A comparative evaluation of frictional resistance and surface roughness of silver coated and uncoated stainless-steel bracket wire assembly- An in-vitro study

Silver ions act as potent antimicrobial agents. Silver coating of brackets and the archwires can help reduce the formation of white spot lesions and caries which is commonly seen with fixed orthodontic treatment. However, this may affect the friction and surface roughness of the bracket-wire assembly which in turn affects the biological tooth movement. MATERIAL AND METHODS: A total of 60 samples were included in the study which was divided into four groups. Group-1: * 15 silver coated 0.022 x 0.028" slot MBT prescription maxillary central incisor brackets * 15 silver coated 0.019 x 0.025" stainless-steel wires; Group-2: * 15 uncoated 0.022 x 0.028" slot MBT prescription maxillary central incisor brackets * 15 silver coated 0.019 x 0.025" stainless-steel wires; Group-3: * 15 silver coated 0.022 x 0.028" slot MBT prescription maxillary central incisor brackets * 15 uncoated 0.019 x 0.025" stainless-steel wires; Group-4: * 15 uncoated 0.022x0.028" slot MBT prescription maxillary central incisor brackets * 15 uncoated 0.019 x 0.025" stainless-steel wires. All brackets and wires used were of American Orthodontics, St. Paul, USA. Surface modification of wires and brackets was carried out using the Vacuum Coating Unit model by Thermal Vacuum Evaporation method with silver nanoparticles (10 nm size). The frictional resistance of all brackets and wires was checked using Universal Testing Machine. RESULTS: On comparison of maximum load, it was found that friction was highest in group 3, followed by group 1, group 4 and group 2. The mean difference between all groups was found to be statistically significant with a P value Group 1> Group 2> Group 3 *Wire roughness: Group 4> Group 1> Group 2> Group 3. CONCLUSIONS: This study concluded that friction was least when only the wire was coated with silver and the bracket was uncoated and it was the most when the bracket was coated and the wire was uncoated. The surface roughness after the friction test was the least when the wire was uncoated. Key words:Silver nanoparticles, Frictional Resistance, Surface Roughness

Melatonin induces drought tolerance by modulating lipoxygenase expression, redox homeostasis and photosynthetic efficiency in Arachis hypogaea L

Melatonin (N-acetyl-5-hydroxy tryptamine), a multipotent biomolecule is well known for its ability to confer tolerance to several abiotic and biotic stresses. The regulation of melatonin-mediated drought tolerance in drought-distinguished varieties can be different due to discriminating redox levels. The present study was focused on assessing the effects of melatonin priming against polyethylene glycol (PEG)-induced stress with respect to the antioxidant system, photosynthetic parameters, lipoxygenase expression, JA and ABA levels in drought-sensitive (Kadiri-7) and drought-tolerant (Kadiri-9) varieties. Exogenous melatonin alleviated the drought stress effects in sensitive variety (Kadiri-7) by increasing the endogenous melatonin content with an improved antioxidant system and photosynthetic attributes. The primed stressed plants of the sensitive variety exhibited reduced expression and activity of the chlorophyll degrading enzymes (Chl-deg PRX, pheophytinase and chlorophyllase) with a concomitant increase in chlorophyll content in comparison to unprimed controls. Interestingly, melatonin priming stimulated higher expression and activity of lipoxygenase (LOX) as well as enhanced the expression of genes involved in the synthesis of jasmonic acid (JA) including its content in drought stressed plants of the sensitive variety. The expression of NCED3 (involved in ABA-biosynthesis) was upregulated while CYP707A2 (ABA-degradation) was downregulated which corresponded with higher ABA levels. Contrastingly, priming caused a decrease in endogenous melatonin content under drought stress in tolerant variety (Kadiri-9) which might be due to feedback inhibition of its synthesis to maintain intracellular redox balance and regulate better plant metabolism. Furthermore, the higher endogenous melatonin content along with improved antioxidant system, photosynthetic efficiency and LOX expression associated with the increased levels of JA and ABA in unprimed stressed plants of the tolerant variety (Kadiri-9) is pointing towards the effectiveness of melatonin in mediating drought stress tolerance. Overall, exogenous melatonin alleviated the adverse effects of drought stress in sensitive variety while having no add-on effect on drought stress responses of tolerant variety which is inherently equipped to withstand the given duration of drought stress treatment

