Face recognition is a challenging problem in computer vision. Difficulties such as slight differences between similar faces of different people, changes in facial expressions, light and illumination condition, and pose variations add extra complications to the face recognition research. Many algorithms are devoted to solving the face recognition problem, among which the family of nonnegative matrix factorization (NMF) algorithms has been widely used as a compact data representation method. Different versions of NMF have been proposed. Wang et al. proposed the graph-based semi-supervised nonnegative learning (S2N2L) algorithm that uses labeled data in constructing intrinsic and penalty graph to enforce separability of labeled data, which leads to a greater discriminating power. Moreover the geometrical structure of labeled and unlabeled data is preserved through using the smoothness assumption by creating a similarity graph that conserves the neighboring information for all labeled and unlabeled data. However, S2N2L is sensitive to light changes, illumination, and partial occlusion. In this thesis, we propose a Semi-Supervised Half-Quadratic NMF (SSHQNMF) algorithm that combines the benefits of S2N2L and the robust NMF by the half- quadratic minimization (HQNMF) algorithm.Our algorithm improves upon the S2N2L algorithm by replacing the Frobenius norm with a robust M-Estimator loss function. A multiplicative update solution for our SSHQNMF algorithmis driven using the half- 4 quadratic (HQ) theory. Extensive experiments on ORL, Yale-A and a subset of the PIE data sets for nine M-estimator loss functions for both SSHQNMF and HQNMF algorithms are investigated, and compared with several state-of-the-art supervised and unsupervised algorithms, along with the original S2N2L algorithm in the context of classification, clustering, and robustness against partial occlusion. The proposed algorithm outperformed the other algorithms. Furthermore, SSHQNMF with Maximum Correntropy (MC) loss function obtained the best results for most test cases.

Ring-opening metathesis polymerization (ROMP) is a robust synthetic technique for synthesizing complex polymer architectures (topologies). To achieve complex architectures, specifically bottlebrush polymers, using ROMP, attaining the highest degree of living character is essential. As the molecular weight of the side chain or backbone increases, the "livingness" of the polymerization suffers due to premature catalyst degradation. Attaining large, well-defined, bottlebrush polymers requires precision so it was our goal to determine how seemingly simple reaction variables could affect the rates of propagation and achievable conversion, as well as why these variables have these effects. We tested several reaction parameters to understand how they affect the rate of polymerization, the rate of catalyst degradation, and the conversion that can be reached. We performed a systematic study using six organic solvents to determine the propagation rate of three macromonomers (MMs), one polystyrene and two poly(n-butyl acrylate) MMs, in ROMP with varying side chain chemistries and end groups, as well as rate of catalyst degradation in each of the solvents. We determined that solvent affected that rate of propagation primarily by interacting with the catalyst, while there was some evidence of polymer sidechain chemistry affecting the rate. We found that ethyl acetate (EtOAc) and CH2Cl2 had the highest rates of propagation compared to the other solvents, while DMF and THF were the slowest. UV-Vis testing on the catalyst in each solvent revealed that DMF and THF had fast rates of catalyst decomposition, while toluene was much slower to decompose. From these experiments we learned that toluene, despite its slower propagation rate, has the most living character, due to its slower rate of decomposition. We also learned that purification greatly affects the propagation rate, with THF requiring purification to have any conversion to bottlebrush polymer, while purification of EtOAc slows the rate of propagation almost 2-fold. From the decrease in rate after purification, and the conclusion that it was due to an acetic acid impurity in the impure EtOAc, we decided to systematically test small molecule additives and found that acids can increase the propagation rate and the conversion of the polynorbornene backbone achievable in ROMP reactions. Notably, in reactions performed in DMF with added CF3COOH we were able to polymerize a norbornene-functionalized unprotected peptide, which was insoluble in most organic solvents, to a higher conversion than in DMF without the added acid. We learned from our research that changing reaction variables can lead to substantial changes in the rate of propagation as well as the achievable conversion in bottlebrush polymer synthesis. By understanding this we can further test other reaction variables and do systematic studies on atmosphere and temperature. We hope this research and future fundamental research can guide scientists toward synthesizing large, well-defined, complex polymer architectures using ROMP. / Doctor of Philosophy / Nature has shown that complex molecular architectures lead to unique material properties. This has inspired scientists to synthetically mimic nature to create these polymer architectures in an effort to obtain novel material properties. Ring-opening metathesis polymerization (ROMP) has become a powerful synthetic method for synthesizing complex polymer architectures. Specifically, ROMP has been used to synthesize bottlebrush polymers, so named due to the polymer backbone with long, densely grafted, polymer side chains attached. These materials exhibit very interesting properties compared to their linear polymer counterparts. Using ROMP to synthesize bottlebrush polymers is not uncommon; however, difficulties can arise if trying to use sidechains that are very long or bulky. We have worked to understand how manipulating some of the reaction parameters can allow us, and other researchers, to synthesize bottlebrush polymers that contain long and/or bulky polymer side chains. We tested the purity and type of solvent that the reaction was performed in on one polystyrene macromonomer and two poly(n-butyl acrylate) macromonomers, as well as adding small molecules, including acids, bases, and salts, to determine if these variables could improve the synthesis of bottlebrush polymers. What we found was that all of the tested variables, solvent, purity, additives, and combinations of all of these variables, did have an effect on the synthesis of these materials. This fundamental information will assist our lab, and many others, in efficiently synthesizing complex architectures, thus achieving unique material properties.

