| 1. |
- Handlin, Linda
(författare)
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Human-Human and Human-Animal Interaction : Some Common Physiological and Psychological Effects
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the present thesis was to investigate hormonal and physiological effects in mothers during a breastfeeding session and in dogs and their owners in response to short-term interaction. In study one, sixty-six mothers receiving either exogenous oxytocin infusion and/or epidural analgesia (EDA) during labor or intramuscular oxytocin injection post partum were studied. Oxytocin, prolactin, adrenocorticotrophic hormone (ACTH) and cortisol levels, as well as blood pressure were measured during a breastfeeding session two days after birth. In response to breastfeeding two days after birth, the mothers displayed a pulsatile release of oxytocin and increasing prolactin levels. In addition, the activity in the HPA-axis was reduced and maternal blood pressure decreased. The results also show that EDA administration in combination with oxytocin during labor resulted insignificantly lower oxytocin levels and higher cortisol levels, as well as higher bloodpressure in response to breastfeeding two days after birth, compared to EDA administration alone. In addition, oxytocin infusions dose-dependently lowered the mothers’ endogenous oxytocin levels two days after birth. In study two, ten female dog owners and their male Labrador dogs participated, together with ten controls. Their levels of oxytocin, cortisol and insulin, as well as their heart rate, were measured. The connection between the quality of the dogowner relationship and hormone levels was also explored. Short-term interaction between dogs and their owners resulted in oxytocin release in both species and their cortisol levels and heart rate were also affected. Oxytocin levels and positive attitudes regarding the dog-owner relationship were positively correlated. In conclusion, both human-human and human-animal interactions induce oxytocin release and promote oxytocin mediated effects, such as decreasing cortisol levels and blood pressure. In addition, social interaction and oxytocin levels arepositively related.
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| 2. |
- Peterson, Gunnel, 1959-
(författare)
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Neck muscle function in individuals with persistent pain and disability after whiplash injury
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Neck pain and disability are common after whiplash injury. One year after the accident up to 50 % still have symptoms called whiplash associated disorders (WAD). Despite decades of research the cause of persistent pain and disability are largely unknown and effective treatment and diagnostic tools are lacking. Altered neck muscle function may cause pain and disability, and real-time non-invasive methods that investigate both superficial and deep neck muscle function need to be evaluated.Aim: The general aim of the work presented in this thesis was to investigate mechanical neck muscle function and evaluate effects of three different exercise interventions related to neck muscle function in individuals with persistent pain and disability after whiplash injury.Method: The thesis comprised two studies, reported in four papers. Study A was a prospective randomized controlled trail with 216 participants. The effects of three exercise interventions; neck-specific exercises, neck-specific exercises with behavioral approach and prescription of physical activity were evaluated. Neck muscle endurance, perceived pain following testing, kinesiophobia and satisfaction with treatment were compared between the three groups (paper I). Study B was an experimental case-control study with participants consecutively recruited from the randomized controlled trial. Deformation and deformation rates in the neck muscles were investigated with real-time ultrasound imaging during ten repetitive arm elevations (paper II-IV). To investigate ventral neck muscles, 26 individuals with WAD were compared with 26 healthy controls (paper II). The dorsal neck muscles were investigated in paper III, including 40 individuals with WAD and 40 controls. In total 46 individuals, 23 with WAD and 23 healthy controls were included in paper IV to develop ventral neck muscle interaction models.Results: Paper I: Participants in the two neck-specific exercise groups (with and without behavioral approach) showed increased dorsal neck muscle endurance (p = 0.003), decreased pain intensity following testing (p = 0.04) and were more satisfied with treatment (p < 0.001) than participants in the prescribed physical activity group. Kinesiophobia did not significantly differ between groups (p > 0.12).Paper II: Deformation and deformation rate showed linear positive relationship between ventral muscle pairs in healthy controls, especially between superficial and deep neck muscles. This relationship was weaker or absent in the WAD group.Paper III: The WAD group had higher deformation rates in the deepest dorsal neck muscles during the first and tenth (only women) arm elevations compared to the control group (p < 0.04). Women in the WAD group showed a weaker linear relationship between the two deepest dorsal neck muscles compared to women in the control group.Paper IV: The results revealed two different ventral neck muscle models in individuals with WAD and healthy controls (R2Y = 0.72, Q2Y = 0.59). The models were capable to detect different neck muscle interplay in people with WAD.Conclusion: Neck-specific exercise intervention with or without a behavioral approach appears to improve neck muscle endurance in individuals with persistent WAD. Decreased pain after the neck muscle endurance test also suggests improved tolerance of load in these two groups. Altered mechanical neck muscle function was revealed in individuals with WAD indicating decreased muscular support for maintain a stable cervical spine during repetitive arm elevations. The results show great promise for improved diagnosis of neck muscle function in WAD.
