The dose response for sprint interval training interventions may affect the time course of aerobic training adaptations

Low vs. high volume sprint-interval training (SIT) sessions have shown similar physiological benefits after 8 weeks. However, the dose response and residual effects of shorter SIT bouts (<10 s) are unknown. Following a 6-wk control period, 13 healthy inactive males were assigned to a low dose (LDG: n = 7) or high dose (HDG: n = 6) supervised 6-wk intervention: ×2/wk of SIT (LDG = 2 sets of 5 × 6 s ON: 18 s OFF bouts; HDG = 4–6 sets); ×1/wk resistance training (3 exercises at 3 × 10 reps). Outcome measures were tested pre and post control (baseline (BL) 1 and 2), 72 h post (0POST), and 3-wk post (3POST) intervention. At 0POST, peak oxygen uptake (VO2peak) increased in the LDG (+16%) and HDG (+11%) vs. BL 2, with no differences between groups (p = 0.381). At 3POST, VO2peak was different between LDG (−11%) and HDG (+3%) vs. 0POST. Positive responses for the intervention’s perceived enjoyment (PE) and rate of perceived exertion (RPE) were found for both groups. Blood pressure, blood lipids, or body composition were not different between groups at any time point. Conclusion: LDG and HDG significantly improved VO2peak at 0POST. However, findings at 3POST suggest compromised VO2peak at 0POST in the HDG due to the delayed time course of adaptations. These findings should be considered when implementing high-dose SIT protocols for non-athletic population

The Influence of Body Mass Index on Sweet Taste Preference in Women

Associations between sweet taste preferences and eating behaviour variables may exist with differences in taste preferences evident with varying body mass index (BMI). However, the strength of influence BMI exerts remains unknown, therefore the aim was to examine the influence of BMI on sweet taste preference in women. Three areas were examined, 1) associations between preferences for sweet taste and sweet/fat combinations and eating behaviours, 2) the differences in sweet taste preferences between overweight and lean women, and 3) whether BMI serves as a moderator for the associations between sweet taste preferences and eating behaviour variables. 86 overweight or lean women provided 7day 24hour recall food diaries before attending a laboratory assessment day. Participants completed the Leeds Food Preference Questionnaire (LFPQ) before consuming an ad libitum meal consisting of sweet and savoury foods. Immediately following consumption participants completed VAS ratings of palatability and taste intensity in response to the test meal foods. Sweet taste preferences were associated with an elevated sweet food intake in an ad libitum meal and preferences for sweet/fat combinations with habitual dietary fat intake. There were no between group differences on any measure. However, there were differences between groups in a small number of associations between taste preferences and eating behaviour variables which were moderated by BMI. The present thesis concluded that overweight and lean women did not differ in their sweet taste preferences or eating behaviours. Although, differences in the associations between taste preference and eating behaviours do exist between overweight and lean women. Future work may wish to consider using direct measures of adiposity within the moderation model. These findings build on previous literature through examination of different components of sweet taste preference and investigates the extent to which BMI moderates differences in the associations with food intake

A Novel Heat Recovery Device for Passive Ventilation Systems

The purpose of this study was to assess the performance of a novel heat recovery device for integration with a passive ventilation system. Current heat recovery devices are not suitable for integration with passive ventilation systems due to the high pressure drop experienced by airstreams across the devices. This would result in low ventilation supply rates required for good indoor air quality. The device could be also reconfigured to dehumidify an incoming airstream, lowering the relative humidity of the air. These modifications would improve the air quality and reduce energy demand on mechanical ventilation systems. The novel heat recovery device was designed and constructed using 3D printing techniques and tested experimentally using different inlet conditions for two counter-current airstreams. Numerical analysis using Computational Fluid Dynamics (CFD) calculated solutions for air velocity, gauge air pressure, air temperature and relative humidity before and after the heat recovery device using the same geometry as the printed prototype. The experimental testing of prototypes of the heat recovery device validated these characteristics. The results from the experiments and CFD analysis showed that the novel design of the heat recovery device achieved the three primary objectives of the project. The pressure drop measured across the heat recovery device was between 10.02-10.31Pa, significantly lower 150Pa experienced in standard devices. The resultant air velocity suggested that an air supply rate of 140.86 litres per second was possible, high enough to provide ventilation to a room with 17 occupants. The device was capable of increasing the temperature of the incoming airstream by up to 0.68°C when the temperature of the outgoing airstream was 40°C. Finally, the relative humidity of an incoming airstream with 100% relative humidity was reduced by up to 67.01%, at regeneration temperatures between 25-40°C, significantly lower than current temperatures of 120°C