This dissertation describes the design and synthesis of a series of half-sandwich amino acid complexes of the form), (aa = α-amino carboxylate), and their utility as asymmetric transfer hydrogenation catalysts of ketones. Variation of the metal center, the n-ring, and the aa was used to tune these systems for specific sets of ketones. Upon reaction with homochiral]s, the ligand environment in all of these complexes is pseudotetrahedral, leading to stereogenic metal ions (SM, RM). The addition of another stereogenic center from the amino acid ligand (the carbon, RC or SC;glycine) gives rise to two pairs of diastereomeric complexes. / Ph. D.

Understanding how nitrifiers react when exposed to low DO conditions could provide a greater understanding of low DO operations in full-scale biological wastewater treatment. Previous methods to observe nitrifier oxygen kinetics do exist in literature, however they are inefficient and labor intensive. Other more efficient methods require the use of selective inhibitors, which alter the characteristics of the biomass. This study developed a time and labor efficient respirometric method to distinctly measure oxygen half-saturation coefficients for both ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) without the use of selective inhibitors. By eliminating the use of inhibitory substances, representative biomass characteristics were maintained throughout the tests. The developed method, called the declining DO method, consisted of using a high-speed dissolved oxygen (DO) probe to measure relative oxygen uptake rates (OUR) within a batch reactor when varying substrates (ammonia and nitrite) were present in excess within the system. A forward model was developed based on Monod kinetics to simultaneously fit Monod curves to the experimental OUR data. These curves were fit by solving for optimum oxygen kinetic parameters representing endogenous respiration, NOB, and AOB. An inverse model using Markov chain Monte Carlo analysis was applied to the results found in the forward model to provide statistical validation of the proposed respirometric method. A separate method, called the substrate utilization rate test, was conducted in parallel with the declining DO tests to compare and verify oxygen half-saturation coefficient results. Parallel tests were conducted using biomass samples from three different Hampton Roads Sanitation District (HRSD) full-scale facilities. Operating conditions between the three HRSD facilities were considered when performing parallel testing, including averages for DO, solids retention time (SRT), and floc size. Average floc size was found to have a significant effect on the observed oxygen half-saturation values. Observed trends for the KO values estimated using the two methods remained consistent throughout all tests, where KO,NOB was always lower than KO,AOB. The comparison of the two methods highlighted some faults associated with the substrate utilization rate test, which is commonly used in literature to observe nitrifier oxygen kinetics. The declining DO method appeared to be more resistant to potential experimental error and required less than half the time compared to the substrate utilization rate test. The development of the declining DO method without the use of selective inhibitors provided a more time and labor efficient technique for estimating apparent KO values for NOB and AOB without sacrificing biomass characteristics representative of the full-scale treatment process. Biomass samples collected from variable treatment process conditions yielded consistent parallel test results, providing further evidence that the proposed declining DO method can be a robust and reliable technique for distinctly measuring apparent oxygen half-saturation values for NOB and AOB. / Master of Science / Wastewater treatment operations utilizing biological nitrogen removal (BNR) require a continuous supply of oxygen for aerobic processes. Energy costs associated with aeration generally accounts for at least 50% of the total energy consumption at conventional activated sludge wastewater treatment facilities. Operating aerobic zones at low average dissolved oxygen (DO) concentrations could be an effective way to significantly reduce aeration costs as well as material costs associated with BNR treatment processes. This study developed a method to measure oxygen kinetics for the two groups of autotrophic bacteria responsible for performing nitrogen removal. The method consisted of measuring relative oxygen uptake rates (OUR) within a batch reactor when varying substrates were available. This method is unique from previously developed techniques in that the use of selective inhibitors was not included, meaning the characteristics of the wastewater were largely unchanged and therefore better represent biomass conditions within the full-scale process. The results of the proposed method were verified using an alternate method for estimating oxygen kinetics. These two methods were conducted in parallel using biomass samples from several full-scale Hampton Roads Sanitation District wastewater treatment facilities utilizing a variety of process designs and operating conditions. Consistent results obtained between the two methods suggested the proposed method is an effective technique for distinctly measuring nitrifier oxygen kinetics.