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| 3. |
- Engell, Maria Terese
(författare)
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Postural strategies in skilled riders
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- For optimal horse-rider communication, high-levels of technical riding-skills are needed which requires both self-coordination of the rider and coordination with the body of the horse. The scientific documentation of the optimal postural position and the technical skills for a rider is limited. It is generally agreed that good riders should be highly symmetric and must continue to develop symmetry in themselves and their horses for optimal performance in riding. On the other hand, asymmetry in riders is recognized as a negative trait. To improve the technical skills needed to develop high-level performance, the kinematics of the core segments of the rider’s body must be understood and objectively characterized. The aim of this thesis was to target the intersegmental postural strategies of the foot, pelvis, trunk and head in skilled riders under three conditions: riding, walking and rocking a balance chair. 3D high-speed motion capture and inertial measurement unit techniques were used. The individual studies acquired and analyzed data from 7 to 20 high-skilled riders. Sagittal-plane riders kinematics were compared between passive and active riding situations; three different intersegmental strategies were found in active riding. Most of the riders applied increased pressure on the withers area during active riding and with increased collection of the horse. Furthermore, associations were found between intersegmental postural strategies while riding, sitting on a balance chair, and walking. During walking the foot with the higher degree of eversion/pronation was associated with greater contralateral pelvic drop in early stance. Skilled riders showed a higher degree of trunk movement compared to pelvic movement while rocking a balance chair. The results suggested high degrees of movement asymmetry in these skilled riders, when comparing the individual segmental strategies on left versus right directions both when seated but unmounted and during riding. It is well accepted in the equestrian community that skilled riders should communicate with the horse through pelvic movements. The ability to characterize the intersegmental postural strategies of the rider´s seat may enhance the possibilities to train body awareness and improve equestrian performance in the future. The long-term goal should be to produce healthier individuals and better performance and the results from this thesis may promote this development.
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| 4. |
- Persson, Sara
(författare)
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The wild male mink as a sentinel for endocrine-disrupting chemicals and reproductive toxicity
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Increasing evidence indicates that pollutants may affect the hormone system of humans and wildlife. These endocrine-disrupting chemicals are related to an increased risk of a variety of diseases and disorders, including adverse effects on the reproductive system. By using a sentinel wildlife species, an early warning of adverse health effects due to pollutants in the environment may be provided. This is also relevant for humans, as wildlife and humans can be exposed to similar mixtures of pollutants. With this in mind, the aim of this thesis is to investigate the possibility of establishing the wild mink (Neovison vison) as a sentinel species in Sweden, for both exposure to pollutants and effects of pollutants on the reproductive system. Mink were collected from local hunters and necropsies were performed focusing on the male reproductive system. The collected mink provided an insight in how to handle the variation in data due to sample season, age and nutritional status. These factors significantly influenced many, but not all, of the concentrations of chlorinated, brominated and perfluorinated compounds and also some reproductive organ variables. In addition, the results offer information on how to optimize the design of future studies, and some baseline data for reproductive organ measurements were compiled. Considerable concentrations of PCBs were found in some areas and the concentrations of PFOS were among the highest ever recorded in mink. Associations were found between measurements on the reproductive organs and pollutant concentrations. The anogenital distance was inversely associated with concentrations of some perfluoroalkyl acids and DDE. Several associations were also found between some PCB congeners and measurements on the penis and baculum. In conclusion, the wild mink males may serve as an indicator for environmental exposure to pollutants in Sweden. In addition, the wild mink seems to be a suitable sentinel species that may provide an early warning of alterations in the male reproductive organs related to environmental pollution.
