464 research outputs found
Sensitivity of surface radiation budget to clouds over the Asian monsoon region
Using the ISCCP-FD surface radiative flux data for the summer season (June to September) of the period 1992 to 1995, an analysis was done to understand the role of clouds on the surface radiation budget over the Asian monsoon region. At the top of atmosphere (TOA) of convective regions of the Asian monsoon region, the short wave radiative forcing (SWCRF) and long wave radiative forcing (LWCRF) do not cancel each other resulting in occurrence of the net cloud radiative forcing values exceeding −30 W/m2. This type of imbalance between SWCRF and LWCRF at TOA is reflected down on the earth surface-atmosphere system also as an imbalance between surface netcloud radiative forcing (NETCRF) and atmospheric NETCRF.
Based on the regression analysis of the cloud effects on the surface radiation budget quantities, it has been observed that generally, the variance explained by multiple type cloud data is 50% more than that of total cloud cover alone. In case of SWCRF, the total cloud cover can explain about 3% (7%) of the variance whereas the three cloud type descriptions of clouds can explain about 44% (42%) of the variance over oceanic (land) regions. This highlights the importance of cloud type information in explaining the variations of surface radiation budget. It has been observed that the clouds produce more cooling effect in short-wave band than the warming effect in long-wave band resulting in a net cooling at the surface. Over the oceanic region, variations in high cloud amount contribute more to variations in SWCRF while over land regions both middle and high cloud variations make substantial contributions to the variations in both SWCRF and NETCRF
Monsoon prediction - Why yet another failure?
The country experienced a deficit of 13 in the summer monsoon of 2004. As in 2002, this deficit was not predicted either by the operational empirical models at India Meteorological Department (IMD) or by the dynamical models at national and international centres. Our analysis of the predictions generated by the operational models at IMD from 1932 onwards suggests that the forecast skill has not improved over the seven decades despite continued changes in the operational models. Clearly, new approaches need to be explored with empirical models. The simulation of year-to-year variation of the monsoon is still a challenging problem for models of the atmosphere as well as the coupled ocean-atmosphere system. We expect dynamical models to generate better prediction only after this problem is successfully addressed
Monsoon variability: Links to major oscillations over the equatorial Pacific and Indian oceans
In this article, we first discuss our perception of the factors which are critical for inter-annual variation of the Indian summer monsoon rainfall and the major milestones leading to this understanding. The nature of the two critical modes for monsoon variability, viz. El Nino Southern Oscillation and equatorial Indian Ocean Oscillation is considered and their links to the monsoon elucidated. We suggest possible reasons for the rather poor skill of simulation of the interannual variation of the Indian summer monsoon rainfall by atmospheric general circulation models, run with the observed sea surface temperature as boundary condition. We discuss implications of what we have learned for the monsoon of 2006, and possible use of information on the two important modes for prediction of the rainfall in all or part of the summer monsoon season. We conclude with our view of what the focus of research and development should be for achieving a substantial improvement in the skill of simulation and prediction of the Indian summer monsoon rainfall in the near future
Prediction of Indian rainfall during the summer monsoon season on the basis of links with equatorial Pacific and Indian Ocean climate indices
Interannual variation of Indian summer monsoon rainfall (ISMR) is linked to El Niño-Southern oscillation (ENSO) as well as the Equatorial Indian Ocean oscillation (EQUINOO) with the link with the seasonal value of the ENSO index being stronger than that with the EQUINOO index. We show that the variation of a composite index determined through bivariate analysis, explains 54% of ISMR variance, suggesting a strong dependence of the skill of monsoon prediction on the skill of prediction of ENSO and EQUINOO. We explored the possibility of prediction of the Indian rainfall during the summer monsoon season on the basis of prior values of the indices. We find that such predictions are possible for July–September rainfall on the basis of June indices and for August–September rainfall based on the July indices. This will be a useful input for second and later stage forecasts made after the commencement of the monsoon seaso
