archives@tulane.edu / 1 / Jessica Margaret Mary Motherwell

Abstract The function of the nervous system is based on the targeted transmission of electrical impulses assuring the coordinated function of tissues and organs. Myelination of the neuronal axons allows the fast saltatory conduction by producing repetitive sites where sodium channels cluster on the axolemma. In the peripheral nervous system (PNS), myelin is formed by differentiation of the Schwann cell plasma membrane. The cells form myelin by first wrapping consecutive layers of the plasma membrane around the axons and then excluding almost all of the cytoplasm from the structure, forming compacted and non-compacted membrane compartments. The myelin-associated glycoprotein (MAG) is located in all of the non-compacted regions of the PNS myelin sheath. Its two isoforms, L-MAG and S-MAG, differ only by the carboxy-terminal tails of their respective cytoplasmic domains. Both of the MAG isoforms are found in PNS myelin. They are differentially expressed during development and, until now, it has been thought that L-MAG is not present in the mature PNS myelin sheaths of murines. This study shows that both MAG isoforms can be found in different non-compacted membrane compartments in the mature PNS myelin sheaths in dorsal root ganglia (DRG)/Schwann cell cocultures. Early myelin development and myelin maturation were analyzed by means of a study of the expression of two early myelin markers, MAG and galactosyl cerebrosides (Gal-CB), believed to play roles in both myelin formation and maintenance. In order to allow the exploitation of the full potential of the DRG/Schwann cell coculture model through the use of mouse mutants, a coculture method was developed in which mouse DRGs and Schwann cells are able, for the first time, to produce significant amounts of myelin. To further explore the role of MAG in myelin maintenance and stability, the stability of purified MAG was studied through extensive degradation experiments.

Disorders affecting articular cartilage are amongst the most common problems in orthopaedics. Osteoarthritis, the end stage of the disease of articular cartilage, reduces the quality of life for tens of millions of people in the world, and has a profound impact on the economics of industrialized countries. Despite progress in articular cartilage research, the problem is still far from being defeated. Various models e.g. in vitro cartilage explants and in vivo animal models, have been established for cartilage research, but each has its own limitations. Thus, a novel ex vivo isolated joint organ culture model was developed. Bovine metatarsophalangeal joints were chosen as a suitable synovial joint because it consists of a hinge-type joint that is similar to the human knee joint, and has a large cartilage surface that provides enough space for multiple sampling in the same joint. The joints were isolated aseptically and placed into culture media. The viability of chondrocytes, glycosaminoglycan (GAG) content of cartilage matrix, cartilage morphology and water content of matrix were evaluated under different culture conditions, i.e. static, static with flowing media, and dynamic with different durations of the movement period. The model was used to investigate the effect on the sharp scalpel cartilage injury of adding serum to the culture medium by culturing the whole joint explants in serum-supplied or serum-free media. The feasibility of investigating the early phases of chondrocyte implantation in this model was also studied: circular holes of 2.5 mm diameter were created by making a pilot hole with a 2.0 mm drill followed by using a fresh 2.5 mm biopsy punch. Allogeneic isolated chondrocytes at different passages were aggregated as cell pellets and implanted in the holes to evaluate their integration ability and the response from the recipient cartilage. Results from the static model showed that, after 28 days culture, the chondrocytes were still alive with 66.5%, 80.9% and 46.9% viability in the superficial, middle and deep zones, respectively. The GAG content of the static model decreased 19.2% after the first week of culture and then lost another 15.0% during the third week. Paradoxically, at end of the 4th week the GAG level rebounded to some extent and increased 19.0% relative to the previous week. Interestingly, the cell viability of all three zones improved if the culture fluid was flowing as seen with the experiments carried out with stirred media or dynamic movement of the articular surfaces. (e.g. for the stirred media after 28 days of culture the chondrocyte viability was 80.6%, 92.4% and 70.4% for the superficial, middle and deep zones respectively.) The GAG content was maintained at a constant level in the contact area of the dynamic model, but decreased as in the media-stirred model and non-contact area of the dynamic model to a similar extent to that observed with the static model. In the injury model, the GAG content fell approximately 10.8% straight after the scalpel cut, but no further loss was observed if the joint was cultured in the serum-supplied media. In contrast, if the injured joint was cultured in the serum-free media, the GAG content continued to fall week by week and finally dropped by 41.7% at the end of the 4th week. In the chondrocyte implantation model, the majority of the host chondrocytes around the circular defect were alive (78.5 % viability). Viewed from the surface, the dead cells were all within 20 μm from the cut edge. The implanted chondrocytes, which were aggregated as cell pellets, began to transform their shapes and spread to the surrounding surface of the recipient cartilage, but did not appear to integrate with the host tissue during the first 2 weeks of culture. The results supported the validity of this ex vivo joint model and demonstrated that the chondrocytes subjected to flow of the media or dynamic loads survived well over a 4 week period. Of importance was the finding that there was no measured loss of the matrix GAG content when the joints were under dynamic load compared to all of the non-loaded conditions. This whole joint model could be of value in providing a more natural and controllable platform where research involving the normal processes or pathologic mechanisms of articular cartilage can be investigated, as well as the early response to newly developed pharmacological agents and cartilage tissue engineering constructs.

