Includes bibliographical references / Background: Previous research has identified health care workers (HCWs) and shift workers as having an increased risk for non-communicable diseases (NCDs). Nurses in particular have a high prevalence of obesity, poor eating habits and insufficient physical activity and are at an increased risk for NCDs. Nurses are required to work non-traditional hours, outside the parameters of traditional day shift. Furthermore, shift work is associated with obesity and lower levels of physical activity. Even though nurses' occupations require them to be active in doing ward rounds and other duties, it is possible for these professionals to be physically active, yet highly sedentary. Sedentary behaviours such as occupational sitting, leisure-time sitting and television (TV) viewing may be associated with overweight and obesity independent of physical activity. Aim: The primary aim of this mini-dissertation was to determine the health concerns, health priorities and barriers to living a healthy lifestyle among nurses and hospital management staff from public hospitals in the Western Cape Metropole, South Africa. The mini-dissertation included two different research methods. Study 1: The main purpose of this qualitative descriptive study was to describe health concerns, health priorities and determinants of healthy lifestyle behaviours among nurses. The objectively measured and self-reported physical activity and sedentary behaviour in day and night shift nurses were compared in Study 2. Combined, the results of these studies may be used to inform the development of worksite-related interventions for South African nurses. Methods: Participants for the first study were purposively sampled from public hospitals based in Cape Town, South Africa. The participants included 103 nurses, of whom 57 worked night shift and 36 worked day-shift. Twelve focus group discussion (FGD's) were conducted with nursing staff to obtain insight into their health concerns, lifestyle behaviours and the nature of and access to worksite health promotion programmes (Whip's). Nine hospital management personnel participated in key informant interviews (KII) to gain their perspective on health promotion in the worksite. The FGDs and interviews were conducted by a trained facilitator using guided questions. These included questions such as: 'What are your main personal health concerns?' and 'How does your work affect your lifestyle behaviours and health?' Thematic analysis was used 12 to analyse the qualitative data with the assistance of (Atlas.ti Qualitative Data Analysis Software (Scientific Software Development GmbH, Berlin, Germany). In a sub-study, 64 nurses (day shift n=30 and night shift n=34) working at two of the five public hospitals volunteered to complete a socio-demographic questionnaire and wear the ActiGraph GT3x accelerometer for 7 consecutive days to measure physical activity levels. Valid data was defined as ≥ 600 minutes wear time per day, minimum of 4 days (2 shift days and 2 non-shift days). In addition, self-reported physical activity was assessed using the Global Physical Activity Questionnaire (GPAQ). Statistical analyses included a T-test to determine differences in PA and SB between day and night shift nurses. If data were normally distributed, ANOVA (analyses of variance) was performed to determine the significant differences in continuous outcome variables between day and night shift nurses. If data were not normally distributed, such as the GPAQ data, a non-parametric comparison Mann Whitney U test was applied. Results: Study 1: Night shift nurses frequently identified weight gain and living with NCDs such as hypertension as their main health concerns. The hospital environment was perceived to have a negative influence on the nurses' lifestyle behaviours, including food service that offered predominantly unhealthy foods. The most commonly delivered WHPPs included independent counselling and advisory services, an online employee wellness programme. The Western Cape Department of Health also offered wellness days in which clinical outcomes, such as blood glucose were measured. Most nurses identified a preference for WHPPs that provided access to fitness facilities or support groups. Both nurses and management personnel frequently mentioned lack of time to prepare healthy meals and/or participate in physical activity due to being overtired from the long working hours. Furthermore, both management and nurses reported a stressful working environment. The fact that the nurses were most concerned with the problems of overweight, obesity and living with NCDs such as diabetes and hypertension indicate that there is a need and desire for WHPP's aimed at addressing these concerns. Study 2: Based on the objectively-measured results from accelerometry, all the nurses in the sub-study met the physical activity recommendations of 150 minutes or more of moderate to vigorous intensity physical activity per w eek. The day shift nurses reported more leisure-time moderate and vigorous intensity physical activity than the night shift nurses (p=0.028). Objectively-measured physical activity also showed that night shift nurses accumulated significantly more moderate intensity physical activity than the day shift nurses ( 16.6 ± 5.6 hrs/week versus 12.1 ± 13 4.5 hrs/week, respectively, p=0.001). In addition, night shift nurses accumulated more steps per day than day shift nurses (10324 ± 3414 versus 8022 ± 3245, p=0.013). Self-reported sedentary behaviour was similar for the two shifts, 3.0 ± 1.8 hours versus 4.0 ± 2.6 hours a day, for day and night shift, respectively. Objectively-measured sedentary behaviour (SB) was significantly lower (as a % of wake time) in night shift compared to day shift workers, 66% and 69%, respectively, p= 0.047. These differences between groups remained significant, even after adjusting for differences in body size and age. Furthermore, results from the Bland – Altman plots indicate that the nurses significantly underreported their sedentary time. Summary: The nurses in this study were concerned about NCDs and being overweight. They expressed an interest and willingness to participate in future hospital-based intervention programmes. The most frequently identified preference for WHPPs was access to fitness facilities or support groups. Despite the fact that all the nurses met the current public health recommendations for physical activity, objectively-measured SB was substantial, with both day and night shift nurses spending an average of 13 hours a day in SB. Findings from this study highlight the need for WHPPs that minimize sedentary behaviour and create a more supportive environment for physical activity.

Includes bibliographical references. / Introduction: Rugby Union is a sport where physical size matters and the bigger, stronger and better conditioned players have an advantage over smaller and less powerful opponents. Research of adolescent rugby players in South Africa showed that Coloured and Black players weighed 8 kg less than their White counterparts. A possible explanation for the difference in size was the lack of weight training facilities in the disadvantaged areas. Therefore to address the potential handicap for these players having to compete against bigger players, the South African Rugby Union and the High Performance Centre at the Sport Science Institute of South Africa developed a mobile schools training system (MSTS). These are fully equipped units with sufficient weight training equipment for an entire team. The aim of this study was to determine whether the fitness characteristics associated with rugby, changed in players after the MSTS was given to a school for several months. Training of players was not controlled or supervised by any personal outside the infrastructure of the school. A secondary aim was to interview the staff member at each school responsible for the MSTS to enquire about their perceptions of the MSTS and whether there were any barriers to the uptake by the schools and players. Methods: Schools with a “rugby ethos” and from a previously disadvantaged background were selected by SARU for the MSTS Programme. Players (U16 and U18 age groups) at these schools participated in the study. A total of 382 players were tested both before they had exposure to the MSTS and approximately 16 weeks later. They were divided into two age groups; U18 (n = 224 forwards and backs) and U16 (n = 158 forwards and backs). The following characteristics were measured; stature, body mass, body % body fat, muscular strength (bilateral grip strength and bench press), muscular endurance (1min push-ups), sprint times (10 m and 40 m) and aerobic capacity (multi-stage shuttle run test). All Tests were conducted during February and October of 2013. A rating of the extent to the players used the MSTS was also calculated and this was used to categorise schools. Data are represented as means ± standard deviation. A repeated measures of analysis of variance (repeated measures of ANOVA) was used to determine whether there were significant differences between the ‘pre and post’ round of testing using either ‘age’, ‘provinces’ and whether the ‘gym was used or not’ as main effects. The interaction between ‘age x time’ and ‘province x time’ and ‘gym usage x time’ was calculated. If any interactions were significant, a Tukey post hoc test was used to identify specific differences. Statistical significance was accepted when p < 0.05. Coaches at the schools participated interviews to determine the barriers to implementation of the programme, and which areas need to be improved. Results: Changes over time was only shown for body mass (p < 0.037) and bench press (p < 0.001) in schools where the gym was used compared to schools who did not use the gym. When comparing U16 vs. U18 age groups, the U18 players were significantly taller, and heavier, had less % body fat, and a better performance for grip strength, bench press, push-ups, 10 m and 40 m sprint time and Multi-stage shuttle test (MSST) compared to the U16 players (p < 0.04 ). There was also a significant interaction (age x time) for stature (p < 0.002), body mass (p < 0.011), % body fat (p < 0.002). When comparing the 5 provinces of the U16 age group, pre-post differences where noted for stature, body mass bench press and the multi stage shuttle test (MSST) between provinces p < 0.00 01. Interactions (province x time) for changes over time between the 5 provinces was shown for stature, body mass, % body fat, bench press, push-up’s, 10 m sprint time and MSST. There were significant pre-post differences between provinces (U18) for stature, body mass, skinfolds, % body fat, bench press and the multi stage shuttle test (MSST) for all p < 0.0001 except skinfolds showed p < 0.041. Interactions (province x time) change over time between the 5 provinces was shown for stature, body mass, % body fat, bench press and push-up’s. An interaction for the age groups was determined for a variable if a level of significance was p < 0.05. The interviews with the coaches raised various issues which comprised the usage of the MSST with the most important being lack of resources at the school , inadequate knowledge of strength and conditioning training, lack of facilities to store the mobile gym and poor nutrition of the players. Conclusion: There is overwhelming evidence in the literature about the benefits of resistance training for youth, from the perspective of improving performance to reducing the risk of injury. The results from the MSTS programme were not as overwhelming as one would believe from the literature. This can be attributed to various reasons; inadequate facilities to house the MSTS, inadequate coaches ’ knowledge and experience in strength and conditioning, and poor nutrition. With increased provision of equipment at schools without adequate support of trained strength and conditioning specialists at each school the programme will be ineffective. To ensure future success of the programme it is recommended that; (i) a needs analysis is done at each school to determine which school has the correct facilities to house the mobile gym so that regular training sessions can take place, (ii) SARU employs qualified trainers at the schools involved in the MSTS programme to supervise all strength and conditioning sessions, (iii) there are regular follow up visits at schools to check on compliance, (iv) objective and subjective assessments are conducted at regular intervals to determine if there are improvements in the targeted variable.