Vegetation Change Detection in Mullaitivu District by using Remote Sensing and GIS Techniques
Landuse and land cover change over time in the world due to uncontrollable rate of population growth and improper resource management which change the natural environment profoundly. Several studies were carried out on the land uses and land covers changes in Sri Lanka. However, little information available on land use and vegetation change in northern parts of the country. Therefore, the objective of the study is to detect the vegetation change in Mullaitivu district of Sri Lanka using Remote Sensing (RS) and Geographic Information System (GIS). In this study, multispectral remotely sensed data of Landsat was used to prepare the land use and land covermap on fourconsecutive years of 2013, 2014, 2016 and 2017. The vegetation change detection was assessed by applying ArcGIS 10.2 through unsupervised classification. Normalised Difference Vegetation Index (NDVI) was used to develop the land use map of the district. The results of this study revealed that areas under vegetation land use such as agriculture, sparse and plantation forest and dense forest were decreased from 2013 to 2017. Changed area of agriculture land use, sparse and plantation forest, and dense forest was 2.3%, 3.6% and 5.2%, respectively and these results showed that about 11% of deduction was observed by vegetation change. However, areas under buildup area was increased by 14% from 2013 to 2017. Area under dense forest was highly decreased followed by open and plantation forest and at the same time area under buildup was increased during same period. However, higher percentage of areas was negatively changed by dense and open-plantation forest. Similarly, higher percentage of areas was positively changed by buildup. These results were clearly indicated that areas under vegetation change was negatively correlated with areas under buildup change and vegetation was highly decreased due to the buildup activities. Therefore, existing policies and legislation should be strictly implemented and amended to conserve the forest in the study areas.Keywords: GIS, Mullaitivu, NDVI, Remotes sensing, Vegetation chang
Exocrine pancreatic insufficiency following gastrectomy and quality of life in patients undergoing gastric resection for malignancy
BACKGROUND:
Gastrectomy for adenocarcinoma stomach is a major procedure that causes significant morbidity to the patient and can influence the quality of life of patients. One major concerns following gastrectomy is the complaints of post-operative steatorrhea and weight loss which is attributed to lipid malabsorption. One of the postulated causes of lipid malabsorption following gastrectomy and Roux en Y reconstruction is exocrine pancreatic enzyme insufficiency.
AIM AND OBJECTIVES:
To find the incidence of exocrine pancreas insufficiency following gastrectomy, for gastric cancer and to assess the quality of life in patients undergoing gastric resection for malignancy.
MATERIALS AND METHOD:
This was a cross-sectional study among patients undergoing gastric resection for adenocarcinoma in the Upper GI surgical unit, Department of General Surgery in Christian Medical College, Vellore. Patients planned for gastrectomy fulfilling the study recruitment criteria and consented for the study were tested for stool elastase pre-operatively and post-operatively. Continuous sampling of all eligible patients were done till sample size was reached. All patients who underwent gastrectomy for adenocarcinoma stomach during the study period in 2017 were assessed for quality of life using a semi structured questionnaire from a validated questionnaire EORTC QLQ C30 and EORTC QLQ STO22 during their postoperative period. Retrospective QOL analysis was performed on the patients who had undergone gastrectomy for adenocarcinoma stomach between the years 2013 and 2016. Data was entered using Epidata 3.1 and analysed using SPSS 23.
RESULTS:
The incidence of exocrine pancreatic insufficiency calculated by stool elastase testing in subtotal and total gastrectomy was 40% and 16.7% respectively. The overall incidence of exocrine pancreatic insufficiency in gastrectomy was 34.6% None of the patients in the study had significant clinical symptoms suggestive of steatorrhea or fat malabsorption. The was no statistical difference between total and subtotal gastrectomy with the incidence of exocrine pancreatic insufficiency. More number of patients at 1-year follow-up have higher pain and eating restriction score which decreases as the follow up time period increases. Quality of life score was not influenced by the type of gastrectomy, method of surgery, stage of disease at presentation or the resection intent. As the follow up time period from time of surgery increases by a month, the overall quality of life score decreases by 2 points.
