• Data pre-processing techniques and tools for predictive modelling using unstructured inputs

      Maslowski, Przemyslaw (University of Bedfordshire, 2020-07)
      Data is a crucial factor within machine learning, as most of the neural networks and machine learning models are data-driven. A trained neural network can be used to predict new data that has not been seen by the model but under the trained patterns. The performance of the predictive model can vary based on the data that is being used while training. Multiple metrics have been produced after a model is trained to evaluate model performance. However, it is difficult to get an intuitive measurement that indicates if the data pre-processing of a model has been improved or not. Therefore, a constructive performance indicator tool that can be used to intuitively measure the performance of pre-processing mechanisms for a given model, has been developed through multiple experiments with 32 datasets. The experiments are set up by collecting multiple unstructured datasets which are subsequently converted into structured datasets and then evaluated by their modelling performance. The experiment results are used to evaluate the importance of each metric and priorities via weights for contextualising the preprocessing experience within the constructivist paradigm. Furthermore, a set of tools have been developed throughout the project to improve the efficiency of machine learning experiments. The developed set of tools are a part of the main software, which is named as the pre-processing assistant. The pre-processing assistant has been published to the public, and it can be used for preparing, processing, and analysing data. The software tools allow users to manipulate datasets and generate Python scripts to train a predictive model. Also, the TensorFlow framework and its machine-learning algorithms have been utilised to develop Python scripts for training and predicting datasets. The software has been used to effectively carry out the experiments which have helped to configure the performance indicator tool. In the end, the most important metrics have been discovered through various experiments. The experiments consist of training the model with and without data pre-processing techniques. The increase in each metric has been adopted to discover significant metrics. The metrics which improve frequently are estimated to be more critical and have been assigned with a higher weight. The performance indicator has been configured based on the final experiment results, and it can be used by others to measure the performance of a predictive model.
    • Decision making ability and thermoregulation in extreme environments during goal line official-like movement patterns

      Watkins, Samuel L. (University of Bedfordshire, 2013-03)
      Goal line officials (GLO) are exposed to extreme environmental conditions when employed to officiate in European cup competitions. Extreme environments have been shown previously to affect various facets of cognitive function. The present study aimed to investigate the effect of such environments on GLO. 13 male participants were exposed to 3 conditions, cold (-5 oC, 50% RH); temperate (18 oC, 50% RH); and hot (30 oC, 50% RH) for 90 minutes per condition, with a 15 minutes half time break after 45 minutes. Decision making ability was measured; using the Psyche Software Package, prior to each exposure (0 minutes), at the end of the first half (45 minutes), immediately after half time (45 minutes), and at the end of the second half (90 minutes). Exposure to cold conditions reduced positive stimuli responses (HIT scores) significantly when compared to hot conditions (P<0.05). Participants ability to track stimuli was also significantly reduced in cold conditions when compared to temperate and hot conditions (P<0.05). Reductions in decision making ability were coupled with reductions in physiological measures; cold exposure significantly reduced core temperature, skin temperature and thermal comfort when compared to temperate and hot conditions (P<0.05). The diminishment in GLO decision making ability during exposure to cold conditions, most notably the ability to respond positively to an infringement and the ability to track important stimuli, e.g. the football and goal line/player, are concerns which could negatively affect the outcome of a football match. Such findings should be considered by football’s governing bodies when assessing the implementation of goal line technology and/or the continued use of GLO.
    • A decision support system for international students

