Germinação e morfologia do desenvolvimento pós-seminal de sementes de Nim-indiano (Azadirachta indica A. Juss. - Meliaceae)

Azadirachta indica A. Juss. é uma espécie nativa das regiões áridas da Ásia e África, mas que atualmente encontra-se distribuída também nas Américas e outras regiões de clima tropical e sub-tropical. É uma planta muito resistente, que apresenta excelentes propriedades medicinais. O objetivo deste trabalho foi definir o tipo de substrato e a temperatura mais adequada à germinação de sementes de nim-indiano (Azadirachta indica A. Juss.) e conhecer a morfologia de seu desenvolvimento pós-seminal, caracterizando as plântulas normais e o tipo de germinação. As sementes foram semeadas nos substratos vermiculita, areia e rolo de papel germitest e mantidas em germinador nas temperaturas de 25°C, 30°C, 35°C e 20-30°C. O delineamento estatístico utilizado foi o inteiramente casualizado, com quatro repetições de 25 sementes, avaliando-se a porcentagem de germinação. Os melhores resultados da germinação são verificados na temperatura constante de 35°C, nos substratos vermiculita e em rolo de papel com contagens de 15 e 30 dias. As plântulas normais são caracterizadas como de germinação epígea.

Teste de condutividade elétrica para semente de pimenta

O presente trabalho teve como objetivo verificar o efeito do número de sementes, do volume de água e do período de embebição no teste de condutividade elétrica para avaliar o vigor de cinco lotes de semente de pimenta e relacionar esses resultados com os testes de germinação, primeira contagem, envelhecimento acelerado e comprimento de plântula. O teste de condutividade elétrica foi realizado com 25 e 50 sementes embebidas em 25mL e 50mL de água destilada, a 25º C, por 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 24 e 48 horas. O teste de condutividade elétrica foi eficiente para a avaliação do vigor de sementes de pimenta, porém a utilização de 25 sementes não permitiu diferenciar os lotes. Para se obter melhor estratificação dos lotes em níveis de vigor, recomenda-se utilizar amostras de 50 sementes, embebidas em 25 mL de água destilada e avaliar a condutividade elétrica após uma hora de embebição.

Equacionamento da qualidade inicial de sementes de milho e soja para aplicação no modelo de probit

Objetivou-se, neste trabalho, equacionar a qualidade inicial das sementes (Ki), utilizada no modelo de probit, para a previsão da longevidade de sementes de milho (Zea mays) e soja (Glycine max), em função do resultado dos testes iniciais de germinação e vigor. Onze lotes de sementes de diferentes cultivares de milho e de soja foram submetidos aos testes de germinação (TG), envelhecimento acelerado (TEA), frio sem solo (TF), para milho, e tetrazólio (TZ), para soja, e a testes de envelhecimento acelerado, com condições constantes do grau de umidade e da temperatura das sementes, para determinar o valor de Ki. Dados da literatura contendo resultados de testes de TEA e TF para milho e TEA e TZ para soja também foram usados nesta pesquisa. Conduziram-se análises de regressão linear simples e múltipla para equacionar: a) Ki em função de TG e TEA para milho e soja, b) TEAm (envelhecimento acelerado do milho) em função de TF; c) TEAs (envelhecimento acelerado da soja) em função de TZ. As equações obtidas foram: Ki = 0,4230 + 0,4464 TG + 0,4131 TEA TEA M = - 0,4408 + 1,214 TF TEA S = - 0,1872 + 0,9875 TZ. A equação de Ki apresentou coeficiente de determinação ajustado (r²) de 0.80 (d.p. 0.18 probit e parâmetros significantes em p < 0.01, p < 0.02 e p < 0.05, respectivamente). A equação de TEAm apresentou r² de 0.80 (d.p. 0.24 probit e parâmetros significantes em p < 0.002). A equação de TEAs apresentou r² de 0.84 (d.p. 0.18 probit e parâmetros significantes em p < 0.005). O valor de Ki pode ser equacionado em função do resultado dos testes iniciais de germinação e vigor para milho e soja (TEA ou TF para milho e TEA ou TZ para soja).

