LAND USE LEGACY REGULATES MICROBIAL COMMUNITY STRUCTURE AND FUNCTION IN TRANSPLANTED CHERNOZEMS

Understanding long-term agricultural influences on soil nutrients and microbial dynamics is often complicated by the heterogeneity of soil environments as well as complex interactions between confounding factors of climate, topography and hydrology. A long-term soil transplant experiment located at the Agriculture and Agri-Food Canada (AAFC) Research Center in Lethbridge, AB provided a unique opportunity to study the long-term effects of agriculture management practices on various soil types, independent of these confounding effects. In 1990, a variety of Chernozemic soils were relocated to a common location and subsequently managed under common conditions. The experiment was a split plot design with soil type and rate of nitrogen (N) fertilizer (0 and 60 kg N ha-1) as the main and subplot factors, respectively and crop residues were removed annually at harvest. A 2012 survey of soil microbial abundance and community structure revealed distinct communities among 10 different soil types, indicating a persistent legacy effect of previous land use, irrespective of the common climatic, topography and management. Next, DNA profiling of archived soils from 1990 and 2011 showed that the contemporary community structures differed from the original 1990 soils but that the degree of divergence was generally linked to the original soil fertility. Thus, although soil fertility of individual transplanted soils changed with common management, variability among soils persisted. Specific differences among transplanted soil microbial community structures were reflected in carbon (C) and N cycling bacteria. For example, nitrifying and denitrifying gene abundance and composition varied among transplanted soils. A 13C stable isotope tracing experiment determined that community composition and function of active cellulose decomposers was different among soils indicating that the subset of the whole soil communities that was active also remained different between transplanted soils, despite common conditions. Overall, soil fertility integrates aspects of pedogenesis, land use and management history which resulted in a legacy effect on the microbial community abundance, composition and function which was more dominant than current conditions. These findings help to broaden our understanding of dominant drivers of agricultural soil ecosystem functioning and microbial communities which will be necessary for predicting the fate of future agricultural systems

Soil origin and land use history determine C cycling in transplanted soils after 21 years

Non-Peer Reviewe

Assessing microbial communities in transplanted soils after 21 years

Non-Peer Reviewe

Response of transplanted Chernozems towards C addition after 21 years of identical climatic, topographic, and management practices

Non-Peer Reviewe

Prevalence, Trends and Associated Socio-Economic Factors of Obesity in South Asia

Aim: Worldwide obesity levels have increased unprecedentedly over the past couple of decades. Although the prevalence, trends and associated socio-economic factors of the condition have been extensively reported in Western populations, less is known regarding South Asian populations. Methods: A review of articles using Medline with combinations of the MeSH terms: 'Obesity', ‘Overweight’ and ‘Abdominal Obesity’ limiting to epidemiology and South Asian countries. Results: Despite methodological heterogeneity and variation according to country, area of residence and gender, the most recent nationally representative and large regional data demonstrates that without any doubt there is an epidemic of obesity, overweight and abdominal obesity in South Asian countries. Prevalence estimates of overweight and obesity (based on Asian cut-offs: overweight ≥ 23 kg/m[superscript]2, obesity ≥ 25 kg/m[superscript]2) ranged from 3.5% in rural Bangladesh to over 65% in the Maldives. Abdominal obesity was more prevalent than general obesity in both sexes in this ethnic group. Countries with the lowest prevalence had the highest upward trend of obesity. Socio-economic factors associated with greater obesity in the region included female gender, middle age, urban residence, higher educational and economic status. Conclusion: South Asia is significantly affected by the obesity epidemic. Collaborative public health interventions to reverse these trends need to be mindful of many socio-economic constraints in order to provide long-term solutions

Quantifying urbanisation as a risk factor for non-communicable disease

Aim of this study was to investigate the poorly understood relationship between the process of urbanization and non-communicable diseases (NCDs) in Sri Lanka using a multi-component, quantitative measure of urbanicity.NCD prevalence data were taken from the Sri Lankan Diabetes and Cardiovascular Study comprising a representative sample of people from seven of the nine provinces in Sri Lanka (n=4,485/5,000; response rate=89.7%). We constructed a measure of the urban environment for seven areas using a seven-item scale based on data from study clusters to develop an ―urbanicity&rdquo; scale. The items were population size, population density, and access to markets, transportation, communications/media, economic factors, environment/sanitation, health, education, and housing quality. Linear and logistic regression models were constructed to examine the relationship between urbanicity and chronic disease risk factors.Among men, urbanicity was positively associated with physical inactivity (OR: 3.22; 2.27 &ndash; 4.57), high body mass index (OR: 2.45; 95% CI: 1.88 &ndash; 3.20) and diabetes mellitus (OR: 2.44; 95% CI: 1.66 &ndash; 3.57). Among women, too, urbanicity was positively associated with physical inactivity (OR: 2.29; 95% CI: 1.64 &ndash; 3.21), high body mass index (OR: 2.92;95% CI: 2.41 &ndash; 3.55) and diabetes mellitus (OR: 2.10; 95% CI: 1.58 &ndash; 2.80).There is a clear relationship between urbanicity and common modifiable risk factors for chronic disease in a representative sample of Sri Lankan adults.<br /