      Wu, Qing (University of Bedfordshire, 2012-10)
      Effective decision making is a complex process and can be influenced by many factors. When making decisions, people always have to deal with many challenges such as: information overload, too many criteria to consider, etc. Decision Support Systems (DSS) emerged to help people make effective and informed decisions in the 1980s. They have been widely used and enhanced in recent years with new emerging internet technologies and decision models, one of them being Multi-criteria decision support systems (MCDSS). MCDSS aims to aid the decision makers to handle semi-structured decisions with multiple criteria. This research aims to help individuals understand the decision making process, especially the multi-criteria decision making process, and develop and test a personal decision support system (DSS) to help individuals make better decisions in the context of university selection by overseas students. The research investigates and analyses the key factors affecting students’ decisions when selecting a suitable university using personal interview and questionnaire survey methods; these find out students’ needs, and help design and develop a personal decision system prototype for international students using the Analytic Hierarchy Process (AHP) method to aid them to select the best suitable university for their postgraduate study in the UK. Then the system is tested with students and their feedback analysed. This process has implications for developing and using DSS as a personal decision support tool, thus to provide a base for future research and development. This research made a number of contributions to DSS research and applications. Firstly, it addressed a gap in the current DSS research by designing and applying DSS for personal decision making using AHP because personal DSS reported in the literature is designed to serve business users. Secondly, it identifies key criteria in students’ decision making on university selection through student interviews and surveys. The key criteria are University ranking, Subject ranking, Completion rate, Location, Accommodation costs, Tuition fees, and Entry Requirements. Thirdly, the system evaluation results show that DSS-US is perceived to be effective, efficient and usable. For effectiveness, users believe that DSS-US has the potential to help them make better decision through personalization in terms of decision making criteria and weight allocation. For efficiency, students find that the system can save them significant amount of time when making their decision by helping them tom access the necessary information and data. Regarding the system usability, all the participants indicate that they were satisfied about the function of DSS-US. In addition, user can ‘play’ with DSUS system to explore different scenarios. They can try different weights to explore different results.
    • Demonstration of a cost efficient “Decision Support System (DSS)” using Visual Studio Applications

      Schmunk, Andreas (University of Bedfordshire, 2012-05)
      Decision support systems (DSS) are a suitable, need-based and cost effective solution for companies to implement analysis tools and streamline various processes. This report demonstrates the applicability of such a tool in a specific context where previously no DSS has been applied. The analysis of contract cancellations within financial companies that entirely depend on these agents is a crucial analytical process for these companies. However, these companies have not yet used a sophisticated DSS that allows a user-friendly and simple analysis in order to derive evidence-based countermeasures. Consequently, this report describes the process of developing and evaluating a DSS that fulfils general and specific requirements. These criteria have been tested while developing the tool in order to guarantee several steps of reiteration. The results clearly show that the developed tool is user-friendly, provides enough analytical depth and can be easily implemented. This prototype is therefore a robust and convincing solution for an important business problem and its benefit can be seen in the fact that participating companies are considering to implement a DSS solution that is based on this prototype.
    • Design and implementation of a communicating method for WSN

      Shaik Khadar Basha, Nazeer Basha (2013)
      The sensor nodes present in the wireless sensor networks are constrained of energy as they are powered with the help of battery. Deployment of the sensor nodes in the hostile environment makes it unfavorable for the people to change the battery of the senor nodes when it is expired. Due to the energy limitations there is a great need of providing any energy efficient way of communication for the wireless sensor networks. Several techniques of offering communications in a sensor network use the classical layered method that results in great overhead of the network and high energy consumption. It will be very better when a unified technique is present for converting the functions of common protocol to the cross layer method. A cross layer protocol is been implemented in this project to provide congestion control, better routing over the cross layers. This cross layer protocol is designed based on the initiative determination present in cross layer module. This method offers congestion control forwarding based on initiatives contention based on receivers and better communication between the sensor nodes of a wireless sensor network. The implementation of this initiative determination is very easy as it just involves the comparison with the threshold values. Through this cross layer protocol the functions of each layer can be combined very easily .The performance of this cross layer protocol is also identified in this project. Through this cross layer protocol better communications can be provided between the sensor nodes of a wireless sensor networks and also is far better than the classic layered protocols with respect to the energy consumption and network performance.
    • Design and implementation of a procedure for VFX content generation

