Ultrastructural Basis and Developmental Control of Blue Iridescence in Selaginella Leaves

The iridescentb lue color of several Selaginellasp ecies is caused by a physical effect, thinfilm interference.P redictionsf or a model film have been confirmedb y electronm icroscopyo f S. willdenowaEnid S. uncinataF. or the latters pecies iridescencec ontributest o leaf absorption at wavelengths above 450 nm and develops in environments enriched with far-red (730 nm) light. This evidence supports the involvement of phytochrome in the developmental control of iridescence.

The will to write: Students' and teachers' perceptions of writing

This study investigated the perceptions of writing among secondary and post-secondary students and their teachers. The focus was on students' writing philosophy and influences, perceptions of the writing process, and perceptions of student writing skills, high stakes assessment tests, and writing across the curriculum. ^ An ethnographic case study was used to investigate the perceptions of writing among ten students and their English teachers in two high schools, a community college, and a university. To establish balance and ethnic plurality, seven females and three males representing the four large ethnic groups in South Florida—African American, Haitian American, European American and Latino—participated. During one four-month term, data from written samples of students' writing, formal and informal interviews, a student focus group, field notes, classroom observations, and a “think-aloud” protocol were collected. ^ Four themes emerged. First, Florida's writing assessment test has a negative influence on students' perceptions of writing. Students' motivation and attitudes as well as their confidence in their abilities were affected by practice and preparation in “recital writing.” Second, writing is a vehicle of social and personal transformation. Students believed that writing is a mean to connect to others and to create change in schools and communities. Third, students lacked the ability to connect writing, thinking and learning. Although students and teachers agree with statements about this connection, students failed to see the relevance of thinking and learning through writing in current or future courses, or in their future careers. Finally, writing context, teachers, schools, peers and gender influenced writing perceptions. Students believed that their writing philosophy, writing process, and perceptions of writing in academia and in the workplace are connected to these five factors. ^ The effect of the Florida writing test pervades students' and teachers' writing perceptions, making a stronger case for writing across the curriculum than previous research. Writing should help students see knowledge as interrelated, honor students' interests and values, and build relationships between and among students, schools and communities. In designing and implementing methods that support and sustain student writing, teachers should provide students with multiple opportunities to expand knowledge, learning, and connection through writing. ^

Cultural influence and learning to teach: Beginning teachers' perceptions of teacher preparation programs and school support systems

Beginning teachers in the field of English Language Arts and Reading are responsible for providing literacy instruction to students. Teachers need a broad background in teaching reading, writing, listening, speaking, and viewing, as well as critical thinking. In secondary schools in particular, beginning English Language Arts and Reading teachers are also faced with the challenge of preparing students to be proficient enough readers and writers to meet required State standards. Beginning teachers must navigate compelling challenges that exist during the first years of teaching. The school support systems available to new teachers are an integral part of their educational development. ^ This qualitative study was conceptualized as an in-depth examination of the experiences and perceptions of eight beginning teachers. They represented different racial/ethnic groups, attended different teacher preparation programs, and taught in different school cultures. The data were collected through formal and informal interviews and classroom observations. A qualitative system of data analysis was used to examine the patterns relating to the interrelationship between teacher preparation programs and school support systems. ^ The experiences of the beginning teachers in this study indicated that teacher education programs should provide preservice teachers with a critical knowledge base for teaching literature, language, and composition. A liberal arts background in English, followed by an extensive program focusing on pedagogy, seems to provide a thorough level of curriculum and instructional practices needed for teaching in 21st century classrooms. The data further suggested that a school support system should pair beginning teachers with mentor teachers and provide a caring, professional environment that seeks to nurture the teacher as she/he develops during the first years of teaching. ^

Thioredoxin and Jab1 control estrogen- and antiestrogen-mediated progression of the cell cycle through p27 interactions

A major problem with breast cancer treatment is the prevalence of antiestrogen resistance, be it de novo or acquired after continued use. Many of the underlying mechanisms of antiestrogen resistance are not clear, although estrogen receptor-mediated actions have been identified as a pathway that is blocked by antiestrogens. Selective estrogen receptor modulators (SERMs), such as tamoxifen, are capable of producing reactive oxygen species (ROS) through metabolic activation, and these ROS, at high levels, can induce irreversible growth arrest that is similar to the growth arrest incurred by SERMs. This suggests that SERM-mediated growth arrest may also be through ROS accumulation. Breast cancer receiving long-term antiestrogen treatment appears to adapt to this increased, persistent level of ROS. This, in turn, leads to the disruption of reversible redox signaling that involves redox-sensitive phosphatases and protein kinases and transcription factors. This has downstream consequences for apoptosis, cell cycle progression, and cell metabolism. For this dissertation, we explored if altering the ROS formed by tamoxifen also alters sensitivity of the drug in resistant cells. We explored an association with a thioredoxin/Jab1/p27 pathway, and a possible role of dysregulation of thioredoxin-mediated redox regulation contributing to the development of antiestrogen resistance in breast cancer. We used standard laboratory techniques to perform proteomic assays that showed cell proliferation, protein concentrations, redox states, and protein-protein interactions. We found that increasing thioredoxin reductase levels, and thus increasing the amount of reduced thioredoxin, increased tamoxifen sensitivity in previously resistant cells, as well as altered estrogen and tamoxifen-induced ROS. We also found that decreasing levels of Jab1 protein also increased tamoxifen sensitivity, and that the downstream effects showed a decrease p27 phosphorylation in both cases. We conclude that the chronic use of tamoxifen can lead to an increase in ROS that alters cell signaling and causing cell growth in the presence of tamoxifen, and that this resistant cell growth can be reversed with an alteration to the thioredoxin/Jab1 pathway.

Phosphorus Availability and Salinity Control Productivity and Demography of the Seagrass Thalassia testudinum in Florida Bay

Biomass, net primary productivity (NPP), foliar elemental content, and demography of Thalassia testudinum were monitored in populations from five sites across Florida Bay beginning in January 2001. Sites were selected to take advantage of the spatial variability in phosphorus (P) availability and salinity climates across the bay. Aboveground biomass and NPP of T. testudinum were determined five to six times annually. Short-shoot demography, belowground biomass, and belowground NPP were assessed from a single destructive harvest at each site and short-shoot cohorts were estimated from leaf scar counts multiplied by site-specific leaf production rates. Biomass, relative growth rate (RGR), and overall NPP were positively correlated with P availability. Additionally, a positive correlation between P availability and the ratio of photosynthetic to non-photosynthetic biomass suggests that T. testudinum increases allocation to aboveground biomass as P availability increases. Population turnover increased with P availability, evident in positive correlations of recruitment and mortality rates with P availability. Departures from seasonally modeled estimates of RGR were found to be influenced by salinity, which depressed RGR when below 20 psu or above 40 psu. Freshwater management in the headwaters of Florida Bay will alter salinity and nutrient climates. It is becoming clear that such changes will affect T. testudinum, with likely feedbacks on ecosystem structure, function, and habitat quality.

The influence of neighbourhood formality status and socio-economic position on self-rated health among adult men and women: a multilevel, cross sectional, population study from Aleppo, Syria

Background There is substantial evidence from high income countries that neighbourhoods have an influence on health independent of individual characteristics. However, neighbourhood characteristics are rarely taken into account in the analysis of urban health studies from developing countries. Informal urban neighbourhoods are home to about half of the population in Aleppo, the second largest city in Syria (population>2.5 million). This study aimed to examine the influence of neighbourhood socioeconomic status (SES) and formality status on self-rated health (SRH) of adult men and women residing in formal and informal urban neighbourhoods in Aleppo. Methods The study used data from 2038 survey respondents to the Aleppo Household Survey, 2004 (age 18–65 years, 54.8% women, response rate 86%). Respondents were nested in 45 neighbourhoods. Five individual-level SES measures, namely education, employment, car ownership, item ownership and household density, were aggregated to the level of neighbourhood. Multilevel regression models were used to investigate associations. Results We did not find evidence of important SRH variation between neighbourhoods. Neighbourhood average of household item ownership was associated with a greater likelihood of reporting excellent SRH in women; odds ratio (OR) for an increase of one item on average was 2.3 (95% CI 1.3-4.4 (versus poor SRH)) and 1.7 (95% CI 1.1-2.5 (versus normal SRH)), adjusted for individual characteristics and neighbourhood formality. After controlling for individual and neighbourhood SES measures, women living in informal neighbourhoods were less likely to report poor SRH than women living in formal neighbourhoods (OR= 0.4; 95% CI (0.2- 0.8) (versus poor SRH) and OR=0.5; 95%; CI (0.3-0.9) (versus normal SRH). Conclusions Findings support evidence from high income countries that certain characteristic of neighbourhoods affect men and women in different ways. Further research from similar urban settings in developing countries is needed to understand the mechanisms by which informal neighbourhoods influence women’s health.

