Randomized controlled trial of an improved version of MobileMums, an intervention for increasing physical activity in women with young children

Background Women with young children (<5 years) are an important group for physical activity intervention. Purpose To evaluate the feasibility, acceptability and efficacy of MobileMums- a physical activity intervention for women with young children. Methods Women were randomized to MobileMums (n=133) or a control group (n=130). MobileMums was delivered primarily via individually-tailored text messages. Moderate to vigorous physical activity (MVPA) was measured by self-report and accelerometer at baseline, end of the intervention (13-weeks) and 6-months later (9-months). Changes were analyzed using repeated measures models. Results MobileMums was feasible to deliver and acceptable to women. Self-reported MVPA duration (minutes/week) and frequency (days/week) increased significantly post intervention (13-week intervention effect 48.5 min/week, 95%CI [13.4, 82.9] and 1.6 days/week, 95%CI [0.6, 2.6]). Intervention effects were not maintained 6-months later. No effects observed in accelerometer-derived MVPA. Conclusions MobileMums increased women’s self-reported MVPA immediately post intervention. Future investigations need to target sustained physical activity improvements.

Quantifying physical activity and the associated barriers for women with ovarian cancer

Objective The purpose of this study was to quantify physical activity levels and determine the barriers to physical activity for women with ovarian cancer. Materials and Methods Women with ovarian cancer from 3 oncology clinics enrolled in the cross-sectional study. Physical activity and barriers to physical activity were measured using the International Physical Activity Questionnaire and Perceived Physical Activity Barriers scale, respectively. Demographic, medical, and anthropometric data were obtained from medical records. Results Ninety-five women (response rate, 41%), with a mean (SD) age of 61 (10.6) years, a body mass index of 26.5 (6.8) kg/m2, and 36.6 (28.2) months since diagnosis, participated in the study. The majority of the participants had stage III (32%) or IV (32%) ovarian cancer, were undergoing chemotherapy (41%), and had a history of chemotherapy (93%). The majority of the participants reduced their physical activity after diagnosis, with 19% meeting recommended physical activity guidelines. The participants undergoing treatment reported lower moderate-vigorous physical activity compared with those not undergoing active treatment (mean [SD], 42 [57] vs 104 [119] min/wk; P < 0.001) and less total physical activity barriers (mean [SD], 49 vs 47; P > 0.4). The greatest barriers to physical activity included fatigue (37.8%), exercise not in routine (34.7%), lack of self-discipline (32.6%), and procrastination (27.4%). Conclusions Women with ovarian cancer have low levels of physical activity. There are disease-specific general barriers to physical activity participation. The majority of the participants reduced their physical activity after diagnosis, with these patients reporting a higher number of total barriers. Behavioral strategies are required to increase physical activity adherence in this population to ensure that recommended guidelines are met to achieve the emerging known benefits of exercise oncology.

Some major problems with existing models and terminology associated with kimberlite pipes from a volcanological perspective, and some suggestions

Five significant problems hinder advances in understanding of the volcanology of kimberlites: (1) kimberlite geology is very model driven; (2) a highly genetic terminology drives deposit or facies interpretation; (3) the effects of alteration on preserved depositional textures have been grossly underestimated; (4) the level of understanding of the physical process significance of preserved textures is limited; and, (5) some inferred processes and deposits are not based on actual, modern volcanological processes. These issues need to be addressed in order to advance understanding of kimberlite volcanological pipe forming processes and deposits. The traditional, steep-sided southern African pipe model (Class I) consists of a steep tapering pipe with a deep root zone, a middle diatreme zone and an upper crater zone (if preserved). Each zone is thought to be dominated by distinctive facies, respectively: hypabyssal kimberlite (HK, descriptively called here massive coherent porphyritic kimberlite), tuffisitic kimberlite breccia (TKB, descriptively here called massive, poorly sorted lapilli tuff) and crater zone facies, which include variably bedded pyroclastic kimberlite and resedimented and reworked volcaniclastic kimberlite (RVK). Porphyritic coherent kimberlite may, however, also be emplaced at different levels in the pipe, as later stage intrusions, as well as dykes in the surrounding country rock. The relationship between HK and TKB is not always clear. Sub-terranean fluidisation as an emplacement process is a largely unsubstantiated hypothesis; modern in-vent volcanological processes should initially be considered to explain observed deposits. Crater zone volcaniclastic deposits can occur within the diatreme zone of some pipes, indicating that the pipe was largely empty at the end of the eruption, and subsequently began to fill-in largely through resedimentation and sourcing of pyroclastic deposits from nearby vents. Classes II and III Canadian kimberlite models have a more factual, descriptive basis, but are still inadequately documented given the recency of their discovery. The diversity amongst kimberlite bodies suggests that a three-model classification is an over-simplification. Every kimberlite is altered to varying degrees, which is an intrinsic consequence of the ultrabasic composition of kimberlite and the in-vent context; few preserve original textures. The effects of syn- to post-emplacement alteration on original textures have not been adequately considered to date, and should be back-stripped to identify original textural elements and configurations. Applying sedimentological textural configurations as a guide to emplacement processes would be useful. The traditional terminology has many connotations about spatial position in pipe and of process. Perhaps the traditional terminology can be retained in the industrial situation as a general lithofacies-mining terminological scheme because it is so entrenched. However, for research purposes a more descriptive lithofacies terminology should be adopted to facilitate detailed understanding of deposit characteristics, important variations in these, and the process origins. For example every deposit of TKB is different in componentry, texture, or depositional structure. However, because so many deposits in many different pipes are called TKB, there is an implication that they are all similar and that similar processes were involved, which is far from clear.