Studies have documented that the use of a lumbar support while in the sitting position results in reduced back and leg pain, centralisation of pain and reduced erector spinae muscle activity in patients with lower back pain (LBP). While the positive effects of a lumbar support in sitting have been studied, few researchers have attempted to document the value of such a support in the supine position. Since many patients with LBP suffer from insomnia and nocturnal discomfort, it may be possible that the use of a foam surface overlay could positively influence their symptoms. Several foam surface overlays are currently used as a popular form of management for patients presenting with LBP. These include the convoluted foam surface ("egg box'' shape), which to my knowledge has not been scientifically studied and the lumbar body support, the value of which has only recently been reported. That study found that patients with chronic LBP have decreased electromyographic (EMG) activity of the erector spinae muscles, lower heart rates (HR) and decreased perception of discomfort (ROD) when lying on this locally designed, triple density, contoured, lumbar body support system (LBS) compared with a conventional flat innerspring mattress (CM). Accordingly the aim of this thesis was to measure the EMG activity, heart rate response, perception of comfort and pattern of pressure distribution after lying on a variety of different surfaces, thus endeavouring to determine a mechanism of action of the LBS. In the first study of this thesis, ten patients with LBP were exposed to a random order, 30 minute period on three sleep surfaces: Lumbar body support on top of a conventional mattress (LBS+ CM), 60 mm convoluted foam surface on top of a conventional mattress (CFS + CM), and a conventional mattress (CM) alone. Each patient acted as his/her own control. Recordings of EMG activity, HR and ROD were measured for each patient. Average HR over the 30 minute period was lower after acute exposure to the LBS+ CM (60 ± 11 b/min) compared to the CM (66 ± 10 b/min, p < 0.05; LBS+ CM vs. CM). Although average HR response to the LBS+ CM was lower compared to CFS + CM (64 ± 9 b/min), this difference was not significant. ROD reported after acute exposure to the LBS+ CM was improved (1.9 ± 0.7 units), compared to the CFS+ CM (3.9 ± 1.0 units) and CM (4.7 ± 2.2 units; p < 0.05). Average EMG activity was lower after 30 minutes on the LBS + CM (2.68 ± 1.1 mv) compared to the CFS+ CM (4.46 ± 2.7 mv) and CM (4.19 ± 2.4 mv; p < 0.05). These results suggest that patients with LBP have reduced EMG activity and HR measurements with lower ROD when lying on a LBS + CM compared with a CM and CFS + CM. The second series of experiments involved a further ten patients with lower back pain, who were required to lie supine in random order on the LBS + CM, on a polystyrene mould (PM) (identical to the shape of the LBS) and on a CM. Recordings of EMG activity, HR and ROD were measured for each patient. Average HR over the 30 minute period was lower on the LBS + CM (60 ± 7 b/min) vs. PM + CM (66 ± 10 b/min) and CM (68 ± 9 b/min; p < 0.01 ). Average ROD was improved when patients lay on the LBS+ CM (1.8 ± 0.6 units) vs. PM + CM (5. 7 ± 2.5 units) and CM (4.1 ± 1.8 units; p < 0.05). Furthermore, average EMG activity was significantly reduced after lying on the LBS + CM (2.5 ± 1.0 mv) vs. PM + CM (4.3 ± 1.9 mv) and CM (4.6 ± 1.8 mv; p < 0.01 ). The findings of this study mirror our initial findings. The elevated EMG activity, heart rate and perception of discomfort after lying on a PM suggests that it could be a combination of both the correct density and the correct contour features that is important in reducing muscle spasm in patients with acute-upon-chronic lower back pain. Average HR over the 30 minute period was lower after acute exposure to the LBS+ CM (60 ± 11 b/min) compared to the CM (66 ± 10 b/min, p < 0.05; LBS+ CM vs. CM). Although average HR response to the LBS+ CM was lower compared to CFS + CM (64 ± 9 b/min), this difference was not significant. ROD reported after acute exposure to the LBS+ CM was improved (1.9 ± 0.7 units), compared to the CFS+ CM (3.9 ± 1.0 units) and CM (4.7 ± 2.2 units; p < 0.05). Average EMG activity was lower after 30 minutes on the LBS + CM (2.68 ± 1.1 mv) compared to the CFS+ CM (4.46 ± 2.7 mv) and CM (4.19 ± 2.4 mv; p < 0.05). These results suggest that patients with LBP have reduced EMG activity and HR measurements with lower ROD when lying on a LBS + CM compared with a CM and CFS + CM. The second series of experiments involved a further ten patients with lower back pain, who were required to lie supine in random order on the LBS + CM, on a polystyrene mould (PM) (identical to the shape of the LBS) and on a CM. Recordings of EMG activity, HR and ROD were measured for each patient. Average HR over the 30 minute period was lower on the LBS + CM (60 ± 7 b/min) vs. PM + CM (66 ± 10 b/min) and CM (68 ± 9 b/min; p < 0.01 ). Average ROD was improved when patients lay on the LBS+ CM (1.8 ± 0.6 units) vs. PM + CM (5. 7 ± 2.5 units) and CM (4.1 ± 1.8 units; p < 0.05). Furthermore, average EMG activity was significantly reduced after lying on the LBS + CM (2.5 ± 1.0 mv) vs. PM + CM (4.3 ± 1.9 mv) and CM (4.6 ± 1.8 mv; p < 0.01 ). The findings of this study mirror our initial findings. The elevated EMG activity, heart rate and perception of discomfort after lying on a PM suggests that it could be a combination of both the correct density and the correct contour features that is important in reducing muscle spasm in patients with acute-upon-chronic lower back pain. body support is altered and pressures are more equally distributed when compared to the pressure distribution of the other surfaces measured, without increases in pressure at any point on the body. Similar average and peak pressure results were obtained for the 90 mm CFS + CM and LBS. Since these results were not mirrored by the 60 mm CFS, the thickness of a foam surface possibly plays a role in reducing pressure. The data of these three separate studies could have implications in the adjunctive treatment of i)low back pain and ii) pressure sores. Firstly, the results of this thesis suggest that the use of a 60 mm foam overlay may not be the optimum form of management for patients presenting with paraspinal muscular spasm. Further, it is postulated, that the density and contour features of the lumbar body support are likely to play a role in reducing EMG activity and heart rate, while improving perception of comfort compared to the flat surfaces (CM and 60 mm CFS), which offer little support to the lumbar region of these patients. X Secondly, either the LBS or 90 mm CFS are likely to reduce the incidence of pressure sores in patients required to lie supine for prolonged periods, due to the reduction in peak and average pressures. In view of the contoured surface, it is unlikely that pressure sores could develop in patients lying on the LBS. This hypothesis needs to be confirmed in longer term studies in patients who are severely debilitated or paraplegic, as they are often most at risk for the development of pressure sores.

