1000 resultados para Brock University


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This study attempted to determine whether or not dialogue journal writing encouraged critical reflection in the adult ESL (English as a Second Language) learner. According to research in adult education and anecdotal evidence, the process ofdialogue journal writing can facilitate critical reflection in the adult learner. However, little research has been conducted to examine whether or not journal writing can facilitate critical reflection in the second language learner. As a result, ten low-intermediate level adult ESL students from Brock University's Intensive English Language Programme participated in a dialogue journal writing programme in their writing class. The participants wrote journal entries over a 10-week period, and were interviewed once throughout the process to determine their perceptions ofthe journal writing experience. They also were observed by the researcher throughout the journal writing sessions to establish whether any behaviours or intrusions might affect the participants' writing processes. After the content ofthe journals and the interviews, and the observations made by the researcher were analysed, it was confirmed that, for these participants, dialogue journal writing did not necessarily encourage critical reflection. Moreover, the participants' perceptions ofjournal writing were that it helped them to practise the syntax, vocabulary, and rhetorical patterns ofEnglish; nevertheless, it did not foster critical reflection or thinking.

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Relationships between surface sediment diatom assemblages and lake trophic status were studied in 50 Canadian Precambrian Shield lakes in the Muskoka-Haliburton and southern Ontario regions. The purpose of this study was to develop mathematical regression models to infer lake trophic status from diatom assemblage data. To achieve this goal, however, additional investigations dealing with the evaluation of lake trophic status and the autecological features of key diatom species were carried out. Because a unifying index and classification for lake trophic status was not available, a new multiple index was developed in this study, by the computation of the physical, chemical and biological data from 85 south Ontario lakes. By using the new trophic parameter, the lake trophic level (TL) was determined: TL = 1.37 In[1 +(TP x Chl-a / SD)], where, TP=total phosphorus, Chl-a=chlorophyll-a and SD=Secchi depth. The boundaries between 7 lake trophic categories (Ultra-oligotrophic lakes: 0-0.24; Oligotrophic lakes: 0.241-1.8; Oligomesotrophic lakes: 1.813.0; Mesotrophic lakes: 3.01-4.20; Mesoeutrophic lakes: 4.21-5.4; Eutrophic lakes: 5.41-10 and Hyper-eutrophic lakes: above 10) were established. The new trophic parameter was more convenient for management of water quality, communication to the public and comparison with other lake trophic status indices than many of the previously published indices because the TL index attempts to Increase understanding of the characteristics of lakes and their comprehensive trophic states. It is more reasonable and clear for a unifying determination of true trophic states of lakes. Diatom specIes autecology analysis was central to this thesis. However, the autecological relationship of diatom species and lake trophic status had not previously been well documented. Based on the investigation of the diatom composition and variety of species abundance in 30 study lakes, the distribution optima of diatom species were determined. These determinations were based on a quantitative method called "weighted average" (Charles 1985). On this basis, the diatom species were classified into five trophic categories (oligotrophic, oligomesotrophic, mesotrophic, mesoeutrophic and eutrophic species groups). The resulting diatom trophic status autecological features were used in the regressIon analysis between diatom assemblages and lake trophic status. When the TL trophic level values of the 30 lakes were regressed against their fi ve corresponding diatom trophic groups, the two mathematical equations for expressing the assumed linear relationship between the diatom assemblages composition were determined by (1) uSIng a single regression technique: Trophic level of lake (TL) = 2.643 - 7.575 log (Index D) (r = 0.88 r2 = 0.77 P = 0.0001; n = 30) Where, Index D = (0% + OM% + M%)/(E% + ME% + M%); 4 (2) uSIng a' multiple regressIon technique: TL=4.285-0.076 0%- 0.055 OM% - 0.026 M% + 0.033 ME% + 0.065 E% (r=0.89, r2=0.792, P=O.OOOl, n=30) There was a significant correlation between measured and diatom inferred trophic levels both by single and multiple regressIon methods (P < 0.0001, n=20), when both models were applied to another 20 test lakes. Their correlation coefficients (r2 ) were also statistically significant (r2 >0.68, n=20). As such, the two transfer function models between diatoms and lake trophic status were validated. The two models obtained as noted above were developed using one group of lakes and then tested using an entirely different group of lakes. This study indicated that diatom assemblages are sensitive to lake trophic status. As indicators of lake trophic status, diatoms are especially useful in situations where no local trophic information is available and in studies of the paleotrophic history of lakes. Diatom autecological information was used to develop a theory assessing water quality and lake trophic status.