There is an urgent need to find novel anticancer therapeutics with different mechanisms of action than platinum-containing drugs, particularly for patients who relapse after having been initially treated with a platinum-containing chemotherapy regimen. This chemoresistance phenomena, along with the serious side effects observed with cisplatin, have led research in Medicinal Inorganic Chemistry to using other precious metals for the design of novel anticancer therapeutics. This work reports on the synthesis and characterisation of a series of organometallic drug candidates based on ruthenium, osmium, rhodium, and iridium, followed by investigation of their cancer-inhibiting properties via in vitro and in vivo studies. The cytotoxicity of these complexes against various human cancer cell lines is presented, as well as preliminary studies on their possible modes of action, determined via gene expression studies, cell cycle and apoptosis analysis, reactive oxygen species detection and mitochondrial-membrane potential assays. In addition, to confirm the surprising absence of in vitro toxicity against normal cells exhibited by some compounds, studies on ex vivo/in vitro isolated human lymphocytes from healthy individuals, have been conducted. One lead molecule has been progressed to in vivo studies in mice and toxicity and efficacy were assessed with a series of assays including determination of the maximum tolerated dose and pharmacodynamic studies. Structural modifications of the lead molecule with water-soluble phosphines were subsequently undertaken, with the aim to improve the stability and solubility of the parent 16-electron specie, and evaluations of the biological activity of these novel complexes are presented.

This dissertation describes the synthesis and antimicrobial use of a series of half-sandwich Ir(III), Rh(III), Co(III) amino acid and ethylenediamine complexes. This investigation focuses on the formulation (ηn-arene)M(L)X, (L = ethylenediamine or α-amino carboxylate), (M= Ir, Rh, Ru, Co). Arene, Ligand and metal center variations were designed to tailor antimicrobial activity specific for each organism studied (Staphylococcus aureus or Mycobacteria). Each of the D/L-amino acids formed a diasteromeric complex with chiral centers on both the metal center and amino acid ligand. The unique chirality of each center elicits different antimicrobial activity against the Mycobacteria studied. The metal center (M), arene ligand (ηn-arene), and amino acid (aa), were changed independently and studied for the antimicrobial activity. In a similar fashion, each of the complexes modified with ethylenediamine and diamine derivatives were studied for their antimicrobial activity against S.aureus. All complexes were synthesized,characterized by nuclear magnetic resonance (NMR), high-resolution mass spectroscopy (HRMS), single-crystal X-ray diffraction, and elemental analysis. During the course of this work it was found that the amino acid complexes with all metal centers were specific for antimicrobial activity against all types of Mycobacteria, while the diamine derivatives were active against different strains of S.aureus. Acitvity was measured to be as low as 2 ug/mL respectively depending on the complex used. A structure activity relationship was developed to determine what combinations of ligand, metal and arene were necessary to achieve the highest antimicrobial activity. The optimal arene R-chain length for CpR was determined to be R=hexyl for all complexes studied. The most active amino acidcomplex was determined to be that of L-phenylglycine for Mycobacteria, the cis-1,2-diaminocyclohexane complex is the most active ligand against S.aureus. Each metal center had similar activity levels. Toxicological studies were performed to test their viablity to be used in mammalian systems. The complexes with the highest activity were studied against several mammailan cell lines and revealed that mammailan cells were undergoing normal cellular processes at up to 40 times the minimal inhibitory concentration (MIC). A study of the MOA or mechanism of action revealed the ability of the amino acid complexes to affect the peptidyl transferase region on the 23s ribosomal subunit of M.smegmatis. This was accomplished by isolating resistant strains of M.smegmatis towards the most effective complex (Cp*hexyl)Ir(L-phenylglycine)-Cl. Cross drug resistance of these mutants was shown with clarithromycin. The DNA of the 23s ribosomal subunit was sequenced revealing a deletion/insertion mutation within domain V (bases 2057-2058). / Ph. D. / This disserataion discribes the discovery of laboratory created synthetic organometallic molecules (carbon and metal containing molecules) that exhibit antimicrobial properties. Each of these molecules are specifically designed and tailored to combat several infectious and antibiotic resistant disesaes. The different and unique compositions of each of these novel molecules allows for a potentially new class of antibiotics. Each of these organometallic molecules was able to be tailored to comabt either Staphylococcus aureus or Mycobacteria. Each of these bacteria have significant health risks and are a growing threat to public health. During the course of this work it was found that the molecules containing amino-acids were specific for activity against all types of Mycobacteria studied. The diamine containing molecules were specific for gram positive bacteria (Staphylococcus aureus). Actvity to confirm this activity was measured by MIC (Minimal inhibitory concetration). This is the amount of the molecule that is needed to stop the growth of the bacteria studied. The complexes with the highest activity were tested for their potential hazardous interactions with mammalian cells. It was revealed that not only do these molecules have activity in combating potentially deadly pathogens but they are not active against several mammalian cell lines. This shows that these can be possible candidates for a new line of antimicriobial drugs.

