48 research outputs found
Effectiveness of medical circumcision communication differentiation for HIV prevention in gay men
Thesis (M.M. (Public and Development Management))--University of the Witwatersrand, Faculty of Commerce, Law and Management, Graduate School of Public and Development Management, 2015.Voluntary Medical Male Circumcision (VMMC) is currently being implemented in South Africa as a prevention mechanism for HIV infection. Scientifically, research has shown that circumcision decreases the rate of heterosexual vagina-to-penis HIV infection. It has not been proven to provide the same effect in anal sex. This limitation has implications for gay men who engage in anal sex. This limitation is not communicated through current media and can place gay men at risk of believing that circumcision may prevent HIV infection via anal sex. This may lead to increased HIV infections in that population. Using a qualitative research strategy and semi-structured interviews, gay men’s perceptions and understandings of VMMC revealed that VMMC media can be misinterpreted and that the anal sex limitation is not present in communication messaging. VMMC policy implementers were interviewed and results revealed that gay men are not considered in VMMC policy. Recommendations from this study include proper policy analysis with the inclusion of consideration of gay men in VMMC policy, so that policy evaluation can include the detection of unintended outcomes on the gay population, such as the increase of HIV infections due to misinterpretation of policy communication
Exploring principals' orientation speeches: sensitising student teachers to school context.
Masters Degree. University of KwaZulu-Natal, Durban.Abstract available in the PDF
A multithreaded hybrid framework for mining frequent itemsets
Mining frequent itemsets is an area of data mining that has beguiled several researchers in recent years. Varied data structures such as Nodesets, DiffNodesets, NegNodesets, N-lists, and Diffsets are among a few that were employed to extract frequent items. However, most of these approaches fell short either in respect of run time or memory. Hybrid frameworks were formulated to repress these issues that encompass the deployment of two or more data structures to facilitate effective mining of frequent itemsets. Such an approach aims to exploit the advantages of either of the data structures while mitigating the problems of relying on either of them alone. However, limited efforts have been made to reinforce the efficiency of such frameworks. To address these issues this paper proposes a novel multithreaded hybrid framework comprising of NegNodesets and N-list structure that uses the multicore feature of today’s processors. While NegNodesets offer a concise representation of itemsets, N-lists rely on List intersection thereby speeding up the mining process. To optimize the extraction of frequent items a hash-based algorithm has been designed here to extract the resultant set of frequent items which further enhances the novelty of the framework
A genetic algorithm coupled with tree-based pruning for mining closed association rules
Due to the voluminous amount of itemsets that are generated, the association rules extracted from these itemsets contain redundancy, and designing an effective approach to address this issue is of paramount importance. Although multiple algorithms were proposed in recent years for mining closed association rules most of them underperform in terms of run time or memory. Another issue that remains challenging is the nature of the dataset. While some of the existing algorithms perform well on dense datasets others perform well on sparse datasets. This paper aims to handle these drawbacks by using a genetic algorithm for mining closed association rules. Recent studies have shown that genetic algorithms perform better than conventional algorithms due to their bitwise operations of crossover and mutation. Bitwise operations are predominantly faster than conventional approaches and bits consume lesser memory thereby improving the overall performance of the algorithm. To address the redundancy in the mined association rules a tree-based pruning algorithm has been designed here. This works on the principle of minimal antecedent and maximal consequent. Experiments have shown that the proposed approach works well on both dense and sparse datasets while surpassing existing techniques with regard to run time and memory
(E)-1-(1-Benzyl-5-methyl-1H-1,2,3-triazol-4-yl)-3-phenylprop-2-en-1-one
The asymmetric unit of the title compound, C19H17N3O, contains two independent molecules. In one molecule, the essentially planar triazole ring [maximum deviation = 0.003 (2) Å] forms dihedral angles of 5.57 (12) and 87.51 (12)° with the two phenyl rings, while in the other molecule [maximum deviation in triazole ring = 0.001 (2) Å] these angles are 1.55 (10) and 82.73 (11)°. The dihedral angles between the two phenyl rings in the two molecules are 87.77 (13) and 81.22 (11)°. In the crystal, the independent molecules are connected via a weak C—H⋯N hydrogen bond, forming dimers. Further stabilization is provided by weak C—H⋯π interactions
4-Benzyl-8-phenyl-1-thia-4-azaspiro[4.5]decan-3-one
In the title compound, C21H23NOS, the thiazolidine ring adopts a twist conformation about one of its C—S bonds, while the cyclohexane ring has a chair conformation. The S and N atoms attached to the spiro C atom are in axial and equatorial orientations, respectively. The thiazolidine ring forms dihedral angles of 86.24 (14) and 31.82 (15)° with the directly attached and remote terminal benzene rings, respectively. The dihedral angle between the two terminal benzene rings is 86.74 (14)°. In the crystal, the only significant directional interaction is a weak C—H⋯π bond, which generates [010] chains
3-Benzyl-2-(furan-2-yl)-1,3-thiazolidin-4-one
In the title compound, C14H13NO2S, the thiazolidine ring is approximately planar with a maximum deviation of 0.112 (1) Å. The furan ring is disordered over two orientations, with an occupancy ratio of 0.901 (5):0.099 (5). The central thiazolidine ring makes dihedral angles of 85.43 (8), 87.50 (11) and 87.9 (9)° with the phenyl ring and the major and minor components of the disordered furan ring, respectively. In the crystal, molecules are connected by weak intermolecular C—H⋯O hydrogen bonds, forming supramolecular chains parallel to the b axis
Experimental and theoretical investigations on the host-guest interaction of diphenylamine with p-sulfonatocalix[4]arene
929-938The intermolecular interaction between diphenylamine (DPA) and p-sulfonatocalix[4]arene (p-SC4) is studied by experimental and computational techniques. The 1:1 stoichiometry of the inclusion complex is deduced from fluorescence titration using Job’s method. The tendency of binding of DPA with p-SC4 is analyzed from emission, excited state lifetime and cyclic voltammetry techniques. The binding constant values acquired from all the titrations are around 103–104 L/mol, reveals the effective binding. The structural interactions and mode of binding of the supramolecular complex are explained by 1H NMR and ROESY spectral studies. The molecular association of DPA with p-SC4 is confirmed by quantum chemical simulations. The higher complexation energy (-76.94 kJ/mol) declares the existence of strong binding between DPA and p-SC4
Cu‐Oxide Nanoparticles Catalyzed Synthesis of Nitriles and Amides from Alcohols and Ammonia in Presence of Air
The synthesis and functionalization of nitrogen-containing compounds continue to be important due to their wide applications. In particular, the preparation of nitriles and amides applying cost-effective and green methodologies is of central importance because these products represent valuable fine and bulk chemicals and serve as key precursors and central intermediates in organic synthesis and drug discovery as well as materials. Here, the preparation of nitriles and primary amides from alcohols and ammonia by a heterogeneous Cu-catalyzed aerobic oxidation process is reported. The optimal catalyst for this synthesis is based on supported copper oxide-nanoparticles, which are prepared by the impregnation and pyrolysis of simple copper nitrate on carbon. Applying these reusable nanoparticles, various simple, substituted, and functionalized aromatic, heterocyclic, and aliphatic nitriles are synthesized starting from inexpensive and easily accessible alcohols and ammonia in the presence of air. In addition, the synthesis of selected primary amides in a water medium is also performed using these Cu nanoparticles. © 2022 The Authors. Advanced Sustainable Systems published by Wiley-VCH GmbH