Animal movement is a ubiquitous process and can have consequences ranging from an individual’s energy expenditure to ecosystem dynamics. This study uses biologgers, primarily accelerometers, to record and examine the at-sea behaviours of black-legged kittiwakes (Rissa tridactyla) during their breeding period. Accelerometers record the acceleration of an instrumented animal to give an indication of their behaviour and movements, yet their output can be particularly difficult to interpret. As such, this thesis begins with a method developed for the assignation of coarse-scale behaviours to accelerometry data. The method is a simple yet objective approach intended to be widely applicable. Using this method, we construct time-activity budgets for incubating and chick-rearing kittiwakes and apply activity-specific estimates of energy expenditure to these behaviours. We identify how kittiwakes allocate their time and what the energetic consequences of variation in time-allocation are. We present empirical evidence for chick-rearing kittiwakes expending more energy than incubating birds and identify that kittiwakes exhibit behavioural compensation whereby they limit energy expenditure across both foraging trips and days. We also examine the flight behaviour of kittiwakes in relation to extrinsic conditions. We find that wind conditions do not seem to influence broader scale patterns in movements during foraging trips, however kittiwakes do display behavioural plasticity in response to wind conditions by optimising their flight speeds towards maximum range speeds. We also identify that to optimise flight speeds, kittiwakes change the strength at which they flap their wings, rather than the frequency. Finally we present a serendipitous observation of predation of kittiwake chicks by a peregrine falcon. Although not directly related to movement ecology, this study documents novel predatory behaviour and highlights the importance of biological forces other than movement. Overall, the work presented in this thesis demonstrates that by examining the movement of individuals, it is possible to gain insights into various important aspects of their biology.

Introdução - Com o crescimento da população idosa cresce a necessidade de incentivo a hábitos de vida saudáveis como a prática de atividade física (AF), bem como sua investigação, a fim de se prevenir a instalação de incapacidades. No entanto, são enormes as dificuldades de medida dessa atividade. O acelerômetro surge como uma das formas objetivas de avaliação da AF destacando-se por sua praticidade e capacidade de armazenamento de dados. Objetivo - Avaliar os níveis e intensidades de AF de idosos através da acelerometria e examinar as associações com fatores sócio-demográficos, de saúde e estilo de vida. Métodos - Estudo transversal com 568 idosos de 65 anos e mais da coorte de 2010 do estudo SABE. Os idosos usaram o acelerômetro ActiGraph (GT3X) por três dias posicionado na cintura. Resultados - A média geral de cpm foi de 341,29 (95 por cento IC 326,79 - 355,80). Não houve diferença entre homens e mulheres. A média de cpm diminuiu com a idade e para os idosos acometidos por todas as doenças, exceto hipertensão, doença pulmonar e doença articular. A mobilidade e CP reduzidas, um maior número de doenças e uma pior autopercepção de saúde estiveram associados de forma independente com menores cpm. Os homens divorciados/separados, os que viviam sozinho e os que possuíam de cino a oito anos de escolaridade apresentaram maiores cpm que as mulheres dessas categorias. A idade, o declínio cognitivo isolado ou associado à disfunção, a hipertensão, a doença cerebrovascular, a mobilidade e a CP, estiveram associados de forma independente à menores níveis de AF gerais e por sexo. Entre as mulheres o estado marital (solteira), a autopercepção de saúde (ruim/muito ruim) e os sintomas depressivos estiveram associados de forma independente a menores níveis de AF. Para os homens a suficiência de renda (não), presença de diabetes e o número de doenças (duas ou mais) estiveram associados de forma independente com menores níveis de AF. Após ajuste pelas demais variáveis, a idade se associou às cpm em ambos os sexos. Para o sexo feminino, a renda per capita e o tabagismo também demosntraram associação, e para os homens apenas o diabetes.Conclusão - Foram observados baixos níveis de AF entre os idosos do município de São Paulo, principalmente com o avançar da idade e na presença de doenças, que são muito comuns nessa população. Esse estudo reforça que a prática de AF deve ser incentivada e demonstra a necessidade de estudos longitudinais para se estabelecer a relação temporal entre esses fatores. / Introduction Togetherwith the growth of the elderly population, it also grows the necessity of encouraging a healthy lifestyle, with the practice of