No / Half-sandwich complexes of precious metals are a versatile class of organometallic compounds. Their accessibility, robustness, and air-stability are examples of the unique properties that allow their applications in various fields of chemistry (e.g. catalysis), and as anticancer drug candidates. Half-sandwich complexes generally follow the 18-electron rule, although some stable 16-electron (16-e) complexes have been isolated. The latter are generally coordinatively unsaturated leading to potential applications in catalysis and as precursors for 18-electron (18-e) complexes. Six 16-e complexes [Ru(η6-p-cymene)(1,2-benzene-1,2-dithiolato)] (1), [Os(η6-p-cymene) (1,2-benzene-1,2-dithiolato)] (2), [Ir(η5-pentamethylcyclopentadiene) (1,2-benzene-1,2-dithiolato)] (3), [Ru(η6-p-cymene)(1,2-dicarba-closo- dodecaborane-1,2-dithiolato)] (4), [Os(η6-p-cymene)(1,2-dicarba-closo- dodecaborane-1,2-dithiolato)] (5), and [Ir(η5-pentamethylcyclopentadiene)(1,2-dicarba-closo-dodecaborane-1,2-dithiolato)] (6) were synthesised by reactions between 1,2-benzenedithiol (1, 2, 3) or 1,2-dicarba-closo-dodecaborane-1,2-dithiol (4, 5, 6) and the corresponding metal dimers. In solution (10-4 M) at ambient temperature, the six complexes are stable electron-deficient 16-electron monomers, although the formation of a more electronically stable 18-electron dimer is observed for complex 1 at millimolar concentrations. The six complexes exhibit dramatic differences in reactivity towards electron-donor molecule. The in-vitro anti-inflammatory activities of the 16-e complexes 1 – 6 were investigated on MRC 5-fibroblast and lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Cells were exposed for 24h to the 16-e complexes 1 – 6 in the concentrations range of 10, 20, 50 and 100uM. After this, drugs were removed and nitric oxide (NO) concentration in the cultured medium was determined by the Griess reaction. Cells were then washed and placed in fresh growth medium for a further 24h as a recovery period. Cell viability was then assessed by MTT assay. Our preliminary data showed that complex 1 – 6 showed some anti-inflammatory effect on both lines, but with slightly differences between them, suggesting that the M-S2C2 scaffold of the electron-deficient complexes is the main structural moiety responsible for such effect. Further studies will focus on the matching these effects with their structures. / Abstract of conference paper.