Magister Commercii (Industrial Psychology) - MCom(IPS) / At present organisations are faced with considerable changes in the business environment due to globalisation illustrated through specialisation and individualisation in the workplace (Rastegar & Aghayan, 2012). To stay abreast of these changes, organisations attempt to gain competitive advantage within the competitive business environments they operate. The competitive advantage referred to is, enhancing the organisation's culture, so as to ensure the employees in the workplace stay committed (Acar, 2012). Dwivedi, Kaushik and Luxmi (2014) further add that organisation culture is a fundamental element to any activity in the organisation. The authors also purport that a good organisational culture, which yields self-actualisation needs such as capability development, empowerment, achievement and recognition leads to a greater level of commitment between employees. The inverse, that is, poor organisational culture, leads to lower levels of commitment with consequences such as increased employee turnover and lower productivity rates (Dwivedi et al., 2014). The purpose of this study was to examine the influence of organisational culture (sub-dimensions being, mission, involvement, adaptability and consistency) on organisational commitment (sub-dimensions being, affective commitment, normative commitment and continuance commitment). The sample was chosen by means of convenience sampling. Two hundred and thirty – six supervisory and managerial staff who were employed at a beverage company in the Western Cape partook in the study. Three questionnaires were utilised to collect the data namely, a self - developed biographical questionnaire, containing six items which was used to collect information pertaining to the demographics of the sample. The second questionnaire utilised was the Denison Organisational Culture Survey, which contained 60 items and the final questionnaire administered was Allen and Meyer's (1990) Organisational Commitment Questionnaire, which contained 24 items. The data was computed using the Statistical Programme for the Social Sciences (SPSS) software version 23 using a multiple regression technique, yielding the following results: The results indicated that a significant proportion of the variance in organisational commitment was explained by mission, involvement, adaptability and consistency. The most statistical significance predictors of organisational commitment were mission and consistency, however, mission contributed to the highest variance. Additionally, the results indicated that a significant proportion of the variance in affective commitment was explained by mission, involvement, adaptability and consistency amongst staff. Involvement, adaptability and mission were found to be significant predictors of affective commitment with involvement accounting for the highest variance. Furthermore, the results showed that a significant proportion of the variance in normative commitment was explained by mission, involvement, adaptability and consistency. Moreover, the most significant predictor of normative commitment was found to be consistency. Further findings found that a significant proportion of the variance in continuance commitment was explained by mission, involvement, adaptability and consistency amongst staff. Moreover, the results indicated that the most significant predictor of continuance commitment was mission. Lastly, limitations for the current study were presented and recommendations for future research and for the organisation were offered.