Socially critical pedagogy and the 'production of skilled performers': Further considerations of teaching and learning in physical education

The growing call for physical educators to move beyond the bounds of performance has been a powerful discourse. However, it is a discourse that has tended to be heavy on theory but light on practical application. This paper discusses recent work in the area of skill acquisition and what this might mean for pedagogical practices in physical education. The acquisition of motor skill has traditionally been a core objective for physical educators, and there has been a perception that child-centred pedagogies have failed in the achievement of this traditional yardstick. However, drawing from the work of Rovegno and Kirk (1995) and Langley (1995; 1997), and making links with current work in the motor learning area, it is possible to show that skill acquisition is not necessarily compromised by child-centred pedagogy. Indeed, working beyond Mosston's discovery threshold and using models such as Games for Understanding, can provide deeper skill-learning experiences as well as being socially just.

Physical activity and screen-time of childhood hematopoietic stem cell transplant survivors

Aim Reduced bone mineral density, impaired cardiovascular fitness, and increased risk of obesity are well-known late effects of Hematopoietic Stem Cell Transplantation (HSCT) in survivors of childhood cancer. These comorbidities can be mitigated through physical activity and limiting screen-time (ST). This study aims to increase the understanding of physical activity and ST behaviours for children following HSCT. Method Children were recruited from two oncology follow-up clinics and completed a questionnaire on their physical activity levels and screen-time. Children were classified as short (≤2yrs) and long term (>2yrs) survivors. Results Fifty-eight children were eligible, of whom forty children age 6 to 18 years (60% males) participated in the study. Less than half (47.5%) met the daily recommendations for physical activity and one third met the ST recommendations. Late survivors reported higher daily physical activity and less ST than early survivors. Among late survivors, females reported higher daily physical activity and less ST than males. Conclusions Our findings suggest that the majority of children following HSCT were not sufficiently active and had excessive screen-time; however this was comparable to healthy populations. Appropriately designed physical activity and screen-time intervention programs should be explored early following transplant for children undergoing HSCT.

The importance of connexin hemichannels during chondroprogenitor cell differentiation in hydrogel versus microtissue culture models

