Master of Science / Department of Biological & Agricultural Engineering / Stacy L. Hutchinson / As an alternative to traditional disinfection methods, the use of an advanced oxidation process (AOP) was investigated for exercise in theatre to expediate water usability. The system utilized for this study was a mobile combination of UV irradiation and ozonation, which provided multiple mechanisms for treatment without the addition of chemicals. As a compact and transportable apparatus, the proposed unit would treat water for secondary purposes including vehicle washing, equipment cleaning, and other demands not involving consumption or personal hygiene. Several varying dilutions of hog farm lagoon water and military vehicle wash water were combined with microbial concentrations up to 9.10E+04 mpn/mL. The inoculant tested was Escherichia coli for frequency of occurrence and similarities to microbes of bioterrorism. The overall results for the AOP treatment do not indicate a connection between inactivation and suspended solids, but there does exist a significant relationship to contact time as indicated by changes in the flow rate. The experimental data showed a correlation to increased inactivation with lower flow rates. Although inactivation was not complete, the once through flow system could be adjusted to recirculate water for additional treatment. Due to time constraints additional testing was not possible, but the benefit could be examined in future research. The relationship of TSS to inactivation was not evident as inactivation occurred in similar distributions whether suspended solids were elevated or reduced.

Abstract Integrated optical (IO) sensor allowing sensitive, label-free, real-time and multi-parameter monitoring of bio-molecular interactions are conventionally fabricated with inorganic dielectrics inherited from CMOS manufacturing technology. Polymers as complement materials to inorganic dielectrics are becoming to have an increasing market share for IO circuits in optical communications networks owing to its good optical properties, versatile processibility and low cost. This work aims at developing disposable low-cost biosensors based mainly on polymeric materials, with a performance comparable to inorganic-dielectric based IO biosensors. This thesis describes the development of polymer IO biosensors based on the Young interferometer (YI) transducer platform for ambient noise compensation and a complete periodic intensity fringe pattern. Three different waveguide configurations were utilized, taking into consideration operational simplicity, fabrication simplicity and enhanced sensitivity. Among the developed polymer biosensors, an unconventional interferometer structure: a vertically placed dual-slab waveguide interferometer and an inverted rib waveguide configuration were employed. To enhance the sensitivity of the waveguides, deposition of Ta2O5 high index coating was performed on the rib waveguide configuration. Along with the development of polymer biosensors based on the inverted-rib waveguide configuration, a fabrication process was also developed featuring UV-imprinting and spin coating. The simple two-step fabrication process demonstrated using a polymer mold is potentially transferable to the roll-to-roll manufacture process. Calibration of the developed sensors was performed by homogeneous refractive index (RI) sensing with glucose de-ionized water solutions. By investigating an antibody – antigen binding interaction involving C-reactive protein and its conjugates, this thesis confirmed the applicability of the developed sensors to specific molecule detection. Moreover, to establish the influence of water molecular absorption on measurement stability, an evaluation was carried out on the polymeric waveguide. Finally, the thesis presented a comparison between the developed sensors, exploring their sensitivities, stabilities, limits of detection (LODs) and other aspects related to operation and fabrication. The results indicated that the Ta2O5-coated polymer waveguide sensor had a high sensing capability. In homogeneous RI sensing, the achieved detection limits were 9×10-7 RIU (refractive index unit), i.e., three times the noise level, and 270 fg/mm2 for surface mass density. / Tiivistelmä Integroidulla optiikalla toteutetut anturit mahdollistavat biomolekulaarisen vuorovaikutuksen tutkimisen käyttäen herkkiä moniparametrisia ja merkkiaineettomia menetelmiä. Näiden bioantureiden valmistukseen käytetään tavallisesti CMOS-teknologian piiristä tuttuja epäorgaanisia puolijohteita ja eristemateriaaleja. Viime aikoina on kuitenkin polymeeristen materiaalien käyttöä integroidussa optiikassa tutkittu merkittävästi johtuen polymeerien hyvistä optisista ominaisuuksista, monipuolisesta työstettävyydestä ja edullisista kustannuksista. Tämän työn tarkoituksena on kehittää edullisia, kertakäyttöisiä, pääasiallisesti polymeerisistä materiaaleista valmistettuja bioantureita, jotka vastaavat suorituskyvyltään epäorgaanisista materiaaleista valmistettuja integroidun optiikan antureita. Tässä työssä kehitetyt polymeeriset integroidun optiikan bioanturit perustuvat Youngin interferometriin mahdollistaen ympäristökohinan kompensoinnin ja ne tuottavat pintavuorovaikutusten tutkimiseen jaksoittaisen interferenssikuvion. Työssä hyödynnettiin kolmea erilaista valokanavarakennetta huomioiden niiden käytön helppous, valmistuksen yksinkertaisuus ja mittausherkkyys. Yksi kehitetyistä polymeerisistä bioantureista koostui päällekkäisistä kerrostetuista polymeerikerroksista. Toisen tutkitun rakenteen toiminta puolestaan perustui käänteiseen harjannevalokanavaan. Mittausherkkyyttä parannettiin pinnoittamalla polymeerirakenne Ta2O5-pinnoitteella. Näin muodostui kerrostettu komposiittivalokanava, joka oli tässä työssä tutkittu kolmas sensorirakenne. Itse bioanturien lisäksi kehitettiin myös valmistusprosessi, jossa hyödynnettiin UV-painatusta ja nestefaasipinnoitusta. Tässä työssä havaittiin lisäksi, että kehitetty yksinkertainen valmistusmenetelmä on paitsi toimiva, myös mahdollisesti siirrettävissä rullalta rullalle valmistus- ja tuotantoteknologiaan. Kehitettyjen anturien kalibrointi suoritettiin homogeenisella taitekerroinmittauksella käyttäen liuoksia, jotka valmistettiin glukoosista ja deionisoidusta vedestä. Kehitettyjen anturien soveltuvuus spesifien molekyylien tunnistamista varten todennettiin tutkimalla vasta-aineiden ja antigeenien sitoutumisreaktioita ja vuorovaikutusta C-reaktiivisella proteiinilla ja sen konjugaateilla. Lisäksi työssä tutkittiin veden absorption vaikutusta mittauksen stabiilisuuteen. Tutkimuksessa suoritettiin vertailu kehitettyjen anturien ja niiden ominaisuuksien välillä kiinnittäen huomiota mittausherkkyyteen, stabiilisuuteen, määritys- ja toteamisrajoihin ja muihin anturien valmistukseen sekä käyttöön liittyviin keskeisiin piirteisiin. Tulokset osoittavat, että Ta2O5-pinnoitetun polymeerivalokanavan mittausherkkyys oli suurin vertailluista rakenteista. Homogeenisessä taitekerroinmittauksessa saavutettu määritys- ja toteamisraja oli 9×10-7 taitekerroinyksikköä (RIU). Pintamassatiheysmittauksessa saavuttu tulos oli 270 fg/mm2.