Daugelis kultūros tyrinėtojų sutinka, kad organizacijos kultūra yra vienas reikšmingų būdų siekti organizacijos vadybos. Tačiau Lietuvos organizacijų vadovai veiklai skatinti ir plėtoti šį svarbiausią valdymo įrankį - organizacijos kultūrą - retai pasitelkia. Šio darbo tyrimo objektas - organizacijos „Natūralios medicinos centras“ darbuotojų kultūrinės charakteristikos ir jų atspindys organizacijos kultūroje. Tyrimo tikslas - nustatyti organizacijos „Natūralios medicinos centras“ kultūrines charakteristikas pagal G.Hofstede išskirtas kultūrines dimensijas, jų priklausomybę nuo demografinių veiksnių ir remiantis šiomis charakteristikomis adaptuoti jas pagal W.G. Ouchi kultūros modelį. Tyrimo duomenų analizė parodė, kad remiantis G.Hofstede tyrimo metodika, tirtoje organizacijoje išryškėjo tokia kultūrinių charakteristikų priklausomybė: labai maža galios distancija - (-14,56); polinkis į kolektyvizmą - 38,38; ry���kus vyriškumas - 127,38; mažas neapibrėžtumo vengimas - (- 84,88) ir vidutinė ilgalaikė orientacija- 64,06. Kultūrinių skirtumų požymiai, kuriuos nustatė G. Hofstede, leidžia nustatyti tiriamos organizacijos akcentuojamas vertybes ir įvertinti kultūrinių grupių panašumus bei skirtumus priklausomai nuo demografinių veiksnių. Todėl tyrimas parodė, kad svarbu organizacijos kultūrą nagrinėti subkultūrų atžvilgiu. Atsižvelgiant į išryškėjusias organizacijos narių kultūrines nuostatas remiantis W.G. Ouchi kultūros modeliu, organizacija „Natūralios medicinos... [toliau žr. visą tekstą] / Foreign scholars have proved that organization culture is one of the major factors of performing organization management. However, managers of Lithuanian enterprises rarely employ this core tool of management, i.e. organization culture in order to promote and develop the enterprise’s activity. The subject of this exploration is the cultural characteristics of the employees of the enterprise Natūralios medicinos centras and their reflection in the organization culture. The aim of the exploration is to identify the cultural characteristics of the enterprise Natūralios medicinos centras on the grounds of the cultural dimensions singled out by Hofstede and their dependence on demographical factors so that to adapt the characteristics on the basis of the cultural model by Ouchi. Analysis of the exploration data has shown that on the grounds of the exploration method by Hofstede, the explored organization manifests the following dependence of cultural characteristics: very small power distance – (– 14.56); aptitude to collectivism – 38.38; prominent masculinity – 127.38; minor avoidance of indefiniteness – (– 84.88) and medium/ long-term orientation – 64.06. Marks of cultural differences established by Hofstede allow identifying the emphasized values of the explored organization and to assess similarities and differences of cultural groups on the basis of demographic factors. As a result, the exploration demonstrates that it is essential to explore organizational values regarding... [to full text]

p. 1-87 / Submitted by Santiago Fabio (fabio.ssantiago@hotmail.com) on 2013-03-20T20:57:33Z No. of bitstreams: 1 77777.pdf: 1238514 bytes, checksum: ee2791bd7d19aff1b18df66a1a9e3f3f (MD5) / Approved for entry into archive by Rodrigo Meirelles(rodrigomei@ufba.br) on 2013-05-07T12:11:14Z (GMT) No. of bitstreams: 1 77777.pdf: 1238514 bytes, checksum: ee2791bd7d19aff1b18df66a1a9e3f3f (MD5) / Made available in DSpace on 2013-05-07T12:11:14Z (GMT). No. of bitstreams: 1 77777.pdf: 1238514 bytes, checksum: ee2791bd7d19aff1b18df66a1a9e3f3f (MD5) Previous issue date: 2004 / Esta Dissertação apresenta um estudo de caso sobre a formação e consolidação da cultura organizacional em uma empresa recém criada, fruto de processo de fusão que envolveu seis outras empresas. Para tanto, utiliza uma pesquisa tipo survey para levantar a percepção dos integrantes e análise de documentação. É investigado o processo de formação e consolidação da cultura, analisando a aderência ao modelo de gestão adotado pela empresa, bem como as características e diferenças observadas nas diferentes unidades que vieram a compor a nova empresa e sua evolução ao longo dos seus dois anos de vida. São, também, apresentados conceitos e definições sobre cultura organizacional, incluindo a discussão sobre a cultura organizacional nos processos de fusões e aquisições. O presente trabalho visa, também, contribuir para a organização estudada, refletindo sobre o resultado das ações empreendidas e fornecendo elementos que podem ser usados para o gerenciamento do processo de mudança ainda em curso. / Salvador

