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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Locomotor activity rhythms and photoperiodic time-measurement in the blowfly Calliphora vicina R-D

Kenny, Niall Anthony P. January 1989 (has links)
No description available.
2

The ecology of red squirrels (Sciurus vulgaris) in deciduous woodlands

Holm, Jessica Lynn January 1990 (has links)
No description available.
3

Social behaviour and activity patterns of the African ice rat Otomys sloggetti robertsi

Hinze, Andrea 16 November 2006 (has links)
Faculty of Science School of Biology 9410199j TEL: 011 673 8139 / I studied the sociality and activity patterns of free-living ice rats Otomys sloggetti robertsi. The ice rat is a medium-sized, diurnal, herbivorous rodent, endemic to the alpine habitats of the southern Drakensberg and Maluti Mountains in southern Africa. These environments are characterized by sub-zero temperatures in winter and high levels of solar radiation in summer, and snow can be expected at any time of the year. Previous research by other scientists indicated that the physiology of ice rats is more similar to congeners living at lower altitudes, and, instead the taxon has morphological and behavioural adaptations for coping with the temperature extremes in its environment. Predator pressure on ice rats was negligible in my study site, making the ice rat an ideal model for testing how environmental factors influence sociality and activity patterns. Sociality was investigated by using direct observations and through experimental manipulations. Colonies comprised 4-17 individuals with several reproductively active males and females. Colony members had a high degree of home range overlap, whereas interactions between colony members were rare and usually resulted in agonistic behaviour. Ice rats responded aggressively to experimentally-caged colony members positioned in different parts of their own colony and these were treated with the same level of aggression as were strangers. Moreover, colony members competed aggressively for better-quality introduced food, particularly in winter. From direct observations of male-female interactions, it appeared that ice rats mate promiscuously, which is most likely a consequence of the multi-male and multi-female colonies. Females spent long periods of time belowground with unweaned young which emerged aboveground independently at four weeks of age. The first litter born in a season dispersed at sexual maturity (males±14 weeks; females±9 weeks), but, since I did not observe the behaviour of litters born later in the breeding season, I was not able to tell if these dispersed as well. I excavated the burrow systems of ice rats and found an intricate interlinking underground tunnel system with sometimes more than 25 entrance holes and 1-2 nesting chambers, which would provide a thermoneutral refuge for the ice rats at night as well as during adverse weather conditions. Because the ratio of the number of animals in the colony to III the number of nest chambers exceeded one, I predicted that huddling occurs belowground, which was confirmed by video recordings of nest chambers. Diurnal aboveground activity patterns of ice rats were influenced by prevailing environmental conditions, which resulted in synchronous aboveground appearance of members in a colony. The summer activity pattern was bimodal, dominated by foraging and sun basking behaviour aboveground, with animals retreating belowground to escape high temperatures and radiation levels prevalent around midday. Ice rats utilized the warmer temperatures throughout the day in winter for aboveground foraging and basking. Otomys s. robertsi displays a spatial shift in its social system: colony members huddle belowground but display temporal territoriality aboveground. Such a social system is contrary to predictions previously made for this taxon (i.e. they live as family groups). Ice rat relatives living at lower altitudes mainly occur as non-social aggregations and one relative, the vlei rat O. irroratus, also displays temporal territoriality. Although sociality is common in rodents inhabiting temperate environments in the northern hemisphere, these rodents do not show territoriality at other times. I conclude that the social system of ice rats, in the absence of significant predation pressure, is determined by a combination of 1) environmental factors driving communal thermoregulation and 2) phylogenetic constraints imposed by competition for limited food resources.
4