CONCLUSIONS:
The incidence of exocrine pancreatic insufficiency following gastric resection for malignancy is low in our population compared to the Western data. Routine supplementation of pancreatic enzyme supplements to all patients undergoing gastrectomy may not be required. However, screening for pancreatic insufficiency by stool elastase testing, in the subgroup of patients who are malnourished or have symptoms of fat malabsorption may help detect this problem, which can be addressed effectively by exocrine pancreatic supplementation
Management strategies of Mootrashmari through Panchakarma
Ashmari is a word termed for those objects resembling stone. Acharya Sushruta described it as one of the Ashta-Mahagadas. He also termed it as ‘Yama’ because it gives intolerable pain. Charaka mentioned Ashmari as one of Bastimarmashritha Vyadhi. In modern science, it is correlated with Urolithiasis. Urolithiasis is the condition where urinary stones are formed or located anywhere in the urinary system. In the modern arena, for Mootrashmari (Urolithiasis) surgical procedures are the only treatment of choice which are not conducive enough as they have the disadvantages of high expenditure, side effects and disease recurrence. present era have highly appreciated the importance and therapeutic efficacy of Panchakarma and has become the integral part of Ayurvedic treatment. Therefore, the Panchakarma modalities are the conservative line of treatments to overcome Mootrashmari
Development of a high resolution land surface dataset for the South Asian monsoon region
In this study, we report the development of a high
resolution land surface dataset for the South Asian
monsoon region for studies on land surface processes,
and land and atmosphere coupling. The high resolu-
tion land data assimilation system was used to develop
the land surface dataset utilizing TRMM rainfall and
ECMWF atmospheric variables as forcing parameters. The dataset was developed at a spatial resolution of 0.5° and temporal resolution of 1 h and spans a period of 6 years, i.e. 1 January 2005 to 31 December 2010. The major highlights in the development of the present dataset are higher spatial and temporal resolution of land surface parameters, use of sub-daily forcing parameters including rainfall, use of MODIS land-use data in lieu of USGS land-use data and weekly varying vegetation fraction instead of monthly vegetation climatology. A comparison of soil moisture and soil temperature with limited surface observations of the IMD suggests reasonable reliability of the land surface data. The model sensible heat flux data are compared with in situ measurements at Ranchi and MEERA reanalysis data. The sensitivity analysis shows that the land surface data are sensitive to rainfall and green vegetation cover data used as the forcing parameters. The dataset has been used to discuss the variations of land surface processes associated with active and break spells and a severe heat wave observed in 2009. The present dataset will be useful for many applications, including initializing numerical models for weather prediction. This high resolution land surface dataset is available for research on request
Determination of quantitative and site-specific DNA methylation of perforin by pyrosequencing
<p>Abstract</p> <p>Background</p> <p>Differential expression of perforin (<it>PRF1</it>), a gene with a pivotal role in immune surveillance, can be attributed to differential methylation of CpG sites in its promoter region. A reproducible method for quantitative and CpG site-specific determination of perforin methylation is required for molecular epidemiologic studies of chronic diseases with immune dysfunction.</p> <p>Findings</p> <p>We developed a pyrosequencing based method to quantify site-specific methylation levels in 32 out of 34 CpG sites in the <it>PRF1 </it>promoter, and also compared methylation pattern in DNAs extracted from whole blood drawn into PAXgene blood DNA tubes (whole blood DNA) or DNA extracted from peripheral blood mononuclear cells (PBMC DNA) from the same normal subjects. Sodium bisulfite treatment of DNA and touchdown PCR were highly reproducible (coefficient of variation 1.63 to 2.18%) to preserve methylation information. Application of optimized pyrosequencing protocol to whole blood DNA revealed that methylation level varied along the promoter in normal subjects with extremely high methylation (mean 86%; range 82–92%) in the distal enhancer region (CpG sites 1–10), a variable methylation (range 49%–83%) in the methylation sensitive region (CpG sites 11–17), and a progressively declining methylation level (range 12%–80%) in the proximal promoter region (CpG sites 18–32) of <it>PRF1</it>. This pattern of methylation remained the same between whole blood and PBMC DNAs, but the absolute values of methylation in 30 out of 32 CpG sites differed significantly, with higher values for all CpG sites in the whole blood DNA.</p> <p>Conclusion</p> <p>This reproducible, site-specific and quantitative method for methylation determination of <it>PRF1 </it>based on pyrosequencing without cloning is well suited for large-scale molecular epidemiologic studies of diseases with immune dysfunction. PBMC DNA may be better suited than whole blood DNA for examining methylation levels in genes associated with immune function.</p
16S rRNA gene taxonomic profiling of endophytic bacteria associated with phylaenopsis roots
Orchids are one of the main groups of ornamental plants commercially exploited. In the present study, we analyzed the diversity of bacterial community in Phalaenopsis root using metagenomic approach. The diversity of bacterial taxonomic category was assessed at different Operational Taxonomic Unit (OTU) levels using Ribosomal Database Project (RDP) pipeline and MG-RAST. At phylum level, Proteobacteria (61.34%) was the most dominant group followed by unclassified derived from bacteria (24.74%) and Actinobacteria (12.52%). Genus level analysis revealed the abundance of Rubrobacter, Pseudomonas and Acinetobacter. The study revealed that of the total species detected 50.83 per cent were unclassified, stressing the importance of metagenomics to assess the diversity of endophytes associated with orchid roots
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