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| 5. |
- Falkenberg Hansen, Kjetil, 1972-
(författare)
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The acoustics and performance of DJ scratching, Analysis and modelling
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focuses on the analysis and modeling of scratching, in other words, the DJ (disk jockey) practice of using the turntable as a musical instrument. There has been experimental use of turntables as musical instruments since their invention, but the use is now mainly ascribed to the musical genre hip-hop and the playing style known as scratching. Scratching has developed to become a skillful instrument-playing practice with complex musical output performed by DJs. The impact on popular music culture has been significant, and for many, the DJ set-up of turntables and a mixer is now a natural instrument choice for undertaking a creative music activity. Six papers are included in this thesis, where the first three approach the acoustics and performance of scratching, and the second three approach scratch modeling and the DJ interface. Additional studies included here expand on the scope of the papers. For the acoustics and performance studies, DJs were recorded playing both demonstrations of standard performance techniques, and expressive performances on sensor-equipped instruments. Analysis of the data revealed that there are both differences and commonalities in playing strategies between musicians, and between expressive intentions. One characteristic feature of scratching is the range of standard playing techniques, but in performances it seems DJs vary the combination of playing techniques more than the rendering of these techniques. The third study describes some of the acoustic parameters of typical scratch improvisations and looks at which musical parameters are typically used for expressive performances. Extracted acoustic and performance parameters from the data show the functional ranges within which DJs normally play. Unlike traditional musical instruments, the equipment used for scratching was not intended to be used for creating music. The interface studies focus on traditional as well as new interfaces for DJs, where parameter mappings between input gestures and output signal are described. Standard performance techniques have been modeled in software called Skipproof, based on results from the first papers. Skipproof was used for testing other types of controllers than turntables, where complex DJ gestures could be manipulated using simplified control actions, enabling even non-experts to play expressively within the stylistic boundaries of DJ scratching. The last paper describes an experiment of using an existing hardware platform, the Reactable, to help designing and prototyping the interaction between different sound models and instrument interfaces, including scratching and Skipproof. In addition to the included papers, studies were conducted of expressivity, description of the emotional contents of scratching, DJ playing activities, and the coupling between playing techniques and sample. The physical affordances of the turntable, mixer and samples, as well as genre conventions of hip-hop, are assumed to explain some of the findings that distinguish scratching from other instrumental sounds or practices.