      Mustafa, Kamran; University of Bedfordshire (University of BedfordshireUniversity of Bedfordshire, 2011)
      As a student of M.Sc. Computer Animation I have tried my best to cover all the aspects of this project. Being a student is great, but sooner or later I am going to have a transition to "the real world". I am about to make that transition; graduation is around the corner and I find myself looking forward to join the workforce. When I look back to my year of study at the University of Bedfordshire, I am amazed that I have learned much but there is much more to learn. The greatest experience I acquired is that with this project I gained a lot of experience to work on the motion capture and learned new techniques that are used in industry to create high quality VFX with 3d animation. I have tried my level best to keep the accuracy in designs and realistic as possible but most important thing is that I have worked for the first time on motion capture and I am very much successful in generating the output that I imagined. The realistic models, usage of MoCaps, mind blowing VFX, environments, materials all have been done according to the perspective of imitating them to the actual objects. By doing this most importantly I have passed through several hurdles and bottlenecks that can appear in the work process. One of the most important characteristic of my project is that I have not used any special purpose hardware for my work. All the designing and modeling has been done on simple core i7 machine without high speed graphics cards or rendering cards. I also haven’t got any motion capture cameras so I bought pre-captured MoCaps from internet. Shots that are rendered in 3DS Max were later on blended with the real life footage using After Effects. After the rendering a lot of work is performed in the Post Production for generating VFX and doing green screening.
    • Designing an arts festival: constructing authenticity

      Saklatvlala, Robin Litza (University of Bedfordshire, 2010-03)
      Through the creation and running of two arts festivals in Luton this research investigates the nature of arts festivals and defines their key attributes. It seeks also to go beyond the tangible attributes and discover what it is that makes a festival more than simply a curated collection of events. It aims to understand what makes an arts festival an authentic experience for participants, sponsors and volunteers. It discusses definitions of authentic arts festivals and applies these definitions and attributes to a pilot case study to determine whether a newly established arts festival can achieve authenticity as defined by Getz. Semi-structured interviews are used to examine the importance of authenticity in festivals to stakeholders involved in funding and organising them and determine if the motivation for establishing an arts festival impacts its authenticity. The research is in response to the recent proliferation and homogenisation of arts festivals, due in a large part to research which demonstrates that they are beneficial for regeneration, tourism, image enhancement and community cohesion. The research concludes arts festivals can begin with staged authenticity but, by meeting a real need and involving communities they can attain an emergent authenticity.
    • Designing and optimization of VOIP PBX infrastructure

      Rana, Naveed Younas (University of Bedfordshire, 2013)
      In the recent decade, communication has stirred from the old wired medium such as public switched telephone network (PSTN) to the Internet. Present, Voice over Internet Protocol (VoIP) Technology used for communication on internet by means of packet switching technique. Several years ago, an internet protocol (IP) based organism was launched, which is known as Private Branch Exchange "PBX", as a substitute of common PSTN systems. For free communication, probably you must have to be pleased with starting of domestic calls. Although, fairly in few cases, VoIP services can considerably condense our periodical phone bills. For instance, if someone makes frequent global phone calls, VoIP talk service is the actual savings treat which cannot achieve by using regular switched phone. VoIP talk services strength help to trim down your phone bills if you deal with a lot of long-distance (international) and as well as domestic phone calls. However, with the VoIP success, threats and challenges also stay behind. In this dissertation, by penetration testing one will know that how to find network vulnerabilities how to attack them to exploit the network for unhealthy activities and also will know about some security techniques to secure a network. And the results will be achieved by penetration testing will indicate of proven of artefact and would be helpful to enhance the level of network security to build a more secure network in future.
    • Detection of session hijacking

      Louis, Jerry (University of Bedfordshire, 2011-01)
      In today‟s world the computer networks have become vulnerable to numerous types of attacks. Either it is wireless network or wired network, one of the most common or effective attacks up-to-date are man-in-the-middle attack, within which session hijacking has been the most attempted attack. The success rate of a session hijacking attack is significantly higher when compared to other attacks. This paper analysis the underlying problem in the detecting strategy and provides a customized solution to detect session hijacking efficiently. This thesis proposes a dual strategy towards developing a defensive mechanism against the session hijacking attempts, the two strategies are IN-Network strategy and OUT-Network Strategy. The implementation to test the above mentioned strategies are carefully designed in order to get the optimum results. The implementation is tested on the user-end, attacker-end and finally on the server end, also this testing of the proposal is performed on two platforms, Windows Operating system – Windows 7 and Linux Operating System – BackTrack. The performance in each of the operating system and the network strategies are carefully iterated to discuss the performance of each of the parameters in its host operating system. The results finally show that the defensive methodology is successfully implemented on both the network strategies.
    • Determining the effect of temperature on species interactions in microcosms: a QPCR approach