Doctor of Philosophy / Food Science Institute / Channa B. Rajashekar / Weiqun Wang / As health-promoting agents, phytochemicals are biosynthesized in the plants that typically respond to environmental stresses. This study focused on the analysis of phytochemical contents in vegetables in response to environmental changes of high tunnel and light spectra. A potential anticancer activity was further studied by developing a novel 3D cell culture model. Three specific studies were conducted as follows. Study 1: High tunnel production has been applied in mid-west for many years due to the advantages of extending growing season and increasing crop yield. Previous studies, however, showed high tunnel resulted in reduction of phenolic contents in vegetables. Therefore, the first study was to confirm the effect of high tunnel on phenolic contents in two varieties of lettuce (‘Two Star’ and ‘Red Fire’) and carotenoid contents in two varieties of tomatoes (‘Mountain Fresh’ and ‘Celebrity’). Phenolics in lettuce and carotenoids in tomato were isolated and quantitated, respectively, by HPLC. High tunnel resulted in a significant reduction of phenolic contents in ‘Two Star’ but not in ‘Red Fire’ lettuce when compared with open field. A significant decrease of carotenoid contents in ‘Celebrity’ but not in ‘Mountain Fresh’ tomato was also observed. Therefore, this study confirmed that high tunnel application reduced phenolic or carotenoid contents in one of the two lettuce or tomato varieties, suggesting the effect of high tunnel production is variable and genotype specific. Study 2: Light is an important environmental factor influenced not only photosynthesis but also phenolic biosynthesis in vegetables. The objective of this study was to investigate the effect of supplemental light spectra including red, far-red, and blue light on phenolic contents in two varieties of lettuce (green-leaf variety ‘Two Star’ and red-leaf variety ‘Red Fire’) and two varieties of spinach (‘Avon’ and ‘Bloomsdale’). The phenolics were extracted and quantitated by HPLC. Far-red and blue light but not red light resulted in an increase of phenolic contents in ‘Two Star’ lettuce. In ‘Red Fire’ lettuce, a significant increase in phenolic contents were observed when exposed to red light, while far-red and blue light reduced phenolic contents. Supplemental lighting did not alter flavonoid contents in two varieties of spinach. Taking together, the results showed that supplemental lighting and its spectral quality had significant effect on the phytochemical contents of lettuce but not spinach, and the impact varied depending upon the variety or species. Study 3: Traditionally, cancer research is primarily relied on in vitro 2D monolayer cell culture and in vivo animal model studies. Given a flat 2D cell culture that usually lacks 3D microenvironmental cell-cell interaction and considering an animal model that is typically expensive and time-consumed, an alternative 3D cell culture has been promising. This pilot study was to develop a novel 3D hydrogel cell culture model of human hepatocarcinoma HepG2 cells or colorectal adenocarcinoma SW480 cells by treating with chlorogenic acid (CGA) at 0-40 μM. The results showed both HepG2 and SW480 cells grew much better in 3D hydrogel culture system than 2D by extended exponential phase and high proliferation. CGA treatment resulted in a dose- and time-response inhibition of HepG2 and SW480 growth in exponential phase, while HepG2 cells were more susceptible than SW480 cells. Establishment of this novel 3D hydrogel culture model for future phytochemical function may bridge the gap between 2D cell culture and in vivo animal model studies. Taken together, this dissertation of three studies focused on phytochemicals from quantitation analysis in vegetables in response to environmental factors of high tunnel and light spectra to a novel 3D hydrogel cell culture development for potential phytochemical anti-cancer function. The conclusions, i.e., (1). high tunnel application reduced phenolic or carotenoid contents in special genotype of lettuce or tomato varieties; (2). lighting and its spectral quality had