A novel design of a desiccant rotary wheel for passive ventilation applications

Rotary desiccant wheels are used to regulate the relative humidity of airstreams. These are commonly integrated into Heating, Ventilation and Air-Conditioning units to reduce the relative humidity of incoming ventilation air. To maximise the surface area, desiccant materials are arranged in a honeycomb matrix structure which results in a high pressure drop across the device requiring fans and blowers to provide adequate ventilation. This restricts the use of rotary desiccant wheels to mechanical ventilation systems. Passive ventilation systems are able to deliver adequate ventilation air but cannot control the humidity of the incoming air. To overcome this, the traditional honeycomb matrix structure of rotary desiccant wheels was redesigned to maintain a pressure drop value below 2 Pa, which is required for passive ventilation purposes. In addition to this, the temperature of the regeneration air for desorption was lowered. Radial blades extending out from the centre of a wheel to the circumference were coated in silica gel particles to form a rotary desiccant wheel. Computational Fluid Dynamics (CFD) modelling of the design was validated using experimental data. Reduction in relative humidity up to 55% was seen from the system whilst maintaining a low pressure drop across the new design. As an outcome of the work presented in this paper, a UK patent GB1506768.9 has been accepted

A study of passive ventilation integrated with heat recovery

To meet the demand for energy demand reduction in heating, ventilation and air-conditioning systems, a novel design incorporating a heat recovery device into a wind tower was proposed. The integrated system uses a rotary thermal wheel for heat recovery at the base of the wind tower. A 1:10 scale prototype of the system was created and tested experimentally in a closed-loop subsonic wind tunnel to validate the Computational Fluid Dynamics (CFD) investigation. Wind towers have been shown to be capable of providing adequate ventilation in line with British Standards and the Chartered Institution of Building Services Engineers (CIBSE) guidelines. Despite the blockage of the rotary thermal wheel, ventilation rates were above recommendations. In a classroom with an occupancy density of 1.8 m2/person, the wind tower with rotary thermal wheel was experimentally shown to provide 9 L/s per person at an inlet air velocity of 3 m/s, 1 L/s per person higher than recommended ventilation rates. This is possible with a pressure drop across the heat exchanger of 4.33 Pa. In addition to sufficient ventilation, the heat in the exhaust airstreams was captured and transferred to the incoming airstream, raising the temperature 2 °C, this passive recovery has the potential to reduce demand on space heating systems