Validação do aplicativo computacional SEEDSOLVE para previsão das perdas de germinação e vigor de sementes armazenadas

Objetivou-se validar o aplicativo computacional SEEDSOLVE para previsão das perdas de germinação e vigor de sementes ortodoxas armazenadas. A validação foi realizada comparando-se valores calculados com valores experimentais das perdas de germinação e vigor de sementes de três cultivares de milho e de soja armazenadas em laboratório, durante um período de 210 dias. Sementes de milho e soja, com três níveis de grau de umidade (11, 13 e 15% para o milho e 9, 11 e 13% para a soja), foram acondicionadas em embalagens de plástico polietileno e armazenadas em câmaras BOD sob três temperaturas (15, 25 e 35ºC). Os resultados das comparações dos dados calculados e experimentais de germinação e vigor durante o armazenamento de sementes dos três lotes de cada espécie, sob diferentes condições de armazenagem, permitiram concluir que o SEEDSOLVE prediz com razoável precisão as perdas de germinação e vigor de sementes de milho e de soja armazenadas.

Alterações fisiológicas e enzimáticas durante a maturação de sementes de pimenta (Capsicum annuum L.)

O trabalho teve como objetivo avaliar as alterações fisiológicas e enzimáticas em sementes de pimenta, cv. Amarela Comprida, obtidas de frutos colhidos em diferentes estádios de maturação e submetidos ao armazenamento pós-colheita. Os frutos foram colhidos aos 40, 50, 60 e 70 dias após a antese (DAA) e submetidos ao armazenamento por 0, 3, 6, 9, 12 e 15 diaspara, então, proceder à extração das sementes.A qualidade fisiológica das sementes foi avaliada pelos testes de germinação, primeira contagem de germinação, deterioração controlada e condutividade elétrica. Avaliaram-se, ainda, as alterações nos sistemas enzimáticos malato desigrogenase (MDH), álcool desidrogenase (ADH), superóxido dismutase (SOD) e peroxidase (PO). Melhores resultados de germinação e vigor e maior atividade de enzimas, envolvidas na respiração e proteção contra radicais livres, são observados em sementes obtidas de frutos colhidos a partir de 60 DAA, não sendo necessário o armazenamento destes após a colheita.

Caracterização morfológica e germinação de sementes de jalapa (Operculina macrocarpa (L.)Urb.)

O objetivo deste trabalho foi avaliar a presença da dormência tegumentar, identificando tratamentos pré-germinativos que possam acelerar e uniformizar a germinação, bem como conhecer a morfologia do desenvolvimento pós seminal em sementes de Operculina macrocarpa. As sementes foram submetidas aos seguintes tratamentos pré-germinativos: imersão em água por 1 hora; imersão em solução de hipoclorito por 1 hora e testemunha, representada por sementes sem tratamento prévio. Os testes de germinação e de emergência foram conduzidos com quatro repetições de 25 e de 20 sementes, em laboratório e em casa-de-vegetação, respectivamente. As avaliações foram realizadas diariamente, durante 30 dias, onde foi calculada a porcentagem de plântulas normais aos 15 e 30 dias e o índice de velocidade de germinação/emergência. A germinação de Operculina macrocarpa é epígea-fanerocotiledonar e a semente apesar de apresentar um tegumento duro não se mostra impermeável à entrada de água, dispensando a adoção de tratamentos pré-germinativos.