Characterising personality traits in cattle using biotelemetry systems

MacKay, Jill Rowan Deans January 2013 (has links)
On-farm assessment of cattle health, behaviour and welfare is often a logistical challenge but necessary for ensuring high standards of welfare and production. Recently, technological advances in engineering have allowed the mass manufacture of biotelemetry systems for use in research and industry. A commercial dairy farm may now have many different systems recording information about each individual animal in the herd. One such biotelemetry system is the collection of activity data via activity monitors. These devices were initially used by farmers to detect oestrus bouts through the resulting rise in activity and over the years have been improved to collect highly accurate and specific data about lying, standing and steps recorded over long periods of time. Long term, unobtrusive recording of individual cattle activity patterns is now becoming a reality on several farms. This raises the possibility of utilising sensors to remotely quantify aspects of cattle behaviour and welfare across different farms relatively quickly, allowing for the improvement of management and breeding strategies. Before this can be achieved, there needs to be a solid understanding of how behaviour affects activity patterns and how such data should be handled. In this project, the IceTag (IceRobotics Ltd., South Queensferry, UK), was used as a biotelemetry system for recording the activity of cattle. The IceTag is a tri-axial accelerometer activity monitor with a sample rate of 16Hz which has been shown to be sensitive (i.e. few false negatives) and specific (i.e. few false positives) when recording lying and standing behaviour on adult cattle. Cattle’s individual variation in behaviour was used as a case study to investigate the usage of this type of biotelemetry system. There were two phases to the study. In the first phase, the capabilities and limitations of the IceTag sensor were investigated. This involved assessing the extent of behavioural reactions to the IceTag in cattle. The behaviour of 28 lactating dairy cattle at the SRUC Dairy Research Centre was assessed for an adverse behavioural effect of the tags. The results of this study recommended a period of 48 hours from attachment before cattle grew accustomed to wearing the tag. Following this, the capabilities of the tags were assessed. Activity traits calculated directly from the tag and derived from tag data were analysed with respect to performance in four short term tests of temperament in 67 beef steers at the SRUC Beef Unit. From this work, the good repeatability of activity traits including average bout length, daily MotionIndex and daily step count encouraged their further usage. Steers which responded fearfully in a temperament test had higher MotionIndex in the home pen (rs = 0.35, P = 0.004) and steers which were more capable of displacing other steers at feeding stations also had longer average standing bouts (rs = 0.26, P = 0.036) and were more variable in their total daily standing duration (rs = 0.27, P = 0.030). This suggested that fear and sociability related behaviours can be detected through analysis of activity patterns. This work was continued at Wageningen University’s Dairy Research Centre where activity was recorded in over 100 dairy cattle. Activity recorded over a forty day period could explain some of the variation in behaviours seen during a subsequent fear test, but not in a social motivation test. The trait ‘neophobia’ was associated with more lying bouts and a greater variation in lying bout duration in dairy cows (R2 adj = 0.15, F3,75 = 5.32, P = 0.002) and bold cows also showed less variation in their lying bout durations (R2 adj = 0.11, F2,75 = 5.63, P = 0.005). In conclusion, remote sensors are a useful addition to the ethologist’s toolbox, enabling researchers to gain some insight into how fearfully a cow may react without assessing this through on-farm behavioural testing. Moreover, this work has found that the effects of personality which can be observed in behavioural testing can also be observed in spontaneous behaviour in the home pen away from testing environments. Biotelemetry systems can be utilised as a welfare assessment tool as they record repeatable activity traits which relate to underlying behavioural dimensions linked to the cow’s behavioural response to stimuli.
5

Cerebral activity prior to skilled motor performance : an electro-encephalographic review

Collins, David John January 1990 (has links)
An electroencephalographic (EEG) protocol was used to examine cerebral activity in the moments proceeding self paced motor performance. Throughout the series of investigations, power in the alpha waveband (8-13 Hz) was used as the dependant variable. In the first investigation, subjects completed a variety of stereotyped 'left and right brain' tasks. These tasks induced a reliable and predictable pattern of lateralised activity. Furthermore, tasks categorised as 'right brain' were shown to induce a more consistent effect. In the second investigation, expert Karate athletes performed a number of Karate specific tasks together with a skill acquisition and cognitive task condition. Significant increases in alpha band power, mediated by task difficulty, were found to be associated with one category of task. In the third study, subjects completed a series of novel tasks, designed to systematically vary the effort and accuracy demands. A significant decrease in alpha band power was shown to be associated with preparation for the asymmetrical high effort task, namely a leg extension against resistance. Outcome of the high accuracy condition was found to significantly mediate alpha band power immediately prior to performance. In the final investigation, the alpha band powers of cricketers, non-cricketing sportsmen and non-sportsmen were compared as they performed a variety of Cricket related, throwing tasks. Significant differences were detected between the different groups and between the different tasks. Once again, success was found to mediate the pattern of alpha band power. It was concluded that the effects observed were probably due to changes in the Rolandic Wicket or Mu rhythm generated in the central and pre-central regions.
6