      Dowdeswell, Emily (University of Bedfordshire, 2016-06)
      Predicting the impact of environmental change is a major goal and challenge in ecology. With climate change threatening the biodiversity and ecosystem functioning of our natural ecosystems, understanding the effects of such change and how these are mediated through a community is of critical importance. Community stability could be severely affected by temperature through extinctions, alterations in species dominance and species-specific responses. One approach to testing the consequences of climate change on a community is to manipulate experimental aquatic microcosms. However, investigating community-level responses to change in experimental microcosms has been limited by the ability to accurately monitor the basal trophic level of bacteria. Here I develop a molecular approach to monitoring bacteria by using qPCR. The qPCR approach was successful for three bacterial species and produced sensitivity to the single cell. The qPCR approach was implemented in an experimental setting to aid the investigation of the relationships between temperature, species interactions and community properties. Direct temperature response was species-specific, but indirect interactions strongly mediated temperature through the community, altering competitor and predator response. Therefore, predicting species and community response to environmental change is dependent on knowledge of specific-species response, indirect pathways of interaction and the effects of community composition.
    • Developing a network storage device using a single board computer

      Maguire, Christopher (University of Bedfordshire, 2018-10-16)
      The aim of this project was to continue the work of the previous project “Developing a Network Storage Device Using a Single Board Computer” using the lessons learned to develop a new device for a different use case. This projects aim was to determine the viability of a portable storage solution that could be powered by batteries. The hardware was a key area of this as a balance needed to be found between performance and power consumption. After researching different hardware options the Raspberry Pi Zero W was selected for this project as it included features that were needed, such as Bluetooth and Wi-Fi, and used the same operating system as the original device and would support the same code. Bluetooth audio receiver capabilities were later added as a required feature. Due to the hardware selection an audio output needed to be added. This was done using a Hardware Attached on top, HAT, called the pHAT DAC this added a 3.5mm audio jack to the PI Zero W. The device was tested at varying locations to determine the how much interference factored into the user experience of the device. Multiple tests were run on different devices, due to the application used for testing the tests were only done on Windows devices.
    • Developing computer-based assessment as a tool to support enquiry led learning

      Collins, Carol Ann (University of Bedfordshire, 2008-03)
      This research explores the possibility of developing Computer-based Assessment (CBA) as a tool to support enquiry-led learning. In this approach learners explore and unpack thoughts and ideas that help them to learn and solve problems. A critical feature of this is feedback and this research focussed on how to design and supply feedback in CBA. Two lines of research were sourced: Computer-assisted Assessment (CM) and Improving Formative Assessment (IFA). Specifically, performance data was collected, analysed and evaluated from the statistical results of 3 CSA tests (approximately 100 undergraduates per test) and from qualitative feedback, the dialogic question and answer responses of (approximately 30 learners x 100 responses) engaged on level 3 activity of the National Qualifications Framework (NQF). The outcome of the research is the development of Kilauea exemplar, a theoretical model of an enquiry led item type applied in a subject specific domain.
    • Development of an optimized sampling regime for the determination of the effects of bioaerosols on health

      Adlington, Vanessa M. (University of Bedfordshire, 2006)
      Bioaerosols vary in size between particle types which affects their airborne properties, influencing the type of sampler that can be used when trying to detect them. Despite this, there is no standardised protocol for measuring bioaerosols. Sampling experiments were performed in indoor environments with low concentrations of bioaerosols (office and domestic residences) to evaluate the sampling efficiencies of the Andersen 6-stage viable impactor, Omega AIRTEST viable sampler, AGI-30 liquid impinger and filter samplers. These sampling methods were evaluated both individually and in comparison with each other. The measurement of indoor particulate concentrations using an LN5 laser monitor and surface sampling of indoor dust were also performed. The most appropriate methodologies for use with each sampler are recommended, based on the sampled data from this study. Representative measures ofbioaerosol concentrations were achieved that were directly comparable with the other methods but it was concluded that no single sampling method is suitable for comprehensive bioaerosol sampling. The effect of human activity in an indoor environment was found to have a particularly significant effect on measured bioaerosol concentrations. Preliminary findings from this study show evidence of a dose-response relationship and suggest that there are a larger number of reported health symptoms for environments with higher bioaerosol concentrations. However, further work requires to be done that will allow predictions to be made about the severity of likely health effects according to measured bioaerosol concentrations for a particular environment.
    • Development of new methods to assess the quality of zebrafish (Danio rerio) ovarian follicles