Study protocol: a randomised controlled trial of supervised resistance training versus aerobic training in Sri Lankan adults with type 2 diabetes mellitus: SL-DART study

Background: The prevalence of type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD) is rising globally. T2DM is particularly problematic in South Asia with an estimated 10–15% of Sri Lankans diagnosed with the disease. Exercise is known to improve blood glucose, lipid profiles, blood pressure and adiposity, key goals in the management of T2DM. However, much of the evidence to date has been gained from white Caucasians who have a different body composition and disease profile compared to South Asians. Similarly, the recreational exercise culture is new to Sri Lankans and the effects of exercise on T2DM has not been studied in this population. Methods: The Sri Lanka Diabetes Aerobic and Resistance Training (SL-DART) Study will be comprised of 2 components. Component 1 is a 12-week randomized controlled trial (RCT) to compare the effects of a supervised progressive resistance exercise program (RT) and aerobic exercise program (AT) with standard treatment/control (CN). Sedentary Sri Lankan adults with T2DM (aged 35–65 years) and with no contraindications to exercise will be randomized into one of 3 groups (AT, RT, CN). Exercise sessions will be conducted 2 days/week for 3 months. Baseline and post-intervention biochemical (glycemic control, lipid and liver profiles, inflammatory markers), anthropometric (height, weight, body circumferences), body composition, physical fitness, food preference (liking and wanting food) and quality of life parameters will be measured and compared between groups. Component 2 will be a qualitative study conducted immediately post-intervention via in-depth interviews to assess the barriers and facilitators for adherence to each exercise program. Discussion: SL-DART Study represents one of the first adequately powered methodologically sound RCTs conducted in South Asia to assess the effects of resistance and aerobic exercise in participants with T2DM. Triangulation of quantitative and qualitative outcomes will enable the design of a culturally appropriate therapeutic physical activity intervention for Sri Lankans with T2DM, and the initiation of a professionally driven and specialized clinical exercise prescription service

Energy and nutrient intakes among Sri Lankan adults

Introduction: The epidemic of nutrition related non-communicable diseases such as type 2 diabetes mellitus and obesity has reached to epidemic portion in the Sri Lanka. However, to date, detailed data on food consumption in the Sri Lankan population is limited. The aim of this study is to identify energy and major nutrient intake among Sri Lankan adults. Methods: A nationally-representative sample of adults was selected using a multi-stage random cluster sampling technique. Results: Data from 463 participants (166 Males, 297 Females) were analyzed. Total energy intake was significantly higher in males (1913 ± 567 kcal/d) than females (1514 ± 458 kcal/d). However, there was no significant gender differences in the percentage of energy from carbohydrate (Male: 72.8 ± 6.4%, Female: 73.9 ± 6.7%), fat (Male: 19.9 ± 6.1%, Female: 18.5 ± 5.7%) and proteins (Male: 10.6 ± 2.1%, Female: 10.9 ± 5.6%). Conclusion: The present study provides the first national estimates of energy and nutrient intake of the Sri Lankan adult population

High dietary diversity is associated with obesity in Sri Lankan adults: An evaluation of three dietary scores.

Background: Dietary diversity is recognized as a key element of a high quality diet. However, diets that offer a greater variety of energy-dense foods could increase food intake and body weight. The aim of this study was to explore association of diet diversity with obesity in Sri Lankan adults. Methods: Six hundred adults aged > 18 years were randomly selected by using multi-stage stratified sample. Dietary intake assessment was undertaken by a 24 hour dietary recall. Three dietary scores, Dietary Diversity Score (DDS), Dietary Diversity Score with Portions (DDSP) and Food Variety Score (FVS) were calculated. Body mass index (BMI) ≥ 25 kg.m−2 is defined as obese and Asian waist circumference cut-offs were used diagnosed abdominal obesity. Results: Mean of DDS for men and women were 6.23 and 6.50 (p=0.06), while DDSP was 3.26 and 3.17 respectively (p=0.24). FVS values were significantly different between men and women 9.55 and 10.24 (p=0.002). Dietary diversity among Sri Lankan adults was significantly associated with gender, residency, ethnicity, education level but not with diabetes status. As dietary scores increased, the percentage consumption was increased in most of food groups except starches. Obese and abdominal obese adults had the highest DDS compared to non-obese groups (p<0.05). With increased dietary diversity the level of BMI, waist circumference and energy consumption was significantly increased in this population. Conclusion: Our data suggests that dietary diversity is positively associated with several socio-demographic characteristics and obesity among Sri Lankan adults. Although high dietary diversity is widely recommended, public health messages should emphasize to improve dietary diversity in selective food items