Malignant melanoma is one of the most rapidly increasing cancers and accounts for about three-quarter of all skin cancer deaths worldwide. Despite compelling evidence that ultraviolet (UV) irradiation causes melanoma the knowledge how various wavelength spectra affect the balance between proliferation and apoptosis controlling the homeostasis of the melanocyte population is still limited. The aim of this thesis was to elucidate the regulation of UVA/B induced apoptotic signaling in human epidermal melanocytes in vitro in relation to redox alterations and antioxidant photoprotection. UVA irradiation induced changes in plasma membrane stability, decreased cell proliferation and increased apoptosis. In comparison, melanocyte plasma membrane was markedly resistant to UVB irradiation although apoptosis was triggered. Thus, UVA irradiation should not be overlooked as an etiologic factor in melanoma development. Further, after irradiation with UVA/B we found alterations in redox state manifested by a reduction of intracellular GSH levels, translocation of nuclear factor-κB from the cytosol to the nucleus, an increase of γ-glutamylcysteine synthetase, the rate-limiting enzyme in GSH synthesis, and an increased apoptosis frequency. α-Tocopherol provided photoprotection through several modes of action affecting redox alterations and signaling, stabilizing the plasma membrane, and decreased proliferation and apoptosis rate, while β-carotene did not show the same protective capacity. Altogether, α-tocopherol might be a useful substance in protecting melanocytes from UV induced damage. We demonstrate UVA/B irradiation to activate the intrinsic pathway of apoptosis in melanocytes where translocation of Bcl-2 family proteins to the mitochondria modulates the apoptosis signal. Interestingly, the anti-apoptotic Bcl-2 family proteins generally thought to be attached to membranes, were localized in the cytosol before UV irradiation and translocated to the mitochondria in the surviving population, which might be a critical event in preventing apoptotic cell death. Lysosomal cathepsins were released to the cytosol acting as pro-apoptotic mediators upstream of activation and translocation of Bax to the mitochondria. When melanocytes were exposed to UVA, p53 participated in apoptosis regulation through interaction with Bcl-2 family proteins, while UVB induced p53-transcriptional activity and apoptosis involving lysosomal membrane permeabilization. Thus, depending on the UV wavelength p53 mediated apoptosis in melanocytes by transcriptional dependent or independent activity. These results emphasize p53 as an important pro-apoptotic component in the regulation of apoptosis. This thesis gives new insight in the harmful and various effects of different wavelengths within the UV spectrum on human melanocytes in vitro. Improved knowledge of the apoptosis regulatory systems in melanocytes might lead to a better understanding of the formation of pigment nevi and malignant melanoma and, in the future, provide better strategies to prevent and eliminate tumor development and progression.