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| 6. |
- Malmsten, Jonas
(författare)
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Reproduction and health of moose in southern Sweden
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Moose (Alces alces) is a highly regarded game species in Fennoscandia, where annual harvest numbers in Sweden, Norway, and Finland together exceed 200,000 animals. For successful management, knowledge about male and female reproduction is essential, as well as the extent to which disease and mortality affect the population. In 2006, a sub-normal reproductive output (calf per cow ratio) was reported from the island of Öland, and a pilot study in 2007 revealed embryonic mortality and occurrence of the tick-borne pathogen Anaplasma phagocytophilum. An expansion of the study (including control areas) was conducted due to the need for updated information on moose reproduction From 2008 to 2011, reproductive organs, blood, spleens, mandibles, and ectoparasites were collected from moose in three areas in southern Sweden. Reproductive organs were inspected macroscopically, weighed and measured, and sperm samples were taken. Morphology of spermatozoa, chromatin analyses, histological examinations, and pathogen analyses were performed at SLU or SVA in Uppsala. Male pubertal age varied from 1.5 to 3.5 years, and the proportion of normal spermatozoa increased significantly with increasing body weight, but decreased temporally over the first month of hunting. Male moose had a low testes:body weight ratio compared with other cervids. Cows showed their first oestrus of the season earlier than heifers, and the hunting period appeared to interfere with oestrus in all females. Onset of puberty in females was positively associated with body weight but not with age. Embryonic mortality and unfertilized oocytes accounted for a significant difference (P<0.01) between ovulation rates and the proportion of viable embryos found in pregnant females. Moose were competent hosts of Anaplasma phagocytophilum, and the prevalence of infection, as determined by PCR, varied both temporally and spatially. Moose calf summer survival rates on Öland were significantly lower than in the mainland populations. The studies performed provide updated information on moose reproductive characteristics, calf survival and moose health. Some changes in population management could potentially improve the reproductive success of moose in southern Sweden. Not all of these parameters might be affected by a change in management, as the surrounding environment and climate play a considerable role in forage availability, the spread of diseases, and calf survival rates.
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| 7. |
- Skoglund, Björn, 1975-
(författare)
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Following the mevalonate pathway to bone heal alley
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The mevalonate pathway is an important biosynthetic pathway, found in all cells of virtually all known pro- as well as eukaryotic organisms. This thesis is an investigation into the use of two drugs, originally developed for different applications, but both affecting the mevalonate pathway, in to models of fracture repair.Using two different rodent models of fracture repair, a commonly used cholesterol lowering drug (statin) and two drugs used to treat osteoporosis (bisphosphonate) were applied both systemically as well as locally in order to enhance fracture repair.Papers I and II investigate the potential of simvastatin to improve the healing of femoral fractures in mice. Papers III and IV explore the use of two bisphosphonates to improve early fixation of stainless steel screws into rat bone.The statin simvastatin lead to an increased strength of the healing cellus. The application of bisphosphonates increased early screw fixation.It seems clear that both drugs have uses in orthopaedic applications. One interesting avenue of further research would be to combine the two classes of drugs and see if we can get the benefits while at the same time diminishing the drawbacks.
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| 8. |
- Vilson, Åsa
(författare)
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Immunity, microbiota & immune-related disorders in German shepherd dogs
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In an epidemiological study based on insurance data we described a breed-specific pattern of diseases in German Shepherd dogs (GSD) and confirmed that this breed is predisposed to immune-related disorders. A prospective study was performed in order to further investigate immunological changes in the GSD using a large number of dogs, 30 bitches and their litters, from the same kennel under well controlled natural conditions. Changes in fecal and serum immunoglobulins were followed from birth to young adult age and possible relationships between these parameters in dams and their offspring were identified. We also described the composition of gut microbiome in dogs and how it changes in different life stages including pregnancy, lactation and growth. The levels of serum IgE, serum IgA and fecal IgA increased from seven weeks of age and were then stabilized at one year of age, there was no relationship in immunoglobulin concentrations between bitches and their 7 weeks old puppies. Dogs with high fecal IgA had a better vaccine response indicating a favorable systemic immune status. We found profound differences in the gut microbiome between mothers and young dogs. Litter mates had a more similar fecal microbiome compared to unrelated dogs. The 7 weeks old puppies were no more similar to the mothers than to unrelated bitches at partum. However, the fecal microbiome of the puppies were significantly more similar to their mothers than to unrelated bitches at 7 weeks postpartum. We observed a change in the relative abundance of different bacteria during lactation, and an increase of diversity from pregnancy to end of lactation. We also found that the diversity of fecal microbiome was affected by living environment but we were unable to demonstrate an effect of pre- and postnatal exposure to the chosen strain of probiotics. Our results provide information to an area within canine microbiology and immunology which is not studied before -this is the first study to describe the gut microbiome as well as immunoglobulins (and their relation to each other) in pregnant and lactating bitches and their offspring. This information is a needed foundation for further research on the relationship between the microbiome at an early age and immune function later in life and of value for the evaluation of interventions.
