Relationship between photoperiod, plasma concentration of ionic calcium and the histology of the prolactin-secreting cells of the rostral pars distalis of the pituitary gland, the corpuscles of stannius and the ultimobranchial gland in the goldfish, Carassius auratus L. /

The relationship between photoperiod, plasma concentration of ionic calcium and the histology of the prolactin-secreting cells of the rostral pars distalis of the pituitary gland, the Corpuscles of Stannius and the Ultimobranchial gland were investigated. Neither the plasma concentration of ionic calcium nor histologically apparent prolactin cell activity could be correlated with photoperiod. Some evidence of a photoperiodic effect on both the Corpuscles of Stannius and the Ultimobranchial gland was obtained. The expected reciprocal relationship between the activity of these glands was not obvious at the histological level . Quantitative and qualitative analysis at the light microscope level revealed, however, that the hormone prolactin-secreting eta cells of the rostral pars distalis and the hypocalcin-secreting cells of the Corpuscles of Stannius may be arranged in a lamellar pattern comprized of synchronous bands of cells in like-phase of a secretory cycle consisting of four stages - synthesis, storage, release and reorganization. Such synchronized cell cycles in these glands have not heretofore been described in literature. It is suggested that the maintenance of at least 255? of the cells in any one phase of the cycle ensures a supply of the required hormone at all times.

The surface electromyography-force relationship during isometric dorsiflexion in males and females

This study evaluated sex-related differences in the tibialis anterior (TA) surface electromyography (EMG) to force relationship. One-hundred participants (50 males and 50 females) performed three isometric contractions at 20, 40, 60, 80, and 100% of maximal voluntary contraction (MVC) in an apparatus designed to isolate the action of the dorsiflexors. The surface EMG signal was amplified (lOOOx), band-pass filtered (10-500Hz), and sampled at 2048 Hz. The load cell signal was low-passed filtered at 100 Hz and sampled at the same rate. Males were stronger than females {P <0.05). However, there was no significant difference in root-mean-square (RMS) values between sexes {P <0.05). Both sexes exhibited a quadratic increase in RMS across force levels (P <0.05). The mean power frequency (MNF) for males was greater than for females {P <0.05). Males and females exhibited a linear increase in both frequency measures up to 80% of MVC (P <0.05). Between 80 and 100% MVC, the frequency values for the females plateaued while males showed a decrease {P <0.05). The magnitude of the difference in MNF between males and females was consistent with sex-specific TA physiology. In general, the pattern of means for RMS and MNF between males and females revealed no sex-related differences in the surface EMG/force relationship. We therefore conclude that there are no sex-related differences in the gradation of muscle force.

Exploring the relationship between ethnicity and hypertension in Canada

Background: Previous work examining differences in hypertension across ethnic groups employ race as the principal variable. While differences in hypertension have been identified across racial groups, there is great variation between ethnic groups amongst racial groupings that could mask differences in hypertension and cardiovascular disease (CVD) risk. In light of Canada's ethnic diversity, research aimed at identifying specific groups that are at a health disadvantage is essential for understanding the health of the overall population. In addition, this research would be beneficial for creating programs and policies aimed at reducing or eliminating these disparities. Since CVD is the leading cause of mortality in Canada and hypertension is one of the most significant and modifiable risk factors for CVD, it is important to move past crude classifications based on race and examine ethnic group differences. The purpose of this study is to examine the relationship between ethnicity and hypertension in Canada, while employing more narrow classifications for ethnicity than previous studies. In addition, because ethnicity has been shown to be representative of an individual's social experience, this study also aims to investigate whether this relationship can be explained by one or all of the following variable: socioeconomic status, physical activity, body mass index, smoking status, daily alcohol consumption or acculturation. Methods. This study used the 2004 Canadian Community Health Survey, cycle 2.1 to compare 29 different ethnic groups in Canada on whether they had high blood pressure that had been diagnosed by a health professional. Associations were examined using logistic regression. Subsequent logistic regression analyses included socioeconomic status, physical activity, body mass index, smoking status, daily alcohol consumption and acculturation to test for the effect of each of these variables on the relationship between ethnicity and hypertension. Results. Ukrainians, Chinese, Portuguese, South Asians, Aboriginals, Blacks, Filipinos and South East Asians were found to have significantly higher odds of having high blood pressure than Canadians (OR's = 1.50, 1.56, 2.72, 1.38, 1.36, 1.66, 2.21 & 2.24 respectively, p<.001). In addition, the only significant mediating effects were between SES and Aboriginals as well as obesity and Aboriginals. None of the other independent variables accounted for >10% of the risk experienced by the ethnic groups that were significantly associated with hypertension. Interpretation: The odds of having high blood pressure in Canada varies considerably across ethnic groups within racial groups indicating previous research is not specific enough to inform policy and program development. Because this study was not able to explain this relationship using the sociodemographic and lifestyle factors mentioned above, future research should be done to determine what places certain ethnic groups at a greater risk in order to tailor interventions aimed at reducing high blood pressure that are suited to the specific needs of each cultural group.