Efeito do armazenamento e do progenitor masculino sobre a qualidade e micromorfologia de sementes de maracujá

A propagação do maracujazeiro é feita por sementes e há evidências de que a planta doadora de pólen pode efetivamente contribuir para a obtenção de frutos e sementes de melhor qualidade. Os objetivos desta pesquisa foram avaliar a qualidade das sementes, após de doze meses de armazenamento, considerando a influência do doador de pólen (progenitor masculino) na qualidade das sementes, assim como descrever a ontogênese da micromorfologia das sementes provenientes de frutos em diferentes estádios de maturação. Os frutos foram obtidos a partir de polinização manual controlada e polinização manual colhendo-se frutos em quatro estádios de maturação: 55, 58, 61 e 64 dias após a antese (DAA). As sementes obtidas destes frutos foram armazenadas em ambiente de laboratório e em ambiente refrigerado por 12 meses e, após este período, submetidas a testes de germinação e vigor. Verificou-se que o controle do progenitor masculino não influenciou a qualidade das sementes e que o armazenamento das sementes por um ano em ambiente refrigerado promoveu aumento na germinação e vigor das sementes de maracujá, obtendo-se melhor qualidade quando os frutos foram colhidos aos 61 e 64 DAA. Houve decréscimo na germinação das sementes armazenadas em ambiente de laboratório quando comparadas às sementes armazenadas em ambiente refrigerado. A ontogênese na superfície da semente é variável nos diferentes estádios de maturação.

Exploring the events that engage graduate students in transformative learning /

This research explored the events that engaged graduate students in transformative learning within a graduate program in education. This context was chosen because one objective of a graduate program is to facilitate critical thinking and transformative learning. The question ofhow adult learners perceive and experience learning steered the direction ofthis study. However, the purpose ofthis research was to study critical incidents that led to profound cognitive and affective changes as perceived by the graduate students. Specifically, the questions to be answered were what critical incidents happened to graduate students while in the Master ofEducation program, how were the incidents experienced, and what transformation resulted? The research design evolved over the course of a year and was highly influenced by previous empirical studies and criticisms oftransformative learning theory. The overall design was qualitative and phenomenological. A critical and interpretive approach was made to empirical data collected through a critical incident questionnaire and in-depth interviews. Inductive analysis allowed theory to be built from the data by making comparisons. New questions emerged and attention was given to social context, the passage oftime, and sequence ofevents in order to give meaning and translation ofthe participants' experiences and to build the interpretive narratives. Deductive analysis was also used on the data and a blending ofthe two forms of analysis; this resulted in the development ofa foundational model for transformative learning to be built.The data revealed critical incidents outside ofthe graduate school program that occurred in childhood or adult life prior to graduate school. Since context of individuals' lives had been an important critique of past transformative learning models and studies, this research expanded the original boundaries of this study beyond graduate school to incorporate incidents that occurred outside of graduate school. Critical incidents were categorized into time-related, people-related, and circumstancerelated themes. It was clear that participants were influenced and molded by the stage oftheir life, personal experiences, familial and cultural conditioning, and even historic events. The model developed in this document fiom an overview ofthe fmdings identifies a four-stage process of life difficulty, disintegration, reintegration, and completion that all participants' followed. The blended analysis was revealed from the description ofhow the incidents were experienced by the participants. The final categories were what were the feelings, what was happening, and what was the enviromnent? The resulting transformation was initially only going to consider cognitive and affective changes, however, it was apparent that contextual changes also occurred for all participants, so this category was also included. The model was described with the construction metaphor of a building "foimdation" to illustrate the variety of conditions that are necessary for transformative learning to occur. Since this was an exploratory study, no prior models or processes were used in data analysis, however, it appeared that the model developed from this study incorporated existing models and provided a more encompassing life picture oftransformative learning.