Personality and job performance: The mediating roles of leader -member exchange quality and action control

The present investigation examined the relationships among personality (as conceptualized by the Big Five Factors), leader-member exchange (LMX) quality, action control, organizational citizenship behaviors (OCB), and overall job performance (OJP). Two mediator variables were proposed and tested in this study: LMX and Action Control. Two-hundred and seven currently employed regular elementary school classroom teachers provided data during the 2000–2001 academic school year. Teachers provided personality, LMX quality (member or subordinate perspective), action control, job tenure, and demographic data. Nine school administrators (i.e., Principals, Assistant Principals) were the source for supervisor ratings of OCB, OJP, and LMX quality (leader or supervisor perspective). In eight of the nine total schools, teachers completed questionnaires during an after-school teacher gathering; in the remaining school location questionnaires were dropped off, distributed to teachers, and re-collected two weeks later. Results indicated a significant relationship between the OCB scale and overall supervisory ratings of OJP. The relationship among the big five factors of personality and OJP did not reach statistical significance, nor did the relationships among personality and OCB. The data indicated that none of the teacher tenure variables (i.e., teacher, school, or time worked with principal tenure) moderated the personality-OCB relationship nor the personality-OJP relationship. Finally, a review of the correlations among the variables of interest precluded conducting a mediation between personality-performance by OCB, mediation of personality-OCB by action control, and mediation of personality-OCB by LMX. In conclusion, the data reveal that personality was not significantly correlated with supervisory ratings of OJP or significantly related to supervisory ratings of overall OCB. Moreover, LMX quality and action control did not mediate the relationships between Personality-OJP nor the Personality-OCB relationship. Significant relationships were found between disengagement and overall LMX quality and between Initiative and overall LMX quality (both LMX-Teacher perspectives) as well as between personality variables and both Disengagement and Initiative action control variables. Despite the limitations inherent in this study, these latter findings suggest “lessons” for teachers and school administrators alike. ^

Effect of Medical Advice for Diet on Diabetes Self-Management and Glycemic Control for Haitian and African Americans with Type 2 Diabetes

Adequate care of type 2 diabetes is reflected by the individual’s adherence to dietary guidance; yet, few patients are engaged in diabetes self-care at the recommended level, regardless of race/ethnicity. Few studies on the effect of dietary medical advice on diabetes self-management (DSM) and glycemic control have been conducted on Haitian and African American adults with type 2 diabetes. These relationships were assessed in total of 254 Blacks with type 2 diabetes (Haitian Americans = 129; African Americans = 125) recruited from Miami-Dade and Broward Counties, Florida by community outreach methods. Although dietary advice received was not significantly different between the two Black ethnicities, given advice “to follow a diet” as a predictor of “using food groups” was significant for Haitian Americans, but not for African Americans. Haitian Americans who were advised to follow a diet were approximately 3 times more likely to sometimes or often use food groups (or exchange lists) in planning meals. Less than optimal glycemic control (A1C > 7.2) was inversely related to DSM for African Americans; but the relationship was not significant for Haitian Americans. A one unit increase in DSM score decreased the odds ratio point estimate of having less than optimal glycemic control (A1C > 7.2%) by a factor of 0.94 in African Americans. These results suggest that medical advice for diet plans may not be communicated effectively for DSM for some races/ethnicities. Research aimed at uncovering the enablers and barriers of diet management specific to Black ethnicities with type 2 diabetes is recommended.

An investigation of the relationships among self-care behaviors, health beliefs, and metabolic control in the non-insulin-dependent diabetic adult

Self-care and health beliefs have been found to be important concepts in the management of chronic diseases such as diabetes mellitus. Poor metabolic control has been associated with a higher incidence of complications in diabetic patients. This study sought to explore any relationships among perceptions of self-care behaviors, health beliefs and metabolic control. The sample consisted of 52 outpatients with non-insulin-dependent diabetes from a large teaching medical center. Interviews were done to obtain the patients' perceptions of their self-care behaviors, and their health beliefs concerning diabetes. Results of glycosylated hemoglobin and/or serum glucose levels were obtained from the medical records. Data were analyzed using Cochran-Mantel-Haenzel statistics, and Pearson's r. Results indicated no significant relationships among perceptions of self-care behaviors, health beliefs and metabolic control. Ethnicity, education and gender were found to be significantly associated with self-care behaviors and health beliefs.

Beliefs of Icelandic elderly living in the greater Reykjavik area toward autonomy and paternalism in caregiving of the elderly

With the aging population and the increase in health care costs, issues of independence and autonomy will have a greater impact on formal and informal health care. Changes in occupational functioning that accompany increased age has raised the demandfor family assistance to the elderly. It is important for occupational therapists to understand the elderly's perceptions toward autonomy and paternalism in caregiving of the elderly because it is assumed that attitudes and beliefs affect how people interact and care for the elderly. A convenience sample of 57 Icelandic elderly were surveyed regarding their attitudes toward autonomy and paternalism in caregiving of the elderly. Results indicated that Icelandic elderly held strong beliefs toward autonomy but were undecided toward paternalism. Significant differences were found between groups. Elderly living at home indicated stronger beliefs on both autonomy and paternalism compared to those living in senior housing complexes. Elderly women held stronger beliefs in autonomy in contrast to the males, who were more paternalistic, and married subjects held stronger beliefs than did single respondents.