      Zampolla, Tiziana (University of BedfordshireUniversity of Bedfordshire, 2009-03)
      High quality fish oocytes are essential for in vitro maturation (IVM), in vitro fertilization (IVF) protocols, and for use in cryopreservation. It is important to develop methods for assessing oocyte quality for applications in aquaculture, the preservation of endangered species and managing fish models used in biomedical research. The lack of reliable methods of evaluating oocyte quality limits progress in these areas. The present study was undertaken to develop new methods to assess ovarian follicle viability and quality of stage III zebrafish (Danio rerio) ovarian follicles. The methods developed were then applied to study the impact of cryoprotectant and/or cryopreservation procedures. A vital staining procedure, not previously used with zebrafish oocytes, has been investigated. FDA-PI (Fluorescein diacetate-Propidium Iodide) staining was found to be a more sensitive then currently used viability tests and it could also be applied to all ovarian follicles developmental stages. Mitochondrial activity and distribution as biological markers was investigated with the mitochondrial membrane potentialsensitive dye JC-1- (5,5’,6,6’-tetrachloro-1,1’,3,3’-tetraethylbenzimidazolylcarbocyanine iodide). Confocal microscopy, Cryo-scanning and electron microscopy studies were undertaken to determine mitochondria distributional arrangement within the ovarian follicle. This provided new information on zebrafish ovarian follicle structure, and showed that mitochondria exhibited a contiguous distribution at the margin of the granulosa cell layer surrounding stage III zebrafish oocytes. Cryoscanning results showed a polygonal structure of the vitelline envelope, which is reported here for the first time with the mitochondrial distributional arrangement in the granulosa cell layer. Mitochondrial distribution and the evaluation of mitochondrial activity proved to be sensitive markers for ovarian follicle quality, providing more detailed information on cryoprotectant impact. The measurement of ATP levels, ADP/ATP ratio and mtDNA copy number were also undertaken following cryoprotectant exposure. These findings, together with the observation of mitochondrial distribution, suggested that even cryoprotectant treatments that are considered to have little or no toxicity can have a deleterious effect on mitochondrial activity, potentially compromising oocyte growth and embryo development. Therefore, a further optimization of the currently used protocol may need to be considered. The study of organelle distribution and organisation would support in vitro maturation and oocyte development fields, as well as their use as biological markers for quality determination. These findings will contribute to a better understanding of oogenesis/folliculogenesis processes in fish.
    • The development of test action bank for active robot learning

      Cao, Tao (University of Bedfordshire, 2009-11)
      In the rapidly expanding service robotics research area, interactions between robots and humans become increasingly cornmon as more and more jobs will require cooperation between the robots and their human users. It is important to address cooperation between a robot and its user. ARL is a promising approach which facilitates a robot to develop high-order beliefs by actively performing test actions in order to obtain its user's intention from his responses to the actions. Test actions are crucial to ARL. This study carried out primary research on developing a Test Action Bank (TAB) to provide test actions for ARL. In this study, a verb-based task classifier was developed to extract tasks from user's commands. Taught tasks and their corresponding test actions were proposed and stored in database to establish the TAB. A backward test actions retrieval method was used to locate a task in a task tree and retrieve its test actions from TAB. A simulation environment was set up with a service robot model and a user model to test TAB and demonstrate some test actions. Simulations were also perfonned in this study, the simulation results proved TAB can successfully provide test actions according to different tasks and the proposed service robot model can demonstrate test actions.
    • Differing isometric contractions can affect neural excitability