This study looks at the biomechanical evaluation involving the measurement of breast displacement and allows a better understanding of breast kinematics and the support needed. The primary aim of the study was to determine how effective the Ultimate shock absorber bra (N04663) (HIU bra) is in reducing breast displacement and improving breast comfort during treadmill running and a two-step star jump test compared to a no bra condition, while wearing three different Shock Absorber support level bras, and participants’ own bra. A group of 17 female participants ages 17-39 were included in the study with cup sizes B-C. Breast measurements were recorded, followed by six randomly selected treadmill and two-step star jump conditions. Non-parametric statistics were used. A significant difference of p=0.039 and p=0.002 was found for residual displacement when comparing the HIU bra to the High impact support level bra and the control. The two-step star jump test showed similar results for residual displacement with the HIU bra compared to the Control and five bras (p=0.00) with the Medium impact support level bra p=0.002. This data illustrates that the HIU bra provides the best support while performing the two-step star jump test as well as in the treadmill test. / Dissertation (MA)--University of Pretoria, 2015. / Biokinetics, Sport and Leisure Sciences / Unrestricted

Background: Long distance road running is continually growing as competitive and recreational sport, globally. Despite its popularity, a high burden of incidence of injury exists among runners. Previous research has focussed on specific injuries, whereas others have investigated isolated risk factors that may contribute to running related injuries. The purpose of the study is to determine possible internal and external screening variables that may predict the incidence of running-related injuries in general. Methods: Forty one recreational runners participated in an observational study over the course of 12 weeks. Screening assessments consisted of injury history, training history, and anthropometric measurements. Functional and performance assessments included the Foot Posture Index (FPI), the Functional Movement Screen (FMS), vertical jump, single leg hop and sit-and-reach tests. Participants were monitored over a period of 12 weeks by completing a weekly online logbook regarding their training and possible incidence of injury. Monitoring was terminated after 12 weeks of observation. Differences between injured and non-injured runners were determined using Independent -T-tests for mean differences, or Mann-Whitney U Test for distributional differences (non-parametric data). Binomial Logistic regression models were used to determine the influence of internal, external functional and external behavioural factors on the risk for running injury, respectively. Results: The total group revealed a cumulative incidence of injury of 63% over the 12 weeks of observation. There was no gender difference between incidences of injuries over the 12 week observation training period (OTP). Injured runners achieved a higher total FMS score (median = 16, Interquartile Range = 3) compared to uninjured runners (median = 15, Interquartile range = 3; p = 0.006). Binomial logistic regression models of external functional (FMS, Vertical Jump, Sit-and-Reach scores) factors [X² (3) = 9.764, p = 0.021] were statistically significant. Only the FMS score contributed significantly to the incidence of injury (p = 0.013) of the three external functional factors in the Regression Model. Discussion and Conclusion: The study adds to current evidence that the assessment of the Functional Movement Screen is important in predicting injury, however, the present study shows that a higher score obtained during the FMS increase your odds to sustain an injury. The study is in contrast with the body of evidence that the incidence of previous injury is the strongest predictor of the incidence of a current injury. The study concluded that the Functional Movement Screen is a useful screening tool to determine a long distance runner's risk for running-related injuries and should be included in health-injury risk assessments of recreational runners.