Perceived learning needs in staff development of some care providers in five long-term care settings in Southern Ontario /

This exploratory descriptive study described what 20 care providers in 5 long-term care facilities perceived to aid or hinder their learning in a work-sponsored learning experience. A Critical Incident Technique (Woolsey, 1986) was the catalyst for the interviews with the culturally and professionally diverse participants. Through data analysis, as described by Moustakas (1994), I found that (a) humour, (b) the learning environment, (c) specific characteristics of the presenter such as moderate pacing, speaking slowly and with simple words, (d) decision-making authority, (e) relevance to practice, and (f) practical applications best met the study participants' learning needs. Conversely, other factors could hinder learning based on the participants' perceptions. These were: (a) other presenter characteristics such as a program that was delivered quickly or spoken at a level above the participants' comprehension, (b) no perceived relevance to practice, (c), other environmental situations, and (d) the timing of the learning session. One of my intentions was to identify the emic view among cultural groups and professional/vocational affiliations. A surprising finding of this study was that neither impacted noticeably on the perceived learning needs of the participants. Further research with a revised research design to facilitate inclusion of more diverse participants will aid in determining if the lack of a difference was unique to this sample or more generalizable on a case-to-case transfer basis to the study population.

Construing social dimensions of personality development: nurses as educators

A convenience sample of twenty registered nurses was recruited from two' general hospitals and two community college nursing schools. Kelly's (1955) Personal Construct Theory provided the theoretical framework to discover how nurses perceived themselves as educators. The nurses completed a self-administered Self-Perception Inventory (Soares, 1983) to determine their perception of self as nurse and ideal self as nurse. In an interview, each of the nurses constructed a rank-order repertory grid adapted from Kelly's (1955) Role Repertory Construct Test. Twelve constructs derived from the Self-Perception Inventory (Soares, 1983) were ranked according to a list of ten elements common to a teaching situation. Rank order correlations among the constructs were determined with Spearman's rho. Using a dependent samples t-test, significant differences were found between perceptions of current and ideal self for staff nurses. Significant differences were also found between nurse educators' perceptions of self and ideal self as nurse. No significant differences were determined in perceptions of self as nurse and ideal self as nurse between the staff nurse and nurse educator groups with an independent samples t-test. However, observations of single constructs revealed that although several constructs are shared between the groups in the perception of self in a teaching situation, both groups hold constructs that operate exclusively in their separate domains. The nature and strength of the relationships between the common and unique constructs are different for each group. Nurses I self-perceptions appear to be influenced by the historical development of nursing, role socialization during nursing education, social expectations and gender issues in the health care system.

The performance and strategies of adolescents in learning to read artificial words /

The present study explored processing strategies used by individuals when they begin to read c;l script. Stimuli were artificial words created from symbols and based on an alphabetic system. The words were.presented to Grade Nine and Ten students, with variations included in the difficulty of orthography and word familiarity, and then scores were recorded on the mean number of trials for defined learning variables. Qualitative findings revealed that subjects 1 earned parts of the visual a'nd auditory features of words prior to hooking up the visual stimulus to the word's name. Performance measures-which appear to affect the rate of learning were as follows: auditory short-term memory, auditory delayed short-term memory, visual delayed short- term memory, and word attack or decod~ng skills. Qualitative data emerging in verbal reports by the subjects revealed that strategies they pefceived to use were, graphic, phonetic decoding and word .reading.

Cognitive set, absorption, and achievement as moderators of the perceptual closure effect in picture priming /

