Many insect populations become darker at high elevations and high latitudes. Despite absence of empirical evidence, it is commonly believed that melanism allows more efficient basking by insects in sunlight, thereby raising body temperature and increasing activity. Variation in melanism within a single population of alpine Colias sulphur butterflies (Lepidoptera:Pieridae) allowed determination of the advantage, in cold environments, for this characteristic. Alternative hypotheses relating the effect of melanism to fecundity, predation, diel activity, and seasonal survivorship were tested by field and laboratory observation and experiment. At low temperature, melanistic females are more fecund. A balancing advantage for light coloured females does not exist at high temperatures. Dark individuals suffer lower predation rates at high altitude than do light individuals; the opposite is not true at low elevation. Duration of diel activity is markedly extended for darker butterflies under cool conditions, but only slightly for light individuals during warm sunny periods. Melanistic individuals are able to prolong the duration of activity for feeding, mate location, oviposition and escape from predation under cold conditions. This appears to the prime benefit for melanism in this population. This is the first demonstration, in a natural population, of the benefit of alpine melanism in insects. / Science, Faculty of / Zoology, Department of / Graduate

Resumo:O objetivo deste trabalho foi avaliar a adaptação marginal de coroas totais cerâmicas utilizando-se o sistema restauradores IPS Empress 2 e o sistema Ceramcap em dois momentos: após confecções dos copings e após aplicações da cerâmica de cobertura. No entanto, dez munhões de aço inoxidáveis, foram torneados produzindo preparos circulares que simulavam os preparos dentais com linha de terminação em ombro de 1, 5 mm, paredes axiais em 6 graus de convergência oclusal, ângulos axio-pulpar e axio-oclusal arredondados, altura de 7 mm, diâmetro na base do preparo de 11 mm e diâmetro na oclusal do preparo de 7, 06 mm. Caixas ou concavidades foram evitadas. Em seguida, foram moldados com silicona de adição e confeccionados os copings, conforme recomendações dos fabricantes. A avaliação da adaptação marginal foi feita com um microscópio óptico de luz visível com aumento de 100 x, acoplado com sistema de coleta de imagem, foram feitas 4 imagens para cada corpo-de-prova, foi utilizado um software Imagelab 2000 para análise das imagens, onde foram coletados 12 pontos de desadaptação para cada imagem. Os valores de desadaptação marginal foram 146 analisados através do teste T student com nível de significância de 5%. Para os sistema cerâmicos IPS Empress 2 e Ceramcap foram encontrados médias de desadaptação respectivamente de (86,1μm e 99,8μm) para os copings e de (84,5μm e 97,9 μm), após aplicado a cerâmica de cobertura. Houve diferença estatística significante entre a confecção dos copings e após as aplicações da cerâmica de cobertura, entre os dois materiais estudados. Em comparação aos dois sistemas estudados, o sistema IPS Empress apresentou menores médias de desadaptação em comparação com o sistema Ceramcap. / Abstract:The objective of this work was to evaluate the adaptation marginal of restoring ceramic total crowns using system IPS 2 Empress and the Ceramcap system at two moments: after confections of copings and after applications of covering ceramics. However, ten stainless steel trunnions, had been tilted producing circular prepare that simulated the dental prepares with line of termination in shoulder of 1, 5 mm, axial walls in 6 degrees of oclusal convergence, rounded off angles to pulpar-axio and occlusal-axio, height of 7 mm, diameter in the base of the 11 preparation of mm and diameter in the oclusal of the preparation of 7, 06 mm. Boxes or concavities had been prevented. After that, they had been molded with silicona of addition and confectioned copings, as recommendations of the manufacturers. The evaluation of the adaptation marginal was made with an optic microscope of visible light with increase of 100 x, connected to system of image collection, had been made 4 images for each body-oftest, was used a software Imagelab 2000 for analysis of the images, where 12 points of mismatch for each image had been collected. The 148 values of mismatch marginal had been analyzed through test T student with level of significance of 5%. For system ceramic IPS 2 Empress and Ceramcap they had been found average of mismatch respectively of (86,1μm and 99,8μm) for copings and of (84,5μm and 97,9 μm), after applied covering ceramics. It had difference significant statistics enters the confection of copings after and the applications of covering ceramics, between the two studied materials. In comparison to the two studied systems, system IPS Empress presented average minors of mismatch...(Complete abstract electronic access below) / Orientador: José Roberto Cyry Saad / Doutor