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House Finches (CarpQdacqs mexiCAnuS) were introduced to Long Island, New York from southern'California in 1940. Apparently, an initial sample of less than 100 birds has given rise to a population that now occupies much of the eastern United States. This study was to determine if morphological and reproductive changes have taken place in introduced eastern birds, which have colonized a novel environment. A study area in Goleta, California (CAL) represented the parental population whereas for comparison, House Finches in St. Catharines, Ontario (ONT) represented the introduced population. Interlocality variation in 25 morphometric characters of 100 adult House Finches was examined statistically. Singleclassification analysis of variance revealed significant interlocality differentiation in seven characters of males and nine of females. Females showed differentiation in more limb elements than males. Analysis of character variation using discriminant and principal component analysis distinguished samples on the basis of variation in shape. Compared to CAL, aNT birds (especially females) had smaller extremities relative to certain core parts and weight. Females showed similar patterns of character covariation in each locality on the second principal component, which suggests that differentiation of the ONT population may not be solely environmentally induced. Sexual dimorphism was evident in four charaoters in aNT and five in CAL. Disoriminant analysis distinguished sex on the basis of variation in shape. Males possessed a relatively larger flying apparatus and small.er hind limbs than females. The dearee of sexual dimorphism did not vary sicnifioantly between looalities. 3 Data on reproduotive parameters were oolleoted in 1983 and 1984 in ONT, and 1984 in CAL. In 1984, Bouse Finohes began breedina approximately three months earlier in CAL than in ONT. In ONT, there was no sianifioant differenoe in mean olutoh initiation date between 1983 and 1984. In both looalities most nests oontained either four or five ea",s, and olutoh size differenoes between looalites were not signifioant. Seasonal deolines in olutch size were evident in ONT but not in CAL. Intralooality variation in e.g weight and size was not related to clutch size. E",g weiaht showed no seasonal trend in ONT, but inoreased sianifioantly with breed ina season in OAL. In both looalities e8'''' weiaht increased sipifioantly with order of layina in olutohes of four but not in clutohes of five. Eag's in ONT in 1983 and 1984 were sip.ificantly larser than in CAL in 1984. The modal inoubation period was 13 days and did not vary sip.ifioantly between localites. In both looalities nestling weiaht on the day of hatohing was oorrelated to fresh ega welaht. For muoh of the period between hatohing and 14 days post-hatoh, ONT nestlinas were signifioantly laraer than CAL nestlings in terms of weiaht. bill length, bill depth, and manus length.

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The present study was carried out to test the hypothesis that photosynthetic bacteria contribute a large portion of the food of filter feeding zooplankton populations in Crawford Lake, Ontario. The temporal and spatial variations of both groups of organisms are strongly dependent on one another. 14 By using C-Iabelled photosynthetic bacteria. the ingestion and clearance rates of Daphnia pulex, ~. rosea, and Keratella spp were estimated during summer and fall of 1982. These quantitative estimations of zooplankton ingestion and clearence rates on photosynthetic bacteria comprised an original addition to the literature. Photosynthetic bacteria comprised a substantial portion of the diet of all four dominant zooplankton species. The evidence for this is based on the ingestion and clearance rates of the dominant zooplankton species. Ingestion rates of D. pulex and D. rosea ranged 5 5 -1 -1 - -- 5 - -- 5 from 8.3X10 -1 to 14.6XlO -1 cells.ind. hr and 8.1X10 to 13.9X10 cells.ind. hr • Their clearance rates ranged from 0.400 to 1.000 -1 -1 -1 -1 ml.ind. hr. and 0.380 to 0.930 ml.ind. hr • The ingestion and clearance -1 -1 -1 -1 rates of Keratella spp were 600 cell.ind. hr and 0.40 ul.ind. hr respectively. Clearance rates were inversely proportional to the concentration of food cells and directly proportional to the body size of the animals. It is believed that despite the very short reg~neration times of photosynthetic bacteria (3-8 hours) their population densities were controlled in part by the feeding rates of the dominant zooplankton in Crawford Lake. By considering the regeneration times of photosynthetic bacteria and the population clearance rates of zooplankton, it was estimated that between 16 to 52% and 11 to 35% of the PHotosynthetic bacteria were' consumed· by Daphnia· pulex. and Q.. rosea per day. The temporal and spatial distribution of Daphnia pulex, !.. rosea, Keratella quadrata, K. coChlearis and photosynthetic bacteria in Crawford Lake were also investigated during the period of October, 1981 to December, 1982. The photosynthetic bacteria in the lake, constituted a major food source for only those zooplankton Which tolerate anaerobic conditions. Changes in temperature and food appeared to correlate with the seasonal changes in zooplankton density. All four dominant species of zooplankton were abundant at the lake's surface (O-4m) during winter and spring and moved downwards with the thermocline as summer stratification proceeded. Photosynthetic bacteria formed a 2 m thick layer at the chemocline. The position of this photosynthetic bacterial J-ayer changed seasonally. In the summer, the bacterial plate moved upwards and following fall mixing it moved downwards. A vertical shift of O.8m (14.5 to 15.3m) was recorded during the period of June to December. The upper limit of the photosynthetic bacteria in the water column was controlled by dissolved oxygen, and sulfide concentrations While their lower limit was controlled by light intensity. A maximum bacterio- 1 chlorophyll concentration of 81 mg Bchl.l was recorded on August 9, 1981. The seasonal distribution of photosynthetic bacteria was controlledinpart' by ·theg.-"z1ai'_.Q;~.zoopl. ank:tCm;-.Qther -ciactors associated with zooplankton grazing were oxygen and sulfide concentrations.

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This research is a qualitative study of cultural reproduction and resistance from students' perspectives. Thirteen teenagers (eight in attendance in regular high schools and five drop-outs) were recruited to take part and were involved to varying degrees through interviews, journal writing, and group interactive sessions. A purposive sampling design was used initially to recruit individuals known to the researcher through contacts in an alternate education setting. Other participants were recruited throughout the research phase. The theoretical aspects are premised on the work of Paul Willis, Michel Foucault, and Pierre Bourdieu. The reflexive praxeology of Bourdieu reflects the position taken as one way of understanding how students construct and respond to the situations of cultural dominance they experience in schools. The same reflexivity is offered for suggestions as to how teachers can respond to their own position in the education system.

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This study used Q methodology to measure the extent to which individuals with five educational roles (student teacher, elementary music teacher, principal, high school music teacher, and music consultant) held five proposed philosophies of music education (hedonic, utilitarian, aesthetic cognitivism, aesthetic formalist, and praxial). Twenty-seven sUbjects participated in the Q study. These subjects were a convenience sample based on their educational role, accessibility, and willingness to participate. Participants completed a background sheet which indicated their background in music, and their responsibility for teaching music. The sUbjects in this Q study rank-ordered a set of 60 Q sort items (each item representing a proposed philosophical position) twice: Sort P to reflect current practice, and Sort I to reflect the ideal situation. The results of the sorting procedures were recorded by the participant on the response page which organized the rankings according to an approximated normal distribution as required by Q methodology. The analysis of the data suggested that the comparison across philosophical positions was significant and that the results of the interaction between philosophical position and educational role were significant, although educational role alone was not significant. Post-hoc analysis of the data was used to determine the significant differences between the levels of the, independent variables used in the model: philosophical position, educational role, and music background. A model of the association of the five philosophical positions was presented and discussed in relation to the Q study results. Further research could refine the Q sort items to better reflect each philosophical position.

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This paper presents two studies, both examining the efficacy of a computer programme (Captain's Log) in training attentional skills. The population of interest is the traumatically brain injured. Study #1 is a single-case design that offers recommendations for the second, .larger (N=5) inquiry. Study #2 is an eight-week hierarchical treatment programme with a multi-based testing component. Attention, memory, listening comprehension, locus-of-control, self-esteem, visuo-spatial, and general outcome measures are employed within the testing schedule. Results suggest that any improvement was a result of practice effects. With a few single-case exceptions, the participants showed little improvement in the dependent measures.

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A review of the literature reveals that there are a number of children in the educational system who are characterized by Attention Deficit Disorder. Further review of the literature reveals that there are information processing programs which have had some success in increasing the learning of these children. Currently, an information processing program which is based on schema theory is being implemented in Lincoln County. Since schema theory based programs build structural, conditional, factual, and procedural schemata which assist the learner in attending to salient factors, learning should be increased. Thirty-four children were selected from a random sampling of Grade Seven classes in Lincoln County. Seventeen of these children were identified by the researcher and classroom teacher as being characterized by Attention Deficit Disorder. From the remaining population, 17 children who were not characterized by Attention Deficit Disorder were randomly selected. The data collected were compared using independent t-tests, paired t-tests, and correlation analysis. Significant differences were found in all cases. The Non-Attention Deficit Disorder children scored significantly higher on all the tests but the Attention Defici t Disorder children had a significantly higher ratio of gain between the pretests and posttests.

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In the first week of a Job preparation Program all twelve female members of the class were invited to be part of a study to determine the effect of Life Skills training on their behaviour over the twelve-week period of the program. Six females volunteered and each was interviewed four times during the Job preparation Program and once after the program ended. The interviews focused on three areas of skill deficiency addressed in Life Skills lessons: their knowledge about themselves and attitude towards themselves; their interpersonal relationships; and their problem-solving ability. The participants' comments over the sixteen-week period of the interviews were used to decide if the total behaviour of the participants, (i.e., what they did, thought, and felt) changed so that each became more effective in satisfying her needs. The study suggested that the total behaviour of three of the six women changed so that they became more effective in satisfying their needs. The fourth female's total behaviour changed in only two of the three areas focused on in the interviews, and the total behaviour of the fifth and sixth females showed no change.

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Female choice is an important element of sexual selection that may vary among females of the same species. Few researchers have investigated the causes of variation in selectivity with respect to potential mates and overall level of motivation toward a stimulus source representative of a mate. This study demonstrates that female age may be one cause of variation in female choice. Females of different ages may have different mate preferences. As females age, they have less time left to reproduce, and their residual reproductive value decreases. This should correspond to a higher reproductive effort which may be represented as increased motivation and/or decreased selectivity. The effect of age on mate choice in Gryllus integer was investigated by using a non-compensating treadmill, called the Kugel, to measure female phonotaxis. Artificially generated male calling songs of varying pulse rates were broadcast in either a singlestimulus or a three-stimulus experimental design. The pulse rates used in the calling song stimuli were 70, 64, 76, 55 and 85 pulses per second. These corresponded to the documented mean pulse rate for the species at the experimental temperature, one standard deviation below and above the mean, and 2.5 standard deviations below and above the mean, respectively. Test females were either 11-14 days or 25-28 days post-ecdysis. Trials usually were conducted two to seven hours into the scotophase. In the single-stimulus experiment, females were presented with stimuli with only one pulse rate. Older females achieved higher vector scores than younger females, indicating that older females are more motivated to mate. Both groups showed little phonotactic response towards 55 or 85 pIs, both of which lie outside the natural range of G. integer calling song at the experimental temperature. Neither group discriminated among the three pulse rates that fell within the natural range of calling song. In the three-stimulus experiment, females were presented with stimuli with one of three pulse rates, 64, 70 or 76 pIs, In alternation. Both age groups had reduced responsiveness in this experiment, perhaps due to an increase in perceived male density. Additionally, younger females responded significantly more to 64 and 70 pIs than to the higher pulse rate, indicating that they are selective with respect to mate choice. Older females did not discriminate among the three pulse rates. Therefore, it was concluded that selectivity decreases with age. A further study was conducted to determine that these effects were due to age and not due to the differing periods without a mating between the two age groups. Again, stimuli were presented in a three-stimulus experimental design. Age was held constant at 28 days and time since last mating varied from 11 to 25 days. Females varyIng in time since last mating did not differ in their responses to the calling song pulse rates. This indicated that the increased motivation and decreased selectivity exhibited In the initial experiments were due to age and not to time without a mating. Neither time of trial nor female weight had an effect upon female phonotaxis. Data are discussed in terms of mate choice, residual reproductive value, and costs of choice.

