A follow-up study of exercise test results and severity of brachycephalic obstructive airway syndrome signs in brachycephalic dogs

To promote successful breeding against brachycephalic obstructive airway syndrome (BOAS), it is important to assess how BOAS signs progress during young adulthood and how evaluation age and ageing affect the results of chosen breeding selection tools. The aims of this study were to assess how veterinary-assessed and owner-reported BOAS signs and exercise test results change when dogs age. Eight English Bulldogs, 25 French Bulldogs, and 31 Pugs that had undergone previous evaluation were re-examined 2- 3 years later. An owner questionnaire regarding BOAS signs, a veterinary assessment of BOAS severity, and exercise, ie walk tests were re-performed. In Pugs, both 6-min walking distance and 1,000-m time worsened and the initial evaluation age had a significant effect on the 1,000-m time. No significant changes were seen in the results of the French Bulldogs but a negative effect on the 1,000-m time was seen with weight gain. Exercise test statistics were not performed with regard to English Bulldogs due to low sample size. The veterinary-assessed BOAS severity class remained the same in the majority of dogs and the BOAS grade worsened mostly in those dogs that were initially evaluated at less than two years of age. Most owners reported no major changes in BOAS severity. BOAS grading and walk tests were easy to repeat and results remained relatively constant in dogs initially evaluated at over two years of age, supporting the use of these breeding selection tools. However, further, large-scale offspring studies are still needed.Peer reviewe

Rethinking impact: Understanding the complexity of poverty and change - overview

The international workshop 'Rethinking Impact: Understanding the Complexity of Poverty and Change' (Cali, Colombia, 26-28 March 2008) explored the challenges inherent in evaluating agricultural research-for-development efforts, identifying lessons and approaches for sustainably improving livelihoods. Use-oriented research which links knowledge with action has greater welfare and development impacts. Researchers must help to link diverse stakeholders in order to create and share knowledge for effective, sustainable action. The legitimacy of such boundary-spanning work needs to be recognised and rewarded, and sufficient resources dedicated to it. Traditional economic-impact assessment does little justice to complex poverty-related activities, which require a diversity of methods and enhanced capacity

Stimulating neuroprotective and regenerative mechanisms in Alzheimer disease

The processes involved in neuroprotection and brain repair are an important aspect of the preservation and restoration of neuronal functions affected by pathological lesions. Mechanisms that stimulate, manage and regulate these processes thus hold potential for the development of treatment strategies for Alzheimer disease (AD). The aim of this thesis was to increase our understanding of the stimulation of neuroprotective and regenerative mechanisms, in particular with respect to amyloid-β (Aβ) accumulation and other pathological processes associated with AD. Mounting evidence suggests that the continuous loss of cholinergic neurons and nicotinic receptors (nAChRs) in the hippocampus and cerebral cortex could be mediated through an interaction between α7 nAChRs and Aβ species. In paper I, we investigated interaction of α7 nAChRs with different forms of Aβ, and the functional consequences of these interactions. We found that α7 nAChRs play an important role in mediating neuroprotective actions against Aβ-induced neurotoxicity, and that the assembly form of Aβ is important for the interaction with α7 nAChRs and the downstream effects in neuronal cells. Fibrillar Aβ appears to cause cytotoxic effects by blocking α7 nAChRs, whereas oligomeric Aβ seems to activate α7 nAChRs to modulate calcium-dependent synaptic function. In paper II, we characterized the neuroprotective and neurotrophic actions of amyloid-modulatory candidate drugs (–)- and (+)- phenserine and its primary metabolites, and investigated the primary signaling pathways responsible for mediating these effects. (+)-Phenserine increased the proliferation of mouse neural progenitor cells in culture via activation of MAPK signaling pathways, including elevated cortical levels of brain-derived neurotrophic factor in mouse brain. In paper III, we investigated the modulating effects of (+)-phenserine on the changes in brain synaptic function, hippocampal neurogenesis, and inflammatory cells at different stages of amyloid pathology. (+)-Phenserine increased proliferation of neural progenitor cells, and increased the maturation of newborn neurons in the hippocampi of young adult Tg2576 mice but not in older mice with advanced Aβ plaque pathology. In paper IV, we investigated the effects of stem cell transplantation and modulation of Aβ and α7 nAChRs on endogenous neurogenesis and astrocytosis, graft survival, and cognition. Intrahippocampi transplantation of human neural stem cells (hNSCs) improved spatial memory in young adult Tg2576 mice, and increased endogenous hippocampal neurogenesis. (+)-Phenserine increased graft survival but blocked the hNSC transplant-mediated increase in endogenous neurogenesis, indicative of interfering mechanisms of action. We found that α7 nAChR-expressing astrocytes accumulated along the needle track after transplantation, and that the numbers of these astrocytes correlated with the degree of endogenous hippocampal neurogenesis. Hence, we postulate a hitherto unexplored role for α7 nAChR-expressing astrocytes in neurogenesis and tissue remodeling. The clinical implications of stimulation of neuroprotection and brain repair in the course of AD are currently under investigation. However, it is my hope that the cumulative findings presented in this thesis will provide a better understanding of the possibilities and limitations of these therapeutic strategies that aim to change or halt the clinical progression of AD

Frequencies of some B blood group alleles in laying hens from a selection and crossbreeding experiment

<p/

Nutrient balancing or spring flush - What determines spruce bark stripping level by red deer?

The distribution and population density of red deer (Cervus elaphus) are increasing in several regions of Europe. The deer may cause severe damage in commercial forestry and agriculture. Bark stripping is the main problem in forests, especially on Norway spruce (Picea abies), and is thought to mostly occur during winter when other forage is scarce. It has been suggested that an imbalance in the nutrient intake, and especially a diet including high amounts of easily-digestible macronutrients, such as agricultural crops, can lead to an increased urge to consume bark. Feeding on brassicas, for example rapeseed (Brassica napus) might have this effect. The aim with this study was to investigate the relationship between intake of rapeseed and bark stripping on Norway spruce by red deer during early spring. We did this by a controlled feeding experiment with four groups of captive red deer in southern Sweden. All groups were given spruce logs every week, while only two groups had access to freshly harvested rapeseed plants. In addition, influence of air temperature and forage nutritional composition was taken into account. Our results show that red deer bark stripping can be considerable not only during winter but also during spring green-up. We found no significant influence of rapeseed on bark stripping performed by the deer. However, at a threshold temperature, deer suddenly started to ingest large amounts of bark biomass, coinciding with a significant change in the bark's concentration of starch. We suggest that the lack of effect of rapeseed feeding can partly be explained by overshadowing effects caused by such seasonal changes of bark character-istics, and partly by the fact that the rapeseed plants in our study contained lower than expected concentrations of easily-digestible macronutrients (apart from protein). We conclude that the risk of damage on spruce can be especially high during certain periods, something that is important to consider when mitigating bark stripping. However, several interactive effects are involved and must be considered in order to more efficiently mitigate damage