Many industrial activities discharge sulphate- and metal-containing wastewaters, including the manufacture of pulp and paper, mining and mineral processing, and petrochemical industries. Acid mine drainage (AMD) is an example of such sulphate- and metal-containing waste streams. Formation of AMD is generally the result of uncontrolled oxidation of the sulphide minerals present in the terrain in which the drainage flows with concomitant leaching of the metals. Acid mine drainage (AMD) and other sulphate- and metal-containing waste streams are amenable to active biological treatment. Anaerobic reduction of sulphate, reaction of produced sulphide with metal ions present in the waste stream, and biooxidation of excess sulphide are three main sub-processes involved in the active biotreatment of AMD. Anaerobic reduction of sulphate can be achieved in continuous stirred tank bioreactors with freely suspended cells or in immobilized cell bioreactors. The application of freely suspended cells in a continuous system dictates a high residence time to prevent cell wash-out, unless a biomass recycle stream is used. In an immobilized cell system biomass residence time becomes uncoupled from the hydraulic residence time, thus operation of bioreactor at shorter residence times becomes possible. In the present work, kinetics of anaerobic sulphate reduction was studied in continuous immobilized cell packed-bed bioreactors. Effects of carrier matrix, concentration of sulphate in the feed and sulphate volumetric loading rate on the performance of the bioreactor were investigated. The bioreactor performance, in terms of sulphate reduction rate, was dependent on the nature of the carrier matrix, specifically the total surface area which was provided by the matrix for the establishment of biofilm. Among the three tested carrier matrices, sand displayed the superior performance and the maximum volumetric reduction rate of 1.7 g/L-h was achieved at the shortest residence time of 0.5 h. This volumetric reduction rate was 40 and 8 folds faster than the volumetric reduction rates obtained with glass beads (0.04 g/L-h; residence time: 28.6 h) and foam BSP (0.2 g/L-h; residence time: 5.3 h), respectively. Further kinetic studies with sand as a carrier matrix indicated that the extent of volumetric reduction rate was dependent on the feed sulphate concentration and volumetric loading rate. At a constant feed sulphate concentration, increases in volumetric loading rate caused the volumetric reduction rate to pass through a maximum, while increases in feed sulphate concentrations from 1.0 g/L to 5.0 g/L led to lower volumetric reduction rates. The maximum volumetric reduction rates achieved in the bioreactors fed with initial sulphate concentration of 1.0, 2.5 and 5.0 g/L were 1.71, 0.82 and 0.68 g/L-h, respectively. The coupling of lactate utilization to sulphate reduction was observed in all experimental runs and the rates calculated based on the experimental data were in close agreement with calculated theoretical rates, using the stoichiometry of the reactions involved. The maximum volumetric reduction rates achieved in the immobilized cell bioreactors were significantly faster than those reported for freely suspended cells employed in the stirred tank bioreactors.

Many industrial activities discharge sulphate- and metal-containing wastewaters, including the manufacture of pulp and paper, mining and mineral processing, and petrochemical industries. Acid mine drainage (AMD) is an example of such sulphate- and metal-containing waste streams. Formation of AMD is generally the result of uncontrolled oxidation of the sulphide minerals present in the terrain in which the drainage flows with concomitant leaching of the metals. Acid mine drainage (AMD) and other sulphate- and metal-containing waste streams are amenable to active biological treatment. Anaerobic reduction of sulphate, reaction of produced sulphide with metal ions present in the waste stream, and biooxidation of excess sulphide are three main sub-processes involved in the active biotreatment of AMD. Anaerobic reduction of sulphate can be achieved in continuous stirred tank bioreactors with freely suspended cells or in immobilized cell bioreactors. The application of freely suspended cells in a continuous system dictates a high residence time to prevent cell wash-out, unless a biomass recycle stream is used. In an immobilized cell system biomass residence time becomes uncoupled from the hydraulic residence time, thus operation of bioreactor at shorter residence times becomes possible. In the present work, kinetics of anaerobic sulphate reduction was studied in continuous immobilized cell packed-bed bioreactors. Effects of carrier matrix, concentration of sulphate in the feed and sulphate volumetric loading rate on the performance of the bioreactor were investigated. The bioreactor performance, in terms of sulphate reduction rate, was dependent on the nature of the carrier matrix, specifically the total surface area which was provided by the matrix for the establishment of biofilm. Among the three tested carrier matrices, sand displayed the superior performance and the maximum volumetric reduction rate of 1.7 g/L-h was achieved at the shortest residence time of 0.5 h. This volumetric reduction rate was 40 and 8 folds faster than the volumetric reduction rates obtained with glass beads (0.04 g/L-h; residence time: 28.6 h) and foam BSP (0.2 g/L-h; residence time: 5.3 h), respectively. Further kinetic studies with sand as a carrier matrix indicated that the extent of volumetric reduction rate was dependent on the feed sulphate concentration and volumetric loading rate. At a constant feed sulphate concentration, increases in volumetric loading rate caused the volumetric reduction rate to pass through a maximum, while increases in feed sulphate concentrations from 1.0 g/L to 5.0 g/L led to lower volumetric reduction rates. The maximum volumetric reduction rates achieved in the bioreactors fed with initial sulphate concentration of 1.0, 2.5 and 5.0 g/L were 1.71, 0.82 and 0.68 g/L-h, respectively. The coupling of lactate utilization to sulphate reduction was observed in all experimental runs and the rates calculated based on the experimental data were in close agreement with calculated theoretical rates, using the stoichiometry of the reactions involved. The maximum volumetric reduction rates achieved in the immobilized cell bioreactors were significantly faster than those reported for freely suspended cells employed in the stirred tank bioreactors.