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Four groups of rainbow trout, Salmo gairdneri, were acclimated to 2°, 10°, and 18°e, and to a diurnal temperature cycle (100 ± 4°C). To evaluate the influence of cycling temperatures in terms of an immediate as opposed to acclimatory response various ventilatory-cardiovascular rate functions were observed for trout, either acclimated to cycling temperatures or acclimated to constant temperatures and exposed to a diurnal temperature cycle for the first time (10° ± 4°C for trout acclimated to 10°C; 18°+ 4°C for trout acclimated to l8°e). Gill resistance and the cardiac to ventilatory rate ratio were then calculated. Following a post preparatory recovery period of 36 hr, measurements were made over a 48 hour period with the first 24 hours being at constant temperature in the case of statically-acclimated fish followed by 24 hours under cyclic temperature conditions. Trout exhibited marked changes in oxygen consumption (Vo ) with temp- 2 erature both between acclimation groups, and in response to the diurnal temperature cycle. This increase in oxygen uptake appears to have been achieved by adjustment of ventilatory and, to some extent, cardiovascular activity. Trout exhibited significant changes in ventilatory rate (VR), stroke volume (Vsv), and flow (VG) in response to temperature. Marked changes in cardiac rate were also observed. These findings are discussed in relation to their importance in convective oxygen transport via water and blood at the gills and tissues. Trout also exhibited marked changes in pressure waveforms associated with the action of the resp; ratory pumps with temperature. Mean differenti a 1 pressure increased with temperature as did gill resistance and utilization. This data is discussed in relation to its importance in diffusive oxygen transport and the conditions for gas exchange at the gills. With one exception, rainbow trout were able to respond to changes in oxygen demand and availability associated with changes in temperature by means of adjustments in ventilation, and possibly pafusion, and the conditions for gas exchange at the gills. Trout acclimated to 18°C, however, and exposed to high cyclic temperatures, showed signs of the ventilatory and cardiovascular distress problems commonly associated with low circulating levels of oxygen in the blood. It appears these trout were unable to fully meet the oxygen requirements associated with c~ling temperatures above 18°C. These findings were discussed in relation to possible limitations in the cardiovascular-ventilatory response at high temperatures. The response of trout acclimated to cycling temperatures was generally similar to that for trout acclimated to constant temperatures and exposed to cycling temperatures for the first time. This result suggested that both groups of fish may have been acclimated to a similar thermal range, regardless of the acclimation regime employed. Such a phenomenon would allow trout of either acclimation group to respond equally well to the imposed temperature cycle. Rainbow trout showed no evidence of significant diurnal rhythm in any parameters observed at constant temperatures (2°, 10°, and 18° C), and under a 12/12 light-dark photoperiod regime. This was not taken to indicate an absence of circadian rhythms in these trout, but rather a deficiency in the recording methods used in the study.

