Physical activity and exercise capacity in people with Sarcoidosis

Purpose: Sarcoidosis is a diverse condition. The condition currently has a limited body of knowledge surrounding the effect and role of physical activity and exercise on quality of life and disease management. Therefore, this project aimed to preliminarily establish trends and correlations in relationship to quality of life and disease management through environmental and lifestyle factors. Methods: The project involved a systematic review into physical activity, exercise capacity and muscle strength, two online epidemiological studies looking at environmental and lifestyle factors alongside type and symptoms of the condition. In addition to qualitative questions helping understand the views of patients. While a final study compared an objective (triaxial accelerometery) measure of physical activity against a standardised self-reported measure (IPAQ), in addition to their relationships with physiological and mental measures of sarcoidosis. Results: Sarcoidosis is typically associated with reduced exercise capacity and muscle strength with reductions more profound in patients reporting fatigue. Although physical activity has been found to be above and below recommended levels. Chapter five found quality of life, number of symptoms and fatigue were predictors (R2=.094) of perceived categories physical activity while accelerometer MVPA found calories burned per day and BMI as predictors (R2=.968). Fatigue was found to be a major issue within the population with number of symptoms and physical activity since diagnosis as predictors within chapter five (R2 =.238) and the SHQ within chapter seven (R2=.797). Conclusions: This was the first study to look at the role of sarcoidosis effects on work-life balance. A large number of patients (41.5%) reported changing or stopping work due to sarcoidosis and thus the role and effects of physical activity needs further investigation, although the findings suggest MVPA cannot be used as the only form of physical activity measure and others such as steps per day; and light activity should be considered, physical activity is shown to be diverse within the population. Exercise rehabilitation can improve associated symptoms and deconditioning within sarcoidosis, while taught coping methods may be beneficial

The response of the maize nitrate transport system to nitrogen demand and supply across the lifecycle

The definitive version is available at www.newphytologist.comAn understanding of nitrate (NO3-) uptake throughout the lifecycle of plants, and how this process responds to nitrogen (N) availability, is an important step towards the development of plants with improved nitrogen use efficiency (NUE). NO3- uptake capacity and transcript levels of putative high- and low-affinity NO3- transporters (NRTs) were profiled across the lifecycle of dwarf maize (Zea mays) plants grown at reduced and adequate NO3-. Plants showed major changes in high-affinity NO3- uptake capacity across the lifecycle, which varied with changing relative growth rates of roots and shoots. Transcript abundances of putative high-affinity NRTs (predominantly ZmNRT2.1 and ZmNRT2.2) were correlated with two distinct peaks in high-affinity root NO3- uptake capacity and also N availability. The reduction in NO3- supply during the lifecycle led to a dramatic increase in NO3- uptake capacity, which preceded changes in transcript levels of NRTs, suggesting a model with short-term post-translational regulation and longer term transcriptional regulation of NO3- uptake capacity. These observations offer new insight into the control of NO3- uptake by both plant developmental processes and N availability, and identify key control points that may be targeted by future plant improvement programmes to enhance N uptake relative to availability and/or demand.Trevor Garnett, Vanessa Conn, Darren Plett, Simon Conn, Juergen Zanghellini, Nenah Mackenzie, Akiko Enju, Karen Francis, Luke Holtham, Ute Roessner, Berin Boughton, Antony Bacic, Neil Shirley, Antoni Rafalski, Kanwarpal Dhugga, Mark Tester, and Brent N. Kaise