Across avian systems, plumage ornamentation is often considered a signal of individual fitness, condition, sex, or status, and varies due to genetics or environmental sources. In species with structural coloration, plumage variation results from differences in the amount of energy allocated to feather growth during molt, presenting a unique opportunity to study the link between individual quality and ornamentation. In cooperative breeding species, such as the Florida Scrub-Jay (Aphelocoma coerulescens), the role of structural color as a signal is particularly important because helpers may delay breeding for one to several years and competition for space is high. Florida Scrub-Jay juveniles are sexually dimorphic in the ultraviolet range, and plumage color predicts social dominance and condition, but not adult reproductive fitness. Little is known about the consistency of ultraviolet reflectance across molts, and I tested the following questions: 1) does plumage color change across molts within individuals; 2) how do environmental variables and stress affect structural color; and 3) does adult color or change in color predict reproductive fitness? I measured relative change in color within individuals by comparing their juvenile and first set of adult feathers after pre-basic molt. I used several measures of nutritional condition, social dynamics, habitat quality, and parasite infection to model color, and I experimentally administered corticosterone during pre-basic molt to examine the effects of increased stress on color. Plumage reflectance was compared with breeding status to investigate the role of color in breeding space acquisition. Plumage reflectance was significantly different within individuals across molts, but juvenile and adult color were correlated. Adults were significantly less bright than juveniles, with higher proportions of UV chroma and hues shifted toward UV wavelengths. Variation in feather color was best explained by sex, mass, parasite infection, and an interaction between area of oak scrub and group size. Juvenile feather color was also strongly associated with mother ID, but this was not the case for adults even though adult color was correlated with juvenile color. Adult chroma was reduced in birds treated with corticosterone, and hues were shifted toward longer wavelengths. No measure of adult color predicted acquisition of breeding space, but change in brightness and hue were significant predictors of acquisition for females, where breeders tended to experience greater reductions in brightness and shifts toward UV hues compared to helpers. This may be due to sex-specific differences in reproductive strategies in Florida Scrub-Jays. Females tend to disperse farther distances and breed earlier than males, potentially expending more energy foraying and searching for breeding space, which could reduce brightness if it is linked with condition. These results suggest that sexual selection is not a dominant factor in plumage ornamentation for Florida Scrub-Jays, and understanding the interaction between plumage color, personality, and reproductive fitness should be a priority for future research.

Vitamin D regulation is associated with several human disorders and contributes to various cellular mechanisms. Calcitriol (commercially available as Rocaltrol), an active Vitamin D metabolite, is known as a neuro-protective and anti-cancer drug but most importantly helps maintaining the calcium homeostasis inside the human body. The effectiveness of calcitriol to perform as an effective therapeutic agent is counteracted by its calcemic effects. In order to obtain better therapeutic results, synthetic calcitriol analogs without these calcemic effects have been recently developed but they are not yet cost-effective and their production is time-consuming. In order to determine the best active form of calcitriol that could provide higher chemotherapeutic activity without these calcemic effects, calcitriol mode of action was studied using yeast as a model system. In order to achieve this, we analyzed the calcitriol effects on yeast cellular growth based on calcium intake levels. In this work, we also assessed yeast strains with gene deletions of selected calcium transporter genes to understand the calcitriol metabolism. For the aim of understanding hypercalcemic effects of calcitriol, we developed a hypothesis based on calcitriol interactions with oxygen. Interestingly, use of an anaerobic model validated the oxygen interactions with calcitriol that might possibly cause calcemic effects on patients. Anaerobically grown yeast treated with calcitriol showed significantly less intracellular calcium levels when imaged under indo-1 calcium binding fluorescence dye as compared to calcitriol treated yeast grown under aerobic conditions. Finally, we predict that calcitriol might control free radical generation within the yeast system based on experiments with AAPH and UV- irradiation.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22497号 / 農博第2401号 / 新制||農||1077(附属図書館) / 学位論文||R2||N5277(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 矢野 浩之, 教授 和田 昌久, 教授 辻井 敬亘 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Non Melanoma Skin Cancer (NMSC) affects 3.3 million Americans each year and results from Ultra Violet Radiation (UVR) damage to DNA in the form of pyrimidine dimers and photoproducts [1]–[5]. Cells directly detect the damage and initiate apoptosis, cell cycle arrest, or DNA repair by modulating p53 and p21 levels [6]–[9]. Current methods of photoprotection include sunscreen, but controversy over safety of some active ingredients necessitates research into more natural alternatives [10]–[12]. In particular, 24 hour incubation with bovine milk sphingomyelin (BSM) has demonstrated photoprotective potential by reducing p21 and p53 levels in keratinocytes (KRTs) after UV radiation [13], [14]. This thesis aims to expand on past BSM research by exploring the mechanism for photoprotection. Normally, sphingomyelin (SM) is metabolically degraded to ceramide which then leads to cell apoptosis [6]. The goals of this thesis were to characterize a fluorescent SM (FSM) to assess changes in intracellular fluorescence distribution after various incubation and post-UV exposure times. FSM was deemed functionally equivalent to BSM by reducing levels of p21 after UV. Furthermore, quantification demonstrated that FSM trafficking and intracellular fluorescence were independent of continuous incubation time, warranting further investigation into shorter timepoints like 1 hour. Across several post-UV timepoints, the 1 hour incubation had a consistently higher average cytoplasmic mean gray value compared to 24 hour incubation. In addition, the no UV control was significantly lower compared to the 24 hour and 12 hour post-UV timepoints. No post-UV differences were observed for the 24 hour incubation, suggesting future work is necessary for the 1 hour incubation, which potentially streamlines future experiments. Two immunofluorescence stains for endogenous SM (lysenin) and ceramide were also optimized for preliminary fluorescence distribution studies and colocalization with FSM. Finally, a 3T3 fibroblast spheroid model was utilized as proof-of-concept for future 3D KRT cultures and depth of dye penetration quantification methods. These findings suggest FSM is an appropriate model for BSM trafficking, a shorter FSM incubation time could potentially be adopted in future studies, dual immunofluorescence staining for SM and ceramide is viable, and spheroids provide a promising model for future 3D KRT studies.