In 2006, 0.18 Mio pediatric nuclear medicine diagnostic exams were performed worldwide. However, for most of the radiopharmaceuticals used data on biokinetics and, as a consequence on dosimetry, are missing or have not been made publicly available. Therefore, most of the dosimetry assessments presented today for diagnostic agents in children and adolescents rely on the biokinetics data of adults. Even for one of the most common nuclear medicine exams for this patient group, renal scintigraphy with 99mTc-MAG3 for assessing renal function measured data on biokinetics is available only from a study performed on four children of different ages. In particular, renal scans are among the most frequent exams performed on infants and toddlers. Due to the young age, this patient group can be classified as a risk group with a higher probability of developing stochastic radiation effects compared to adults. As there are only limited data on biokinetics and dosimetry in this patient group, the aim of this study is to reassess the dosimetry and the associated radiation risk for a larger number of infants undergoing 99mTc-MAG3 renal scans based on a retrospective analysis of existing patient data. Data were collected retrospectively from 34 patients younger than 20 months with normal (20 patients) and abnormal renal function (14 patients) undergoing 99mTc-MAG3 scans. The patient-specific organ activity was estimated based on a retrospective calibration which was performed based on a set of two 3D-printed infant kidneys (newborns: 8.6 ml; 1-year-old: 23.4 ml) filled with known activities. Both phantoms were scanned at different positions along the anteroposterior axis inside a water phantom, providing depth- and size-dependent attenuation correction factors for planar imaging. Time-activity curves were determined by drawing kidney, bladder, and whole body regions-of-interest for each patient, and subsequently applying the calibration factor for conversion of counts to activity. Patient-specific time-integrated activity coefficients were obtained by integrating the organ-specific time-activity curves. Absorbed and effective dose coefficients for each patient were assessed with OLINDA/EXM for the provided newborn and 1-year-old phantom. Based on absorbed dose values, the radiation risk estimation was performed individually for each of the 34 patients with the National Cancer Institute’s Radiation Risk Assessment Tool. The patients’ organ-specific mean absorbed dose coefficients for the patients with normal renal function were 0.04±0.03 mGy/MBq for the kidneys and 0.27±0.24 mGy/MBq for the bladder. This resulted in a mean effective dose coefficient of 0.02±0.02 mSv/MBq. Based on the dosimetry results, the evaluation of the excess lifetime risk (ELR) for the development of radiation-induced cancer showed that the group of newborns has an ELR of 16.8 per 100,000 persons, which is higher in comparison with the 1-year-old group with an ELR of 14.7 per 100,000 persons. With regard to the 14 patients with abnormal renal function, the mean values for the organ absorbed dose coefficients for the patients were: 0.40±0.34 mGy/MBq for the kidneys and 0.46±0.37 mGy/MBq for the bladder. The corresponding effective dose coefficients (mSv/MBq) was: 0.05±0.02 mSv/MBq. The mean ELR (per 100,000 persons) for developing cancer from radiation exposure for patients with abnormal renal function was 29.2±18.7 per 100,000 persons. As a result, the radiation-associated stochastic risk increases with the organ doses, taking age- and gender-specific influences into account. Overall, the lifetime radiation risk associated with the 99mTc-MAG3 scans is very low in comparison to the general population risk for developing cancer. Furthermore, due to the increasing demand for PET-scans in children and adolescents with 68Ga-labelled peptides, in this work published data sets for those compounds were analyzed to derive recommendations for the administered activities in children and adolescents. The recommendation for the activities to be administered were based on the weight-independent effective dose model, proposed by the EANM Pediatric Dosage Card for application in pediatric nuclear medicine. The aim was to derive recommendations on administered activities for obtaining age-independent effective doses. Consequently, the corresponding weight-dependent effective dose coefficients were rescaled according to the formalism of the EANM dosage card, to determine the radiopharmaceutical class of 68Ga-labeled peptides (“multiples”), and to calculate the baseline activities based on the biokinetics of these compounds and an upper limit of the administered activity of 185 MBq for an adult. Analogous to 18F-fluoride, a minimum activity of 14 MBq is recommended. As a result, for those pediatric nuclear medicine applications involving 68Ga-labeled peptides, new values for the EANM dosage card were proposed and implemented based on the results derived in this work. Overall, despite the low additional radiation-related cancer risk, all efforts should be undertaken to optimize administered activities in children and adolescents for obtaining sufficient diagnostic information with minimal associated radiation risk. / Im Jahr 2006 wurden weltweit 0,18 Mio. nuklearmedizinische Diagnostikuntersuchungen bei Kindern durchgeführt. Für die meisten Radiopharmazeutika fehlen jedoch Daten zur Biokinetik und damit zur Dosimetrie oder diese wurden nicht öffentlich