significant effect on the phytochemical contents of lettuce but not spinach; (3). establishment of a novel 3D hydrogel culture model for phytochemical treatment may bridge the gap between 2D cell culture and in vivo animal model studies, could be of particular significance in health-promoting phytochemical research and functional food application. Study 1: High tunnel production has been applied in mid-west for many years due to the advantages of extending growing season and increasing crop yield. Previous studies, however, showed high tunnel resulted in reduction of phenolic contents in vegetables. Therefore, the first study was to confirm the effect of high tunnel on phenolic contents in two varieties of lettuce (‘Two Star’ and ‘Red Fire’) and carotenoid contents in two varieties of tomatoes (‘Mountain Fresh’ and ‘Celebrity’). Phenolics in lettuce and carotenoids in tomato were isolated and quantitated, respectively, by HPLC. High tunnel resulted in a significant reduction of phenolic contents in ‘Two Star’ but not in ‘Red Fire’ lettuce when compared with open field. A significant decrease of carotenoid contents in ‘Celebrity’ but not in ‘Mountain Fresh’ tomato was also observed. Therefore, this study confirmed that high tunnel application reduced phenolic or carotenoid contents in one of the two lettuce or tomato varieties, suggesting the effect of high tunnel production is variable and genotype specific. Study 2: Light is an important environmental factor influenced not only photosynthesis but also phenolic biosynthesis in vegetables. The objective of this study was to investigate the effect of supplemental light spectra including red, far-red, and blue light on phenolic contents in two varieties of lettuce (green-leaf variety ‘Two Star’ and red-leaf variety ‘Red Fire’) and two varieties of spinach (‘Avon’ and ‘Bloomsdale’). The phenolics were extracted and quantitated by HPLC. Far-red and blue light but not red light resulted in an increase of phenolic contents in ‘Two Star’ lettuce. In ‘Red Fire’ lettuce, a significant increase in phenolic contents were observed when exposed to red light, while far-red and blue light reduced phenolic contents. Supplemental lighting did not alter flavonoid contents in two varieties of spinach. Taking together, the results showed that supplemental lighting and its spectral quality had significant effect on the phytochemical contents of lettuce but not spinach, and the impact varied depending upon the variety or species. Study 3: Traditionally, cancer research is primarily relied on in vitro 2D monolayer cell culture and in vivo animal model studies. Given a flat 2D cell culture that usually lacks 3D microenvironmental cell-cell interaction and considering an animal model that is typically expensive and time-consumed, an alternative 3D cell culture has been promising. This pilot study was to develop a novel 3D hydrogel cell culture model of human hepatocarcinoma HepG2 cells or colorectal adenocarcinoma SW480 cells by treating with chlorogenic acid (CGA) at 0-40 M. The results showed both HepG2 and SW480 cells grew much better in 3D hydrogel culture system than 2D by extended exponential phase and high proliferation. CGA treatment resulted in a dose- and time-response inhibition of HepG2 and SW480 growth in exponential phase, while HepG2 cells were more susceptible than SW480 cells. Establishment of this novel 3D hydrogel culture model for future phytochemical function may bridge the gap between 2D cell culture and in vivo animal model studies. Taken together, this dissertation of three studies focused on phytochemicals from quantitation analysis in vegetables in response to environmental factors of high tunnel and light spectra to a novel 3D hydrogel cell culture development for potential phytochemical anti-cancer function. The conclusions, i.e., (1). high tunnel application reduced phenolic or carotenoid contents in special genotype of lettuce or tomato varieties; (2). lighting and its spectral quality had significant effect on the phytochemical contents of lettuce but not spinach; (3). establishment of a novel 3D hydrogel culture model for phytochemical treatment may bridge the gap between 2D cell culture and in vivo animal model studies, could be of particular significance in health-promoting phytochemical research and functional food application.

No description available.

