Genetic and Phenotypic Trends for Growth and Overall Efficiency in Bonsmara Beef Cattle

Animal Breedin

Engineering development and control design of a system for paraplegic tricycling

The aim of this study was the design of a cycle device to be used by patients with Spinal Cord Injury (SCI), using the technique of Functional Electrical Stimulation (FES). A complete literature review of former projects in the areas of Design Engineering, Control Engineering, Physiologic and Psychologic investigations in SCI FES cycling was done. All results achieved so far were summarized. Based on the review, a commercially available tricycle was modified for the demands of SCI people. A 10 Bit shaft encoder was used to feed back information from the tricycle and the cyclist. A software for the stimulation of the muscles in the lower limbs was developed. The Real Time Toolbox of Matlab was used for the data acquisition between the tricycle and the PC. A simple approach was invented to find a good first approximation of the individual stimulation pattern for the Gluteal, Hamstring, and Quadriceps muscle groups. Initial experiments were done. A velocity compensation routine, which was part of the software as well, allowed a healthy subject, stimulated via FES, to increase the pedal frequency to more than 100 rev per minute. A closed loop controller, based on system identification and analytical controller design, was implemented into the software as well. Experiments showed that the controller was able to fix the pedal frequency to a constant value on one hand, but also to solve dynamic tasks on the other hand. This is a significant original contribution, as this type of feedback controller has not previously been applied in FES cycling. The system described in the thesis is currently being used in a pilot study of FES cycling with three paraplegic subjects at the Southern General Hospital in Glasgow

Life Sciences Program Tasks and Bibliography

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1995. Additionally, this inaugural edition of the Task Book includes information for FY 1994 programs. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive Internet web pag

Piospheres in semi-arid rangeland: Consequences of spatially constrained plant-herbivore interactions

This thesis explains two aspects of animal spatial foraging behaviour arising as a direct consequence of animals' need to drink water: the concentration of animal impacts, and the response of animals to those impacts. In semi-arid rangelands, the foraging range of free-ranging large mammalian herbivores is constrained by the distribution of drinking water during the dry season. Animal impacts become concentrated around these watering sites according to the geometrical relationship between the available foraging area and the distance from water, and the spatial distribution of animal impacts becomes organised along a utilisation gradient termed a "piosphere". During the dry season the temporal distribution of the impacts is determined by the day-to-day foraging behaviour of the animals. The specific conditions under which these spatial foraging processes determine the piosphere pattern have been identified in this thesis. At the core of this investigation are questions about the response of animals to the heterogeneity of their resources. Aspects of spatial foraging are widely commented on whilst explaining the consequences of piosphere phenomena for individual animal intake, population dynamics, feeding strategies and management. Implicated are our notions of optimal foraging, scale in animal response, and resource matching. This thesis addressed each of these. In the specific context of piospheres, the role of energy balance in optimal foraging was also tested. Field experiments for this thesis showed a relationship between goat browsing activity and measures of spatial impact. As a preliminary step to investigating animal response to resource heterogeneity, the spatial pattern of foraging behaviour/impacts was described using spatial statistics. Browsing activity varied daily revealing animal assessment of the spatial heterogeneity of their resources and an energetic basis for foraging decisions. This foraging behaviour was shown to be determined by individual plants rather than at larger scales of plant aggregation. A further experiment investigated the claim that defoliation has limited impact on browser intake rate, suggesting that piospheres may have few consequences for browser intake. This experiment identified a constraining influence of browse characteristics at the small scale on goat foraging by relating animal intake rate to plant bite size and distribution. Computer simulation experiments for this thesis supported these empirical findings by showing that the distribution of spatial impacts was sensitive to the marginal value of forage resources, and identified plant bite size and distribution as the causal factors in limiting animal intake rate in the presence of a piosphere. As a further description of spatial pattern, piospheres were characterised by applying a contemporary ecological theory that ranks resource patches into a spatial hierarchy. Ecosystem dynamics emerge from the interactions between these patches, with piospheres being an emergent property of a natural plant-herbivore system under specific conditions of constrained foraging. The generation of a piosphere was shown to be a function of intake constraints and available foraging area, whilst piosphere extent was shown to be independent of daily energy balance including expenditure on travel costs. A threshold distance for animal foraging range arising from a hypothesised conflict between daily energy intake and expenditure was shown not to exist, whereas evidence for an intermediate distance from water as a focus for accumulated foraging activity was identified. Individual animal foraging efficiency in the computer model was shown to be sensitive to the piosphere, while animal population dynamics were found to be determined in the longer term by dry season key resources near watering points. Time lags were found to operate in the maintenance of the gradient, and the density dependent moderation of the animal population. The latter was a direct result of the inability of animal populations to match the distribution of their resources with the distribution of their foraging behaviour, because of their daily drinking requirements. The result is that animal forage intake was compromised by the low density of dry season forage in the vicinity of a water point. This thesis also proposes that piospheres exert selection pressures on traits to maximise energy gain from the spatial heterogeneity of dry season resources, and that these have played a role in the evolution of large mammalian herbivores

The follow-up of a cohort of anti-hiv seropositive haemophiliacs for up to 15 years from seroconversion

111 men with haemophilia registered at the Royal Free Hospital Haemophilia Centre became infected with HIV between 1979 and 1985 after treatment with infected blood products. These men have been followed for up to 15 years since HIV seroconversion. This thesis presents an epidemiologic follow-up of this cohort of patients. By the end of 1994, 47 men had developed AIDS and 45 had died, Kaplan-Meier progression rates of 56.5[percent] (9570 confidence interval 39.5-73.6) and 46.9[percent] (9570 confidence interval 35.6-582) by 14 years after seroconversion respectively. Prior to the development of AIDS, 82 of the men had developed at least one more minor condition indicative of their HIV infection. Older individuals and those who seroconverted prior to 1981 and from 1983 onwards appear to have a more rapid progression of disease. The CD4 lymphocyte count, which drops throughout infection, is a strong prognostic marker for disease progression. The rate of CD4 decline, the Immunoglobulin A level and the development of p24 antigenaemia all add some additional prognostic information to that provided by the most recent CD4 count alone. In contrast, the CD8 lymphocyte count simply identifies those individuals with the lowest and most rapidly declining CD4 counts. Whilst the beta-2 microglobulin level appears to provide additional prognostic information to the CD4 count at high CD4 levels, it is of less value at lower counts. The development of a bacterial infection prior to AIDS suggests that a patient's condition is likely to deteriorate, irrespective of their immune status. Despite being the best marker of progression, the CD4 count is, unfortunately, measured imperfectly. This has the effect of reducing the apparent relationship with disease progression and may lead to erroneous conclusions about the value of other covariates in a proportional hazards model

NOTIFICATION !!!

All the content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition

NOTIFICATION !!!

All the content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition

NOTIFICATION !!!

All the content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition

NOTIFICATION!!!

The full content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition