Thesis (M.Cur.) -- University of Limpopo, 2018 / Graduate throughput of student nurses is one of the priorities of the National Department of Health in Republic of South Africa. New nurse graduates are expected to curb the obvious shortage of nurses in the nursing profession.The purpose of the study was to design the strategies to enhance graduate throughput of student nurses. The study design was quantitative, cross-sectional descriptive, research design. The study population included all student nurses who have repeated a level of study. Probability cluster random sampling was employed to select the respondents based on the examination results for both levels. Data were collected through a self-developed questionnaire. Questionnaires were distributed to 239 respondents (167 student nurses and 72 nurse-educators were completed and returned and questionnaires were analysed) Ethical clearance was obtained from Turfloop Research Ethics Committee, Limpopo Province Department of Health Ethics Committee and Limpopo College Campuses management. The researcher ensured that measures of reliability and validity are adhered to and ethical principle for conducting research that involves human-beings was considered. Data were analysed using Statistical Package for Social Sciences (SPSS) version 23 for Windows. Descriptive statistics were used to analyse, describe and summarize data in which the findings were presented in the form of distribution tables, graphs and inferential statistics. The study revealed that poor academic performance and achievement of student nurses was caused by work overload, academic stress, anxiety, low morale, lack of dedication, prioritizing social activities and ill health.Strategies to overcome the causes of poor academic performance and achievement of student nurses were developed. The strategies are-; selection criteria, adequate resources and equipment, conducive-learning environment, student nurses counselling, student nurses discipline, academic curriculum, strategies and programs, innovative teaching strategies, expertise placement, in-service trainings, mutual student-nurse, nurse-educator relationship, adequate resources and equipment as well as awards and incentives.

In a CR network, the maximum SUs throughput is desired generally. In this thesis, We investigate and formulate the problem of the secondary users¡¦ throughput maximization in cognitive radio systems under channel capacity constrain. By using KKT theorem, an objec- tive function is developed to obtain an optimal solution for the SU throughput maximization problem. An numerical example is also presented for illustration. The most important results revealed in the example show that the maximum SU throughput is achieved by cooperating an optimal number of SU pairs instead of cooperating all the SU pairs.

Network Address Translation (NAT) is a method by which Internet Protocol (IP) addresses are translated from one group to another, in a manner transparent to the end users. It translates the source and destination addresses and ports in the Internet Protocol datagram. There are several benefits for using NAT. NAT can be installed without changes to hosts or routers, it allows reuse of globally routable addresses, it facilitates easy migration or addition of new networks and it provides a method to keep private network addresses hidden from the outside world. NAT, however, is a processor- and memory-intensive activity for any device that implements it. This is because NAT involves reading from and writing to the header and payload information of every IP packet to do the address translation, a performance-intensive activity. It causes an increase in Central Processing Unit (CPU) and memory utilization and may impair throughput and increase the latency experienced by a packet. Thus, understanding the performance impact of NAT on a network device (in particular, a router) becomes an important factor when implementing NAT in any live network. This thesis aims to understand and quantify the impact of Network Address Translation on a network router by doing a series of performance tests after specifying the performance parameters to measure and, then, clearly defining the performance testing methodology that is used to study each of the performance parameters. After a discussion of previous research, the measurement system and subsequent measurement results are described. / Master of Science