      Wyld, Kevin (University of Bedfordshire, 2011-05)
      Postactivation potentiation (PAP) of human skeletal muscle has been credited for improved performance in complex training situation, were a conditioning exercise is performed prior to a performance task. The mechanisms behind PAP have not been fully elucidated; it has been proposed that an increase in phosphorylation of the myosin regulatory light chains and/or increased spinal excitability could explain performance changes. However, which mechanism induces PAP has not been investigated as yet, while the optimum intensity of the conditioning exercise or the best rest period to induce optimal PAP levels has not been established. The purpose of the current investigation was to examine a range of different intensity conditioning contractions over a 60 minutes recovery period, on PAP response. Method: to gain reliability of the patellar tendon tap test a rubber tipped hammer was embedded into a machine. Twelve participants (8 males age 23.7 ± 4.9 yr, mass 78.3 ± 12.9 kg, height 1.75 ± 0.1 m and 4 females age 22 ± 3.2 yr, mass 60.6 ± 4.1 kg, height 1.66 ± 0.1 m) had three differing hammer tap forces (270 ± 0.79 N, CV 0.2 %, middle 252 ± 0.74 N, CV 0.2 % and lowest 121 ± 0.64 N, CV 0.5 %) delivered in a randomised order over 3 x 10 minute periods with sporadic intervals between each tap. The hammer tap force that reported the highest reliability was then used in a follow up study. The second study investigated skeletal muscles response to differing intensities of conditioning exercise, over a 60 minute rest period. The conditioning exercises consisted of 3 sets of isometric leg extensions of the dominant leg at 100%, 90%, 80% and 70% of a 1 RM, each set consisted of a 5 s contraction followed by 55 s passive rest. Subsequent neural excitability and intra-muscular activation were assessed in response to the patellar tendon tap test. Neural excitability was assessed via integrated EMG responses and goniometer movement of the lower leg. Results: The highest force (270 ± 0.79 N) gave the best reliability for hammer tap contact to the start of lower limb movement (17.3 %) compared to the other two hammer forces, this was used in the second study. In the second study no significant differences were observed between the hammer tapping the tendon and the start of muscle activation (F = 1.843, p>0.05) or muscle activation to the start of lower limb movement (F=1.587, p>0.05) between any of the conditioning contraction intensities or between any recovery periods. After 2 minutes recovery there was a trend for the maximal intensity conditioning exercise to reduce neural excitability. After 4 minutes rest all intensities of conditioning exercise caused a trend for an increase in neural excitability and intra-muscle activation. Conclusion: The poor reliability of the patellar tendon tap test maybe due to individual variations in tendon biology. Although this study improved the reliability compared to previous work, the technique was still too varied to ascertain conclusive results, beyond trends in data. Therefore, reliability of this technique needs to be addressed further to allow it to be recognised as a method to measure spinal excitability. At this moment in time no definitive rest period guidelines can be given to coaches for complex training or even if it enhances performances over traditional training methods. It is therefore recommended that coaches should view this training modality with caution, and not rely solely on this method, when more established valid methods to improve athletes’ explosive power performance, are readily available.
    • Digital creativity - an investigation into architectural design in the electronic age

      Dobson, Adrian; University of Bedfodshire (University of Bedfordshire, 2005-10)
      This study explores approaches to architectural creativity and collaborative design in the contemporary digital design context. The thesis identifies key trends and developments in the historical and present-day evolution of the creative use of computers by architects in education and practice. It examines the current manifestations of digitally supported architectural design, and investigates the ways in which computers and electronic communication technologies are being utilised in the design process. In the context of, and informed by, this investigative survey the author evolves three key models or analogues for the application of computer based techniques in the creative design process. Each design analogue has been tested with the collaboration of undergraduate architecture students and their academic teaching staff through experimental pedagogic design projects, which have been used to evaluate their validity and effectiveness. The working principles developed through these projects have also been applied in a realworld context, through a live professional case study architectural project undertaken by the author in commercial architectural practice. The concluding section examines the current state of play in the relationship between theoretical ideas and the practice of architectural design using digital techniques, to assess the methodological validity of the design analogues in the educational and practice spheres, and to make recommendations for future areas of research.
    • Do different voice qualities have the ability to evoke an emotional response within the listener?

