an art identity in South Africa to the end of the 1930s, is a study of the ideas, ideals and contributions of the German-Jewish artist Erich Mayer concerning the establishment of a national art identity in South Africa. Mayer was born in Germany in 1876. Because of ill health he came to South Africa, where he settled in 1898 and developed an affinity with the Afrikaner pioneers in the rural areas. This natural connection with the Afrikaner pioneers was the main motivation behind his participation in the Anglo-Boer War. With his sound European background and training at various art academies in Berlin and Stuttgart, he soon realised that a knowledge of European art history or any awareness of an aesthetic consciousness concerning the fine and applied arts was sadly lacking within the general South African community and more specifically amongst the early Afrikaners. As a student, Mayer developed a keen interest in traditional German arts and crafts, which, according to him, contributed to the specific national Germanic character. This interest prompted him to conduct research and document examples of folk art among the Afrikaners as well as other indigenous communities, in an attempt to establish an aesthetic awareness in South Africans, and more specifically among Afrikaners. Mayer was of the opinion that the development and marketing of these cultural objects and artefacts would contribute towards a unique art identity with a strong South African national character. Apart from his interests in the fine and applied arts, Mayer also researched the vernacular architecture, furniture design and household articles of both Afrikaner pioneers and Africans. He travelled widely in South Africa, researching his interests and presented lectures on these themes which he published in newspapers and magazines in an effort to create an awareness of the rich indigenous folk art.Hierdie proefskrif is 'n studie oor die bydrae van die Duits-Joodse kunstenaar Erich Mayer tot die vestiging van 'n estetiese bewussyn en die bevordering van 'n kunsidentiteit in Suid-Afrika tot aan die einde van die 1930's. Mayer is in 1876 in Duitsland gebore. Weens gesondheidsredes het hy hom in 1898 in Suid-Afrika gevestig waar hy veral met die Boerepioniers op die platteland geidentifiseer het em hom gou tuis gevoel het in die landelike milieu. Hierdie natuurlike toegeneentheid tot die vroee Afrikaners het aanleiding gegee tot sy later deelname aan die Anglo-Boereoorlog. Met sy grondige Europese agtergrond en opleiding aan verskillende kunsakademies in Berlyn en Stuttgart, het Mayer gou besef dat die Suid-Afrikaanse gemeenskap in die algemeen, maar veral die vroee Afrikaners in die besonder, 'n algehele gebrek geopenbaar het aan enige Euopese kunshistoriese kennis of enige estetiese bewussyn oor die beeldende en toegepaste kunste. Mayer is vroeg reeds blootgestel aan en het besonder belanggestel in die kunshandwerk van die Duitsers wat deel uitgemaak het van eeue-oue Duitse tradisies en wat bygedra het tot die unieke nasionale volksaard van die Duitsers. Met hierdie belangstelling het Mayer stelselmatig begin om die unieke kunshandwerk van die Afrikanerpioniers te versamel. Hy het hier 'n geleentheid gesien om via voorbeelde van plaaslike kunshandwerk 'n estetiese bewussyn by die Suid-Afrikaans gemeenskap en meer spesifiek by die Afrikaner aan te wakker. Mayer was van mening dat die sinvolle ontwikkeling en bemarking van hierdie kulturele voorwerpe en ontwerpe daartoe sou kon bydra om 'n eie kunsidentiteit met sterk nasionale karakter in Suid-Afrika tot stand te bring. Wat die beeldende en toegepaste kunste betref, het Mayer 'n wye belangstellingsveld gehad en het hy ook omvattende navorsing oor die inheemse boukuns, meubelontwerpe en kunshandwerkartikels van die vroee Boerepioniers, asook oor die van die inheemse bevolkingsgroepe, onderneem. Hy het die land deurreis op soek na geskikte voorbeelde van kunshandwerkartikels, gereeld lesings aangebied en artikels gepubliseer, die alledaagse Boerelewe op die platteland visueel gedokumenteer en op die manier 'n besondere ryk nalatenskap daargestel.HistoryD. Litt et Phil. (Geskiedenis

The role of early childhood development and education (ECDE) in supporting learning and well-being in rural early childhood and primary schools in South Africa