Physical activity assessed by accelerometry in children

Nilsson, Andreas January 2008 (has links)
<p>Physical activity (PA) is likely to constitute an important aspect of health-related behaviour in growing children. However, the knowledge on levels and patterns of PA in children is limited, due to the difficulty of precisely measuring this complex behaviour in normal daily living. Information on variables that significantly contributes to the variability in PA patterns is warranted as it may inform strategies for promoting physically active lifestyles in school-age youth. The overall purpose of the present studies was to increase the knowledge about the use of accelerometry when assessing PA in children, and examine sources of variability in objectively assessed PA behaviour in children. The study samples included 1954 nine- and 15-year-old children from four geographical locations in Europe (Norway, Denmark, Estonia and Portugal), and additionally 16 Swedish seven-year-old boys and girls. PA was assessed by the MTI accelerometer during free-living conditions, including both weekdays and weekend days. A part of the PA assessment was conducted using different time sampling intervals (epochs). Predictions of estimates of daily energy expenditure from accelerometer output were calculated using previously published equations. Potential correlates of PA behaviour were assessed by self-report. The main findings were; a) the epoch setting had a significant effect when interpreting time spent at higher intensities of PA in young children, b) predicted energy expenditure differed substantially between equations, c) between- and within-day differences in overall levels of PA, time spent at moderate-to-vigorous intensity physical activity and time spent sedentary differed between age, gender and geographical location, d) outdoor play and sports participation were differentially associated with objectively measured PA in 9- and 15-year-old children. It is concluded that the sporadic nature of children’s physical activity require very short epoch settings for detecting high intensity PA, and that different published equations for estimations of daily energy expenditure cannot be used interchangeably. The interpretations of average energy expenditure from available equations should be made with caution. Based on a large sample of children of different ages, weekend days and leisure time during weekdays seem appropriate targets when promoting PA in order to increase the proportion of children achieving current recommendations on health enhancing PA. Further, significant correlates of PA behaviour dependent on age group are presented, which should be considered when planning interventions for promoting PA in school-age youth.</p>
7

Effects of Early Embryonic Alcohol Exposure on Activity Patterns in Zebrafish (Danio rerio)

Seguin, Diane 15 February 2010 (has links)
SFWT Zebrafish were exposed to various concentrations of EtOH at 24 hours post-fertilization for a period of two hours. When fish reached maturity they were placed in individual tanks in a larger open field. A preliminary strain comparison was also conducted using control (EtOH untreated) SFWT and AB fish. The behaviour of fish was recorded for 24 hours during a normal light:dark cycle. Motor patterns and general activity were quantified and analyzed and several behaviors were found to change significantly throughout the daytime and nighttime period. Also, fish exposed to the highest concentration of alcohol were found to exhibit significantly reduced amount of thrashing towards other subjects as compared to fish in the control group confirming previous results that demonstrated reduction of shoaling after early embryonic alcohol exposure.
8

Effects of Early Embryonic Alcohol Exposure on Activity Patterns in Zebrafish (Danio rerio)