physical activity (PA), as well as its investigation, aiming at the prevention of potential disabilities. Nevertheless, the difficulties related to the measurement of such physical activity pose a considerable level of challenge. The accelerometer appears as an objective way of evaluating the PA, being distinguished by its practicality and ability to store data. Objective To evaluate the levels and intensities of PA in elderly people through accelerometry and examine the associations with socio-demographic, health and lifestyle factors.Methods Transversal study with 568 elderly citizens, aged 65 and above, who attended 2010 cohort of SABE Study. The elderly used the accelerometer ActiGraph (GT3X) for three days, placed in their waist. Results The general average cpm was 341,29 (95 per cent CI 326,79 355,80). There was no variation between men and women. The average cpmreduced according to the persons age and presence of diseases, except for hypertension, lung diseases and articular diseases. The reduced mobility and CP, a greater number of diseases and a worse auto health perceptionwere associated independently with lower cpm figures. The divorced/separated men, those who live on their own and those with five to eight years in the education system present higher cpm than women in those categories. The age, isolated cognitive decline or association with the disfunction, hypertension, cerebrovascular disease, mobility and calf circumference (CC), were associated independently with lower levels of general PA and per gender. Amongst women, the marital status (single), the auto health perception (bad/very bad) and the depression symptoms were associated independently to lower levels of PA. For men, the income sufficiency (no), presence of diabetes and number of diseases (two or more) were associated independently to lower levels of PA. Afteradjustment to other variables, the age was associated to the cpm in both genders. For the female, the income per capita and smoking also demonstrated association, and for men only the diabetes.Conclusion Lower levels of PA were observed in the elderly of the city of São Paulo, especially with age advancing and the presence of diseases, that are very common in this population. This study reinforces that the practice of PA should be encouraged and it demonstrates the necessity of longitudinal studies to establish the time relation with these factors.

This thesis addresses the hypothesis that a single, waist-mounted triaxial accelerometer (TA) can be used to monitor human movement patterns in unsupervised, freeliving subjects over extended periods, and that it can be used to quantitatively measure parameters that can provide clinical insight into the health status of the subject. A rigorous theoretical and experimental understanding of the signals obtained from a TA is developed. The effect of the placement of the TA device on the waist is explored and a model relating device position to TA signal is developed for a range of postures and activities. A classification framework for movement identification using the signals from a waist-mounted TA is presented. This framework is based on a hierarchical binary processing tree and is designed for real time use. An implementation of this framework for monitoring housebound patients is presented. Algorithms for detecting falls, distinguishing between activity and rest, classifiying transitions between different postural orientations, and for identifying periods of standing, sitting, lying and walking are developed. In evaluation studies performed in controlled laboratory conditions, every algorithm performed with better than 90% accuracy. Once movements are identified, movement-specific parameters sensitive to changes in functional status are extracted from the signal. A two stage methodology for employing the accelerometry system in monitoring free-living subjects is introduced. The first stage involved monitoring specific movements through a directed routine. The second stage involved monitoring of free movement. Signals obtained from the directed routine are used to extract clinically relevant, movement-specific parameters. Signals obtained from the period of free movement are monitored for falls and other abnormal events. General parameters of movement, including energy expenditure, are also measured. The system was evaluated in a series of field studies in laboratory and home environments, in supervised and unsupervised settings, using cohorts of healthy subjects. A pilot trial was conducted in which six healthy elderly subjects wore the TA device for a period of up to three months. The technical performance and useability of the system were evaluated. Clinically significant parameters were measured and the effects of age and health status on the measured parameters were evaluated.