Although there are over 1,600 Engineered Nanomaterials (ENMs)-containing consumer products available, our understanding of ENM safety is still limited. Airborne ENMs can readily enter the human body through inhalation potentially leading to many adverse health effects such as cardiovascular and pulmonary diseases. The conventional in vitro submerged cell culture method was developed decades ago and has been widely used as a fast screening method to elucidate cellular toxicity upon exposure to hazardous materials; however, it has many limitations compared with the in vivo models. Our group has previously utilized and validated an integrated low flow system capable of generating and depositing airborne nanoparticles (NPs) directly onto cells at an air-liquid interface (ALI) condition, and our results confirmed that this exposure system produced reproducible toxicological data for ENMs including gold (Au), 16% silver coated onto silica (16% Ag-SiO2), and copper oxide (CuO). To further improve this ALI method for an even closer representation of the in vivo model, a co-culture model containing three cell lines (A549, THP-1 differentiated macrophages, and EA.hy 926) was established and validated for testing ENMs toxicity. The co-culture model was exposed to 16% Ag-SiO2 and CuO NPs under the same protocol (4 h ALI exposure with a concentration of 3.5 mg/m3) as monoculture (A549 only) for comparison. Toxicity was assessed by measuring cell viability, reactive oxygen species (ROS) production, lactate dehydrogenase (LDH) release, and interleukin (IL) 8 level. Results showed that 16% Ag-SiO2 NPs induced higher ROS generation, and CuO NPs produced a significant level of proinflammatory response compared with monoculture. In addition, the co-culture model exhibited a similar response with the primary human bronchial epithelia cell line (HBEC) in terms of ROS and IL-8 responses after CuO NPs exposure, suggesting a more advanced refinement of the conventional model for in vitro inhalation study.

[pt] Entender como características culturais interferem no desempenho de uma empresa, é extremamente relevante em mercados cada vez mais competitivos e dinâmicos. Assim sendo, o objetivo deste trabalho é analisar a relação da Cultura e o Desempenho Organizacional. A partir da revisão da literatura foi realizado um estudo de caso em uma empresa privada do setor de seguros, que se destaca no mercado em que atua, estando entre as maiores seguradoras independentes do Brasil em Vida, Previdência e Capitalização e ao longo dos anos, recebeu prêmios e participou dos mais importantes rankings financeiros nacionais, reunindo certificações que reforçam a credibilidade, o desempenho e a excelência em sua gestão. A pesquisa coletou dados referentes ao resultado do desempenho organizacional, mais especificamente o resultado dos indicadores financeiros - Return on Sales (ROS), Return on Asset (ROA) e Retorno sobre Patrimônio Líquido (ROE) e, pela aplicação do questionário do modelo de Cultura Organizacional de Denison - DOCS (1990) no seu quadro gerencial, foi possível avaliar as características chaves da cultura organizacional, sob as dimensões de Missão, Consistência, Envolvimento e Adaptabilidade. A análise qualitativa dos dados coletados evidenciou que existe relação entre o resultado das dimensões culturais e os indicadores de rentabilidade, e sugere a importância do aprofundamento desta linha de pesquisa em outras organizações. / [en] Understanding how organizational cultures interfere with a company s performance, and what are the important cultural characteristics to leverage this performance, is extremely relevant in increasingly competitive and dynamic markets. Therefore, the objective of this work is to analyze the relationship between Culture and Organizational Performance. From the literature review, a case study was conducted in a private insurance company, which stands out in the market in which it operates, being among the largest independent insurers in Brazil in Life, Private Pension and Savings Bonds and over the years, received awards and participated in the most important national financial rankings, gathering certifications that reinforce the credibility, the performance and the excellence in its management. The survey collected data on the results of organizational performance, more specifically the result of the financial indicators - Return on Sales (ROS), Return on Asset (ROA) and Return on Equity (ROE) and, by applying the Denison Organizational Culture Model - DOCS questionnaire to managers, it was possible to evaluate the key characteristics of the organizational culture, under the dimensions of Mission, Consistency, Involvement and Adaptability. The qualitative analysis of the data collected showed that there is a relationship between the results of the cultural dimensions and the indicators of profitability and suggests the importance of future research on this subject in other organizations.