Albuminuria and Diabetic Retinopathy in Type 2 Diabetes Mellitus Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular Genetic Study (SN-DREAMS, report 12)

<p>Abstract</p> <p>Background</p> <p>The concordance of microalbuminuria and diabetic retinopathy (DR) has been well reported in persons with type 1 diabetes; however, for type 2 diabetes, there is paucity of data especially from population-based studies. The aim of this study was to estimate the prevalence of albuminuria (micro - and macroalbuminuria) among persons with type 2 diabetes and determine its role as a risk factor for presence and severity of DR.</p> <p>Methods</p> <p>A population-based cross sectional study was conducted in cohort of 1414 subjects with type 2 diabetes from Chennai metropolis. All the subjects underwent comprehensive eye examination including 45 degrees four-field stereoscopic digital photography. DR was clinically graded using Early Treatment Diabetic Retinopathy Study scales. A morning urine sample was tested for albuminuria. Subjects were considered to have microalbuminuria, if the urinary albumin excretion was between 30 and 300 mg/24 hours, and macroalbuminuria at more than 300 mg/24 hours. The statistical software used was SPSS for Windows, Chicago, IL. Student t-test for comparing continuous variables, and <it>χ</it>²test, to compare proportions amongst groups were used.</p> <p>Results</p> <p>The prevalence of microalbuminuria in the study subjects was 15.9% (226/1414), and that of macroalbuminuria, 2.7% (38/1414). Individuals with macroalbuminuria in comparison to micro- or normoalbuminuria showed a greater prevalence of DR (60.5% vs. 31.0% vs. 14.1%, p < 0.001), and also a greater severity of the disease (60.9% vs. 21.4 vs. 9.9, p < 0.001).</p> <p>Conclusions</p> <p>Every 6^thindividual in the population of type 2 diabetes is likely to have albuminuria. Subjects with microalbuminuria were around 2 times as likely to have DR as those without microalbuminuria, and this risk became almost 6 times in the presence of macroalbuminuria.</p

Mainstreaming Gender and Empowering Women in Agriculture in the Thar Region of India, Research Report No 69

Social inequities based on gender norms reinforce nonparticipation of women in decision making at various levels, consequently depriving them of the benefits arising out of any technological advances. These advances could be in all fields in general, and in particular financial services. Integration of a gender responsive approach in all development initiatives assumes great importance in the context of economic relations in an agrarian economy. Despite the fact that women contribute immensely to agriculture and allied activities and consequently to food security, rural economy and development, their contributions go largely unrecognized. The need to empower women and mainstream gender in agriculture is necessary not only due to the extent and importance of their contribution but also for ensuring creation of equitable economic relations and progressive social milieu. This is important to build capacity of the large human capital (women) supporting agricultural production, marketing and consumption. As part of the CGIAR Research Program on ‘Dryland Systems: Integrated Agriculture Production System for the Poor and Vulnerable in Dry Areas’, ICRISAT in collaboration with GRAVIS, has implemented a project in eight randomly identified villages in three districts - Barmer, Jaisalmer and Jodhpur in western Rajasthan. The program is aimed at developing technological, policy and institutional innovations to improve food security and livelihoods using an integrated systems approach. The project reaches out directly to more than 3000 poor rural farming households, about 11% of which are headed by women..

Techniques to screen sorghums for resistance to insect pests

Sorghum is an important cereal crop in Asia, Africa, Americas and Australia. Grain yields on farmers’ fi elds in Asia and Africa are generally low (500−800 kg ha-1) mainly due to insect pest damage. Nearly 150 insect species have been reported as pests on sorghum (Sharma 1993), of which sorghum shoot fl y (Atherigona soccata), stem borers (Chilo partellus, Busseola fusca, Eldana saccharina and Diatraea spp.), armyworms (Mythimna separata, Spodoptera frugiperda and S. exempta), shoot bug (Peregrinus maidis), aphids (Schizaphis graminum and Melanaphis sacchari), spider mites (Oligonychus spp.), grasshoppers and locusts (Hieroglyphus, Oedaleus, Aliopus, Schistocerca, and Locusta), sorghum midge (Stenodiplosis sorghicola), mirid head bugs (Calocoris angustatus and Eurystylus oldi), and head caterpillars (Helicoverpa, Eublemma, Cryptoblabes, Pyroderces, and Nola) are the major pests worldwide. Other insects reported to be damaging sorghum are of regional/local importance. Annual losses due to insect pests differ in magnitude on a regional basis. They have been estimated to be $1,089 million in the semi-arid tropics (SAT),$250 million in United States, and $80 million in Australia (ICRISAT 1992). In India, nearly 32% of sorghum crop is lost due to insect pests (Borad and Mittal 1983)

Comparative mapping of Brassica juncea and Arabidopsis thaliana using Intron Polymorphism (IP) markers: homoeologous relationships, diversification and evolution of the A, B and C Brassica genomes

Background: Extensive mapping efforts are currently underway for the establishment of comparative genomics between the model plant, Arabidopsis thaliana and various Brassica species. Most of these studies have deployed RFLP markers, the use of which is a laborious and time-consuming process. We therefore tested the efficacy of PCR-based Intron Polymorphism (IP) markers to analyze genome-wide synteny between the oilseed crop, Brassica juncea (AABB genome) and A. thaliana and analyzed the arrangement of 24 (previously described) genomic block segments in the A, B and C Brassica genomes to study the evolutionary events contributing to karyotype variations in the three diploid Brassica genomes. Results: IP markers were highly efficient and generated easily discernable polymorphisms on agarose gels. Comparative analysis of the segmental organization of the A and B genomes of B. juncea (present study) with the A and B genomes of B. napus and B. nigra respectively (described earlier), revealed a high degree of colinearity suggesting minimal macro-level changes after polyploidization. The ancestral block arrangements that remained unaltered during evolution and the karyotype rearrangements that originated in the Oleracea lineage after its divergence from Rapa lineage were identified. Genomic rearrangements leading to the gain or loss of one chromosome each between the A-B and A-C lineages were deciphered. Complete homoeology in terms of block organization was found between three linkage groups (LG) each for the A-B and A-C genomes. Based on the homoeology shared between the A, B and C genomes, a new nomenclature for the B genome LGs was assigned to establish uniformity in the international Brassica LG nomenclature code. Conclusion: IP markers were highly effective in generating comparative relationships between Arabidopsis and various Brassica species. Comparative genomics between the three Brassica lineages established the major rearrangements, translocations and fusions pivotal to karyotype diversification between the A, B and C genomes of Brassica species. The inter-relationships established between the Brassica lineages vis-&#224;-vis Arabidopsis would facilitate the identification and isolation of candidate genes contributing to traits of agronomic value in crop Brassicas and the development of unified tools for Brassica genomics

Degradation of the insecticidal toxin produced by Bacillus thuringiensis var. kurstaki by extracellular proteases produced by Chrysosporium sp.

Aims:  Some Cry proteins produced by the soil bacterium Bacillus thuringiensis (Bt) or by transgenic Bt plants persist in agricultural soils for an extended period of time, which may pose a hazard for nontarget soil organisms. The aims of our study were to screen for soil fungi capable of degrading the Cry1Ac toxin and to identify the mechanisms that lead to the inactivation of this protein.Methods and Results:  Of the eight fungal strains screened, only one, Chrysosporium sp., was found to produce extracellular proteases capable of degrading the 66-kDa Cry1Ac at the N-terminal end of amino acid 125 (alanine). The proteolytic products of the Cry1Ac toxin did not exhibit any insecticidal activity against Helicoverpa armigera, in contrast to its high toxicity exhibited in the native form.Conclusions:  Proteases elaborated by the Chrysosporium sp. degrade the Cry1Ac toxin in a way that it looses its insecticidal activity against H. armigera.Significance and Impact of the Study: Chrysosporium sp., a specific soil micro-organism capable of producing proteases that degrade the Cry1Ac toxin into inactive products under controlled conditions is being reported for the first time. Application of this observation needs to be further tested in field conditions

Diagonal ear lobe crease in diabetic south Indian population: Is it associated with Diabetic Retinopathy?. Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular-genetics Study (SN-DREAMS, Report no. 3)