Appropriate selection of scaffold architecture is a key challenge in cartilage tissue engineering. Gap junction-mediated intercellular contacts play important roles in precartilage condensation of mesenchymal cells. However, scaffold architecture could potentially restrict cell-cell communication and differentiation. This is particularly important when choosing the appropriate culture platform as well as scaffold-based strategy for clinical translation, that is, hydrogel or microtissues, for investigating differentiation of chondroprogenitor cells in cartilage tissue engineering. We, therefore, studied the influence of gap junction-mediated cell-cell communication on chondrogenesis of bone marrow-derived mesenchymal stromal cells (BM-MSCs) and articular chondrocytes. Expanded human chondrocytes and BM-MSCs were either (re-) differentiated in micromass cell pellets or encapsulated as isolated cells in alginate hydrogels. Samples were treated with and without the gap junction inhibitor 18-α glycyrrhetinic acid (18αGCA). DNA and glycosaminoglycan (GAG) content and gene expression levels (collagen I/II/X, aggrecan, and connexin 43) were quantified at various time points. Protein localization was determined using immunofluorescence, and adenosine-5'-triphosphate (ATP) was measured in conditioned media. While GAG/DNA was higher in alginate compared with pellets for chondrocytes, there were no differences in chondrogenic gene expression between culture models. Gap junction blocking reduced collagen II and extracellular ATP in all chondrocyte cultures and in BM-MSC hydrogels. However, differentiation capacity was not abolished completely by 18αGCA. Connexin 43 levels were high throughout chondrocyte cultures and peaked only later during BM-MSC differentiation, consistent with the delayed response of BM-MSCs to 18αGCA. Alginate hydrogels and microtissues are equally suited culture platforms for the chondrogenic (re-)differentiation of expanded human articular chondrocytes and BM-MSCs. Therefore, reducing direct cell-cell contacts does not affect in vitro chondrogenesis. However, blocking gap junctions compromises cell differentiation, pointing to a prominent role for hemichannel function in this process. Therefore, scaffold design strategies that promote an increasing distance between single chondroprogenitor cells do not restrict their differentiation potential in tissue-engineered constructs.

Living well with diabetes: 24-month outcomes from a randomized trial of telephone-delivered weight loss and physical activity intervention to improve glycemic control

OBJECTIVE: To evaluate the effectiveness of a telephone-delivered behavioral weight loss and physical activity intervention targeting Australian primary care patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Pragmatic randomized controlled trial of telephone counseling (n = 151) versus usual care (n = 151). Reported here are 18-month (end-of-intervention) and 24-month (maintenance) primary outcomes of weight, moderate-to-vigorous-intensity physical activity (MVPA; via accelerometer), and HbA1c level. Secondary outcomes include dietary energy intake and diet quality, waist circumference, lipid levels, and blood pressure. Data were analyzed via adjusted linear mixed models with multiple imputation of missing data. RESULTS: Relative to usual-care participants, telephone counseling participants achieved modest, but significant, improvements in weight loss (relative rate [RR] -1.42% of baseline body weight [95% CI -2.54 to -0.30% of baseline body weight]), MVPA (RR 1.42 [95% CI 1.06-1.90]), diet quality (2.72 [95% CI 0.55-4.89]), and waist circumference (-1.84 cm [95% CI -3.16 to -0.51 cm]), but not in HbA1c level (RR 0.99 [95% CI 0.96-1.02]), or other cardio-metabolic markers. None of the outcomes showed a significant change/deterioration over the maintenance period. However, only the intervention effect for MVPA remained statistically significant at 24 months. CONCLUSIONS: The modest improvements in weight loss and behavior change, but the lack of changes in cardio-metabolic markers, may limit the utility, scalability, and sustainability of such an approach.

Adult total wellness: group differences based on sitting time and physical activity level

Background An increasing body of evidence associates a high level of sitting time with poor health outcomes. The benefits of moderate to vigorous-intensity physical activities to various aspects of health are now well documented; however, individuals may engage in moderate-intensity physical activity for at least 30 minutes on five or more days of the week and still exhibit a high level of sitting time. This purpose of this study was to examine differences in total wellness among adults relative to high/low levels of sitting time combined with insufficient/sufficient physical activity (PA). The construct of total wellness incorporates a holistic approach to the body, mind and spirit components of life, an approach which may be more encompassing than some definitions of health. Methods Data were obtained from 226 adult respondents (27 ± 6 years), including 116 (51%) males and 110 (49%) females. Total PA and total sitting time were assessed with the International Physical Activity Questionnaire (IPAQ) (short-version). The Wellness Evaluation of Lifestyle Inventory was used to assess total wellness. An analysis of covariance (ANCOVA) was utilised to assess the effects of the sitting time/physical activity group on total wellness. A covariate was included to partial out the effects of age, sex and work status (student or employed). Cross-tabulations were used to show associations between the IPAQ derived high/low levels of sitting time with insufficient/sufficient PA and the three total wellness groups (i.e. high level of wellness, moderate wellness and wellness development needed). Results The majority of the participants were located in the high total sitting time and sufficient PA group. There were statistical differences among the IPAQ groups for total wellness [F (2,220) = 32.5 (p <0.001)]. A Chi-square test revealed a significant difference in the distribution of the IPAQ categories within the classification of wellness [χ2 (N = 226) = 54.5, p < .001]. One-hundred percent (100%) of participants who self-rated as high total sitting time/insufficient PA were found in the wellness development needed group. In contrast, 72% of participants who were located in the low total sitting time/sufficient PA group were situated in the moderate wellness group. Conclusion Many participants who meet the physical activity guidelines, in this sample, sit for longer periods of time than the median Australian sitting time. An understanding of the effects of the enhanced PA and reduced sitting time on total wellness can add to the development of public health initiatives. Keywords: IPAQ; The Wellness Evaluation of Lifestyle (WEL); Sedentary lifestyle

