Some New-Irresolute and Closed Maps in Fuzzy Topological Spaces

Abstract In this paper weaker and stronger forms of fuzzy b-mappings are introduced and studied using the concept of fuzzy generalized b-closed sets which are named as fagb-continuous, fagb-irresolute and fagb-closed maps. Also f gbT * 1/2 spaces, fuzzy b-locally closed sets, fb-homeomorphisms, fb*-homeomorphisms, fgb-neighbourhood and fgbq-neighbourhood are introduced and studied. Several interesting results are obtained. Mathematics Subject Classification: 94D0

Investigation of Sf-9 Cell Metabolism Before and After Baculovirus Infection Using Biovolume: a Case for the Improvement of Adeno-Associated Viral Vector Production

Adeno-associated viral (AAV) vectors have been shown to be potential vectors for the treatment of diseases, including protocols using RNA interference (RNAi). AAV vector production in insect cells using the baculovirus vector expression system has been a major advance in furthering their use. A major limitation of AAV vector production at high cell densities is a reduction in cell specific yield, which is thought to be caused by nutrient limitations. Nutrient consumption profiles after infection, however, have still not been fully characterized, probably due to the difficulty of characterizing consumption patterns based on increases in cell density, which are minimal after infection. It is known, however, that cells increase in size after infection; therefore, the driving hypothesis of this thesis was that biovolume, or the total volume enclosed by the membrane of viable cells, which accounts for both cell density and cell size, could be used to characterize nutrient consumption patterns both before and after infection. The relationships between nutrient consumption and change in cell density and biovolume were examined by statistical correlation analysis. It was found that in uninfected cultures, no significant correlation differences, using either cell density or biovolume, were observed since cell size remained relatively constant; however, in infected cultures, more than half of the nutrients were found to be better correlated with biovolume than with cell density. When examining the nutrient and metabolite concentration data on a biovolume basis, nutrient consumption remained relatively constant. It is hypothesized that since it has been reported that the rate of cell respiration increases after infection, a more complete oxidation of nutrients occurs to satisfy increased energy needs during infection. By having a basis to base nutrient consumption, we can better assess the needs of the culture. This will allow the development of feeding strategies based on cellular requirements instead of supplying the cultures with generic nutrient cocktails. It is expected that different nutrient mixtures can be used to target different goals such as 1) enhancing cell growth (before infection) and 2) improving the production of recombinant products (after infection). This will not only increase the efficiency of AAV vector production, but will also reduce the cost of production and make the process more economical by eliminating the addition of unnecessary nutrients. Although promising, some limitations of using biovolume still exist. A first limitation is the biovolume measure itself. This measure requires a device that measures cell size, such as a Coulter Counter Multisizer (Beckman-Coulter, Miami, FL, USA), which can be expensive. Capacitance probes can be a more cost effective tool to estimate biovolume; however, the availability of capacitance probes is still not common. A second limitation is the interpretation of the biovolume profiles, which can depend strongly on the fraction of cells in culture that are infected. If the culture is infected asynchronously, then there will be many different cell populations in the culture. Future work may require separating the cell size distribution into populations of viable and non-viable cells to get a better biovolume measure as opposed to assuming that viability is well distributed over the entire range of cell sizes. In infected cultures where the viability may be low, it is likely that the cell size distribution of non-viable cells will be concentrated at the lower end of the distribution (smaller diameter) rather than being well distributed over the whole range. If this is the case, for the infected cultures with low viability, the mean cell diameter calculated will be underestimated, which will lead to an overestimation of nutrient consumption for cultures with low viability. This will certainly affect the accuracy of the nutrient consumption profiles. By separating cell size distribution data into different cell populations of viable and nonviable, the accuracy can be improved

Exploring the perceptions of psychiatric patients regarding marijuana use

There is limited understanding on marijuana use by psychiatric patients, specifically with regard as to why they continue to smoke marijuana despite the negative consequences, such as readmittance to psychiatric hospitals following marijuana-induced psychosis. It is, therefore, important to understand why psychiatric patients continue to use marijuana, despite experiencing its negative effects. The purpose of this study was to explore and describe the perceptions of psychiatric patients with regard to marijuana use in Potchefstroom, North West Province, as well as to formulate recommendations for nursing education, nursing research and nursing practice, with the aim of reducing the readmission of psychiatric patients following marijuana-induced psychosis. A qualitative, exploratory, descriptive and contextual research design was followed in order to give ‘voice’ to the perceptions of psychiatric patients about marijuana use. Purposive sampling was utilised to identify participants who complied with selection criteria. The sample size was determined by data saturation, which was reached after 10 individual interviews with psychiatric patients. Unstructured individual interviews were utilised to gather data after written approval from the Ethics committee of the North-West University (Potchefstroom Campus), North West Provincial Department of Health, the clinical manager of the psychiatric hospital where data were collected, as well as from the psychiatric patients. The co-coder and the researcher analysed the data independently. The findings of this study include perceptions of psychiatric patients on the use of marijuana, the negative effects of marijuana use, marijuana use and mental illness, and quitting marijuana. Recommendations were formulated for nursing education, nursing research as well as for nursing practice. Opsomming Insig in die gebruik van marijuana deur psigiatriese pasiënte is beperk, spesifiek met betrekking tot hulle redes vir voortgesette marijuana verbruik ten spyte van die negatiewe gevolge daarvan, byvoorbeeld hertoelating tot psigiatriese hospitale na marijuanageïnduseerde psigotiese episodes. Dit is dus belangrik om te verstaan waarom psigiatriese pasiënte voortgaan om marijuana te gebruik ten spyte van die negatiewe uitwerking daarvan. Hierdie navorsing was ten doel om die persepsies van psigiatriese pasiënte in verband met die gebruik van marijuana in Potchefstroom in die Noordwesprovinsie te verken en te beskryf. So kan aanbevelings gemaak word vir verpleegonderrig, verpleegnavorsing en verpleegpraktyk om meer toepaslike versorging en behandeling te verseker en uiteindelik die heropname van psigiatriese pasiënte as gevolg van marijuana-geïnduseerde psigose te verminder. ‘n Kwalitatiewe, verkennende, beskrywende en kontekstuele navorsingsontwerp is gevolg om ‘n ‘stem’ te gee aan die persepsies van psigiatriese pasiënte aangaande die gebruik van marijuana. Doelgerigte steekproefneming is gebruik om deelnemers te identifiseer wat sou voldoen aan seleksiekriteria. Die steekproefgrootte is bepaal deur dataversadiging, wat bereik is na 10 individuele onderhoude met psigiatriese pasiënte. Ongestruktureerde individuele onderhoude is gebruik om data te versamel ná geskrewe toestemming van die Etiekkomitee van die Noordwes-Universiteit (Potchefstroom Kampus), van die Noordwes Provinsiale Departement van Gesondheid, die Kliniese bestuurder van die psigiatriese hospitaal waar die data versamel is, sowel as van die psigiatriese pasiënte. Die medekodeerder en die navorser het die data onafhanklik van mekaar geanaliseer. Die bevindings van hierdie studie het die persepsies wat psigiatriese pasiënte het oor die gebruik van marijuana, die negatiewe effekte van die gebruik van marijuana, die gebruik van marijuana en psigiatriese toestande, en die staking van die gebruik van marijuana, uitgelig. Aanbevelings is geformuleer vir verpleegonderrig en verpleegnavorsing, sowel as vir die praktyk van verpleegkunde