Enhancing the quality of first-year Biology teaching at the University of Stellenbosch

Thesis (MPhil) (Higher Education)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: Transformation in biology teaching is inevitable. There is a global concern about the quality of undergraduate biology teaching, especially when considering the growth in the fields of biotechnology and the molecular sciences. Programmes of learning have to be market orientated, and the contents of curricula have to equip students for entrance into a specific career. At the University of Stellenbosch the School for Biological Sciences has developed an interdisciplinary approach to first-year biology teaching. The new programmes in Biological Sciences, implemented in 2000, contain first-year curricula that introduce students to the disciplines of genetics, botany, zoology, microbiology, biochemistry and statistics. This involves participation by six departments, and lecture facilitation in two languages for up to 600 students. As contact sessions between lecturers and students are limited, self-study is becoming increasingly important, and lectures should be fully exploited to obtain deep learning. This study investigated various ways to enhance the teaching and learning process for first-year biology students in a module fraught with growing pains and problems. The influence of software support on student learning was evaluated, while the introduction of an innovative approach to teaching statistics to first-year students was analyzed. Supplementing the statistics section with video-recordings of the lectures was further considered as a possible way of overcoming various obstacles in especially this section of the module. The application of a practical laboratory course to enhance the quality of the theoretical lectures was also investigated and evaluated. It can be concluded that no simple solution could be found to solve the variety of problems that arose with implementation of the new programmes of learning. Technology proved to be invaluable, but should be applied after thorough needs assessment and impact studies have been performed. Provision of IT tools and facilities do not necessarily imply their application and effect, and innovation and inspiration still proved to be most effective in enhancing biology teaching.AFRIKAANSE OPSOMMING: Transformasie in biologie-onderrig is onvermydelik. Daar is wêreldwye kommer oor die kwaliteit van voorgraadse biologie-onderrig, veral in die lig van die vooruitgang in biotegnologie en die molekulêre wetenskappe. Programme van onderrig moet markgerig wees, en die inhoud van leerplanne loopbaangerig. Die Skool vir Biologiese Wetenskappe van die Universiteit van Stellenbosch het sedert sy stigting 'n interdissiplinêre benadering tot eerstejaarsbiologie-onderrig ontwikkel. Die nuwe programme in die Biologiese Wetenskappe wat in 2000 geïmplementeer is, bevat eerstejaarskurrikula wat studente bekendstel aan die dissiplines van genetika, botanie, sooloqie, mikrobiologie, biochemie en statistiek. Ses departemente is hierby betrokke, en lesings word in twee tale vir tot 600 studente aangebied. Aangesien kontaksessies tussen dosente en studente beperk is, word selfstudie toenemend belangrik, en lesure moet ten volle benut word om 'n diepgaande leerproses te verkry. Hierdie studie ondersoek derhalwe verskeie potensiële maniere waarop die onderrigen leerproses by eerstejaarbiologie-studente versterk kan word. Die invloed van sagteware-ondersteuning by die leerproses is geëvalueer, terwyl 'n nuwe innoverende benadering tot statistiek-onderrig vir eerstejaarstudente geanaliseer is. Uitbreiding en ondersteuning van die statistiek-seksie, d.m.v. videoopnames van die lesings, is verder oorweeg om verskeie van die hindernisse in veral hierdie deel van die module te oorkom. Die toepassing van 'n laboratoriumkursus om die kwaliteit van die teoretiese lesings uit te brei is ook geëvalueer. Daar kan saamgevat word dat geen enkelvoudige oplossing bestaan om die verskeidenheid van probleme op te los wat met implementering van die programme ontstaan het nie. Tegnologie is onontbeerlik, maar moet toegepas word nadat behoorlike behoeftebepaling en impakstudies uitgevoer is. Verskaffing van informasietegnologie impliseer nie noodwendig die nodige toepassing en effek nie, en innovasie en inspirasie blyk steeds onontbeerlik te wees om biologie-onderrig uit te brei en te versterk

SEM and TEM for identification of capsular fibrosis and cellular behavior around breast implants – a descriptive analysis

Background Capsular fibrosis (CF) is the most common long-term complication in implant-based breast augmentation. It is well accepted that the foreign body response (FBR) instigates the development of fibrotic disease. Our study aims to compare murine and human samples of CF and describe the cellular and extracellular matrix (ECM) composition using scanning and transmission electron microscopy (SEM and TEM). Results Miniature microtextured silicone breast implants were implanted in mice and subsequently harvested at days 15, 30, and 90 post-operation. Isolated human capsules with the most aggravated form of CF (Baker IV) were harvested post-operation. Both were analyzed with SEM and TEM to assess cellular infiltration and ECM structure. An architectural shift of collagen fiber arrangement from unidirectional to multidirectional was observed at day 90 when compared to days 15 and 30. Fibrosis was observed with an increase of histiocytic infiltration. Moreover, bacterial accumulation was seen around silicone fragments. These findings were common in both murine and human capsules. Conclusions This murine model accurately recapitulates CF found in humans and can be utilized for future research on cellular invasion in capsular fibrosis. This descriptive study helps to gain a better understanding of cellular mechanisms involved in the FBR. Increases of ECM and cellularity were observed over time with SEM and TEM analysis

