Die Bybel en die natuurwetenskappe

’n Studie van die literatuur in verband met die onderwerp toon dat daar 'n verskeidenheid van standpunte, selfs onder Christene, hieroor is

Statistiek as Christelike wetenskap

The legitimacy of the concept of Christian scholarship has often been denied, especially in connection with the more exact sciences such as physics, mathematics and statistics. In this article it is argued that in accordance with modern philosophies of science, the various scientific disciplines should he viewed within a coherently ranging series of ever more encompassing contexts. This provides a view of science very different from the so called “standard view of science” and moreover amenable to a Christian approach of science. Various contexts of statistical science is discussed and their coherence with the statistical subject matter indicated. The question about the role of the Bible in this approach is considered

Stoking the Research Fire: Three Views

Most academics are fired up for research right after graduate school, but after a few years on the job, the flame might wane. Perhaps you are over-burdened with service or administration and can\u27t imagine finding time for a research project. Budget cuts may have you feeling overworked or uninspired. Perhaps you\u27ve achieved your goal of becoming tenured and you wonder what comes next. The purpose of this collection of essays, presented originally at a 2011 midwinter conference, is to share ways to stoke a passion for research. The perspectives included here represent three stages of academic life: tenure-track assistant professor, tenured associate professor, and full professor

Short message service (SMS) language and written language skills: educators’ perspectives

SMS language is English language slang, used as a means of mobile phone text messaging. This practice may impact on the written language skills of learners at school. The main aim of this study was to determine the perspectives of Grade 8 and 9 English (as Home Language) educators in Gauteng regarding the possible influence of SMS language on certain aspects of learners’ written language skills. If an influence was perceived by the educators, their perceptions regarding the degree and nature of the influence were also explored. A quantitative research design, utilising a questionnaire, was employed. The sample of participants comprised 22 educators employed at independent secondary schools within Gauteng, South Africa. The results indicated that the majority of educators viewed SMS language as having a negative influence on the written language skills of Grade 8 and 9 learners. The influence was perceived as occurring in the learners’ spelling, punctuation, and sentence length. A further finding was that the majority of educators address the negative influences of SMS language when encountered in written tasks.Keywords: English Home Language teaching; SMS language; text messaging; written language skill

Phagocytosis and macrophage polarisation on bacterially contaminated dental implant materials and effects on tissue integration

Bacterial contamination is hard to avoid during dental implant surgery. Macrophages and their polarisation play a decisive role in bacterial colonisation and tissue integration on bacterially contaminated dental implants. The present study investigated the role of macrophages in stimulating tissue coverage overgrowth of contaminating oral bacteria on polished titanium (Ti-P) and acid-etched zirconium dioxide (ZrO2-MA) dental implant materials. Different co-culture models were employed to determine phagocytosis rates of Streptococcus mitis or Staphylococcus aureus contaminating a dental implant surface and the influence of contaminating bacteria and osteoblasts (U2OS) on macrophage polarisation. S. aureus was phagocytized in higher numbers than S. mitis in bi-cultures on smooth Ti-P surfaces. Contaminating S. mitis stimulated near full polarisation of macrophages from a non-Ym1-expressing- to a Ym1-expressing-phenotype on smooth Ti-P, but on ZrO2-MA both phenotypes occurred. In tri-cultures with U2OS-cells on smooth Ti-P, a larger percentage of macrophages remained in their non-Ym1-expressing, "fighting" M1-like phenotype to clear Ti-P surfaces from contaminating bacteria. On ZrO2-MA surfaces, more macrophages tended towards their "fixand-repair" M2-like phenotype than on Ti-P surfaces. Surface coverage of smooth, bacterially contaminated Ti-P surfaces by U2OS-cells was more effectively stimulated by fighting, M1-like macrophages than on ZrO2-MA surfaces. Comprehensive guidelines are provided for the development of infection-resistant, dental implant materials, including bacteria, tissue and immune cells. These guidelines point to more promising results for clinical application of Ti-P as compared with ZrO2-MA

Polarization of Macrophages, Cellular Adhesion, and Spreading on Bacterially Contaminated Gold Nanoparticle-Coatings in Vitro

Biomaterial-associated infections often arise from contaminating bacteria adhering to an implant surface that are introduced during surgical implantation and not effectively eradicated by antibiotic treatment. Whether or not infection develops from contaminating bacteria depends on an interplay between bacteria contaminating the biomaterial surface and tissue cells trying to integrate the surface with the aid of immune cells. The biomaterial surface plays a crucial role in defining the outcome of this race for the surface. Tissue integration is considered the best protection of a biomaterial implant against infectious bacteria. This paper aims to determine whether and how macrophages aid osteoblasts and human mesenchymal stem cells to adhere and spread over gold nanoparticle (GNP)-coatings with different hydrophilicity and roughness in the absence or presence of contaminating, adhering bacteria. All GNP-coatings had identical chemical surface composition, and water contact angles decreased with increasing roughness. Upon increasing the roughness of the GNP-coatings, the presence of contaminating Staphylococcus epidermidis in biculture with cells gradually decreased surface coverage by adhering and spreading cells, as in the absence of staphylococci. More virulent Staphylococcus aureus fully impeded cellular adhesion and spreading on smooth gold- or GNP-coatings, while Escherichia coli allowed minor cellular interaction. Murine macrophages in monoculture tended toward their pro-inflammatory "fighting" M1-phenotype on all coatings to combat the biomaterial, but in bicultures with contaminating, adhering bacteria, macrophages demonstrated Ym1 expression, indicative of polarization toward their anti-inflammatory "fix-and-repair" M2-phenotype. Damage repair of cells by macrophages improved cellular interactions on intermediately hydrophilic/rough (water contact angle 30 deg/surface roughness 118 nm) GNP-coatings in the presence of contaminating, adhering Gram-positive staphylococci but provided little aid in the presence of Gram-negative E. coli. Thus, the merits on GNP-coatings to influence the race for the surface and prevent biomaterial-associated infection critically depend on their hydrophilicity/roughness and the bacterial strain involved in contaminating the biomaterial surface