Sweet Food Preferences and Associated Appetite Regulatory Mechanisms

Obesity rates have increased globally alongside intake of palatable, energy-dense foods. Sweet preferring individuals display increased energy intake, experiencing greater risk of developing obesity. Sweet preferences require study to illuminate potential barriers to successful weight loss and responses to sweet foods reformulated with high intensity sweeteners (HIS). The following thesis presents exploratory analyses of two randomised clinical trials investigating; i) the stability of sweet preferences, ii) the relationship between baseline sweet preferences and eating behaviour traits, iii) comparison of two differing dietary weight loss protocols on sweet related outcomes, iv) the impact of acute and repeated consumption of HIS and sucrose sweetened products on subsequent sweet preferences and eating behaviours and finally, v) an exploration of the potential effect of sweet liker phenotypes on the impact of acute and repeated consumption of HIS and sucrose sweetened products on subsequent preferences and eating behaviours. Results showed; i) sweet food preferences were demonstrated to be stable across a period of weight loss, ii) participants with overweight/obesity presented with greater scores on eating behaviour traits involving a loss of control around food, iii) the method of dietary weight loss did not impact outcomes, iv) there was no difference in sucrose and HIS products on subsequent sweet food preferences and v) the reduction in sweet wanting after consuming a sweet food differs between sweet phenotype groups. It is concluded that sweet preferences are a stable trait that does not change during weight loss, and reformulated sweet foods may facilitate a reduction in sugar and energy density whilst maintaining consumer palatability

A review of heat recovery technology for passive ventilation applications

A review of current heat recovery devices was undertaken in an attempt to determine the major factors preventing the integration of heat recovery technology into passive ventilation systems. The increase in space heating and cooling demand in recent years combined with statutory requirements to reduce greenhouse gas emissions in the UK requires technology to be as efficient as possible, consuming the lowest amount of energy necessary. Heat recovery technology can meet this demand by lowering the energy demand necessary for heating and cooling by pre-heating or pre-cooling. Six different heat recovery devices were analysed and compared for suitability for integration into passive ventilation systems. Heat pipes and rotary thermal wheels are suggested as the technologies with the most potential for integration due to high thermal efficiency and low pressure loss across the heat recovery device in comparison to the other technologies. High efficiency is necessary to recover the maximum amount of thermal energy available. Low pressure loss across the heat exchanger is required to maintain adequate ventilation rates. The integration of heat recovery technology into passive ventilation has the potential to reduce energy demand in buildings but further research is required to optimise the recovery devices for simple installation, high efficiency and low pressure loss

Electron Transfer Dissociation with Supplemental Activation to Differentiate Aspartic and Isoaspartic Residues in Doubly Charged Peptide Cations

Electron-transfer dissociation (ETD) with supplemental activation of the doubly charged deamidated tryptic digested peptide ions allows differentiation of isoaspartic acid and aspartic acid residues using the c + 57 or z• − 57 peaks. The diagnostic peak clearly localizes and characterizes the isoaspartic acid residue. Supplemental activation in ETD of the doubly charged peptide ions involves resonant excitation of the charge reduced precursor radical cations and leads to further dissociation, including extra backbone cleavages and secondary fragmentation. Supplemental activation is essential to obtain a high quality ETD spectrum (especially for doubly charged peptide ions) with sequence information. Unfortunately, the low-resolution of the ion trap mass spectrometer makes detection of the diagnostic peak, [M-60], for the aspartic acid residue difficult due to interference with side-chain loss from arginine and glutamic acid residues

CFD simulation and optimisation of a low energy ventilation and cooling system

Mechanical Heating Ventilation and Air-Conditioning (HVAC) systems account for 60% of the total energy consumption of buildings. As a sector, buildings contributes about 40% of the total global energy demand. By using passive technology coupled with natural ventilation from wind towers, significant amounts of energy can be saved, reducing the emissions of greenhouse gases. In this study, the development of Computational Fluid Dynamics (CFD) analysis in aiding the development of wind towers was explored. Initial concepts of simple wind tower mechanics to detailed design of wind towers which integrate modifications specifically to improve the efficiency of wind towers were detailed. From this, using CFD analysis, heat transfer devices were integrated into a wind tower to provide cooling for incoming air, thus negating the reliance on mechanical HVAC systems. A commercial CFD code Fluent was used in this study to simulate the airflow inside the wind tower model with the heat transfer devices. Scaled wind tunnel testing was used to validate the computational model. The airflow supply velocity was measured and compared with the numerical results and good correlation was observed. Additionally, the spacing between the heat transfer devices was varied to optimise the performance. The technology presented here is subject to a patent application (PCT/GB2014/052263)