Long- and short-term nitrate uptake regulation in maize

Cereal crops supply a major proportion of the world’s food and their production capacity is tightly linked to nitrogen (N) fertiliser use. With on average less than half of the applied N being captured by crops, there is scope and need to improve N uptake in cereals. With nitrate (NO₃⁻) being the main form of N available to cereal crops there has been a significant global research effort to understand plant NO₃⁻ uptake. Despite this, our understanding of how the NO₃⁻ uptake system is regulated remains limited. To advance our understanding of the NO₃⁻ uptake system and its regulation, three knowledge gaps were identified and explored in this thesis. Firstly, there is an identified need to better understand the NO₃⁻ uptake system and the signalling molecules which modulate it. Secondly, with the literature containing alternative approaches to studying NO₃⁻ uptake, there is a need to appreciate how these studies relate to better leverage the existing literature. And finally, with strong transcriptional control governing the NO₃⁻ uptake system, new leads were sought for modulating transcription of NO₃⁻ transporter genes. To explore these knowledge gaps, dwarf maize (Zea mays L. var. Gaspe Flint) was grown hydroponically with either sufficient or limiting NO₃⁻ availability. During the vegetative growth period a subset of plants grown were moved from sufficient to limiting NO₃⁻ conditions and a range of physiological parameters were measured. The results showed: the high affinity NO₃⁻ uptake system (HATS) appears to contribute a major proportion of total NO₃⁻ uptake capacity and responds to N demand at external concentrations where it was previously thought to be saturated; NO₃⁻ itself appears to play a key role in modulating the NO₃⁻ uptake system, and; temporal variation of NRT transcripts are more variable than previously understood. The observed responses to reduction in NO₃⁻ revealed a series of responses leading to a new model for the control of the NO₃⁻ uptake system. Using the same growth system, plants were grown under steady state NO₃⁻ conditions and a starvation and re-supply (primary nitrate response – PNR) response was explored in parallel. The information generated provided data to relate the PNR literature to longer term steady state studies. The ZmNRT2.5 gene was highlighted as an interesting candidate for revealing cis-trans regulatory elements associated with low N responses. To explore this, a combined phylogenomics and co-expressed gene promoter analysis was undertaken. A number of evolutionarily and functionally conserved regions were identified in the ZmNRT2.5 promoter with six regions showing no resemblance to known transcription factor binding sites. These sequences provide a new resource for the discovery of cis-trans regulatory mechanisms associated with the low N expression of ZmNRT2.5. The findings in this thesis have identified key time points for future transcriptome analysis, and revealed putative cis-elements as new leads for discovering novel cis-trans regulatory elements associated with the regulation of NO₃⁻ uptake. Ultimately, further research may lead to the identification of key regulatory genes as candidates for the improvement of N uptake efficiency and overall N use efficiency in cereal crops.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Agriculture, Food and Wine, 2015

The relationship between a direct measure of physical activity against self-reported physical activity, muscle strength, quality of life and exercise capacity in pulmonary sarcoidosis

Background: Sarcoidosis is a diverse condition. The condition currently has a limited body of knowledge surrounding the effect and role of physical activity, diet and exercise on quality of life and disease management. Yet, physical activity is frequently suggested as beneficial within sarcoidosis however little is currently known about physical activity patterns within the condition as well as its role and effect on other key physiological and mental variables. Additionally, self-reported measures such as the IPAQ are regularly utilised within research due to their ease of use and low cost however their validity and accuracy within sarcoidosis in comparison to an objective measure (tri-axial accelerometer) is currently unknown. Methods: A lab-based approach was utilised with participants visiting twice to validate their variable measurements. Participants undertook exercise capacity (6 MWT), lung function (FEV1, FVC, PEF), muscle strength (HGS, QPT, HPT, EFMS), quality of life (SHQ) and fatigue (FAS) tests in addition to wearing a tri-axial accelerometer for five days between visits. Results: Participants recorded above recommended levels of physical activity via the accelerometer (152 mins MVPA per day) and was strongly correlated to self-reported MVPA (0.875, p=0.022) although a large difference was recorded (52 mins per day) between the two methods. Handgrip strength was strongly correlated with gender (0.809), body fat percentage (0.794), elbow flexor muscle strength (0.961) and forced vital capacity (0.865). Conclusions: Physical activity patterns are diverse within sarcoidosis much like the general public, while physical activity’s relation to other variables appears limited although the variables are multi-faceted. Handgrip strength and six-minute walk distance may be a good indicator of a range of other key variables within the condition

Nitrate uptake and its regulation in relation to improving nitrogen use efficiency in cereals

On average less than half of the applied N is captured by crops, thus there is scope and need to improveN uptake in cereals. With nitrate (NO3−) being the main form of N available to cereal crops there hasbeen a significant global research effort to understand plant NO3−uptake. Despite this, our knowledgeof the NO3−uptake system is not sufficient to easily target ways to improve NO3−uptake. Based on thisthere is an identified need to better understand the NO3−uptake system and the signalling moleculesthat modulate it. With strong transcriptional control governing the NO3−uptake system, we also neednew leads for modulating transcription of NO3−transporter genesDarren C. Plett, Luke R. Holtham, Mamoru Okamoto, Trevor P. Garnet