Redox Regulation of Ras Proteins in Dictyostelium discoideum

Reactive oxygen species are a normal consequence of life in an aerobic environment. However when they deviate from the narrow permissible range in cells, oxidative damage can occur. Dictyostelium discoideum is a model organism ideal for the study of cell signaling events such as those affected by oxidative stress. It was previously shown that Ras signaling in Dictyostelium is affected by genetic inactivation of the antioxidant enzyme Superoxide dismutase C (SodC) and in vitro data suggests that the NKCD motif of Ras is the redox target of superoxide. The main objective of this project was to determine the mechanism of superoxide mediated Ras regulation in vivo. To accomplish the main objective, we cloned, and in some cases, mutated different Ras proteins and later determined their activity in wild type and sodC- cells. RasC and RasD showed normal activation in sodC- cells, however RasG and RasS displayed high Ras activity. These last two Ras proteins contain the NKC118D motif inside the nucleotide binding region. A mutation of cysteine118 to alanine in RasG rendered the protein less active in sodC- than the wild type RasG protein and a mutation alanine118 to cysteine in RasD conferred redox sensitivity to this small GTPase. Additionally, the propensity of RasG to be targeted by superoxide was evident when the environment of wild type cells was manipulated to induce the internal generation of superoxide through changes in the extracellular ion levels mainly magnesium. Lack of magnesium ions increased the intracellular level of superoxide and severely hampered directional cell migration. Chemotaxis of cells expressing RasG was negatively impacted by the absence of magnesium ions; however rasG- cells did not seem to be affected in their ability to perform chemotaxis. The last experiment implies that RasG is an important mediator of cell signaling during oxidative stress, responsible for preventing cells from continuing their developmental program. Our study suggests that the cysteine residue in the NKCD motif is essential for mediating the redox sensitivity of Ras proteins in Dictyostelium and that RasG is an essential mediator of the response to oxidative stress in this organism.

Religion & ethnic identity among Mexican youths in Homestead, Florida

Immigrant youth are the fastest growing component of the U.S. population and Mexicans are the largest immigrant group in the U.S. The manner in which they integrate into U.S. society and the ways that they become civically engaged, will greatly determine the nature of civil society in the United States over the next few decades. Moreover, religion is increasingly recognized as an important factor in immigrant adaptation. Based upon fieldwork of participant observation and interviews in Homestead, Florida, this thesis examined the relationship among Mexican youths' identity, religion and civic engagement. I found that if these youths are active in religious practices they will be more likely to identify themselves as part of the dominant group, in this case American society. Religious groups are powerful tools that can help these youth reach the greater community.

Redox regulation of Ras proteins in Dictyostelium discoideum

Reactive oxygen species are a normal consequence of life in an aerobic environment. However when they deviate from the narrow permissible range in cells, oxidative damage can occur. Dictyostelium discoideum is a model organism ideal for the study of cell signaling events such as those affected by oxidative stress. It was previously shown that Ras signaling in Dictyostelium is affected by genetic inactivation of the antioxidant enzyme Superoxide dismutase C (SodC) and in vitro data suggests that the NKCD motif of Ras is the redox target of superoxide.^ The main objective of this project was to determine the mechanism of superoxide mediated Ras regulation in vivo. To accomplish the main objective, we cloned, and in some cases, mutated different Ras proteins and later determined their activity in wild type and sodC- cells. RasC and RasD showed normal activation in sodC- cells, however RasG and RasS displayed high Ras activity. These last two Ras proteins contain the NKC118D motif inside the nucleotide binding region. A mutation of cysteine 118 to alanine in RasG rendered the protein less active in sodC- than the wild type RasG protein and a mutation alanine118 to cysteine in RasD conferred redox sensitivity to this small GTPase. Additionally, the propensity of RasG to be targeted by superoxide was evident when the environment of wild type cells was manipulated to induce the internal generation of superoxide through changes in the extracellular ion levels mainly magnesium. Lack of magnesium ions increased the intracellular level of superoxide and severely hampered directional cell migration. Chemotaxis of cells expressing RasG was negatively impacted by the absence of magnesium ions; however rasG- cells did not seem to be affected in their ability to perform chemotaxis. The last experiment implies that RasG is an important mediator of cell signaling during oxidative stress, responsible for preventing cells from continuing their developmental program. Our study suggests that the cysteine residue in the NKCD motif is essential for mediating the redox sensitivity of Ras proteins in Dictyostelium and that RasG is an essential mediator of the response to oxidative stress in this organism.^

Characterizations of the major coral diseases of the Philippines: Ulcerative white spot disease and novel growth anomalies of Porites