This paper examines how early childhood and primary schools can be constructed as enabling spaces to improve the learning and well-being of children aged six to nine who live in multidimensionally poor, low-resourced rural communities in South Africa. Quality early childhood development and education (ECDE) can be the catalyst to break the cycle of poverty for many young children in rural areas. A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses flowchart. A comprehensive search strategy using electronic databases and hand searches systematically whittled down an initial database of 30,080 articles to 16 articles for this study. A thematic analysis identified enablers and constraints for supporting children’s learning and well-being across three themes: (1) infrastructure, educational resources and child agency (2) initial teacher education (ITE) and (3) socioeconomic status. The findings and discussion highlight child agency as an enabler to learning and well-being and the structural and pedagogical challenges of implementing ITE curricula specific to rural educational contexts

Electricity supply industry modeling for multiple objectives under demand growth uncertainty

Appropriate energy–environment–economic (E3) modelling provides key information for policy makers in the electricity supply industry (ESI) faced with navigating a sustainable development path. Key challenges include engaging with stakeholder values and preferences, and exploring trade-offs between competing objectives in the face of underlying uncertainty. As a case study we represent the South African ESI using a partial equilibrium E3 modelling approach, and extend the approach to include multiple objectives under selected future uncertainties. This extension is achieved by assigning cost penalties to non-cost attributes to force the model's least-cost objective function to better satisfy non-cost criteria. This paper incorporates aspects of flexibility to demand growth uncertainty into each future expansion alternative by introducing stochastic programming with recourse into the model. Technology lead times are taken into account by the inclusion of a decision node along the time horizon where aspects of real options theory are considered within the planning process. Hedging in the recourse programming is automatically translated from being purely financial, to include the other attributes that the cost penalties represent. From a retrospective analysis of the cost penalties, the correct market signals, can be derived to meet policy goal, with due regard to demand uncertainty

ANALYSIS OF A TWO LACTATION TARGET ANIMAL SAFETY STUDY OF SOMIDOBOVE SUSTAINED RELEASE INJECTION IN MULTIPAROUS DAIRY COWS

An overview is given of the primary basis for the scientific inference that somidobove sustained release injection is safe for multiparous dairy cows. The process of analysis and interpretation of the voluminous data collected from a target animal safety study which started with 28 cows and lasted two lactations is described. This was a repeated measures study with most of 60 variables being measured or summarized every 28 days resulting in approximately 1500 measurements per cow. The statistical analysis was designed to screen the variables for biological change caused by treatment and consisted of a univariate analysis of variance for repeated measures data both within a lactation and across two lactations. Graphs of least squares means with error bounds and p-value plots of ANOVA p-values helped communicate statistical findings. A cross disciplinary approach interpreted analyses and arrived at inferences

Identification of the Anti Listerial

Partially purified fractions of the n-hexane extract of Garcinia kola seeds were obtained through column chromatography and their constituents were identified through the use of gas chromatography coupled to mass spectrometry (GC-MS). Three fractions were obtained by elution with benzene as the mobile phase and silica gel 60 as the stationery phase and these were named Benz1, Benz2, and Benz3 in the order of their elution. The antiListerial activities of these fractions were assessed through MIC determination and only Benz2 and Benz3 were found to be active with MIC’s ranging from 0.625 to 2.5 mg/mL. The results of the GC-MS analysis showed Benz2 to have 9 compounds whilst Benz3 had 7 compounds, with the major compounds in both fractions being 9,19-Cyclolanost-24-en-3-ol, (3.β.) and 9,19-Cyclolanostan-3-ol,24-methylene-, (3.β.). The Benz2 fraction was found to have mainly indifferent interactions with ampicillin and penicillin G whilst mainly additive interactions were observed with ciprofloxacin. The Benz3 fraction’s interactions were found to be 50% synergistic with penicillin G and 25% synergistic with ciprofloxacin and ampicillin. A commercially available 9,19-Cyclolanost-24-en-3-ol, (3.β.) was found not to exhibit any antiListerial activities at maximum test concentrations of 5 mg/mL, suggesting that the compound could be acting in synergy with the other compounds in the eluted fractions of Garcinia kola seeds