A relationship between photosynthesis and translocation in plants stressed by ionizing radiation

Since previous investigations have shown that low levels of ionizing radiation can induce a reduction in the rates of apparent photosynthesis and in the magnitude of photoassimilated l4C exported out of a leaf, the present studies were designed and conducted to determine the relationship, if any, between the radiation effects on these two physiological processes. The experiments were particularly designed to determine if the radiation-induced reduction in export is the result of the reduction in photosynthesis and hence availability of materials for translocation or the result of a reduction in the amount of energy available for the vein loading process. This study has shown that the radiation-induced reduction in l4C export out of a leaf is likely related to a loss of energy available for the vein loading process rather than a reduction in the supply of materials available for export due to reduced C02 uptake. The process of photophosphorylation was shown to be reduced by exposure to radiation to an extent similar to the reduction in the export of l4C which was also observed. Both of these processes returned to their pre-irradiation rates 120 minutes following radiatruon exposure. The rate of photosynthetic C02 uptake was also reduced by radiation exposur~ howeve~ this process did not return to the control level nor was the extent of reduction as large as observed for photophosphorylation and photoassimilate export. The observed relationship between the reductions of export and photoph~sphorylation pointed to the utilization of photosynthetically produced ATP in the vein loading process. The radiation-induced reduction in the export of l4C was observed at the highest light intensity used in this study which would also imply the involvement of the photophosphorylation process as an energy seurce for vein loading. The lack of radiation-induced reduction in export at low light intensities was interpreted as being due to the utilization of respiratory derived ATP, a process known to be insensitive to radiation at the levels used in this study, as the energy source for the vein loading process. Studies using plants not stressed by radiation showed that there was an increase in export of 14C with higher light intensities. In summary, the data has been interpreted as showing that at high light intensities the ATP, produced by photophosphorylation, is available for use in the vein loading process. The site of ATP utilization could not be determined from the data obtained in this study but possible sites have been indicated from the work done by other physiologists and are discussed in the thesis.

A social-cognitive model of monitoring and its relationship to behaviour in a naturalistic observation : development and individual differences

years 8 months) and 24 older (M == 7 years 4 months) children. A Monitoring Process Model (MPM) was developed and tested in order to ascertain at which component process ofthe MPM age differences would emerge. The MPM had four components: (1) assessment; (2) evaluation; (3) planning; and (4) behavioural control. The MPM was assessed directly using a referential communication task in which the children were asked to make a series of five Lego buildings (a baseline condition and one building for each MPM component). Children listened to instructions from one experimenter while a second experimenter in the room (a confederate) intetjected varying levels ofverbal feedback in order to assist the children and control the component ofthe MPM. This design allowed us to determine at which "stage" ofprocessing children would most likely have difficulty monitoring themselves in this social-cognitive task. Developmental differences were obselVed for the evaluation, planning and behavioural control components suggesting that older children were able to be more successful with the more explicit metacomponents. Interestingly, however, there was no age difference in terms ofLego task success in the baseline condition suggesting that without the intelVention ofthe confederate younger children monitored the task about as well as older children. This pattern ofresults indicates that the younger children were disrupted by the feedback rather than helped. On the other hand, the older children were able to incorporate the feedback offered by the confederate into a plan ofaction. Another aim ofthis study was to assess similar processing components to those investigated by the MPM Lego task in a more naturalistic observation. Together the use ofthe Lego Task ( a social cognitive task) and the naturalistic social interaction allowed for the appraisal of cross-domain continuities and discontinuities in monitoring behaviours. In this vein, analyses were undertaken in order to ascertain whether or not successful performance in the MPM Lego Task would predict cross-domain competence in the more naturalistic social interchange. Indeed, success in the two latter components ofthe MPM (planning and behavioural control) was related to overall competence in the naturalistic task. However, this cross-domain prediction was not evident for all levels ofthe naturalistic interchange suggesting that the nature ofthe feedback a child receives is an important determinant ofresponse competency. Individual difference measures reflecting the children's general cognitive capacity (Working Memory and Digit Span) and verbal ability (vocabulary) were also taken in an effort to account for more variance in the prediction oftask success. However, these individual difference measures did not serve to enhance the prediction oftask performance in either the Lego Task or the naturalistic task. Similarly, parental responses to questionnaires pertaining to their child's temperament and social experience also failed to increase prediction oftask performance. On-line measures ofthe children's engagement, positive affect and anxiety also failed to predict competence ratings.

