Animal organ dissections in high schools : is there more than just cutting?

In Life Sciences education internationally, including South Africa, the study of animal and organ morphology has traditionally involved dissections since the early nineteenth century. The major purpose of this study was to investigate how the engagement of learners with animal organ dissections may influence the development of problem-solving skills and how teachers use animal dissections to develop these skills of Grade 11 learners in Life Sciences (Biology) education. A mixed-methods research design was used for this study. Data were collected from a pre-test and a post-test (which had predominantly problem-solving questions), a learner questionnaire, lesson observations and teacher interviews. Tests and questionnaires were administered to 224 Grade 11 Life Sciences learners. Six Grade 11 Life Sciences teachers at four high schools from different environments participated in the study. The pre-test and post-test scores were compared using a parametric matched t-test. The comparison for the five cognitive levels including rote learning and problem-solving as well as the total calculation were all highly significant with p-values <0.0001. The learners’ responses in the questionnaire and the teachers’ responses during the interviews indicate their acknowledgement that animal organ dissection may be used to develop problem-solving skills. The results show that there is more to animal organ dissection than just cutting and drawing; it may be used as a problem-solving teaching strategy. The level of learner engagement with animal organ dissections can determine the level of development of problem-solving skills. This study recommends that teachers should be encouraged to link animal organ dissections to specific anatomical and physiological problems where applicable, and to allow learners to solve these problems when performing the dissections; they should not merely let the learners cut, draw and label the organ.http://www.tandfonline.com/loi/rmse202016-06-03am201

Isolation and identification of a South African lentivirus from jaagsiekte lungs

In the course of attempts to grow the jaagsiekte retrovirus in cell culture, a typical lentivirus was isolated for the first time in South Africa from adenomatous lungs. Morphologically the virus could not be distinguished from other lentiviruses, but serologically it was shown to be more closely related to visna virus than to caprine arthritis-encephalitis virus. However, a preliminary restriction enzyme analysis of the linear proviral DNA of this new lentivirus (SA-DMVV) revealed that it is significantly district from visna virus and CAEV and therefore may represent a third type of lentivirus. Antibodies to the virus were demonstrated in a number of sheep in various parts of the country, but a direct link to a disease condition was not found. Attempts to produce lung lesions by intratracheal injection of the virus have been unsuccessful to date but a transient arthritis was produced by intra-articular inoculation. Viral replication seems to be enhanced in jaagsiekte lungs.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Prospective biology teachers' attitudes toward animal dissection : implications and recommendations for the teaching of biology

A sample of 242 prospective biology teachers at a South African university responded to a questionnaire on animal dissection in a science-related context. The students were required to answer questions relating to their experiences and attitudes toward animal dissection. The influence of gender, culture, and religion on their attitudes is discussed. The implications of the findings for teaching biological science are considered and a number of recommendations are made in regard to animal dissection in the biology classroom

Nucleotide sequence of human papillomavirus (HPV) type 41: an unusual HPV type without a typical E2 binding site consensus sequence.

The complete nucleotide sequence of human papillomavirus type 41 (HPV-41) has been determined. HPV-41 was originally isolated from a facial wart, but its DNA has subsequently been detected in some skin carcinomas and premalignant keratoses (Grimmel et al., Int. J. Cancer, 1988, 41, 5-9; de Villiers, Grimmel and Neumann, unpublished results). The analysis of the cloned HPV-41 nucleic acid reveals that its genome organisation is characteristic as for other papillomavirus types. Yet, the analysis indicates at the same time that this virus is most distantly related to all other types of human-pathogenic papillomaviruses sequenced thus far and appears to identify HPV-41 as the first member of a new subgroup of HPV. The overall nucleotide homology to other sequenced HPV types is below 50%. The closest other HPV type is represented by HPV-18, sharing 49% identical nucleotides. The typical E2 binding sequence ACCN6GGT, found in all papillomaviruses analyzed to date, does not occur in the URR of the HPV-41 genome. Modified E2 binding sequences, as described for BPV 1 (Li et al., Genes Dev. 1989, 3, 510-526), are located in the domain proximal to the E6 ORF. These are ACCN6GTT, AACN6GGT and the two perfect palindromic sequences AACGAATTCGTT

Klinisch-biomedizinische Forschung an ausseruniversitaeteren Einrichtungen. Teilvorhaben: Die Rolle von Virus-Infektionen und molekular genetische Veraenderungen von Harnblasentumoren Abschlussbericht

SIGLEAvailable from TIB Hannover: DtF QN1(62,59) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Phylogenetic relationships, character evolution and biogeography of southern African members of Zygophyllum (Zygophyllaceae) based on three plastid regions

The plastid coding rbcL and non-coding trnLF regions of 53 of 55 southern African Zygophyllum species were sequenced and used to evaluate the phylogenetic relationships within the southern African representatives of the genus. Published sequences of the same gene regions of Australian, Asian and North African Zygophyllum species were included to assess the relationships of the species from these regions to the southern African species. The addition of Z. stapffii from Namibia, found to be conspecific with Z. orbiculatum from Angola, lead to a greatly resolved tree. The molecular results were largely congruent with a recent sectional classification of the southern African species and supported their subdivision into subgenera Agrophyllum and Zygophyllum. Reconstruction of the character evolution of capsule dehiscence, seed attachment and seed mucilage showed that these characters allowed a division of southern African species into the two subgenera but that this could not be applied to species occurring elsewhere. Other morphological characters were found to vary and unique character combinations, rather than unique characters, were found to be of systematic value in sectional delimitation. The study suggests that repeated radiations from the horn of Africa to southern Africa and Asia and back lead to the present distribution of the taxa in the subfamily Zygophylloideae. Although this study supports some of the recent taxonomic changes in the group, the unresolved relationships between the proposed genera Tetraena and Roepera and those retained as Zygophyllum species suggest that changes to the taxonomy may have been premature. © 2008 Elsevier Inc. All rights reserved.Articl