Comparing multilevel and Bayesian spatial random effects survival models to assess geographical inequalities in colorectal cancer survival: a case study

Background Multilevel and spatial models are being increasingly used to obtain substantive information on area-level inequalities in cancer survival. Multilevel models assume independent geographical areas, whereas spatial models explicitly incorporate geographical correlation, often via a conditional autoregressive prior. However the relative merits of these methods for large population-based studies have not been explored. Using a case-study approach, we report on the implications of using multilevel and spatial survival models to study geographical inequalities in all-cause survival. Methods Multilevel discrete-time and Bayesian spatial survival models were used to study geographical inequalities in all-cause survival for a population-based colorectal cancer cohort of 22,727 cases aged 20–84 years diagnosed during 1997–2007 from Queensland, Australia. Results Both approaches were viable on this large dataset, and produced similar estimates of the fixed effects. After adding area-level covariates, the between-area variability in survival using multilevel discrete-time models was no longer significant. Spatial inequalities in survival were also markedly reduced after adjusting for aggregated area-level covariates. Only the multilevel approach however, provided an estimation of the contribution of geographical variation to the total variation in survival between individual patients. Conclusions With little difference observed between the two approaches in the estimation of fixed effects, multilevel models should be favored if there is a clear hierarchical data structure and measuring the independent impact of individual- and area-level effects on survival differences is of primary interest. Bayesian spatial analyses may be preferred if spatial correlation between areas is important and if the priority is to assess small-area variations in survival and map spatial patterns. Both approaches can be readily fitted to geographically enabled survival data from international settings

Particle emissions from biodiesels with different physical properties and chemical composition

Biodiesels produced from different feedstocks usually have wide variations in their fatty acid methyl ester (FAME) so that their physical properties and chemical composition are also different. The aim of this study is to investigate the effect of the physical properties and chemical composition of biodiesels on engine exhaust particle emissions. Alongside with neat diesel, four biodiesels with variations in carbon chain length and degree of unsaturation have been used at three blending ratios (B100, B50, B20) in a common rail engine. It is found that particle emission increased with the increase of carbon chain length. However, for similar carbon chain length, particle emissions from biodiesel having relatively high average unsaturation are found to be slightly less than that of low average unsaturation. Particle size is also found to be dependent on fuel type. The fuel or fuel mix responsible for higher particle mass (PM) and particle number (PN) emissions is also found responsible for larger particle median size. Particle emissions reduced consistently with fuel oxygen content regardless of the proportion of biodiesel in the blends, whereas it increased with fuel viscosity and surface tension only for higher diesel–biodiesel blend percentages (B100, B50). However, since fuel oxygen content increases with the decreasing carbon chain length, it is not clear which of these factors drives the lower particle emission. Overall, it is evident from the results presented here that chemical composition of biodiesel is more important than its physical properties in controlling exhaust particle emissions.

A mouse model for spondyloepiphyseal dysplasia congenita with secondary osteoarthritis due to a Col2a1 mutation

Progeny of mice treated with the mutagen N-ethyl-N-nitrosourea (ENU) revealed a mouse, designated Longpockets (Lpk), with short humeri, abnormal vertebrae, and disorganized growth plates, features consistent with spondyloepiphyseal dysplasia congenita (SEDC). The Lpk phenotype was inherited as an autosomal dominant trait. Lpk/+ mice were viable and fertile and Lpk/Lpk mice died perinatally. Lpk was mapped to chromosome 15 and mutational analysis of likely candidates from the interval revealed a Col2a1 missense Ser1386Pro mutation. Transient transfection of wild-type and Ser1386Pro mutant Col2a1 c-Myc constructs in COS-7 cells and CH8 chondrocytes demonstrated abnormal processing and endoplasmic reticulum retention of the mutant protein. Histology revealed growth plate disorganization in 14-day-old Lpk/+ mice and embryonic cartilage from Lpk/+ and Lpk/Lpk mice had reduced safranin-O and type-II collagen staining in the extracellular matrix. The wild-type and Lpk/+ embryos had vertical columns of proliferating chondrocytes, whereas those in Lpk/Lpk mice were perpendicular to the direction of bone growth. Electron microscopy of cartilage from 18.5 dpc wild-type, Lpk/+, and Lpk/Lpk embryos revealed fewer and less elaborate collagen fibrils in the mutants, with enlarged vacuoles in the endoplasmic reticulum that contained amorphous inclusions. Micro-computed tomography (CT) scans of 12-week-old Lpk/+ mice revealed them to have decreased bone mineral density, and total bone volume, with erosions and osteophytes at the joints. Thus, an ENU mouse model with a Ser1386Pro mutation of the Col2a1 C-propeptide domain that results in abnormal collagen processing and phenotypic features consistent with SEDC and secondary osteoarthritis has been established.

