Sporobolus stapfianus, a model desiccation-tolerant grass

Sporobolus stapfianus Gandoger, one of ~40 known ‘anabiotic’grass species (i.e. ‘able to regain vital activity from a state of latent life’), is the most versatile tool for research into desiccation tolerance in vegetative grass tissue. Current knowledge on this species is presented, including the features that suit it for investigations into the plant’s ability to survive dehydration of its leaf protoplasm. The main contributors to desiccation tolerance in S. stapfianus leaves appear to be: accumulation during dehydration of protectants of membranes and proteins; mechanisms limiting oxidative damage; a retention of protein synthetic activity in late stages of drying that is linked with changes in gene expression and in the proteomic array; and an ability to retain net synthesis of ATP during drying. S. stapfianus exemplifies an advanced stage of an evolutionary trend in desiccation tolerant plants towards increased importance of the dehydration phase (for induction of tolerance, for synthesis of protectants and for proteomic changes).

The resurrection plant Sporobolus stapfianus: An unlikely model for engineering enhanced plant biomass?

The resurrection grass Sporobolus stapfianus Gandoger can rapidly recover from extended periods of time in the desiccated state (water potential equilibrated to 2% relative humidity) (Gaff and Ellis, Bothalia 11:305–308 1974; Gaff and Loveys, Transactions of the Malaysian Society of Plant Physiology 3:286–287 1993). Physiological studies have been conducted in S. stapfianus to investigate the responses utilised by these desiccation-tolerant plants to cope with severe water-deficit. In a number of instances, more recent gene expression analyses in S. stapfianus have shed light on the molecular and cellular mechanisms mediating these responses. S. stapfianus is a versatile research tool for investigating desiccation-tolerance in vegetative grass tissue, with several useful characteristics for differentiating desiccation-tolerance adaptive genes from the many dehydration-responsive genes present in plants. A number of genes orthologous to those isolated from dehydrating S. stapfianus have been successfully used to enhance drought and salt tolerance in model plants as well as important crop species. In addition to the ability to desiccate and rehydrate successfully, the survival of resurrection plants in regions experiencing short sporadic rainfall events may depend substantially on the ability to tightly down-regulate cell division and cell wall loosening activities with decreasing water availability and then grow rapidly after rainfall while water is plentiful. Hence, an analysis of gene transcripts present in the desiccated tissue of resurrection plants may reveal important growth-related genes. Recent findings support the proposition that, as well as being a versatile model for devising strategies for protecting plants from water-loss, resurrection plants may be a very useful tool for pinpointing genes to target for enhancing growth rate and biomass production.

Effect of creatine ingestion on glucose tolerance and insulin sensitivity in men

Purpose: This study investigated whether acute (5 d) and/or short-term (28 d) creatine (Cr) ingestion altered glucose tolerance or insulin action in healthy, untrained men (aged 26.9 ± 5.7 yr; SD). Methods : Subjects were randomly allocated to either a Cr (N = 8) or placebo group (N = 9) and were tested in the control condition (presupplementation), and after 5 and a further 28 d of supplementation. The Cr group ingested 20 g and 3 g·d-1 of Cr for the first 5 and following 28 d, respectively. The placebo group ingested similar amounts of glucose over the same time period. During each testing period, subjects underwent an oral glucose tolerance test (OGTT) to determine insulin sensitivity, and six subjects from each group underwent a muscle biopsy before each OGTT. Results : Cr supplementation resulted in an increased (P < 0.05) muscle TCr content after both the acute and short-term loading phase compared with placebo. Neither acute nor short-term Cr supplementation influenced skeletal muscle glycogen content, glucose tolerance, or measures of insulin sensitivity. Conclusions: These findings demonstrated that acute Cr supplementation (20 g·d-1 for 5 d) followed by short-term Cr supplementation (3 g·d-1 for 28 d) did not alter insulin action in healthy, active untrained men.

A solution for fault tolerance in replicated database systems

A distributed database system is subject to site failure and link failure. This paper presents a reactive system approach to achieving fault tolerance in such a system. The reactive system concepts are an attractive paradigm for system design, development and maintenance because it separates policies from mechanisms. In the paper we give a solution using different reactive modules to implement the fault tolerant policies and the failure detection mechanisms. The solution shows that they can be separated without impact on each other; thus the system can adapt to constant changes in environments and user requirements.