zugänglich gemacht. Daher basieren die meisten der heute vorgestellten Dosimetriedaten für Diagnostika bei Kindern und Jugendlichen auf den biokinetischen Daten von Erwachsenen. Selbst für eine der häufigsten nuklearmedizinischen Untersuchungen für diese Patientengruppe, die Nierenszintigraphie mit 99mTc-MAG3 für Bestimmung der Nierenfunktion, wurden Daten zur Biokinetik bisher nur für vier Kinder unterschiedlichen Alters erhoben. Insbesondere Nierenuntersuchungen gehören zu den häufigsten Untersuchungen bei Säuglingen und Kleinkindern. Aufgrund des jungen Alters kann diese Patientengruppe als Hochrisikogruppe mit einer höheren Wahrscheinlichkeit für das Eintreten stochastischer Strahlenwirkungen im Vergleich zu Erwachsenen eingestuft werden. Da es in dieser Patientengruppe nur begrenzte Daten zur Biokinetik und Dosimetrie gibt, ist das Ziel dieser Arbeit, die Dosimetrie und das damit verbundene Strahlenrisiko für eine größere Anzahl von Kleinkindern, die sich 99mTc-MAG3-Nierenscans unterziehen, auf der Grundlage einer retrospektiven Analyse bestehender Patientendaten neu zu bewerten. Die Daten wurden retrospektiv von 34 Patienten unter 20 Monaten mit normaler (20 Patienten) und eingeschränkter Nierenfunktion (14 Patienten) erhoben, bei denen 99mTc-MAG3-Scans durchgeführt wurden. Die patientenspezifische Organaktivität wurde basierend auf einer retrospektiven Kalibrierung abgeschätzt. Diese Kalibrierung basiert auf einem Satz von zwei 3D-gedruckten Säuglingsnieren, die mit bekannten Aktivitäten gefüllt wurden. Beide Phantome wurden an verschiedenen Positionen entlang der anteroposterioren Achse innerhalb eines Wasserphantoms gescannt und lieferten tiefen- und größenabhängige Schwächungskorrekturfaktoren für die planare Bildgebung. Die Zeit-Aktivitäts-Kurven wurden bestimmt, indem für jeden Patienten Nieren-, Blasen- und Ganzkörperregionen eingezeichnet und anschließend der entsprechende Kalibrierfaktor für die Umwandlung der Zählraten in Aktivität angewendet wurde. Patientenspezifische zeitintegrierte Aktivitätskoeffizienten wurden durch Integration der organspezifischen Zeit-Aktivitätskurven ermittelt. Die Energie- und effektiven Dosiskoeffizienten für jeden Patienten wurden mit OLINDA/EXM für das bereitgestellte Neugeborenen- und 1-Jahres-Phantom ermittelt. Basierend auf diesen Werten für die Energiedosen wurde eine individuelle Abschätzung des Strahlenrisikos für jeden der 34 Patienten mit dem Radiation Risk Assessment Tool des National Cancer Institute durchgeführt. Die organspezifischen mittleren Energiedosiskoeffizienten der Patienten mit normaler Nierenfunktion lagen bei 0,04±0,03 mGy/MBq für die Nieren und 0,27±0,24 mGy/MBq für die Blase, was in einem mittleren effektiven Dosiskoeffizienten von 0,02±0,02 mSv/MBq resultiert. Basierend auf den Ergebnissen der Dosimetrie, zeigte die Auswertung des zusätzlichen Lebenszeitrisikos ("excess lifetime risk", ELR) für die Entwicklung von strahleninduziertem Krebs, dass die Gruppe der Neugeborenen ein ELR von 16,8 pro 100.000 Personen aufweist, was höher ist als das der Gruppe der 1-jährigen mit 14,7 pro 100.000 Personen. Bei den 14 Patienten mit abnormaler Nierenfunktion waren die Mittelwerte für die Koeffizienten der organspezifischen Energiedosen für die Patienten: 0,40±0,34 mGy/MBq für die Nieren; 0,46±0,37 mGy/MBq für die Blase. Der effektivendosiskoeffizienten (mSv/MBq) waren: 0,05±0,02 mSv/MBq. Der mittlere ELR (pro 100.000 Personen) für die Entstehung von Krebs durch die Strahlenexposition von Patienten mit abnormaler Nierenfunktion betrug 29,2±18,7 pro 100.000 Personen. Das mit der Strahlung verbundene stochastische Risiko steigt mit den Organdosen unter Berücksichtigung alters- und geschlechtsspezifischer Einflüsse. Im Allgemeinen ist das mit den 99mTc-MAG3-Scans verbundene lebenslange Strahlenrisiko im Vergleich zum allgemeinen Bevölkerungsrisiko für die Entstehung von Krebs sehr gering. Aufgrund der steigenden Nachfrage nach PET-Scans bei Kindern und Jugendlichen mit 68Ga-markierten Peptiden wurden zusätzlich publizierte Datensätze für diese Verbindungen analysiert, um Empfehlungen für zu verabreichende Aktivitäten bei Kindern und Jugendlichen abzuleiten. Die Dosisberechnungen dazu basierten auf dem Modell einer gewichtsunabhängigen effektiven Dosis, das von der EANM Pediatric Dosage Card für den Einsatz in der pädiatrischen Nuklearmedizin vorgeschlagen wurde. Ziel war es, Empfehlungen zu verabreichenden Aktivitäten so aufzuteilen, dass sich altersunabhängige effektive Dosen ergeben. Dazu wurden die entsprechenden gewichtsabhängigen effektiven Dosiskoeffizienten gemäß dem Formalismus der EANM-Dosierungsempfehlung neu berechnet, um die radiopharmazeutische Klasse der 68Ga-markierten Peptide ("Multiples") zu bestimmen und die Werte für Basisaktivität zu berechnen. Diese basierend auf den Biokinetiken dieser Verbindungen und einer Obergrenze der verabreichten Aktivität von 185 MBq für einen Erwachsenen. Analog zu 18F-Fluorid, wird eine Mindestaktivität von 14 MBq empfohlen. Darauf basierend wurden für die pädiatrischen nuklearmedizinischen Anwendungen mit 68Ga-markierten Peptiden neue Werte für die EANM-Dosierungsempfehlung vorgeschlagen. Insgesamt sollten, trotz des geringen zusätzlichen strahlenbedingten Krebsrisikos, alle Anstrengungen unternommen werden, um die verabreichten Aktivitäten bei Kindern und Jugendlichen zu optimieren, um ausreichende diagnostische Informationen bei minimalem zusätzlichem Strahlenrisiko zu erhalten.