Yes / Ruthenium compounds have been shown to be promising alternatives to platinum(II) drugs. However, their clinical success depends on achieving mechanisms of action that overcome Pt-resistance mechanisms. Electron-deficient organoruthenium complexes are an understudied class of compounds that exhibit unusual reactivity in solution and might offer novel anticancer mechanisms of action. Here, we evaluate the in vitro and in vivo anticancer properties of the electron-deficient organoruthenium complex [(p-cymene)Ru(maleonitriledithiolate)]. This compound is found to be highly cytotoxic: 5 to 60 times more potent than cisplatin towards ovarian (A2780 and A2780cisR), colon (HCT116 p53+/+ and HCT116 p53−/−), and non-small cell lung H460 cancer cell lines. It shows no cross-resistance and is equally cytotoxic to both A2780 and A2780cisR cell lines. Furthermore, unlike cisplatin, the remarkable in vitro antiproliferative activity of this compound appears to be p53-independent. In vivo evaluation in the hollow-fibre assay across a panel of cancer cell types and subcutaneous H460 non-small cell lung cancer xenograft model hints at the activity of the complex. Although the impressive in vitro data are not fully corroborated by the in vivo follow-up, this work is the first preclinical study of electron-deficient half-sandwich complexes and highlights their promise as anticancer drug candidates. / UF150295/Royal Society; University of Bradford; Government Department of Business, Energy and Industrial Strategy; SBF003\1170/British Heart Foundation Springboard Award; AMS_/Academy of Medical Sciences/United Kingdom

Yes / Electron‐deficient half‐sandwich complexes are a class of under‐studied organometallics with demonstrated potential as metallodrug candidates. The present study investigates the effect of two 16‐electron organoruthenium complexes ([( p‐ cym)Ru(benzene‐1,2‐dithiolato)] ( 1 ) and [( p ‐cym)Ru(maleonitriledithiolate)] ( 2 )) on the cell viability of non‐immortalised human lymphocytes from healthy individuals. The genotoxic effects of 1 and 2 in lymphocytes using the Comet and cytokinesis‐block micronucleus assays is also investigated. Gene expression studies were carried out on a panel of genes involved in apoptosis and DNA damage repair response. Results show that the two 16‐electron complexes do not have significant effect on the cell viability of human lymphocytes from healthy individuals. However, an increase in DNA damage is induced by both compounds, presumably through oxidative stress production. / This project was supported by the Royal Society (University Research Fellowship No. UF150295 to NPEB), the University of Bradford (RDF Award), and by the Academy of Medical Sciences/the Wellcome Trust/ the Government Department of Business, Energy and Industrial Strategy/ the British Heart Foundation Springboard Award [SBF003\1170 to NPEB].

Uma nova família de distribuições denominada distribuição beta generalizada semi-normal, que inclui algumas distribuições importantes como casos especiais, tais como as distribuições semi-normal e generalizada semi-normal (Cooray e Ananda, 2008), é proposta neste trabalho. Para essa nova família de distribuições, foi realizado o estudo da função densidade probabilidade, função de distribuição acumulada e da função de taxa de falha (ou risco), que não dependeram de funções matemáticas complicadas. Obteve-se uma expressão formal para os momentos, função geradora de momentos, função densidade da distribuição de estatística de ordem, desvios médios, entropia, contabilidade e para as curvas de Bonferroni e Lorenz. Examinaram-se os estimadores de máxima verossimilhança dos parâmetros e deduziu- se a matriz de informação esperada. Neste trabalho é proposto, também, um modelo de regressão utilizando a distribuição beta generalizada semi-normal. A utilidade dessa nova distribuição é ilustrada através de dois conjuntos de dados, mostrando que ela é mais flexível na análise de dados de tempo de vida do que outras distribuições existentes na literatura. / A new family of distributions so-called beta generalized half-normal distribution, which includes some important distributions as special cases, such as the half-normal and generalized half-normal (Cooray and Ananda, 2008) distributions, is proposed in this work. For this new family of distributions, we studied the probability density function, cumulative distribution function and failure rate function (or hazard function), which did not depend on complicated mathematical functions. We obtained a formal expression for the moments, moment generating function, density function of order statistics distribution, mean deviation, entropy, reliability and Bonferroni and Lorenz curves. We examined maximum likelihood estimation of parameters and provided the information matrix. This work also proposed a regression model using the beta generalized half-normal distribution. The usefulness of the new distribution is illustrated through two data sets by showing that it is quite °exible in analyzing lifetime data instead other distributions in the literature.