Randomised controlled trial evaluating lifestyle interventions in people with impaired glucose tolerance

Aim

To evaluate the effectiveness of lifestyle interventions in people with impaired glucose tolerance (IGT).
Methods

Participants with IGT (n = 78), diagnosed on two consecutive oral glucose tolerance tests (OGTTs), were randomly assigned to a 2-year lifestyle intervention or to a control group. Main outcome measures were changes from baseline in: nutrient intake; physical activity; anthropometry, glucose tolerance and insulin sensitivity. Measurements were repeated at 6, 12 and 24 months follow-up.
Results

After 24 months follow-up, there was a significant fall in total fat consumption (difference in change between groups (Δ intervention − Δ control) = −17.9, 95% confidence interval (CI) −33.6 to −2.1 g/day) as a result of the intervention. Body mass was significantly lower in the intervention group compared with controls after 6 months (−1.6, 95% CI −2.9 to −0.4 kg) and 24 months (−3.3, 95% CI −5.7 to −0.89 kg). Whole body insulin sensitivity, assessed by the short insulin tolerance test (ITT), improved after 12 months in the intervention group (0.52, 95% CI 0.15–0.89%/min).
Conclusions

These findings complement the findings of the Finnish Diabetes Prevention Study and the American Diabetes Prevention Study, both of which tested intensive interventions, by showing that pragmatic lifestyle interventions result in improvements in obesity and whole body insulin sensitivity in individuals with IGT, without change in other cardiovascular risk factors.

Randomised controlled trial evaluating the effectiveness of behavioural interventions to modify cardiovascular risk factors in men and women with imparied glucose tolerance: outcomes at 6 months

Aims: To evaluate the efficacy of interventions to promote a healthy diet and physical activity in people with impaired glucose tolerance (IGT). Methods: A randomised controlled trial in Newcastle upon Tyne, UK, 1995–98. Participants included 67 adults (38 men; 29 women) aged 24–75 years with IGT. The intervention consisted of regular diet and physical activity counselling based on the stages of change model. Main outcome measures were changes between baseline and 6 months in nutrient intake; physical activity; anthropometric and physiological measurements including serum lipids; glucose tolerance; insulin sensitivity. Results: The difference in change in total fat consumption was significant between intervention and control groups (difference −21.8 (95% confidence interval (CI) −37.8 to −5.8) g/day, P=0.008). A significantly larger proportion of intervention participants reported taking up vigorous activity than controls (difference 30.1, (95% CI 4.3–52.7)%, P=0.021). The change in body mass index was significantly different between groups (difference −0.95 (95% CI −1.5 to −0.4) kg/m2, P=0.001). There was no significant difference in change in mean 2-h plasma glucose between groups (difference −0.19 (95% CI −1.1 to 0.71) mmol/l, NS) or in serum cholesterol (difference 0.02 (95% CI −0.26 to 0.31) mmol/l, NS). The difference in change in fasting serum insulin between groups was significant (difference −3.4 (95% CI −5.8 to −1.1) mU/l, P=0.005). Conclusions: After 6 months of intensive lifestyle intervention in participants with IGT, there were changes in diet and physical activity, some cardiovascular risk factors and insulin sensitivity, but not glucose tolerance. Further follow-up is in progress to investigate whether these changes are sustained or augmented over 2 years.

A solution for fault-tolerance in replicated database systems

A distributed database system is subject to site failure and link failure. This paper presents a reactive system approach to achieving the fault-tolerance in such a system. The reactive system concepts are an attractive paradigm for system design, development and maintenance because it separates policies from mechanisms. In the paper we give a solution using different reactive modules to implement the fault-tolerant policies and the failure detection mechanisms. The solution shows that they can be separated without impact on each other thus the system can adapt to constant changes in user requirements.

The rising prevalence of diabetes and impaired glucose tolerance : the Australian diabetes, obesity and lifestyle study

OBJECTIVE—To determine the population-based prevalence of diabetes and other categories of glucose intolerance (impaired glucose tolerance [IGT] and impaired fasting glucose [IFG]) in Australia and to compare the prevalence with previous Australian data.

RESEARCH DESIGN AND METHODS—A national sample involving 11,247 participants aged >=25 years living in 42 randomly selected areas from the six states and the Northern Territory were examined in a cross-sectional survey using the 75-g oral glucose tolerance test to assess fasting and 2-h plasma glucose concentrations. The World Health Organization diagnostic criteria were used to determine the prevalence of abnormal glucose tolerance.

RESULTS—The prevalence of diabetes in Australia was 8.0% in men and 6.8% in women, and an additional 17.4% of men and 15.4% of women had IGT or IFG. Even in the youngest age group (25–34 years), 5.7% of subjects had abnormal glucose tolerance. The overall diabetes prevalence in Australia was 7.4%, and an additional 16.4% had IGT or IFG. Diabetes prevalence has more than doubled since 1981, and this is only partially explained by changes in age profile and obesity.

CONCLUSIONS—Australia has a rapidly rising prevalence of diabetes and other categories of abnormal glucose tolerance. The prevalence of abnormal glucose tolerance in Australia is one of the highest yet reported from a developed nation with a predominantly Europid background.

Abbreviations: 2hPG, 2-h plasma glucose • AusDiab, Australian Diabetes, Obesity and Lifestyle Study • CD, Census Collector District • FPG, fasting plasma glucose • IFG, impaired fasting glucose • IGT, impaired glucose tolerance • KDM, known diabetes mellitus • NDM, newly diagnosed diabetes mellitus • OGTT, oral glucose tolerance test • WHO, World Health Organization