The present study examined individual differences in Absorption and fantasy, as well as in Achiievement and achievement striving as possible moderators of the perceptual closure effect found by Snodgrass and Feenan (1990). The study also examined whether different instructions (experiential versus instrumental) interact with the personality variables to moderate the relationship between priming and subsequent performance on a picture completion task. 1 28 participants completed two sessions, one to fill out the MPQ and NEO personality inventories and the other to complete the experimental task. The experimental task consisted of a priming phase and a test phase, with pictures presented on a computer screen for both phases. Participants were shown 30 pictures in the priming phase, and then shovm the 30 primed pictures along with 30 new pictures for the test phase. Participants were randomly assigned to receive one of the two different instruction sets for the task. Two measures of performance were calculated, most fragmented measure and threshold. Results of the present study confirm that a five-second exposure time is long enough to produce the perceptual closure effect. The analysis of the two-way interaction effects indicated a significant quadratic interaction of Absorption with priming level on threshold performance. The results were in the opposite direction of predictions. Possible explanations for the Absorption results include lack of optimal conditions, lack of intrinsic motivation and measurement problems. Primary analyses also revealed two significant between-subject effects of fantasy and achievement striving on performance collapsed across priming levels. These results suggest that fantasy has a beneficial effect on performance at test for pictures primed at all levels, whereas achievement striving seems to have an adverse effect on performance at test for pictures primed at all levels. Results of the secondary analyses with a revised threshold performance measure indicated a significant quadratic interaction of Absorption, condition and priming level. In the experiential condition, test performance, based on Absorption scores for pictures primed at level 4, showed a positive slope and performance for pictures primed at levels 1 and 7 based on Absorption showed a negative slope. The reverse effect was found in the instrumental condition. The results suggest that Absorption, in combination with experiential involvement, may affect implicit memory. A second significant result of the secondary analyses was a linear three-way interaction of Achievement, condition and priming level on performance. Results suggest that as Achievement scores increased, test performance improved for less fragmented primed pictures in the instrumental condition and test performance improved for more highly fragmented primes in the experiential condition. Results from the secondary analyses suggest that the revised threshold measure may be more sensitive to individual differences. Results of the exploratory analyses with Openness to Experience, Conscientiousness and agentic positive emotionality (PEM-A) measures indicated no significant effects of any of these personality variables. Results suggest that facets of the scales may be more useful with regard to perceptual research, and that future research should examine narrowly focused personality traits as opposed to broader constructs.

The effects of a 12-week multifactorial exercise and balance training program on balance control in older adults

The current thesis investigated the effects of a 12-week multifactorial exercise and balance training program on balance control in older adults. Participants completed a baseline testing session which included a series of questionnaires, anthropometric measures, and 18 stance and walking tests. Those who were randomly assigned to the exercise group participated in the 12-week training program while the comparison group was asked not to change anything in his/her lifestyle during the 12-week control period, but were invited to participate in the training program after his/her control period. The same testing protocol was repeated after the 12-week period. The results indicated that there were improvements in the time to complete the walking tests but no change in trunk sway in both the exercise and comparison groups. No changes in stance durations or trunk sway were observed. The findings suggest that the current training program showed no significant improvement in balance control in healthy older adults.

Investigating the Relationships Between Teacher Identity Norms and Collaboration

The purpose of this study was to investigate how teacher identity norms relate to teacher collaboration among the practices of elementary teachers in Ontario. Using quantitative research methods, the data indicated two clusters of teacher identity norms. The norm cluster of innovation, interdependence, and cooperation showed positive correlations with collaboration and the norm cluster of conservatism, individualism, and competition showed negative correlations with collaboration. The two clusters of norms also correlated with each other. The data showed that teachers highly valued collaboration as part of their teaching practice but did not always experience it in their school setting. The analysis suggested that if schools reinforce norms of innovation, interdependence, and cooperation, collaboration will be nurtured. Further, the data showed that if norms of conservatism, individualism, and competition are continued in school cultures, then collaboration will not be sustained. As a broad educational reform agenda, teacher collaboration is used (a) to support school cultures, (b) to change teaching practices, and (c) to implement policy-based initiatives. This research is expected to benefit teachers in its capacity to inform policy makers concerning the highly complex nature of teacher collaboration and some of the factors that impact it. With an understanding of the relationships between teacher identity norms and collaboration, it may be possible for policy makers to provide appropriate support structures that reinforce collaboration in teachers' practices as well as predict potential levels of collaboration within school cultures.

Elaboración del manual de operaciones del personal administrativo en la Preparatoria No. 2 de la Universidad Autónoma de Nuevo León

Tesis ( Maestro en Ciencias de la Administración con Especialidad en Relaciones Industriales) - UANL, 2002