Exploring the relationship between professional and organizational commitment : the attitudes of Ontario chartered accountancy students

This study was undertaken to investigate the attitudes of chartered accountancy (CA) students toward professional commitment and organizational commitment. The focus of the study was to discover if a relationship between these two constructs existed and determine which situational and individual characteristics facilitate or impede commitment. The sample included those CA students who wrote the 1995 UFE (n=423). Four instruments were used for data collection: Job Diagnostic Survey, Organizational Commitment Questionnaire, Career Commitment Questionnaire, Career Facilitation Survey, and individual demographic inquiry. The study found a significant relationship between professional commitment and organizational commitment. Situational characteristics tended to influence organizational commitment, while individual characteristics more often governed professional commitment. Specific satisfactions, general satisfaction, growth satisfaction, and satisfaction with compensation, co-workers, and supervision were found to facilitate organizational commitment. Organizational commitment was also influenced by supplemental job characteristics, internal work motivation, career facilitation, and autonomy. Implications for practice involved the cooperation and collaboration of the governing body for the CA profession and the CA firms in activities addressing pertinent issues that influence commitment. Implications for future research were also discussed.

Sediment genotoxicity and its relationship to the frequency of chironomid labial plate deformities

Sediment samples were taken from seven locations in the WeIland River in December 1986 and April 1987. The DMSO extracts of these sediment samples showed a significant (p

The interpretation of music videos : an interactive relationship between medium and viewer

There is a great deal of evidence to support the examination of an interactive relationship between the medium and the viewer in the interpretation of mainstream media. The exact nature of this relationship, however, is not well understood. The current study was carried out to assess the variables that may help explain why certain people interpret media, such as music videos, differently than others. Jensen's concept of reception analysis describes the relationship between the medium and the audience, and thus remains a strong focus within this study. Differences in the interpretation of music videos were investigated as a function of Absorption, gender role, screen size, age and viewing experience. Multiple regression analyses uncovered independent predictions of sexuality and violence scores by absorption and experience, as well as an interaction between absorption and screen size in the sexuality rating of the music videos.

The relationship between stem-form, stand-closure and site -conditions : the influence of environmental conditions on tree allometry and forest structure in west-central Alberta

Changes in the configuration of a tree stern result insignificant differences in its total volume and in the proportion of that volume that is merchantable timber. Tree allometry, as represented by stem-fo~, is the result of the vertical force of gravity and the horizontal force of wind. The effect of wind force is demonstrated in the relationship between stem-form, standclosure and site-conditions. An increase in wind force on the individual tree due to a decrease in stand density should produce a more tapered tree. The density of the stand is determined by the conditions that the trees are growing under. The ability of the tree to respond to increased wind force may also be a function of these conditions . This stem-form/stand-closure/site-conditions relationship was examined using a pre-existing database from westcentral Alberta. This database consisted of environmental, vegetation, soils and timber data covering a wide range of sites. There were 653 sample trees with 82 variables that formed the basis of the analysis. There were eight tree species consisting of Pinus contorta, Picea mariana, Picea engelmannii x glauca, Abies lasiocarpa, Larix laricina, Populus tremuloides, Betula papyrifera and Populus balsamifera plus a comprehensive all-species data set. As the actual conformation of the stern is very individual, stem-fo~was represented by the diameter at breast height to total height r~tio. The four stand-closure variables, crown closure, total basal area, total volume and total number of stems were reduced to total basal area and total number of stems utilizing a bivariate correlation matrix by species. Site-conditions were subdivided into macro, meso and micro variables and reduced in number 3 using cross-tabulations, bivariate correlation and principal components analysis as screening tools. The stem-fo~/stand-closure relationship was examined using bivariate correlation coefficients for stem-fo~ with total number of stems and stem-fo~ with total basal area. The stem-fo~/site-conditions and the stand-closure/site- conditions relationships were examined using multiple correlation coefficients. The stem-form/stand-closure/site-conditions relationship was examined using multiple correlation coefficients in separate analyses for both total number of stems and total basal area. An increase in stand-closure produced a decrease in stem-form for both total number of stems and total basal area for most species. There was a significant relationship between stem-form and site-conditions and between stand-closure and site-conditions for both total number of stems and total basal area for most species. There was a significant relationship between the stemform and site-conditions, including the stand-closure, for most species; total number of stems was involved independently of the site-conditions in the prediction of stem-form and total basal area was not. Larix laricina and Betula papyrifera were the exceptions to the trends observed with most species. The influence of both stand-closure (total number of stems in particular) and site-conditions (elevation in particular) suggest that forest management practices should include these- ecological parameters in determining appropriate restocking levels.

The relationship between creativity and moral judgment

A sample of 50 male and female subjects ranging in age from 12 to 73 were divided into three groups according to the scale of maturity of moral judgment developed by Lawrence Kohlberg. Subjects were also tested on a measure of creativity developed by Torrance after the formulations of Guilford in order to test the hypothesis that the re^- lationship between creativity and maturity of moral judgment is curvilinear. Researchers have failed to develop any working hypothesis concerning the relationship between creativity and moral judgment or postulate any consistent theoretical framework concerning the possible relationship between these two constructs. The empirical investigation involved a scientific testing of a random selection of elementary subjects9 high school adolescents, and creative adults. Tests included Kohlberg8s Moral dilemmas and Guilford's Product Improvement Task. A trend analysis was conducted to reveal whether or not a curvilinear relationship existed between the independent variable (Moral Maturity Stages) and the de~ pe dent variable (creativity performance under each level). Curvilinear trends were observed in two out of four creativity subscales but were not statistically significant. It was concluded that these contradictory findings were due to the relatively small number of subjects tested, the narrow range or moral judgment scores, and the limited conception of creativity defined by the creativity measure used (The Product Improvement Task). It was suggested that an instrument assessing an identity status would be most useful as well as a creativity measure better suited for a theory of creativity essentially developmental in perspective.

Work values and the job characteristics - job outcome relationship

The importance and achievement of work values were found to be significant variables in the job characteristics-job outcome relationship when investigated with a sample of 117 correctional nurses. Data collected via mailed questionnaires were analyzed using Pearson correlation coefficients and stepwise multiple regression. The results indicated that the achievement of intrinsic work values was found to mediate the relationship between job characteristics and internal work motivation and satisfaction, adding considerable explained variance to each of the job outcomes. In addition, the importance of the same intrinsic work values moderated the overall relationship as well as the relationship between job characteristics and achievement of work values. The importance of work values did not, however, moderate the achievement of work values-job outcome relationship as predicted. The practical implications for correctional administrators and nurses, as well as implications for further research were discussed.

Job satisfaction among nurses and its relationship to reflective practice /

This study was undertaken to explore job satisfaction among nurses and its relationship to reflective practice. It is a qualitative study that listens to the perspectives of 7 mental health nurses who work In a conmiunity hospital in southern Ontario. A pilot survey was conducted prior to the face-to -face interviews in order to develop meaningful questions to utilize in the interviews. Nurses participating in the study were ensured anonjnnlty and an opportunity to have their own personal perspectives heard. A convenient sample was obtained from the hospital in which the researcher worked as an educator and professional practice consultant. The concept of job satisfaction was found to be driven by the desire to do important work and to make a difference in patients' lives. The nurses articulated that it is directly related to other factors, such as the opportunity to work in one's area, of preference, involvement in decisionmaking processes, better patient/ staff ratios, and affordable, accessible continuing educational opportunities. Those nurses who have embraced reflective practice for many years seem to be able to sort out that which drives them to stay in nursing and that which will influence them to leave. The constraints of the study cO-e that it is a small qualitative study; therefore, the results are not generallzable. Reflection is integral to the practice of mental heallth nursing find a tool that is used extensively in therapy with patients. Future research could involve studing a different group of nurses who may be more task focused than mental health nurses.