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| 9. |
- Mao, Xiaowei
(författare)
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Population level genome-wide association studies in dairy cattle
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In recent years, genome-wide association studies (GWAS) has become a dominant tool for detecting genetic architectures for complex traits. Thousands of associated genetic variants have been reported. However, the resolution of these studies was limited by the available marker density for the quantitative trait loci (QTL) region. Moreover, the X chromosome and non-additive genetic effects has often been excluded from GWAS, despite of their potentially important biological functions. In chapter 2, we carried out the fine-mapping of a previously reported QTL in Holstein cattle on Bos taurus autosome 18 (BTA18) for calving traits, using imputed high-density SNP chip (HD) genotypes followed by imputed whole-genome sequence (WGS) variants. Genes SIGLEC12, CD33 and CEACAM18 were proposed as candidate genes. In addition, pleiotropic effects of this QTL region were observed on direct calving traits and conformation traits. In chapter 3, we performed a GWAS for growth traits in Nordic Holstein, Jersey, and Red Dairy Cattle. First, GWAS was performed within breeds using WGS variants. Then a meta-analysis was performed to combine information across the three breeds. Several QTL were identified to have large effects on growth traits in Holstein and Red Dairy Cattle, but only one QTL located nearby gene CYP19A1 on chromosome 10 was shared between Holstein and Red Dairy Cattle. Meta-analysis of these three breeds enhanced the power to detect QTL. In chapter 4, we performed the imputation of markers on the X chromosome in Holstein cattle for non-genotyped animals and animals genotyped with low density (Illumina BovineLD) chips, using animals genotyped with medium density (Illumina BovineSNP50) chips. We found that the imputation accuracy of markers on the X chromosome was improved by treating the pseudoautosomal region as autosomal and by increasing the proportion of females in the reference group. In chapter 5, we aimed to detect dominance effects on female fertility traits in Danish Holstein cattle using Illumina BovineSNP50 data, and evaluate the power, precision, and type 1 error of detecting dominance effects through simulations. Four QTL were detected for IFL in heifers, while one QTL was detected for cows. All these five QTL were detected with significant additive and dominance effects. Simulations showed that the current sample size had limited power to detect dominance effects for female fertility in cattle.
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| 10. |
- Sellman, Stefan, 1984-
(författare)
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Quantifying Risk in Epidemiological and Ecological Contexts
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The rates of globalization and growth of the human population puts ever increasing pressure on the agricultural sector to intensify and grow more complex, and with this intensification comes an increased risk of outbreaks of infectious livestock diseases. At the same time, and for the same reasons, the detrimental effect that humans have on other species with which we share the environment has never been more apparent, as the current rates of species loss from ecological communities rival those of ancient mass extinction events. In order to find ways to lessen the effects of and eventually solve such problems we need ways to quantify the risks involved, something that can be difficult when for instance the sheer size or sensitivity of the systems makes practical experimentation unsuitable. For these situations mathematical models have become invaluable tools due to their flexibility and noninvasiveness. This thesis presents four works involving the quantification of risk in livestock epidemic and ecological contexts using mathematical models. Two of them deal with extinctions of species within model ecological communities, and how species interactions play a role in the identity of the lost species following perturbations to specific species (Papers I and II). The other two regard how the spatial layout of the underlying population of livestock premises affect the risk of foot and mouth disease outbreaks among farms in the USA, and how models of such outbreaks can be optimized to improve their usefulness (Papers III and IV).Ecological communities consist of species and the often intricate pattern of interactions between them. These interspecies connections can propagate effects caused by disturbances in one end of the network, through the community via the links, to other parts of the network. In some cases, a reduction in the abundance of one species can cause the extinction of a second species before the first species disappears, something called functional extinction. Despite this, many conservation efforts revolve around simply keeping populations of single species at a high enough level for their own survival. In a model setting, the study of Paper I explores and attempts to quantify how common such functional extinctions are in relation to the alternative outcome that a