Le Strontium 90 (90Sr) est un radionucléide d’origine anthropogénique, relâché en grandes quantités dans l’environnement à la suite d’essais nucléaires aériens ou d’accidents d’installations nucléaires. Le 90Sr persiste à long terme dans l’environnement, ce qui conduit à la contamination chronique par ingestion de populations des territoires contaminés. L’induction de tumeurs osseuses liées à la fixation du 90Sr a été largement décrite. Par contre, l’occurrence d’effets non cancéreux est beaucoup moins connue. Nous avons utilisé un modèle murin avec une contamination chronique par ingestion d’eau contenant 20 kBq/l de 90Sr. Une étude de biocinétique a confirmé l’accumulation de 90Sr dans les os, avec un taux d’accumulation plus rapide durant la croissance osseuse. Cette accumulation est plus élevée dans les os des femelles que chez les males. Les doses absorbées au corps entier varient de 0.33 ± 0.06 mGy (naissance) à 10.6 ± 0.1 mGy (20 semaines). La dose au squelette peut aller jusqu’à 55 mGy. L’ingestion de 90Sr induit une modification de l’expression des gènes impliqués induisant à un déséquilibre favorisant la résorption osseuse, mais sans répercussion sur la morphologie de l’os. Aucun effet majeur n’a été observé pour le système hématopoïétique. Par contre, des modifications mineures du système immunitaire ont été observées. Afin d’évaluer la fonctionnalité du système immunitaire, un test de vaccination avec les antigènes TT et KLH a été utilisé. Les résultats montrent chez les animaux contaminés une diminution significative de la production d’immunoglobulines spécifiques, une modification de la balance Th1/Th2 dans la rate et une différenciation lymphoïde B perturbée. Ces résultats permettent de mieux comprendre certaines des conséquences non cancéreuses de l’exposition chronique à faible dose à des radionucléides à demi-vie longue pouvant être rejetés accidentellement. / Strontium 90 (90Sr) is a radionuclide of anthropogenic origin released in large quantities in the environment as a result of nuclear atmospheric tests or accidents at nuclear facilities. 90Sr persists on a long-term basis in the environment, leading to chronic contamination by ingestion of populations living on contaminated territories. The induction of bone tumours associated with the fixation of 90Sr has been widely described. However, the occurrence of non-cancer effects is much less known. We used a mouse model with chronic contamination by ingestion of water containing 20 kBq/l of 90Sr. A biokinetic study confirmed the accumulation of 90Sr in the bones, with an increased rate of accumulation during bone growth. This accumulation was higher in the bones of females than in males. The whole-body absorbed doses ranged from 0.33 ± 0.06 mGy (birth) to 10.6 ± 0.1 mGy (20 weeks). The absorbed dose for the skeleton was up to 55 mGy. Ingestion of 90Sr induced a change in the expression of genes inducing an imbalance in favour of bone resorption, but without effect on bone morphology. No significant effect was observed for the hematopoietic system. On the other hand, minor modifications were observed for the immune system. To evaluate the functionality of the immune system, a vaccination test with TT and KLH antigens was used. Results showed in contaminated animals a significant decrease in the production of specific immunoglobulins, changes in the Th1/Th2 balance in the spleen and a disrupted B lymphocyte differentiation. These results improve the understanding of some of the non-cancerous consequences of chronic exposure at low dose of radionuclides with a long half-life, which can be accidentally released.

Over the last two decades, implementation of membrane bioreactors (MBRs) has increased due to their superior effluent quality and low plant footprint. However, they are still viewed as a high-cost option, both with regards to capital and operating expenditure (capex and opex). The present thesis extends the understanding of the impact of design and operational parameters of membrane bioreactors on energy demand, and ultimately whole life cost. A simple heuristic aeration model based on a general algorithm for flux vs. aeration shows the benefits of adjusting the membrane aeration intensity to the hydraulic load. It is experimentally demonstrated that a lower aeration demand is required for sustainable operation when comparing 10:30 to continuous aeration, with associated energy savings of up to 75%, without being penalised in terms of the fouling rate. The applicability of activated sludge modelling (ASM) to MBRs is verified on a community-scale MBR, resulting in accurate predictions of the dynamic nutrient profile. Lastly, a methodology is proposed to optimise the energy consumption by linking the biological model with empirical correlations for energy demand, taking into account of the impact of high MLSS concentrations on oxygen transfer. The determining factors for costing of MBRs differ significantly depending on the size of the plant. Operational cost reduction in small MBRs relies on process robustness with minimal manual intervention to suppress labour costs, while energy consumption, mainly for aeration, is the major contributor to opex for a large MBR. A cost sensitivity analysis shows that other main factors influencing the cost of a large MBR, both in terms of capex and opex, are membrane costs and replacement interval, future trends in energy prices, sustainable flux, and the average plant utilisation which depends on the amount of contingency built in to cope with changes in the feed flow.