Estimating the parameters of stochastic volatility models using option price data

This article describes a maximum likelihood method for estimating the parameters of the standard square-root stochastic volatility model and a variant of the model that includes jumps in equity prices. The model is fitted to data on the S&P 500 Index and the prices of vanilla options written on the index, for the period 1990 to 2011. The method is able to estimate both the parameters of the physical measure (associated with the index) and the parameters of the risk-neutral measure (associated with the options), including the volatility and jump risk premia. The estimation is implemented using a particle filter whose efficacy is demonstrated under simulation. The computational load of this estimation method, which previously has been prohibitive, is managed by the effective use of parallel computing using graphics processing units (GPUs). The empirical results indicate that the parameters of the models are reliably estimated and consistent with values reported in previous work. In particular, both the volatility risk premium and the jump risk premium are found to be significant.

Compositional agent-based models for electricity distribution networks

This thesis presents a novel approach to building large-scale agent-based models of networked physical systems using a compositional approach to provide extensibility and flexibility in building the models and simulations. A software framework (MODAM - MODular Agent-based Model) was implemented for this purpose, and validated through simulations. These simulations allow assessment of the impact of technological change on the electricity distribution network looking at the trajectories of electricity consumption at key locations over many years.

Solid volume fraction estimation of bone:marrow replica models using ultrasound transit time spectroscopy

The acceptance of broadband ultrasound attenuation (BUA) for the assessment of osteoporosis suffers from a limited understanding of both ultrasound wave propagation through cancellous bone and its exact dependence upon the material and structural properties. It has recently been proposed that ultrasound wave propagation in cancellous bone may be described by a concept of parallel sonic rays; the transit time of each ray defined by the proportion of bone and marrow propagated. A Transit Time Spectrum (TTS) describes the proportion of sonic rays having a particular transit time, effectively describing the lateral inhomogeneity of transit times over the surface aperture of the receive ultrasound transducer. The aim of this study was to test the hypothesis that the solid volume fraction (SVF) of simplified bone:marrow replica models may be reliably estimated from the corresponding ultrasound transit time spectrum. Transit time spectra were derived via digital deconvolution of the experimentally measured input and output ultrasonic signals, and compared to predicted TTS based on the parallel sonic ray concept, demonstrating agreement in both position and amplitude of spectral peaks. Solid volume fraction was calculated from the TTS; agreement between true (geometric calculation) with predicted (computer simulation) and experimentally-derived values were R2=99.9% and R2=97.3% respectively. It is therefore envisaged that ultrasound transit time spectroscopy (UTTS) offers the potential to reliably estimate bone mineral density and hence the established T-score parameter for clinical osteoporosis assessment.

Optimization models for expanding a railway’s theoretical capacity

Changing the topology of a railway network can greatly affect its capacity. Railway networks however can be altered in a multitude of different ways. As each way has significant immediate and long term financial ramifications, it is a difficult task to decide how and where to expand the network. In response some railway capacity expansion models (RCEM) have been developed to help capacity planning activities, and to remove physical bottlenecks in the current railway system. The exact purpose of these models is to decide given a fixed budget, where track duplications and track sub divisions should be made, in order to increase theoretical capacity most. These models are high level and strategic, and this is why increases to the theoretical capacity is concentrated upon. The optimization models have been applied to a case study to demonstrate their application and their worth. The case study evidently shows how automated approaches of this nature could be a formidable alternative to current manual planning techniques and simulation. If the exact effect of track duplications and sub-divisions can be sufficiently approximated, this approach will be very applicable.