Bacteriophages, a promising antimicrobial alternative to modern antibiotics, can rapidly overcome bacterial resistance. However, the propagation of therapeutic phages in gram-negative bacteria leads to proinflammatory contaminants, notably endotoxins (lipopolysaccharides). To meet strict regulations on endotoxin levels, the widely accepted method for phage purification is based on polyethylene glycol precipitation followed by cesium chloride density gradient ultracentrifugation. This method, while effective, is labor-intensive and produces only small quantities of purified phage products. Moreover, the current studies on using membrane adsorbers in this application have primarily focused on removing endotoxins or recovering phages, without addressing the variability in physical properties of bacteriophages that necessitates strain-specific process development. In contrast, this thesis introduces a novel high-throughput flat sheet membrane screening approach. This approach not only aims to evaluate the effect of varying solution conditions on bacteriophage purification but also provides a comprehensive solution to the limitations of the current method, guiding larger-scale purification work. Using two clinically derived bacteriophage, this work demonstrates that the multi well device used in this work is appropriate for this application, with little background binding of bacteriophage to the device itself. Bacteriophage binding to the membrane was found to be both sensitive to the dilution of the preparation and contact time with a given membrane. The device was used to evaluate the overall binding productivity of the membranes, finding that the Natrix and Sartobind Q membranes possess superior productivity to that of Mustang Q. Furthermore, this work demonstrated that the method could be used to rapidly screen the effects of varying sodium chloride molarity on both bacteriophage and endotoxin binding, with the effect of greater NaCl molarity on both bacteriophage and endotoxin binding being generally comparable to expectations.Finally, this work demonstrates that improvements in the translatability of screened conditions to larger-scale techniques (e.g., Syringe Filtration) require a better understanding of the underlying interactions occurring between the biomolecules and membranes. / Thesis / Master of Applied Science (MASc)

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The use of Ethernet and Internet Protocol (IP) networking technologies in flight test instrumentation and telemetry systems is rapidly increasing, driven by the ubiquity, scalability, and flexibility of networking technologies. Networks first made a positive impact in ground station infrastructure and have recently been emerging in test article data acquisition infrastructure in programs such as the A380, 787, P-8A, and Future Combat Systems. The next logical step is to provide a two-way network telemetry link to fully extend the flexibility of the network between the test articles and ground station. The United States Department of Defense (DoD) integrated Network-Enhanced Telemetry (iNET) program is currently working to build a standardized network telemetry link for exactly this purpose. When developing a network telemetry link, the limited availability of telemetry spectrum must be considered and thus it is critical to choose system-level approaches to maximize the throughput achieved from the link. This paper first presents the statistics of the network data that would typically use this link based on empirical data from current network-based flight test instrumentation systems. Several approaches to using a network telemetry link are then presented. Predicted achievable throughputs of each approach are presented that are derived from the statistics of the empirical test data. Based on this, the paper presents recommendations for building systems using network telemetry links.

Random access schemes are primarily used for data transmission in the uplink of cellular networks. Every user in a random access network is programmed to follow a predetermined transmit control policy that is designed to achieve optimal network performance. This approach, however, is not very efficient in cellular networks where channel conditions vary from time to time. Employing a fixed transmission policy may not guarantee optimal performance. To alleviate this problem, recently, channel aware random access schemes have been proposed wherein information available at the physical (PHY) layer is utilized at the higher layers to maximize network throughput. Such a cross-layer approach naturally has its share of challenges and problems. The objective of the proposed research is to study the effect of multicarrier diversity on channel aware random access schemes. First, we describe two generic random access schemes - channel aware multicarrier random access (CAMCRA) and no selection random access (NS-RA) for multicarrier networks. The former is based on judicious carrier selection and exploits multicarrier diversity while the latter does not perform carrier selection. For illustration purposes, we consider the well-known Aloha protocol and study the effect of channel state imperfection on the overall network throughput. We show that networks employing the NS-RA scheme are extremely sensitive to channel measurement errors. More precisely, the asymptotic average throughput of the NS-RA scheme under uncertain channel conditions is zero. The CAMCRA scheme, however, is very robust to channel estimation errors and maintains the same order of throughput.