<p>Abstract</p> <p>Background</p> <p>To report the prevalence of ear lobe crease (ELC), a sign of coronary heart disease, in subjects (more than 40 years old) with diabetes and find its association with diabetic retinopathy.</p> <p>Methods</p> <p>Subjects were recruited from the Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular-genetics Study (SN-DREAMS), a cross-sectional study between 2003 and 2006; the data were analyzed for the1414 eligible subjects with diabetes. All patients' fundi were photographed using 45° four-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on the modified Klein classification. The presence of ELC was evaluated on physical examination.</p> <p>Results</p> <p>The prevalence of ELC, among the subjects with diabetes, was 59.7%. The ELC group were older, had longer duration of diabetes, had poor glycemic control and had a high socio-economic status compared to the group without ELC and the variables were statistically significant. There was no statistical difference in the prevalence of diabetic retinopathy in two groups. On multivariate analysis for any diabetic retinopathy, the adjusted OR for women was 0.69 (95% CI 0.51-0.93) (p = 0.014); for age >70 years, 0.49 (95% CI 0.26-0.89) (p = 0.024); for increasing duration of diabetes (per year increase), 1.11(95% CI 1.09-1.14) (p < 0.0001); and for poor glycemic control (per unit increase in glycosylated heamoglobin), 1.26 (95% CI 1.19-1.35) (p < 0.0001). For sight-threatening diabetic retinopathy, no variable was significant on multivariable analysis. In predicting any diabetic retinopathy, the presence of ELC had sensitivity of 60.4%, and specificity, 40.5%. The area under the ROC curve was 0.50 (95% CI 0.46-0.54) (p 0.02).</p> <p>Conclusion</p> <p>The ELC was observed in nearly 60% of the urban south Indian population. However, the present study does not support the use of ELC as a screening tool for both any diabetic retinopathy and sight-threatening retinopathy.</p

Chemical Characterization of Selected Benchmark Spots for C Sequestration in the Semi-Arid Tropics, India. Global Theme on Agroecosystems Report no. 32

Soil organic carbon (SOC) plays an important role as a source of plant nutrients and in maintaining the soil integrity. Any land use management that increases SOC by removing CO2 from the atmosphere by storing it in the soil, is termed as carbon sequestration. This study was conducted to learn about the role of various agricultural practices on soil nutrient dynamics and its relationship with SOC in various land use systems of semi-arid tropics (SAT). The study area covered 28 SAT benchmark spots, 21 out of which were on black soils and 7 on red soils, covering areas of 15.29 m ha and 6.34 m ha, respectively. Soils were sampled from the benchmark sites/pedons during 2000–03 and processed for chemical analysis. It was observed that irrespective of bioclimatic zones, land use under horticultural and agricultural systems in general, and paddy systems in particular, had maximum content of organic carbon and total N. The soil parameter viz. clay fraction also influenced the total N and total P, and hence organic carbon in black and red soils showed significant positive correlation with total N and P. Results indicated that perennials could sequester carbon better when compared to annual crops. The nutrient stocks and soil organic C and N ratio (carbon/nitrogen C:N), and carbon/phosphorus (C:P) were computed in addition to SOC for the purpose of identifying the maintained soil quality. It was observed that the C:N ratio varied from 16:1 to 22:1 under different zones and it was highest under semi-arid (moist) zones in black soils. Similarly C:P ratio of soils under various bioclimatic zones revealed that it was highest under sub-humid (moist), followed by arid zone and lowest under semiarid zones. The C:N ratio of studied soils under various systems was wider than commonly accepted values reported for other tropical soils. The mean total N content of black soils was 0.042% and in case of red soils it was 0.052%, which corresponds to a minimum threshold level of 0.063% and 0.078% for black and red soils, respectively. Thus within the defined range of C:N ratios, those soils having SOC content of above values was considered along with minimum threshold values of total nitrogen stocks (Mg ha-1) to arrive at the better systems. The minimum values of TN stocks was calculated with the established equation and the values for the corresponding levels of SOC was found to be 1.95 Mg ha-1 for black soils and 2.30 Mg ha-1 for red soils (both the soils types having an average bulk density of 1.5 Mg m-3). Thus the soil total N stocks of systems that were found above the minimum threshold values are considered as better production systems. The nutrient stocks and nutrient ratio in addition to soil organic carbon was used as the main criteria to develop the soil C:N index. The index varied between 0.27 and 0.87 with an average of 0.57 under the various systems spread over different bioclimatic zones and soil types. The variation of soil C:N index in different soil types showed that, the fertility status of red soils in terms of SOC and soil nutrient stocks in majority of the pedons was higher as compared to black soils. The variation in the soil C: N index due to bioclimatic zones in black and red soils, showed that semiarid (moist) zone in black soils had the highest soil C: N index while the lowest was observed in sub-humid (moist) zone. As the MAR decreased from 1200 mm to 850 mm, the index increased from 0.30 to 0.38. Thus among the zones, the semi-arid moist was found to sequester more carbon. The variation in soil C:N index in different land use based systems such as horticultural (0.50) and forest systems (0.40) had better C:N index as compared to agricultural system in black soils. In red soils, forest system (0.76) had better C:N index as compared to agricultural system dominated by annual crops. Another significant observation was that permanent fallow land also had the potential to sequester carbon based on the magnitude of soil C:N index. The variation in the soil C:N index with the three major crop based systems studied showed that cereal based cropping systems sequester more carbon as compared to cotton and soybean based systems and can be promoted