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22481号 / 農博第2385号 / 新制||農||1075(附属図書館) / 学位論文||R2||N5261(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 縄田 栄治, 教授 北山 兼弘, 教授 冨永 達 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Thesis (M.Sc. (Biochemistry)) -- University of Limpopo, 2020 / Despite major advancements in the development of various chemotherapuetic agents, treatment for lung cancer remains costly, ineffective, toxic to neighbouring normal noncancerous cells and still hampered by high level of remissions (Wistuba et al., 2018; Tana et al., 2016; Schiller et al., 2002). Synthesis of novel quinoxalines with a wide spectrum of biological activities has recently received considerable attention with promising anticancer drug activity since most of them do not affect non-cancerous cells and are derived from readily available less costly raw materials (Srivastava et al., 2014). Since combination treatment has been shown to augment and improve single drug treatment, trace elements were employed in this study in combination with quinoxalines derivatives (Gomez et al., 2016; Kocdor et al., 2015; Ku et al., 2012; John et al., 2010; Killile and Killilea, 2007). Zinc is an essential element that is integral to many proteins and transcription factors which regulate key cellular functions such as the response to oxidative stress, DNA replication, DNA damage repair, cell cycle progression, and apoptosis (Dhawan and Chadha, 2010). Owing to the importance of these two approaches, the aim of this study was to provide in vitro preliminary anticancer activity data on A549 lung cancer cells using combination of zinc and quinoxaline derivatives. An assessment of the quinoxaline derivatives ferric reducing power and DPPH free radical scavenging activity was performed. The cytotoxic and anti-proliferation activity of these derivatives and zinc on cancer cell lines was determined using the MTT assay. The ability of the quinoxaline derivatives and zinc to modulate oxidative stress was evaluated using the H2DCFDA fluorescence assay. Cell cycle arrest stages were analysed by flow cytometry through propidium iodide cell cycle analyses. The ability of the quinoxaline derivatives to induce apoptosis in cancer cells was assessed using DAPI/PI, Acridine Orange/Ethidium Bromide (AO/EB) and Annexin V-FITC/Dead Cell assays. Western blot was used to investigate the Bcl/Bax expression ratios in A549 lung cancer cells after treatment with quinoxaline derivatives, zinc and in combination. Of the four quinoxaline derivatives tested, 3-(quinoxaline-3-yl) prop-2-ynyl methanosulphate (LA-39B) and 3-(quinoxaline-3-yl) prop-2-yn-1-ol (LA-55) produced significant anticancer properties against A549 lung cancer cells at minimal concentrations of 25μM. Both quinoxaline derivatives displayed antioxidant properties and did not induce cell death in non-cancerous Raw 267.4 macrophage cells. Cytotoxicity was observed in A549 lung cancer, HeLa cervical cancer and MCF-7 breast cancer cells albeit inhibition was more pronounced in A549 lung cancer cells. Treatment of cancer cells with zinc also resulted in pronounced cytotoxicity at a minimal concentration of 25μM. Although reduced oxidative stress was observed in Raw 264.7 macrophages, in A549 lung cancer cells both compounds were able to increase ROS production which was accompanied by high levels of apoptosis when treated with derivatives and zinc alone but when in combination an improved higher level of apoptosis is observed. The improved anti-cancer activity of this drug combination treatment was further accompanied by lower Bcl/Bax expression ratios with upregulation of Bax in A549 lung cancer cells. The results of the study suggest that 3-(quinoxaline-3-yl) prop-2-ynyl methanosulphate and 3-(quinoxaline-3-yl) prop- 2-yn-1-ol are potential candidates drug for treatment of lung cancer. The use of these quinoxaline derivatives in combination with zinc can offer alternative treatment options for lung cancer.

It is no surprise that there is a shortage of women engineers. The reasons for the shortage have been researched and discussed in myriad papers, and suggestions for improvement continue to evolve. However, there are few studies that have specifically identified the positive aspects that attract women to engineering and keep them actively engaged in the field. This paper examines how women engineers view their education, their work, and their motivation to remain in the field. A qualitative research design was used to understand the motivation and adaptability factors women use to support their decision to major in engineering and stay in the engineering profession. Women engineers were interviewed using broad questions about motivation and adaptability. Interviews were transcribed and coded, looking for common threads of factors that suggest not only why women engineers persist in the field, but also how they thrive. Findings focus on the experiences, insights, and meaning of women interviewed. A grounded theory approach was used to describe the success factors found in practicing women engineers. The study found categories of attraction to the field, learning environment, motivation and adaptability. Sub-categories of motivation are intrinsic motivational factors such as the desire to make a difference, as well as extrinsic factors such as having an income that allows the kind of lifestyle that supports the family. Women engineers are comfortable with and enjoy working with male peers and when barriers arise, women learn to adapt in the male dominated field. Adaptability was indicated in areas of gender, culture, and communication. Women found strength in the ability to ‘read’ their clients, and provide insight to their teams. Sufficient knowledge from the field advances theory and offers strategies to programs for administrators and faculty of schools of engineering as well as engineering firms, who have interest in recruitment, and retention of female students. Future research includes expanding the research to other areas of the United States, and improving engineering education pedagogy with more active and experiential learning.