SAMMAMFATTNING Bakgrund: Reaktiv hyperemi definieras som ett övergående ökat blodflöde över det normala efter en tids ischemi. Det kan registreras med laserdopplerteknik. Att registrera reaktiv hyperemi är ett sätt att värdera mikrocirkulationen. Det finns många flödesvariabler att studera varav tid till maxflöde efter ocklusion är en. Det har gjorts studier som undersöker om det finns ett samband mellan reaktiv hyperemi och fysisk aktivitet/syreupptagningsförmåga. Det har inte gjorts någon studie som undersöker tid till maxflöde och fysisk aktivitet. Syftet var att undersöka om det finns ett samband mellan fysisk aktivitet och reaktiv hyperemi med avseende på tid till maxflöde. Material och metod: Testpersoner fick bära en accelerometer en vecka under dygnets alla vakna timmar samt göra en registrering av reaktiv hyperemi med laserdoppler. För statistiska beräkningar användes oparat T-test för att undersöka skillnad mellan olika grad av fysisk aktivitet och tid till maxflöde. Resultat: Ingen statistiskt signifikant skillnad mellan olika aktivitetsgrad och tid till maxflöde kunde observeras. Slutsats: Den här studien visade inte på statistiskt signifikant samband mellan blodflöde och fysisk aktivitet.

PURPOSE: To determine if participation in a short-term, high intensity physical education (PE) intervention that respected the multiple goals of the PE curriculum would result in any health- and/or fitness-related improvements for grade four and five students. METHODS: Seventy-six students were divided into a control and intervention group (CG & IG). During 15 successive classes, the IG participated in six minutes of high intensity activities while no changes were made to the structure of the CG’s PE class. Accelerometers and direct observation were used to quantify the percentage of moderate-to-vigorous physical activity (%MVPA). Health- and performance-related measures were assessed pre- and post-intervention. RESULTS: Students spent an average of 27% of their PE class engaged in MVPA. Within this category, the intervention was successful at increasing students’ VPA levels by 7.7%. Observations regarding pedagogical practices are also reported. CONCLUSIONS: Participating in a PE intervention can increase students’ PA levels without compromising the goals of the PE curriculum.

A monitoração objetiva da atividade física traz grandes benefícios para a medicina veterinária, tanto em animais de estimação quanto de produção, por ser considerada um indicador de saúde e bem-estar animal. Conhecer o padrão natural de movimentação dos animais traz a possibilidade de correlacionar processos como dor ou estresse com uma eventual mudança de comportamento. Atualmente, os acelerômetros estão sendo amplamente utilizados para monitorar a atividade física de maneira objetiva, pois são dispositivos eletrônicos pequenos que permitem quantificar a frequência, duração e intensidade da atividade física através da mensuração da aceleração do movimento corporal. O objetivo deste trabalho é avaliar se o acelerômetro é capaz de quantificar a atividade física de equinos e identificar os diferentes níveis de atividade e andaduras. Foram utilizados 12 cavalos adultos, de diferentes raças utilizadas em provas de salto, equipados com seis acelerômetros fixados, um na cabeça, um na cernelha e um em cada membro torácico e um em cada membro pélvico. Os animais permanecerem em repouso durante 2 minutos e foram conduzidos, montados por um cavaleiro experiente, a passo, trote e galope durante 4 minutos no sentido horário e 4 minutos no sentido anti-horário. Os dados foram registrados em diferentes intervalos de amostragem ou epochs (15, 10, 5, 3 e 1 segundo) e convertidos em counts por minuto para que pudessem ser comparados. O acelerômetro foi capaz de medir a atividade física e de identificar quando o animal estava em repouso, ao passo, ao trote e ao galope em todos os locais analisados. Porém, os dados registrados na cernelha e nos membros pélvicos foram mais precisos para classificar as andaduras. O acelerômetro localizado na cabeça registrou os maiores valores quando o animal estava em repouso, o que reflete uma maior movimentação desta região mesmo quando não há deslocamento do animal. Não houve diferença estatisticamente significativa entre os dados registrados nos diferentes epochs. Concluise que o acelerômetro foi capaz de mensurar a atividade física na espécie equina e identificar o nível de atividade e andaduras, sendo que o posicionamento na cernelha e membro pélvico foram considerados mais