Chemical Characterization of Selected Benchmark Spots for C Sequestration in the Semi-Arid Tropics, India

Soil organic carbon (SOC) plays an important role as a source of plant nutrients and in maintaining the soil integrity. Any land use management that increases SOC by removing CO2 from the atmosphere by storing it in the soil, is termed as carbon sequestration. This study was conducted to learn about the role of various agricultural practices on soil nutrient dynamics and its relationship with SOC in various land use systems of semi-arid tropics (SAT). The study area covered 28 SAT benchmark spots, 21 out of which were on black soils and 7 on red soils, covering areas of 15.29 m ha and 6.34 m ha, respectively. Soils were sampled from the benchmark sites/pedons during 2000–03 and processed for chemical analysis. It was observed that irrespective of bioclimatic zones, land use under horticultural and agricultural systems in general, and paddy systems in particular, had maximum content of organic carbon and total N. The soil parameter viz. clay fraction also influenced the total N and total P, and hence organic carbon in black and red soils showed significant positive correlation with total N and P. Results indicated that perennials could sequester carbon better when compared to annual crops. The nutrient stocks and soil organic C and N ratio (carbon/nitrogen C:N), and carbon/phosphorus (C:P) were computed in addition to SOC for the purpose of identifying the maintained soil quality. It was observed that the C:N ratio varied from 16:1 to 22:1 under different zones and it was highest under semi-arid (moist) zones in black soils. Similarly C:P ratio of soils under various bioclimatic zones revealed that it was highest under sub-humid (moist), followed by arid zone and lowest under semiarid zones. The C:N ratio of studied soils under various systems was wider than commonly accepted values reported for other tropical soils. The mean total N content of black soils was 0.042% and in case of red soils it was 0.052%, which corresponds to a minimum threshold level of 0.063% and 0.078% for black and red soils, respectively. Thus within the defined range of C:N ratios, those soils having SOC content of above values was considered along with minimum threshold values of total nitrogen stocks (Mg ha-1) to arrive at the better systems. The minimum values of TN stocks was calculated with the established equation and the values for the corresponding levels of SOC was found to be 1.95 Mg ha-1 for black soils and 2.30 Mg ha-1 for red soils (both the soils types having an average bulk density of 1.5 Mg m-3). Thus the soil total N stocks of systems that were found above the minimum threshold values are considered as better production systems. The nutrient stocks and nutrient ratio in addition to soil organic carbon was used as the main criteria to develop the soil C:N index. The index varied between 0.27 and 0.87 with an average of 0.57 under the various systems spread over different bioclimatic zones and soil types. The variation of soil C:N index in different soil types showed that, the fertility status of red soils in terms of SOC and soil nutrient stocks in majority of the pedons was higher as compared to black soils. The variation in the soil C: N index due to bioclimatic zones in black and red soils, showed that semiarid (moist) zone in black soils had the highest soil C: N index while the lowest was observed in sub-humid (moist) zone. As the MAR decreased from 1200 mm to 850 mm, the index increased from 0.30 to 0.38. Thus among the zones, the semi-arid moist was found to sequester more carbon. The variation in soil C:N index in different land use based systems such as horticultural (0.50) and forest systems (0.40) had better C:N index as compared to agricultural system in black soils. In red soils, forest system (0.76) had better C:N index as compared to agricultural system dominated by annual crops. Another significant observation was that permanent fallow land also had the potential to sequester carbon based on the magnitude of soil C:N index. The variation in the soil C:N index with the three major crop based systems studied showed that cereal based cropping systems sequester more carbon as compared to cotton and soybean based systems and can be promoted