This study takes an integrative approach to intercultural adaptation by looking at the role of values (i.e. social norms) in the acculturation of Canadian expatriates living in Vietnam. By viewing intercultural adaptation as a process by which expats and host-members “establish (or re-establish) and maintain relatively stable, reciprocal, and functional relationships” (Kim, 2001, p. 3) with their environment, this study focuses on moments of apparent ambiguity, misunderstanding or malaise experienced by expats in their host-community. This emphasis will enable us to better understand how expatriates make sense of their values and social norms during these instances. This research not only sheds light on the ways in which expats make sense of their values, but also how their narratives and stories participate in creating, constituting, and cultivating certain figures during their intercultural adaptation process. The data gathered reveals that the ways in which expats make sense of their values during moments of malaise with their host-community varies quite meaningfully depending on various situational, institutional and personal factors at play during each interaction, as well as what matters most to expats during those moments. Thus, these findings assist in showcasing that misunderstandings experienced in the host-community are complex, as expats consider many factors in order to make sense of, respond to, and adapt to each individual situation.

Cities today have become a playground for man-made security threats. From terrorism, drug abuse, and different forms of physical violence that impedes the smooth functioning of the activities of those living within the city spaces. Considering the present day violence and insecurity in our cities, it is vital not only to embark on preventive measures, but also to learn how to cope with and adapt to them. Since it would be an illusion to think of eliminating violence, resilience becomes an important aspect, a gateway to move on with our daily activities without fear and with greater hope for a better future. It is in this respect that I decided in this thesis to talk about resilience within our municipalities with a special focus on the city of Johannesburg in South Africa.

Sound transmission by the hyoid apparatus during echolocation in bats Chelsie C.G. Snipes1 and Richard T. Carter1 1 East Tennessee State University, Johnson City TN, USA The morphology of the stylohyal-tympanic bone articulation found in laryngeally echolocating bats is highly indicative of a function associated with signal production. One untested hypothesis is that this morphology allows the transfer of a sound signal from the larynx to the tympanic bones (auditory bulla) via the hyoid apparatus during signal production by the larynx. To test this hypothesis, we used µCT data, CAD editing software, and finite element analysis (FEA) to model the propagation of sound through the hyoid chain into the tympanic bones. This involved making digital segmentations from the µCT data of the tympanic bones and cartilaginous segments and converting it into a digital mesh body. Since the cartilaginous segments are not visible in CTs, we segmented the air in each gap and subsequently used a Boolean function in CAD software to fit each bony end into their respective cartilaginous segment. Further post-processing of the model included a reduction in the number of facets bodies and smoothing surfaces which allowed us to convert it into a solid body model. The solid body geometry was then uploaded into FEA software and assigned material properties for cortical bone, cartilage, and bulla. Additional biomechanical data, including Young’s Modulus, Poisson’s ratio, and speed of sound through each material were defined in previous literature. We ran two FEA analysis with our model: the first was an acoustic analysis that modelled sound propagation through our material (bone and cartilage), and the second was a coupled modal and structural analysis that modelled resonant behavior and sound pressure wave propagation from the hyoid body to the tympanic bones. Our models support the hypothesis that bats use this physical connection between the larynx and auditory bulla to transfer sound (mechanical excitation). Our models show both pressure waves and vibration due to resonance could be used to transfer this signal and this resonance behavior can be modulated by restraining the hyoid apparatus, perhaps through muscle contraction. We propose that by modulating the resonant behavior of the hyoid apparatus, bats can selectively filter which frequencies of sound are transferred from the larynx to the auditory bulla during echolocation signal production.

Many studies have investigated the ecological factors that affect behavior in Micrathena gracilis, a diurnal orb-weaving spider that forages exclusively on flying insects during the day. However, none yet have considered how the temporal distributions of prey and predator occurrences shape their daily behavioral rhythms, especially web construction which involves a heavy energetic investment well in advance of potential nutritional benefit. Recently, other spider species have been found to express significant circadian plasticity, suggesting that circadian clock-controlled rhythms may play a larger role in niche partitioning than once thought. Despite the appearance of significant insect abundance in the evenings, M. gracilis individuals stop foraging, take down their webs, and retreat before they can capitalize on this opportunity. Is the nutritional benefit of this forfeited prey significant compared to what they collect during the day, and if so, what potential cost might justify opting out of this potential gain? To investigate, sticky traps for prey collection and a camera array for recording predator activity were used at a local field site to survey what risks and rewards these spiders face throughout the 24-hour day. Spider activity in a lab environment and web captures in the field were also used to confirm behavioral patterns and nutrient uptake throughout the day. It was found that significant prey biomass is given up shortly after the time that spiders typically retreat, suggesting that the spiders truly forfeit this prey and do not simply retreat due to a gradual decrease in overall prey availability. Spiders reliably cease foraging in the early evening and show agitation throughout the night when not comfortably hidden, suggesting that significant extension of foraging behavior may be harshly punished. However, recorded predation events from the camera array were much rarer than anticipated, and no predation was confirmed in the evening. These results support the notion that these spiders’ circadian rhythms are shaped by factors other than prey availability, but more work is necessary to identify these factors

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