The thesis deals with photocatalysis of organic pollutants on UV-activated anatase particles, on UV-activated anatase particles with hydrogen peroxide and hydrogen peroxide itself. The measurement is carried out on a pilot plant UV photoreactor. The aim of the thesis is to determine the effectiveness of azo dyes and antibiotics degradation. The level of azo dyes and antibiotics degradation is measured by UV-VIS spectrometry.

There are many potential areas for the utilization of GaN-based nitride materials, including ultraviolet photodetectors. Ultraviolet photodetectors are used in the military for missile plume detection and space communications. Medically, ultraviolet photodiodes are used in monitoring skin cancer. Schottky barrier metal-semiconductor contacts are choice devices for the manufacture of ultraviolet photodiodes due to higher short wavelength sensitivity and fast response. They also require simple fabrication technology; suffer lower breakdown voltages, and record larger leakage currents at lower voltages as compared to p-n structures of the same semiconductor material. Thus the formation of a Schottky contact with high barrier height, low leakage current, and good thermal stability in order to withstand high temperature processing and operation are some of the most important factors in improving the performance of Schottky barrier photodiodes to be used for ultraviolet detection. The first stage of this study was to establish a chemical cleaning and etching technique. It was found that KOH was suitable in reducing C from the surface and that (NH4)2S further reduced the surface oxides. The next phase of the work was to select a metal that will allow UV light to pass through at a high transmission percentage: a combination of annealed Ni/Au was found to be ideal. The transmission percentage of this alloy was found to be above 80%. The next phase was the fabrication of Ni/Au Schottky barrier diodes on GaN to study the electrical characteristics of the diodes. Electrical characterization of the diodes showed that the dominant current transport mechanism was thermionic emission, masked by the effects of series resistance, which resulted from the condition of the GaN surface. Finally, we fabricated GaN UV photodiodes and characterized them in the optoelectronic station designed and produced during this research. Device responsivity as high as 31.8 mA/W for GaN and 3.8 mA/W for AlGaN were recorded. The calculated quantum efficiencies of the photodiodes were 11 % for GaN and 1.7 % for AlGaN respectively. / Thesis (PhD)--University of Pretoria, 2010. / Physics / unrestricted

Visual features of the wing colour, with special reference to the intensity of UV reflectance of the Green-veined White (Pieris napi) were investigated. Several studies revealed that only females of Pieris napi possess UV reflectance on dorsal wing surface. Based on UV sensitive photography, we analysed correlation between environmental conditions (productivity and climate) and 3 patches on forewing of 347 specimens of P. napi from Palaearctic region. Males significantly differ in level of intensity of UV reflectance from females. UV intensity in females is 25% higher in comparison with males. This phenomenon is explained by different deposition of wing pterins. Further, environment significantly affects UV intensity on the forewings of females, but not males. Moreover, we accomplished the analysis of fluctuating asymmetry. First we subjected the environmental variables to PCA. In females, the first PCA axis (temperature seasonality, temperature annual range and longitude) significantly correlated with UV intensity. In males, the second PCA axis (latitude and altitude) was significantly correlated with FA. Additionally, we performed Two-Block Partial Least- Squares (PLS) analysis to assess co-variation between intraspecific shape...