Doctor of Philosophy / Genetics Interdepartmental Program - Plant Pathology / Jesse A. Poland / A major challenge for 21st century plant geneticists is to predict plant performance based on genetic information. This is a daunting challenge, especially when there are thousands of genes that control complex traits as well as the extreme variation that results from the environment where plants are grown. Rapid advances in technology are assisting in overcoming the obstacle of connecting the genotype to phenotype. Next generation sequencing has provided a wealth of genomic information resulting in numerous completely sequenced genomes and the ability to quickly genotype thousands of individuals. The ability to pair the dense genotypic data with phenotypic data, the observed plant performance, will culminate in successfully predicting cultivar performance. While genomics has advanced rapidly, phenomics, the science and ability to measure plant phenotypes, has slowly progressed, resulting in an imbalance of genotypic to phenotypic data. The disproportion of high-throughput phenotyping (HTP) data is a bottleneck to many genetic and association mapping studies as well as genomic selection (GS). To alleviate the phenomics bottleneck, an affordable and portable phenotyping platform, Phenocart, was developed and evaluated. The Phenocart was capable of taking multiple types of georeferenced measurements including normalized difference vegetation index and canopy temperature, throughout the growing season. The Phenocart performed as well as existing manual measurements while increasing the amount of data exponentially. The deluge of phenotypic data offered opportunities to evaluate lines at specific time points, as well as combining data throughout the season to assess for genotypic differences. Finally in an effort to predict crop performance, the phenotypic data was used in GS models. The models combined molecular marker data from genotyping-by-sequencing with high-throughput phenotyping for plant phenotypic characterization. Utilizing HTP data, rather than just the often measured yield, increased the accuracy of GS models. Achieving the goal of connecting genotype to phenotype has direct impact on plant breeding by allowing selection of higher yielding crops as well as selecting crops that are adapted to local environments. This will allow for a faster rate of improvement in crops, which is imperative to meet the growing global population demand for plant products.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / On the surface, network-based telemetry systems would appear to be simple, stateless, information collecting entities. Unfortunately, the reality of networking technologies brings a hierarchy of control loops into the system setup. At the top level, the command and status collection data loop that users manipulate the system with is a feedback loop. The commands themselves are transmitted across the network through competing streams of data, which are guided and controlled by Transmission Control Protocol (TCP) mechanisms. TCP mechanisms themselves have control loops in order to avoid congestion, provide reliability, and generally optimize flow. These TCP streams flowing across a network fabric compete at choke points, such as network switches, routers, and wireless telemetry links - all of which are also guided by control loops. This paper discusses the hierarchy of control loops present in a TmNS, provides an analysis of how these loops interact, and describes key points to be considered for telemetry systems.

While tissue-engineering approaches of heart valves have made great strides towards creating functional tissues in vitro, the instruments used, named bioreactors, cannot efficiently integrate multiple stimuli to accurately emulate the physiological microenvironment. To address this, we conceptually designed and built a bioreactor system that applied a range of mechanical tension conditions, modulated matrix stiffness, and introduced biochemical signals in a combinatorial and high-throughput manner. Proof-of-concept experiments on PAVIC-seeded hydrogels were performed to assess the independent and combined effects of tensile strain, matrix stiffness and TGF-β1 on myofibroblast differentiation by measuring α-SMA expression, a marker that indicates a disease-associated phenotype. We found that matrix stiffness and TGF-β1 significantly increased α-SMA levels (p < 0.001), while the effect of mechanical strain was only significant on soft gels (~12 kPa) without TGF-β1. This study therefore demonstrated independent and integrated effects of multiple stimuli in regulating key cellular events in the aortic valve.

This thesis presents new spherical harmonic (SH) approaches for ligand-based high-throughput virtual screening (HTVS). If it is assumed that small drug molecules may be adequately superposed and distinguished by co-locating their centers of mass and by performing rotational correlations of their shapes, then to a good approximation each molecule may be represented very compactly using a two dimensional (2D) SH surface envelope. Of course, this assumes that the true molecular surface is star-like, or single-valued, with respect to radial rays projecting from the selected origin. However, this often holds to a very good approximation for small globular molecules. Even when this is not the case, it is nonetheless reasonable to suppose that similar molecules should give similar radial projections and, therefore, that they should share very similar SH representations. Following this premise, a new program called “SpotLight” was developed. The results obtained with this software show that SH-based global shape matching provides a powerful new way to perform HTVS. SH surface representations are increasingly being applied to a broad range of object recognition and registration tasks, and have also been used to model protein-ligand shape complementarity. Most current shape similarity techniques search for global similarities, and may therefore miss finding active compounds with different overall shapes and sizes but which share similar substructures or surface features. Existing molecular fragment matching algorithms can identify common covalent substructures but they are not well suited for performing scaffold-hopping shape-based database searches. This thesis introduces a novel SH fragment-based shape matching approach that can exploit knowledge of structures of existing protein-ligand complexes to perform virtual screening using as queries SH surface fragments derived from crystallographic ligand binding surfaces.