      Penny, Michaela (University of Bedfordshire, 2015-07)
      The purpose of this research is to establish whether different voice qualities evoke an emotional response within the listener. To assist the research, a study was conducted under controlled conditions using eight participants. They were asked to take part in a modified version of Donald Winnicott’s squiggle game. This involved allowing the hand to draw freely whilst listening to an original composition for solo voice. The voice qualities demonstrated in the composition were those defined by researcher, voice scientist and teacher, Jo Estill. Participants were informed that a squiggle in an upward direction would indicate an increase in intensity of emotional response. The results revealed that the voice qualities featured in the composition evoked some form of emotional response within the listener. However, an inability to control all variables meant that it was not possible to decipher whether these responses were elicited as a result of voice quality alone.
    • Effect of aerobic exercise in different environmental temperatures on gut hormones, appetite and energy intake

      Horner, Matthew (University of Bedfordshire, 2018-01)
      Introduction: A strategy that combines both increasing energy expenditure and reducing energy intake (EI) to induce a negative energy balance is key for preventing and managing obesity. Exercise has been shown to reduce EI in a subsequent meal, an increase in temperature has also been shown to decrease appetite stimulation. Exercise in a hot environment may augment the appetite suppressing effect of exercise. However, there is currently little evidence available regarding the effect of environmental temperature during exercise on appetite. This study focused on the effect of exercise in different environmental temperatures on gut hormones and EI. Methods: A total of 8 healthy males completed four 5.5 hour conditions in a counterbalanced order. A preliminary visit consisting of a submaximal and maximal exercise test was conducted prior to experimental visits. For experimental visits, participants arrived in a fasted, euhydrated state at 08:30 and were fitted with a cannula, heart rate monitor, rectal and skin thermistors before completing one of four conditions: exercise in 10°C, 20°C or 30°C or resting control. Participants ran for 60 minutes on a treadmill at 70% of maximal oxygen uptake or rested for 60 minutes before resting for 4.5 hours. Blood samples were taken at 0 (fasted), 1, 1.5, 2, 3, 4 and 5 hr. Perceptions of hunger were assessed using visual analogue scales at 0, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 and 5 h. Ad libitum meals were provided at 1.5 hr and 5 hr. Results: Although there was a significant reduction in relative energy intake in all exercise conditions (p < 0.001), this was not augmented or attenuated by any change in environmental temperature. This decrease was also not supported by any decrease in acylated ghrelin or increase in PYY. Furthermore, the only significant decrease in overall appetite was stimulated by the intake of food in meal 1 (p < 0.001). There was also no significant difference in total energy intake, lending to the notion that the decrease in relative energy intake can be partially, if not completely attributed to the increase in energy expenditure from exercise. Conclusion: These results suggest that exercise produces an energy deficit through a reduction in relative energy intake, regardless of environmental temperature. Further research into the effects of exercise in different environmental temperatures in an overweight and obese population is warranted.
    • Effect of environmental temperature on appetite, energy intake and appetite-regulating hormones during rest

      Horsfall, Rachel; University of Bedfordshire (University of Bedfordshire, 2017-04)
      There is evidence to suggest that the exercise-induced suppression in appetite is more pronounced when exercise is performed in the heat compared with colder environments. Whether such effects of environmental temperature are seen at rest remains unknown. The aim of this study was to examine the effect of environmental temperature on energy intake (EI), appetite and appetite-regulating hormones during rest. Nine men (aged 21.4 ±1.3 years) rested for 5.5-hours in three conditions i) a thermoneutral environment (20˚C), ii) a hot environment (30˚C) and iii) a cold environment (10˚C). After baseline measures, each participant was supplied with a standardised breakfast meal containing 6 kcal·kg body mass-1. Further blood samples were collected at 0.5, 1, 1.5, 2, 3, 4, 5 and 5.5 h during the postprandial period, with an ad libitum pasta meal provided at 4-4.5 h to measure EI. Perceptions of appetite were assessed using 100-mm visual analogue scales every 30 min. Blood samples were analysed for gut hormone concentrations. Significant effects of condition for ad libitum EI (P = 0.002) were found; EI was higher in 10˚C and 20˚C compared with 30˚C. The findings of the present study support the limited evidence that environmental temperatures may modulate EI.