Coral reefs are in decline worldwide and coral disease is a significant contributing factor. However, etiologies of coral diseases are still not well understood. In contrast with the Caribbean, extremely little is known about coral diseases in the Philippines. In 2005, off Southeast Negros Island, Philippines, I investigated relationships between environmental parameters and prevalence of the two most common coral diseases, ulcerative white spot (UWS) and massive Porites growth anomalies (MPGAs). Samples were collected along a disease prevalence gradient 40.5 km long. Principal component analyses showed prevalence of MPGAs was positively correlated with water column nitrogen, organic carbon of surface sediments, and colony density. UWS was positively correlated with water column phosphorus. This is the first quantitative evidence linking anthropogenically-impacted water and sediment to a higher prevalence of these diseases. Histological and cytological alterations were investigated by comparing tissues from two distinct types of MPGA lesions (types 1 and 2) and healthy coral using light and electron microscopy. Skeletal abnormalities and sloughing, swelling, thinning, and loss of tissues in MPGAs resembled tissues exposed to bacterial or fungal toxins. Both lesion types had decreases in symbiotic zooxanthellae, which supply nutrients to corals. Notable alterations included migrations of chromophore cells (amoebocytes) (1) nocturnally to outer epithelia to perform wound-healing, including plugging gaps and secreting melanin in degraded tissues, and (2) diurnally to the interior of the tissue possibly to prevent shading zooxanthellae in order to maximize photosynthate production. Depletion of melanin (active in wound healing) in type 2 lesions suggested type 2 tissues were overtaxed and less stable. MPGAs contained an abundance of endolithic fungi and virus-like particles, which may result from higher nutrient levels and play roles in disease development. Swollen cells and mucus frequently blocked gastrovascular canals (GVCs) in MPGAs. Type 1 lesions appeared to compensate for impeded flow of wastes and nutrients through these canals with proliferation of new GVCs, which were responsible for the observed thickened tissues. In contrast, type 2 tissues were thin and more degraded. Dysplasia and putative neoplasia were also observed in MPGAs which may result from the tissue regeneration capacity being overwhelmed.

Barcelona: Espacio literario, espacio urbano en la novela Catalana femenina del Siglo XX

This dissertation analyses, through a rhetorical framework and a literary approach, texts written in Catalan and Castilian by four Catalan female writers (Dolors Monserdà, Maria Aurèlia Capmany, Esther Tusquets, Monserrat Roig ), whose works cover from 1900 to the 1980. Utilizing this urban feminine literature, it discusses the historical-geographical vision about the changes in Catalan society during the twentieth century with its consequences for the urban space, especially the space occupied by women. It is also established that Barcelona's recovery and literary vindication by women has been done through the written text, as literary affirmation and as a matter of conscience in which the city could not be summed up as a backdrop, but rather as an active part of a literary creation, active in the double sense, as a socio-historical space in the novel and as characteristic of their works. The primary purpose of this dissertation is to demonstrate that the use of the city as a setting for the novels determines and characterizes those female writers' texts. Consequently, these writings are literary material relevant and essential to the understanding of the Barcelonian women's space. However their use of space is not arbitrary, on the contrary it corresponds to a social order established by the patriarchy where the relation of women to the world is embodied in the intentional and socially restricted space and movements of their bodies. The theoretical perspectives of this study are based on Montserrat Roig's feminist urban space theories. Her theory advocates the right to individuality, denouncing the patriarchal and hierarchical social system present in gendered space from the outside male world to the domestic feminized space. I also turn to the writings of Maria Aurèlia Capmany, who addresses cultural aspects of women's roles revealing a purposive controlled patriarchal society according to a historical-geographical analysis. This study of texts permits a new reading of the Catalan capital and demonstrates that Catalan women writers have consciously willed to give birth to a new history of the city: the history of women as protagonist citizens, producers, reproducers, and consumers of the space represented by the Catalan capital

Icelandic occupational therapists' attitudes toward educational and professional issues

The entire population of Icelandic occupational therapists were surveyed concerning characteristics and attitudes toward professionalism and educational goals. There were 87 questionnaires sent out and 80 (92%) were returned and used for analysis. This data will have a positive impact upon the development of the first Icelandic occupational therapy curriculum. Icelandic occupational therapists, in general, value academic skills over technical skills, are active in their association, willing to take on duties for the advancement of the profession and are interested in conducting research. The attitudes of the Icelandic occupational therapists were generally quite uniform. T- tests and one-way ANOVAs (p < .05) revealed some significant differences in a number of attitudes by education level, length of professional experience and country of education. The results show the importance of providing Icelandic occupational therapy practitioners with the opportunity to take part in research. This study will serve as a foundation for future studies on Icelandic occupational therapists and provide reference data for later comparison.