External push and internal pull forces recruit curvature-sensing N-BAR domain proteins to the plasma membrane

Many of the more than 20 mammalian proteins with N-BAR domains1-2 control cell architecture3 and endocytosis4-5 by associating with curved sections of the plasma membrane (PM)6. It is not well understood whether N-BAR proteins are recruited directly by processes that mechanically curve the PM or indirectly by PM-associated adaptor proteins that recruit proteins with N-BAR domains that then induce membrane curvature. Here, we show that externally-induced inward deformation of the PM by cone-shaped nanostructures (Nanocones) and internally-induced inward deformation by contracting actin cables both trigger recruitment of isolated N-BAR domains to the curved PM. Markedly, live-cell imaging in adherent cells showed selective recruitment of full length N-BAR proteins and isolated N-BAR domains to PM sub-regions above Nanocone stripes. Electron microscopy confirmed that N-BAR domains are recruited to local membrane sites curved by Nanocones. We further showed that N-BAR domains are periodically recruited to curved PM sites during local lamellipodia retraction in the front of migrating cells. Recruitment required Myosin II-generated force applied to PM connected actin cables. Together, our study shows that N-BAR domains can be directly recruited to the PM by external push or internal pull forces that locally curve the PM

Vision, challenges and opportunities for a Plant Cell Atlas

With growing populations and pressing environmental problems, future economies will be increasingly plant-based. Now is the time to reimagine plant science as a critical component of fundamental science, agriculture, environmental stewardship, energy, technology and healthcare. This effort requires a conceptual and technological framework to identify and map all cell types, and to comprehensively annotate the localization and organization of molecules at cellular and tissue levels. This framework, called the Plant Cell Atlas (PCA), will be critical for understanding and engineering plant development, physiology and environmental responses. A workshop was convened to discuss the purpose and utility of such an initiative, resulting in a roadmap that acknowledges the current knowledge gaps and technical challenges, and underscores how the PCA initiative can help to overcome them.</jats:p

Airtight container for the transfer of atmosphere-sensitive materials into vacuum-operated characterization instruments

This paper describes the design and operation of a simple airtight container devised to facilitate the transfer of atmosphere-sensitive samples from a glovebox to the vacuum chamber of an analytical instrument such as a scanning electron microscope. The use of this device for characterizing the microstructure of highly hygroscopic strontium iodide ceramics by scanning electron microscopy is illustrated as an application example

Elevated AIM2-mediated pyroptosis triggered by hypercytotoxic Francisella mutant strains is attributed to increased intracellular bacteriolysis

Intracellular bacterial pathogens Francisella novicida and the Live Vaccine Strain (LVS) are recognized in the macrophage cytosol by the AIM2 inflammasome, which leads to the activation of caspase-1 and the processing and secretion of active IL-1β, IL-18 and pyroptosis. Previous studies have reported that F. novicida and LVS mutants in specific genes (e.g. FTT0584, mviN and ripA) induce elevated inflammasome activation and hypercytotoxicity in host cells, leading to the proposal that F. novicida and LVS may have proteins that actively modulate inflammasome activation. However, there has been no direct evidence of such inflammasome evasion mechanisms. Here, we demonstrate for the first time that the above mutants, along with a wide range of F. novicida hypercytotoxic mutants that are deficient for membrane-associated proteins (ΔFTT0584, ΔmviN, ΔripA, ΔfopA and ΔFTN1217) or deficient for genes involved in O-antigen or LPS biosynthesis (ΔwbtA and ΔlpxH) lyse more intracellularly, thus activating increased levels of AIM2-dependent pyroptosis and other innate immune signalling pathways. This suggests that an inflammasome-specific evasion mechanism may not be present in F. novicida and LVS. Furthermore, future studies may need to consider increased bacterial lysis as a possible cause of elevated stimulation of multiple innate immune pathways when the protein composition or surface carbohydrates of the bacterial membrane is altered

Visualization of Aspergillus fumigatus biofilms with Scanning Electron Microscopy and Variable Pressure-Scanning Electron Microscopy: A comparison of processing techniques

Aspergillus fumigatus biofilms consist of a three-dimensional network of cellular hyphae and extracellular matrix. They are involved in infections of immune-compromised individuals, particularly those with cystic fibrosis. These structures are associated with persistence of infection, resistance to host immunity, and antimicrobial resistance. Thorough understanding of structure and function is imperative in the design of therapeutic drugs. Optimization of processing parameters, including aldehyde fixation, heavy metal contrasting, drying techniques and Ionic Liquid treatment, was undertaken for an ultrastructural approach to understand cellular and extracellular biofilm components. Conventional and Variable Pressure Scanning Electron Microscopy were applied to analyze the structure of biofilms attached to plastic and formed at an air-liquid interface. (C) 2016 Elsevier B.V. All rights reserved