perturbed species itself becomes extinct. This is done by first constructing stable model food webs describing predator-prey interactions of up to 50 species, parameterized through allometric relationships between metabolic processes and body size. Then the smallest amount of extra mortality that can be applied to each and every species in the web before any species become extinct is determined. The study shows that in these model communities, more often than not (>80%) another species, rather than the species that is subjected to the additional mortality will be the one to become extinct first.The approach of Paper I is taken further in Paper II by applying the same methodology to ecological networks that include mixtures of both antagonistic (predator-prey) and mutualistic (e.g. pollination and seed dispersal) interactions. The results further reinforce the findings of Paper I, and show that ecological networks containing a mixture of antagonistic and mutualistic interactions are more sensitive to functional extinctions than purely antagonistic or purely mutualistic ones, an important finding considering the diversity of interaction types in natural systems. Furthermore, the type of species found to have the lowest threshold before becoming functionally extinct were those with a mixture of interaction types, such as pollinating insects. Both Paper I and II consolidate the notion that when doing conservation work it is important to have the entire community in mind by considering the population sizes that are viable from a multi-species perspective, rather than just focusing on the minimum population sizes that are viable for the individual species.In Papers III and IV the focus changes somewhat, from models of ecological systems to models of how infectious livestock disease spread between farms in spatially explicit contexts. For this kind of model, information about the spatial distribution of the hosts is of course crucial, but not always readily available. In the USA, the only available information about livestock premises demography is aggregated at the county scale, meaning that the spatial distribution of the premises within each county is unknown. However, a method exists to simulate realistic stochastic spatial configurations of premises using a set of predictor variables, such as topology, climate and roads. An alternative approach that have been used previously is to assume a uniformly random spatial distribution of premises within each county. But to what extent does the choice between these two methods affect the model’s evaluation of the risk of disease outbreaks? In Paper III, this is analyzed specifically for foot and mouth disease. Through simulated outbreaks and by looking at the reproductive ratio of the disease, the outbreak dynamics within the two different spatial configurations of premises are compared. The results show that there is a clear difference in the risk of outbreaks between them, with the non-uniform distributions showing a general pattern of higher outbreak risk. However this difference is dependent on the size and geographic location of the county that the outbreak start in with larger counties in the west of the US showing a stronger effect.When running numerical simulations with large scale models such as the one used in Paper III, a considerable amount of replication is usually necessary in order to account for the high degree of stochasticity inherent to the problem. Even further replication is required when performing sensitivity analyses of model parameters or when exploring different scenarios, for instance when trying to determine the optimal control strategy for a disease. For this reason, the amount and quality of results that can be produced by such studies can quickly become limited by the availability of computational resources. Finding ways to optimize the computations involved with regard to simulation time is therefore of great value as it can be directly related to the robustness of the results. In Paper IV, an efficient optimization method for the kind of kernel-based local disease spread model used in paper III is presented. The method revolves around constructing a grid structure that is overlaid on top of the farm landscape and dividing the infection process into two steps, first evaluating if any farms within one of the grid squares can become infected given an over-estimation of the probability of infection, and then only if so, evaluate actual infection of a subset of the farms within the receiving square. The method is compared to similar published methods and is shown to be more efficient in most cases, while also being easy to implement and understand. Furthermore, while other methods often involve approximations of the transmission process in order to improve computational speed, the method of Paper IV is shown to be exact. This is a major advantage, since with an approximative method the extent to which the results are affected by the simplification is unknown unless the effect of the approximation is explicitly quantified. In most cases, such quantification would require extensive simulations with the unsimplified approach, something which of course may not be feasible.
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