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Therllloelynalllics of lllodel 11lel1ll)rane systeills containing 1110nollnsaturatecl I)lloSI)holil) ids is strongly infllienced l)y the I)osition of the C==C dOlll)le })ond in tIle acyl chain. The telllI)eratllres of both chain-nlelting (TM) and La -+ HI! (TH) I)hase traIlsitions are lowered by IIp to 20°C when C==C is Inoved froln positions 6 or 11 to I)osition 9 in an 18-carl)on chain. This work is an attellll)t to ellicidate the uIlderlying Illoleclilar Illechanisllls reSI)Onsi])le for tllese draillatic tllerillodynaillic changes. Mixtllres of di-18: 1 l)hoSI)hatidylethanolanline with C==C at l)ositioIlS 6, 9, 11 were llsed, witll a sI1lall aI1lOlint of I)erdellterated tetradecanol, known to })e a gooel rel)Orter of the cllain Illoleclilar order. SI)ectral second 11I0I1lents were llsed to Illonitor tIle La -+ HII I)hase transition, which was fOllnd to ])e ])road (2-6°C), with a slight llysteresis on heatiIlg/cooling. The orientational order I)rofiles were nleasllred 1lSiIlg 2H Illiclear Illagnetic resonance and changes in these order I)rofiles between La aIld HII I)hases silow l)oth a local increase in order in the vicinity of the C==C bonds and an o\Terall decrease ill the average orientational order of the chain as a whole. These Sll])tle changes recluire })oth high-fidelity SI)ectrosCol)y and a careflll data analysis that takes into aCCOllnt the effects due to l)artiall1lagnetically-indllced orientational ordering of the l)ilayers. In tIle COIltext of SOllle recently rel)Orted cross-relaxation 11leaSlirenlents in Silllilar l)llOSI)llolil)iels, 0111' reslilts sllggest that large-anll)litllde conforlllational changes in the interior of tIle I110del 111eI11])ranes I)lay a 1110re significant role than I)reviollsly thOllght.

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Intracerebroventricular (ICV) administration of bombesin (BN) induces a syndrome characterized by stereotypic locomotion and grooming, hyperactivity and sleep elimination, hyperglycemia and hypothermia, hyperhemodynamics, feeding inhibition, and gastrointestinal function changes. Mammalian BN-like peptides (MBNs), e.g. gastrin-releasing peptide (GRP), Neuromedin C (NMC), and Neuromedin B (NMB), have been detected in the central nervous system. Radio-labeled BN binds to specific sites in discrete cerebral regions. Two specific BN receptor subtypes (GRP receptor and NMB receptor) have been identified in numerous brain regions. The quantitative 2-[14C]deoxyglucose ([14C]20G) autoradiographic method was used to map local cerebral glucose utilization (LCGU) in the rat brain following ICV injection of BN (vehicle, BN O.1Jlg, O.5Jlg). At each dose, experiments were conducted in freely moving or restrained conditions to determine whether alterations in cerebral function were the result of BN central administration, or were the result of BN-induced motor stereotypy. The anteroventral thalamic nucleus (AV) (p=O.029), especially its ventrolateral portion (AVVL) (p

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Cytoch ro me c oxidase (ferrocytochrome c : 02 oxidoreductase ; EC 1.9. 3.1) is the terminal enzyme in the mitochondrial electron transport chain, catalyzing the transfer of electrons from ferrocytochrome c to molecular oxygen. The effects of two large amphiphilic molecules .. valinomycin and dibucaine upon the spectra of the isolated enzyme and upon the activity of both isolated enzyme and enzyme in membrane systems are investigated by using spectrophotometric and oxygen electrode techniques. The results show that both valinomycin and dibucaine change the Soret region of the spectrum and cause a partial inhibition in a concentration range higher than that in which they act as ionophores. It is concluded that both valinomycin and dibucain~ binding induce a conformational change of the protein structure which modifies the spectrum of the a3 CUB centre and diminishes the rate of electron transfer between cytochrome a and the binuclear centre.