The role of Cytochrome P450 17-alpha-Hydroxylase/ 17,20-Lyase (CYP17) in the stress coping ability in a divergently selected Merino sheep population

South African Merino sheep were selected divergently from the same base population for their ability to rear multiples. Two distinct populations were formed over a period of more than 20 years of selection. Reproduction (and therefore presumably fitness) in the line selected in the upward direction (H-line) was substantially improved compared to the line selected in the downward direction (L-line). In the present study, it was demonstrated that the H-line was more stresstolerant than the L-line in terms of their glucose and cortisol response when challenged with insulin. Sheep from the breeding program were genotyped according to one of two cytochrome P450 17α-hydroxylase/17-20 lyase (CYP17) alleles, as these genotypes were previously linked to the ability of Angora goats to cope with external stressors. However, no association was found between CYP17 genotype and selection line. The difference in insulin induced stress response between the H- and the L-line can therefore not be attributed to CYP17 genotype

Thermoelectric effect in high mobility single layer epitaxial graphene

The thermoelectric response of high mobility single layer epitaxial graphene on silicon carbide substrates as a function of temperature and magnetic field have been investigated. For the temperature dependence of the thermopower, a strong deviation from the Mott relation has been observed even when the carrier density is high, which reflects the importance of the screening effect. In the quantum Hall regime, the amplitude of the thermopower peaks is lower than a quantum value predicted by theories, despite the high mobility of the sample. A systematic reduction of the amplitude with decreasing temperature suggests that the suppression of the thermopower is intrinsic to Dirac electrons in graphene.Comment: 5 pages, 4 figure

Do mathematics learning facilitators implement metacognitive strategies?

It is widely accepted that mathematical skills are critically important in ourtechnologically sophisticated world. Educators' metacognition directs, plans,monitors, evaluates and reflects their instructional behaviour and this can promote learners ' learning with und ers tanding. The p urpos e of this study was to investigate the exten t to which mathematics educators implemented and taught metacognit ive strategies. Res ults of the quantitative part of the study were triangulated with the results of the qualitative part. Results suggested that whereas mathematics educators may well have possess ed metacognitive skills and utilised them intuitively, thes e s kills were not implemented to a s atisfa ctory extent in the classes we observed

The quality of service delivery by the estate agency industry in Bloemfontein

Published Article'n Groot hoeveelheid eiendomsagente het tot die eiendomsagentskapsbedryf toegetree in die laaste paar jaar. Tersel fdertyd het die kliënte se beoordeling van die kwaliteit van dienslewering deur eiendomsagente in die bedryf 'n afwaartse neiging getoon. Hierdie persepsie van swak kwaliteit lei tot 'n negatiewe impak op die bedryf. Navorsing gedurende 2004 het uitgewys dat kliënte in die Bloemfontein streek oor die algemeen nie tevrede is met die gehalte van dienslewering deur eiendomsagente in die bedryf nie. Respondente het sekere areas waar verbeterde hoë vlak dienslewering kan plaasvind, uitgewys. Hierdie navorsing en aanbevelings het dit moontlik gemaak om 'n model te ontwikkel vir die verkryging van maksimale tevredenheid van beide kopers en verkopers. A large number of estate agents entered the real estate industry in the last few years. At the same time the client rating of the quality of services offered by estate agents in the industry followed a downward trend. This perception of poor quality is causing a negative impact on the industry. Research done in 2004 has identified that clients within the Bloemfontein region are generally not satisfied with the level of service delivery by estate agents within the industry. Respondents did identify certain areas that could be improved in order for estate agents to deliver a superior level of service. On the basis of this research and recommendations, it was possible to develop a model of the service delivery that will maximise the satisfaction of both buyers and sellers

Time and cost assessment of the manufacturing of tooling by metal casting in rapid prototyping sand moulds

Published ArticleIn this paper the time and cost parameters of tooling manufacturing by metal casting in rapid prototyping sand moulds are assessed and comparison is made with alternative tool making processes such as computer numerical control machining and investment casting (Paris Process). To that end two case studies obtained from local companies were carried out. The tool manufacturing was conducted according to a five steps process chain referred to as Rapid Casting for Tooling (RCT). These steps include CAD modelling, casting simulation, rapid prototyping, metal casting and finishing operations. In particular the Rapid Prototyping (RP) step for producing the sand moulds was achieved with the aid of an EOSINT S 550 Laser Sintering machine and a Spectrum 510 Three Dimensional Printer. The results indicate that RP is the rate determining step and cost driver of the proposed tooling manufacturing technique. In addition it was found that this tool making process is faster but more expensive than machining and investment casting

Half integer quantum Hall effect in high mobility single layer epitaxial graphene

The quantum Hall effect, with a Berry's phase of $\pi$ is demonstrated here on a single graphene layer grown on the C-face of 4H silicon carbide. The mobility is $\sim$ 20,000 cm$^2$/V$\cdot$s at 4 K and ~15,000 cm$^2$/V$\cdot$s at 300 K despite contamination and substrate steps. This is comparable to the best exfoliated graphene flakes on SiO$_2$ and an order of magnitude larger than Si-face epitaxial graphene monolayers. These and other properties indicate that C-face epitaxial graphene is a viable platform for graphene-based electronics.Comment: Some modifications in the text and figures, 7 pages, 2 figure

Wafer bonding solution to epitaxial graphene - silicon integration

The development of graphene electronics requires the integration of graphene devices with Si-CMOS technology. Most strategies involve the transfer of graphene sheets onto silicon, with the inherent difficulties of clean transfer and subsequent graphene nano-patterning that degrades considerably the electronic mobility of nanopatterned graphene. Epitaxial graphene (EG) by contrast is grown on an essentially perfect crystalline (semi-insulating) surface, and graphene nanostructures with exceptional properties have been realized by a selective growth process on tailored SiC surface that requires no graphene patterning. However, the temperatures required in this structured growth process are too high for silicon technology. Here we demonstrate a new graphene to Si integration strategy, with a bonded and interconnected compact double-wafer structure. Using silicon-on-insulator technology (SOI) a thin monocrystalline silicon layer ready for CMOS processing is applied on top of epitaxial graphene on SiC. The parallel Si and graphene platforms are interconnected by metal vias. This method inspired by the industrial development of 3d hyper-integration stacking thin-film electronic devices preserves the advantages of epitaxial graphene and enables the full spectrum of CMOS processing.Comment: 15 pages, 7 figure

The role of Cytochrome P450 17-alpha-Hydroxylase/ 17,20-Lyase (CYP17) in the stress coping ability in a divergently selected Merino sheep population

South African Merino sheep were selected divergently from the same base population for their ability to rear multiples. Two distinct populations were formed over a period of more than 20 years of selection. Reproduction (and therefore presumably fitness) in the line selected in the upward direction (H-line) was substantially improved compared to the line selected in the downward direction (L-line). In the present study, it was demonstrated that the H-line was more stresstolerant than the L-line in terms of their glucose and cortisol response when challenged with insulin. Sheep from the breeding program were genotyped according to one of two cytochrome P450 17α-hydroxylase/17-20 lyase (CYP17) alleles, as these genotypes were previously linked to the ability of Angora goats to cope with external stressors. However, no association was found between CYP17 genotype and selection line. The difference in insulin induced stress response between the H- and the L-line can therefore not be attributed to CYP17 genotype

Theology, News and Notes - Vol. 55, No. 03

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1163/thumbnail.jp