adequados devido a maior precisão dos dados registrados. Além disso, os resultados obtidos não foram influenciados pelos diferentes intervalos de amostragem, portanto sugere-se que a utilização de epochs de 15 segundos é considerado adequado para o monitoramento da atividade física em equinos. / Objective monitoring of physical activity brings great benefits to veterinary medicine in pet and livestock animals, as it is considered an indicator of animal health and welfare. Knowing the natural pattern of animal movement provides relevant information, that later can be used to evaluate the possibility of pain or stress if there is a change in behavior. Nowadays, accelerometers are widely used to monitor physical activity in an objective way, since they are small electronic devices that allow quantifying the frequency, duration and intensity of physical activity by measuring the acceleration of body movement. The objective of this study is to evaluate the accelerometer capability to quantify the physical activity of horses and identify the different levels of activity and gaits. Twelve adult jumping horses of different breeds wore six accelerometers, one fixed on the head, one fixed on the withers and one fixed at each forelimb and each hindlimb. The animals would stand for 2 minutes, and then exercised by an experienced rider in three different gaits (walk, trot and gallop) for 4 minutes in a clockwise direction and 4 minutes in an anticlockwise direction. The data were recorded at different epochs (15, 10, 5, 3 and 1 second) and converted into counts per minute to be analyzed. Regardless of the location, the accelerometer was able to measure physical activity and to identify when the animal was at rest, walking, trotting and galloping. However, data recorded on the withers and hindlimbs were more accurate to classify gait. The accelerometer located on the head recorded the highest values when the animal was at rest, which reflects a greater movement of this region even when there is no displacement of the animal. There was no statistically significant difference between the data recorded in the different epochs. Therefore, we conclude that the accelerometer is able to measure physical activity in the horses, and to identify the level of activity and gaits, and the positioning at the withers and hindlimbs were considered more adequate due to the greater accuracy of the recorded data. In addition, the results obtained were not influenced by the different epochs used, so it we suggest that the use of 15-second epochs is considered adequate for the monitoring of physical activity in horses.

STUDY 1. INTRODUCTION. Insufficient physical activity is a major risk factor for developing type 2 diabetes. Using isotemporal substitution models, the influence of replacing modest durations of sedentary time with physical activity on diabetes risk scores can be studied. The aims of this study were to examine the relationship between diabetes risk scores, sedentary time and physical activity measured using wrist worn accelerometry, and to model the changes in risk scores by reallocating movement behaviours from lower to a higher intensity. METHODS. Data from 251 (93 males; aged 56.7 ± 8.8) participants from a mixed ethnicity cohort from Leicestershire, UK were selected for analysis. The relationship between diabetes risk (using the Leicester Diabetes Risk Assessment Score), physical activity and sedentary time was identified using multiple linear regressions and isotemporal substitution analysis. Models were calculated for main effects and also adjusted for peak oxygen uptake (VO2) and accelerometer wear time. RESULTS. Both unadjusted and adjusted models revealed that diabetes risk was inversely related to sedentary time, and positively related to light and moderate to vigorous physical activity (MVPA) (p < 0.0005). Unadjusted, the replacement of sedentary time with 10 minutes of either light or MVPA resulted in a reduction in diabetes risk score of -0.22 and -0.54, respectively. There was an eight to nine times greater reduction in risk for the same MVPA replacement models when the least active participants were compared to the pooled analysis (3.601 unadjusted). CONCLUSION. Diabetes risk is associated with sedentary time and physical activity estimated from wrist worn accelerometry. The replacement of sedentary time with MVPA is most beneficial for the least active individuals. STUDY 2. INTRODUCTION. Most associations between physical behaviours and health are assessed using intensity