Characterizations of the Major Coral Diseases of the Philippines: Ulcerative White Spot Disease and Novel Growth Anomalies of Porites

Coral reefs are in decline worldwide and coral disease is a significant contributing factor. However, etiologies of coral diseases are still not well understood. In contrast with the Caribbean, extremely little is known about coral diseases in the Philippines. In 2005, off Southeast Negros Island, Philippines, I investigated relationships between environmental parameters and prevalence of the two most common coral diseases, ulcerative white spot (UWS) and massive Porites growth anomalies (MPGAs). Samples were collected along a disease prevalence gradient 40.5 km long. Principal component analyses showed prevalence of MPGAs was positively correlated with water column nitrogen, organic carbon of surface sediments, and colony density. UWS was positively correlated with water column phosphorus. This is the first quantitative evidence linking anthropogenically-impacted water and sediment to a higher prevalence of these diseases. Histological and cytological alterations were investigated by comparing tissues from two distinct types of MPGA lesions (types 1 and 2) and healthy coral using light and electron microscopy. Skeletal abnormalities and sloughing, swelling, thinning, and loss of tissues in MPGAs resembled tissues exposed to bacterial or fungal toxins. Both lesion types had decreases in symbiotic zooxanthellae, which supply nutrients to corals. Notable alterations included migrations of chromophore cells (amoebocytes) (1) nocturnally to outer epithelia to perform wound-healing, including plugging gaps and secreting melanin in degraded tissues, and (2) diurnally to the interior of the tissue possibly to prevent shading zooxanthellae in order to maximize photosynthate production. Depletion of melanin (active in wound healing) in type 2 lesions suggested type 2 tissues were overtaxed and less stable. MPGAs contained an abundance of endolithic fungi and virus-like particles, which may result from higher nutrient levels and play roles in disease development. Swollen cells and mucus frequently blocked gastrovascular canals (GVCs) in MPGAs. Type 1 lesions appeared to compensate for impeded flow of wastes and nutrients through these canals with proliferation of new GVCs, which were responsible for the observed thickened tissues. In contrast, type 2 tissues were thin and more degraded. Dysplasia and putative neoplasia were also observed in MPGAs which may result from the tissue regeneration capacity being overwhelmed.

Barcelona: Espacio Literario, Espacio Urbano en la Novela Catalana Femenina del Siglo XX

This dissertation analyses, through a rhetorical framework and a literary approach, texts written in Catalan and Castilian by four Catalan female writers (Dolors Monserdà, Maria Aurèlia Capmany, Esther Tusquets, Monserrat Roig ), whose works cover from 1900 to the 1980. Utilizing this urban feminine literature, it discusses the historical-geographical vision about the changes in Catalan society during the twentieth century with its consequences for the urban space, especially the space occupied by women. It is also established that Barcelona’s recovery and literary vindication by women has been done through the written text, as literary affirmation and as a matter of conscience in which the city could not be summed up as a backdrop, but rather as an active part of a literary creation, active in the double sense, as a socio-historical space in the novel and as characteristic of their works. The primary purpose of this dissertation is to demonstrate that the use of the city as a setting for the novels determines and characterizes those female writers’ texts. Consequently, these writings are literary material relevant and essential to the understanding of the Barcelonian women’s space. However their use of space is not arbitrary, on the contrary it corresponds to a social order established by the patriarchy where the relation of women to the world is embodied in the intentional and socially restricted space and movements of their bodies. The theoretical perspectives of this study are based on Montserrat Roig’s feminist urban space theories. Her theory advocates the right to individuality, denouncing the patriarchal and hierarchical social system present in gendered space from the outside male world to the domestic feminized space. I also turn to the writings of Maria Aurèlia Capmany, who addresses cultural aspects of women’s roles revealing a purposive controlled patriarchal society according to a historical-geographical analysis. This study of texts permits a new reading of the Catalan capital and demonstrates that Catalan women writers have consciously willed to give birth to a new history of the city: the history of women as protagonist citizens, producers, reproducers, and consumers of the space represented by the Catalan capital

Emergency and Transitional Shelters [Literature Review]

Over the past two decades the number of recorded disasters has doubled from approximately 200 to over 400 disasters per year. Such an increase in the frequency of disasters has not been without consequence, producing ever-greater waves of population displacements throughout the developing world. The United Nation’s Inter-Agency Standing Committee (IASC) responsible for the coordination of international humanitarian responses states unequivocally that populations displaced by disaster have a right to protection and the provision of basic necessities such as adequate food, water, clothing, sanitation, and essential health services (IASC, 2006 and The Sphere Project, 2011). Shelter responses are often a vital node around which many of these humanitarian concerns are addressed. This document is a review of 3 case studies, 6 field reports, 1 concept paper, 16 guidelines, 1 call for proposals, and 4 strategic framework documents prepared by organizations active in the humanitarian shelter sector on emergency and transitional shelters. While emergency shelter response is focused primarily on protection and relief during and immediately after a disaster has occurred, the transitional shelter approach emphasizes integrating disaster response into an immediate transition towards reconstruction, recovery, and sustainable development.