Seguin, Diane 15 February 2010 (has links)
SFWT Zebrafish were exposed to various concentrations of EtOH at 24 hours post-fertilization for a period of two hours. When fish reached maturity they were placed in individual tanks in a larger open field. A preliminary strain comparison was also conducted using control (EtOH untreated) SFWT and AB fish. The behaviour of fish was recorded for 24 hours during a normal light:dark cycle. Motor patterns and general activity were quantified and analyzed and several behaviors were found to change significantly throughout the daytime and nighttime period. Also, fish exposed to the highest concentration of alcohol were found to exhibit significantly reduced amount of thrashing towards other subjects as compared to fish in the control group confirming previous results that demonstrated reduction of shoaling after early embryonic alcohol exposure.
9

Ecological Study of the Common Moorhen (Gallinula chloropus)

Chen, Chung-ying 21 July 2005 (has links)
The Common Moorhen (Gallinula chloropus) is a member of the rail family that usually inhabits slow moving or still bodies of water and can spread relatively rapidly and colonize a wide range of habitats. This species is a common resident bird, but a study of its basic ecology has not been published in Taiwan. The objective of this study was to examine the Common Moorhen¡¦s general breeding biology, as well as its diurnal activity patterns. I also made an attempt to describe its breeding behavior and time course. The possibility of morphometric characters difference between the male and female of the species was also examined. The study was conducted from December 2003 to May 2005 in Tainan county and Kaosiung Zhouzai wetland park. The majority of Common Moorhen breeding groups recorded during the study were monogamous. Both male and female birds share the tasks such as incubating the eggs, repairing nest and feeding chicks. The incubation period lasted about 21 days. Our study indicates that the clutch sizes of Common Moorhens ranged between 1 and 8 per female with two to five is typical. The primer P2 and P8 sexing method was successful in identifying the sexes of 52 Common Moorhen. The male was a little bigger than the female. There was significant difference in egg length, width and weight among individual females. Only a nest¡¦s inside diameter correlated to (linear regression) the number of eggs. I think that the number of Common Moorhen populations studied in this study can be quite high, which may be due to :(1) they seem to be breed all year long with good parental care and a successful breeding system (2) some individuals may have well concealed nesting areas, and (3) they have few predators in Taiwan, (4) high survival rate of chicks.
10

Physical activity assessed by accelerometry in children

Nilsson, Andreas January 2008 (has links)
Physical activity (PA) is likely to constitute an important aspect of health-related behaviour in growing children. However, the knowledge on levels and patterns of PA in children is limited, due to the difficulty of precisely measuring this complex behaviour in normal daily living. Information on variables that significantly contributes to the variability in PA patterns is warranted as it may inform strategies for promoting physically active lifestyles in school-age youth. The overall purpose of the present studies was to increase the knowledge about the use of accelerometry when assessing PA in children, and examine sources of variability in objectively assessed PA behaviour in children. The study samples included 1954 nine- and 15-year-old children from four geographical locations in Europe (Norway, Denmark, Estonia and Portugal), and additionally 16 Swedish seven-year-old boys and girls. PA was assessed by the MTI accelerometer during free-living conditions, including both weekdays and weekend days. A part of the PA assessment was conducted using different time sampling intervals (epochs). Predictions of estimates of daily energy expenditure from accelerometer output were calculated using previously published equations. Potential correlates of PA behaviour were assessed by self-report. The main findings were; a) the epoch setting had a significant effect when interpreting time spent at higher intensities of PA in young children, b) predicted energy expenditure differed substantially between equations, c) between- and within-day differences in overall levels of PA, time spent at moderate-to-vigorous intensity physical activity and time spent sedentary differed between age, gender and geographical location, d) outdoor play and sports participation were differentially associated with objectively measured PA in 9- and 15-year-old children. It is concluded that the sporadic nature of children’s physical activity require very short epoch settings for detecting high intensity PA, and that different published equations for estimations of daily energy expenditure cannot be used interchangeably. The interpretations of average energy expenditure from available equations should be made with caution. Based on a large sample of children of different ages, weekend days and leisure time during weekdays seem appropriate targets when promoting PA in order to increase the proportion of children achieving current recommendations on health enhancing PA. Further, significant correlates of PA behaviour dependent on age group are presented, which should be considered when planning interventions for promoting PA in school-age youth.

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