and duration based estimations; however, individuals accrue physical activity in differing ways and behavioural profiles have been linked with varying cardiometabolic risk factors. The frequency or regularity of behaviour may hold additional relationships with health, but have not been extensively explored. Accelerometers provide researchers with a large stream of raw data to analyse. The aim of this paper was to calculate a novel method of behavioural regularity called sample entropy from wrist worn accelerometry and to ascertain whether there are associations with cardiometabolic risk factors in adults. METHODS. Data from 290 (107 males; aged 57.0 ± 8.8) participants from a mixed ethnicity cohort from Leicestershire, UK were selected for analysis. Entropy scores were calculated using 60-second count data within MATLAB. The relationship between entropy scores, physical activity, sedentary time and cardiometabolic risk factors was identified using multiple linear regressions. Models were calculated for main effects and also adjusted for age, sex, accelerometer wear time and body mass index (BMI). RESULTS. Sample entropy scores were significantly related to high-density lipoprotein (HDL) cholesterol (b = 0.148, p = 0.042), triglycerides (b = -0.293, p = 0.042) and glycated haemoglobin (HbA1c) (b = -0.225, p = 0.006), even after adjustment for confounding variables. Traditional intensity estimates of physical activity were not associated; however, the frequency of breaks in sedentary time were significantly related to entropy scores (b = 0.004, p = 0.002). CONCLUSION. Using a novel measure of signal complexity, associations have been revealed with cardiometabolic risk factors; however further analysis in a larger, more diverse dataset is required to ascertain the utility of this technique within behavioural research and if so, what constitutes typical/average levels of entropy within a population. STUDY 3. INTRODUCTION. Acute physiological changes such as reductions in postprandial glucose excursions have been demonstrated within experimental studies that have compared being physically active to sedentary conditions. However, for this information to be truly useful, the coupling of behaviour and glucose data in a free-living environment needs to be achieved. The aim of the study was to ascertain if there is a relationship between objectively measured physical activity, sedentary time and glucose variability using glucose monitoring in an adult population. METHODS. Data from 29 participants recruited from a mixed gender sample from Leicestershire, UK were selected for analysis. Physical activity, sedentary time and interstitial glucose was measured continuously over 14 days using an accelerometer and the Freestyle Libre flash glucose monitor. Daily time (minutes) spent sedentary, and in light activity and moderate to vigorous physical activity (MVPA) were regressed against glycaemic variability indices including daily mean (average) glucose, standard deviation and mean amplitude of glycaemic excursions (MAGE). Generalised Estimating Equations were calculated between behaviour and glycaemic variability variables. Models were calculated for main effects and also adjusted for age, gender and accelerometer wear time. RESULTS. Physical activity and sedentary time were associated with measures of glucose variability, however low fitness individuals showed a stronger relationship between MVPA and MAGE (MAGE: whole sample b = -0.002, low fitness b = -0.012. Additionally, after adjustment for covariates, sedentary time was positively associated with a higher daily mean glucose (b = 0.001, p = 0.001) and MAGE (b = 0.002, p < 0.0005) for the low fitness group. MVPA was negatively associated with mean glucose (b = -0.004, p < 0.0005) and MAGE (b = -0.012, p < 0.0005); however, standard deviation of glucose was not associated with behaviour of any intensity. The magnitudes of the relationships were small, although participants were non-diabetics and exhibited relatively good glucose control i.e. minimal fluctuations in daily glucose variability. CONCLUSION. This study shows that sedentary time, physical activity and glucose variability are related. Despite supporting the previous laboratory research, it is uncertain whether any changes in glucose will reliably occur in all individuals. MVPA confers the largest reductions in glucose variability indices, yet as one of the few studies to couple behaviour and glucose data, more research is needed on larger and more diverse samples.

A castração de cães é um procedimento eletivo frequentemente realizado, e a sua prática tem sido associada com a queda nos níveis de atividade física e com ganho de peso. A grande maioria das pesquisas que envolvem a atividade física é realizada através de questionários que fornecem dados aceitáveis, porém subjetivos. Este trabalho teve por objetivo analisar de forma quantitativa, através do uso do acelerômetro, os níveis de atividade física e o ganho de peso de cadelas antes e após a castração. Foram utilizadas 21 cadelas e monitoradas através do acelerômetro em quatro momentos: antes, um mês, três meses e seis meses após a ovariossalpingohisterectomia. Os cães também foram avaliados quanto ao ambiente, peso, escore de condição corporal e porte. Não houve redução estatisticamente significativa dos níveis de atividade física após a castração. Ao fim dos seis meses de pós-operatório as atividades sedentária, leve a moderada e vigorosa permaneceram iguais àquelas anteriores à castração. O ambiente não influenciou o comportamento dos animais, pois apresentaram níveis de atividade muito semelhantes. Cadelas com sobrepeso tiveram maior variação de atividade em relação a cadelas de peso ideal e cadelas de porte grande maior variação em relação aquelas de porte médio e pequeno. Houve significativo ganho de peso de 8,75% ao fim dos seis meses de estudo, independente do ambiente, escore corporal e porte. Foi possível relacionar à variação da atividade vigorosa e leve moderada somada a vigorosa com o ganho de peso. Assim, conclui-se que até seis meses após a castração os animais não alteram os níveis de atividade física, mas apresentam significativo ganho de peso no mesmo período. / Neutering dogs is an elective procedure often performed, and its practice has been associated with the declined levels of physical activity and weight gain. The very majority of research involving physical activity is conducted through questionnaires that provide acceptable data, however those data are subjective. This study aimed to analyze quantitatively the physical activity and the weight gain in bitches before and after castration throughout accelerometer. Twenty one monitored bitches by accelerometer were evaluated in four stages: before, one month, three months and six months after ovariosalpingohysterectomy. The dogs were also evaluated in regards for the environment, weight, body condition score and size. There was no statistically significant reduction in levels of physical activity after castration. At the end of the six months post-operative sedentary, mild to moderate and vigorous activities remained the same as pre-castration versions. The environment did not influence the behavior of animals, since the activity levels remained very similar. Bitches overweight had a higher variation of activity in relation to bitches of ideal weight and large sized dogs greater variation regarding those medium and small-sized. There was significant weight gain of 8,75% at the end of the six months of study, regardless of the environment, body condition and size. It was possible to relate the variation of vigorous activity and mild to moderate added to vigorous activity with weight gain. Thus, it is concluded that up to six months after castration animals do not change the physical activity levels, but they present significant weight gain in the same period.

A monitoração objetiva da atividade física traz grandes benefícios para a medicina veterinária, tanto em animais de estimação quanto de produção, por ser considerada um indicador de saúde e bem-estar animal. Conhecer o padrão natural de movimentação dos animais traz a possibilidade de correlacionar processos como dor ou estresse com uma eventual mudança de comportamento. Atualmente, os acelerômetros estão sendo amplamente utilizados para monitorar a atividade física de maneira objetiva, pois são dispositivos eletrônicos pequenos que permitem quantificar a frequência, duração e intensidade da atividade física através da mensuração da aceleração do movimento corporal. O objetivo deste trabalho é avaliar se o acelerômetro é capaz de quantificar a atividade física de equinos e identificar os diferentes níveis de atividade e andaduras. Foram utilizados 12 cavalos adultos, de diferentes raças utilizadas em provas de salto, equipados com seis acelerômetros fixados, um na cabeça, um na cernelha e um em cada membro torácico e um em cada membro pélvico. Os animais permanecerem em repouso durante 2 minutos e foram conduzidos, montados por um cavaleiro experiente, a passo, trote e galope durante 4 minutos no sentido horário e 4 minutos no sentido anti-horário. Os dados foram registrados em diferentes intervalos de amostragem ou epochs (15, 10, 5, 3 e 1 segundo) e convertidos em counts por minuto para que pudessem ser comparados. O acelerômetro foi capaz de medir a atividade física e de identificar quando o animal estava em repouso, ao passo, ao trote e ao galope em todos os locais analisados. Porém, os dados registrados na cernelha e nos membros pélvicos foram mais precisos para classificar as andaduras. O acelerômetro localizado na cabeça registrou os maiores valores quando o animal estava em repouso, o que reflete uma maior movimentação desta região mesmo quando não há deslocamento do animal. Não houve diferença estatisticamente significativa entre os dados registrados nos diferentes epochs. Concluise que o acelerômetro foi capaz de mensurar a atividade física na espécie equina e identificar o nível de atividade e andaduras, sendo que o posicionamento na cernelha e membro pélvico foram considerados mais adequados devido a maior precisão dos dados registrados. Além disso, os resultados obtidos não foram influenciados pelos diferentes intervalos de amostragem, portanto sugere-se que a utilização de epochs de 15 segundos é considerado adequado para o monitoramento da atividade física em equinos. / Objective monitoring of physical activity brings great benefits to veterinary medicine in pet and livestock animals, as it is considered an indicator of animal health and welfare. Knowing the natural pattern of animal movement provides relevant information, that later can be used to evaluate the possibility of pain or stress if there is a change in behavior. Nowadays, accelerometers are widely used to monitor physical activity in an objective way, since they are small electronic devices that allow quantifying the frequency, duration and intensity of physical activity by measuring the acceleration of body movement. The objective of this study is to evaluate the accelerometer capability to quantify the physical activity of horses and identify the different levels of activity and gaits. Twelve adult jumping horses of different breeds wore six accelerometers, one fixed on the head, one fixed on the withers and one fixed at each forelimb and each hindlimb. The animals would stand for 2 minutes, and then exercised by an experienced rider in three different gaits (walk, trot and gallop) for 4 minutes in a clockwise direction and 4 minutes in an anticlockwise direction. The data were recorded at different epochs (15, 10, 5, 3 and 1 second) and converted into counts per minute to be analyzed. Regardless of the location, the accelerometer was able to measure physical activity and to identify when the animal was at rest, walking, trotting and galloping. However, data recorded on the withers and hindlimbs were more accurate to classify gait. The accelerometer located on the head recorded the highest values when the animal was at rest, which reflects a greater movement of this region even when there is no displacement of the animal. There was no statistically significant difference between the data recorded in the different epochs. Therefore, we conclude that the accelerometer is able to measure physical activity in the horses, and to identify the level of activity and gaits, and the positioning at the withers and hindlimbs were considered more adequate due to the greater accuracy of the recorded data. In addition, the results obtained were not influenced by the different epochs used, so it we suggest that the use of 15-second epochs is considered adequate for the monitoring of physical activity in horses.

Pregnancy-related complications affect approximately 15% of pregnancies and, if severe, can have long-term consequences. Timely recognition of physiological deterioration is known to reduce the prevalence and severity of complications. However pregnancy-associated changes in vital signs (blood pressure, heart rate, temperature, oxygen saturation, and respiratory rate) complicate the detection of abnormal physiology, and these changes are not well documented. This thesis describes the development of algorithms to ensure the collection of good-quality vital-sign data during the antenatal and postnatal stages of pregnancy, and the design of an evidence-based obstetric early warning score. Vital-sign information from 1,000 pregnant women during pregnancy, labour, and after delivery was collected during the 4P study using pulse oximetry, oscillometry for blood pressure measurement and a tympanic thermometer. Dynamic time warping was used to assess beat-by-beat quality in the photoplethysmograph (PPG) waveform obtained from the pulse oximeter. The resulting signal quality index enabled the exclusion of poor-quality sections and their associated measurements of heart rate and peripheral oxygen saturation. A robust measurement of respiratory rate was obtained by combining information from the PPG waveform, and accelerometer and gyroscope waveforms from a smartphone. After processing, frequency-based techniques, such as Fourier analysis and auto-regressive modelling, and time-domain peak detection were fused to estimate respiratory rate. When compared with the reference respiratory rate obtained from midwife measurement, the lowest mean absolute error of 1.16 breaths per minute was obtained from respiratory rate estimates from the y-axis of the gyroscope. Antenatal and postnatal reference ranges for each vital sign were developed with a standard polynomial multilevel (hierarchical) model using 10,000 vital sign measurements from 620 healthy women in the 4P study. Vital-sign trajectories confirmed known trends of blood pressure and heart rate changes during pregnancy, and provided new information about other vital-sign trends. Additional covariates were included to investigate the effect of parity and body mass index (BMI) on vital-sign trends. The outer centiles of the vital sign reference ranges were used to design an obstetric early warning score (C-ObsEWS) that took into account gestational age or time after delivery. The investigations in this thesis contribute additional knowledge of pregnancy-associated vital-sign changes, and lead to an initial proposal for an evidence-based obstetric early warning score specific to the stage of pregnancy.