Comparative Soil Organic Carbon Dynamics in Tropical and Subtropical Grassland Ecosystems

Grassland ecosystems play significant role in mitigating the climate change by sequestering atmospheric CO2. One fifth of the total terrestrial C is stored in the root zone of grasslands as soil organic carbon. However, because of lack of proper management, overgrazing, and conversion to crop lands, these grasslands are becoming a source of CO2 emissions. It has been observed that in Imperata grasslands of Northeast India, a third of total C captured annually is lost though CO2 emissions. In the absence of intensified grazing and burning, these grasslands exhibit significantly high capacity to store SOC stocks. On the other hand, Southern grasslands of China inherently have a weak C sink. Grazing and burning together significantly increased CO2 fluxes as observed in Andean grasslands. With the introduction of high yielding grass species and with liberal use of chemical fertilizers, grazing land intensification has been found to rather promote SOC sequestration. It has been observed that in C4 grass species dominated tropical and sub-tropical grasslands; there occurs a rapid transfer of plant C into mineral-dominated C pools. With change of C3 to C4 grass species, the grazer effects rather shift from negative to positive even under decreasing precipitation conditions. Similarly, rise in atmospheric temperatures due to climate change affects grasslands differently depending on the dominating grass species. Graminoids and shrubs appear to benefit from elevated temperatures while forbs are likely to decrease in abundance through competitive elimination. Extreme heat waves and frequent drought events is decreasing the extent and capacity of forests as C sink as compared to grasslands. Grasslands have been shown to be comparatively more resilient to changes in climate. The resilience of grasslands to rising temperatures, drought and fire events helps to preserve sequestered terrestrial C in the root-zone of grassland soil and prevent it from re-entering atmosphere

Drought Mitigation in Bundelkahand Grassland Ecosystem for Improving Livelihood of Farming Community-A Case Study

Bundelkhand grassland ecosystem (23º20´ and 26°20´N latitude and 78°20´ and 81°40´E longitude) is an undulating rain fed region (annual rain fall, 768-1087 mm) spread over an area of 7.08 m ha in central India in the states of Madhya Pradesh and Uttar Pradesh. This region has to support 16 million human and 8.5 million animal populations. Area is prone to surface run off losses, severe soil erosion and increasingly more drought events, leading to only mono-cropping. Lively-hood of the people, which is mainly the live-stock rearing and marginal agriculture, is at stake. In-situ conservation of rain water, forage management, and environmental services are the main issues to be addressed at priority to enhance productivity per unit area of this biome. Development funds amounting to about 1000 million US$, provided for constructing sustainable infrastructure like check-dams, dug-wells, embankments, rising of crest height etc. has significantly improved the surface and ground water resources. Impact evaluation as discussed in this paper includes water resource development, watershed management, crop and live-stock productivity, and rural drinking water. A robust and resilient management system has been developed through farmer’s participatory integrated watershed management program. Major aim is in-situ conservation of the rain water and recharging the dug wells, open wells, village ponds, and farm ponds. It has remarkably improved the financial condition of farming community. Initiation of restoration process of this grassland biome has increased its carrying capacity by 41%. An additional 25% land area has come under irrigation resulting in increase of net-sown area by 11%, cropping intensity by 6%, and farm income by 35%

Synthesis of a stable gold hydrosol by the reduction of chloroaurate ions by the amino acid, aspartic acid

Development of reliable protocols for the synthesis of nanoparticles of well-defined sizes and good monodispersity is an important aspect of nanotechnology. In this paper, we present details of the synthesis of gold nanoparticles of good monodispersity by the reduction of aqueous chloroaurate ions by the amino acid, aspartic acid. The colloidal gold solution thus formed is extremely stable in time, indicating electrostatic stabilization via nanoparticle surface-bound amino acid molecules. This observation has been used to modulate the size of the gold nanoparticles in solution by varying the molar ratio of chloroaurate ions to aspartic acid in the reaction medium. Characterization of the aspartic acid-reduced gold nanoparticles was carried out by UV-visible spectroscopy, thermogravimetric analysis and transmission electron microscopy. The use of amino acids in the synthesis and stabilization of gold nanoparticle in water has important implications in the development of new protocols for generation of bioconjugate materials

One-step synthesis of hydrophobized gold nanoparticles of controllable size by the reduction of aqueous chloroaurate ions by hexadecylaniline at the liquid-liquid interface

Vigorous stirring of a biphasic mixture containing hexadecylaniline in chloroform and aqueous chloroauric acid results in the formation of gold nanoparticles of controllable size in the organic phase

Effect of halogen addition to monolayer protected gold nanoparticles

The effects of N-halosuccinimide and halogen addition to monolayer protected gold nanoparticles (Au NPs) dispersed in organic media are described. Contrary to the expectation that nanoparticles dispersed in organic media are stable against aggregation, N-iodosuccinimide addition induced aggregation of octadecylamine capped gold nanoparticles in chloroform or toluene. It was observed that even KI and CuI addition could bring about the aggregation though they are very sparingly soluble in organic solvents. It was also found that even molecular iodine could bring about the above mentioned aggregation. Interestingly, when CuI is used the aggregated structures readily convert to very thin flat nanostructures upon exposure to an electron beam or UV irradiation. In fact when the aggregation is induced by the addition of KI or N-iodosuccinamide we do not see the flattening of the aggregated structures exemplifying the important role of Cu ions in making these flat structures

Factors related to abdominal pain in gastroparesis: contrast to patients with predominant nausea and vomiting

Background Factors associated with abdominal pain in gastroparesis are incompletely evaluated and comparisons of pain vs other symptoms are limited. This study related pain to clinical factors in gastroparesis and contrasted pain/discomfort‐ with nausea/vomiting‐predominant disease. Methods Clinical and scintigraphy data were compared in 393 patients from seven centers of the NIDDK Gastroparesis Clinical Research Consortium with moderate‐severe (Patient Assessment of Upper Gastrointestinal Disorders Symptoms [ PAGI ‐ SYM ] score ≥3) vs none‐mild ( PAGI ‐ SYM  < 3) upper abdominal pain and predominant pain/discomfort vs nausea/vomiting. Key Results Upper abdominal pain was moderate‐severe in 261 (66%). Pain/discomfort was predominant in 81 (21%); nausea/vomiting was predominant in 172 (44%). Moderate‐severe pain was more prevalent with idiopathic gastroparesis and with lack of infectious prodrome (P ≤ 0.05) and correlated with scores for nausea/vomiting, bloating, lower abdominal pain/discomfort, bowel disturbances, and opiate and antiemetic use (P < 0.05), but not gastric emptying or diabetic neuropathy or control. Gastroparesis severity, quality of life, and depression and anxiety were worse with moderate‐severe pain (P ≤ 0.008). Factors associated with moderate‐severe pain were similar in diabetic and idiopathic gastroparesis. Compared to predominant nausea/vomiting, predominant pain/discomfort was associated with impaired quality of life, greater opiate, and less antiemetic use (P < 0.01), but similar severity and gastric retention. Conclusions & Inferences Moderate‐severe abdominal pain is prevalent in gastroparesis, impairs quality of life, and is associated with idiopathic etiology, lack of infectious prodrome, and opiate use. Pain is predominant in one fifth of gastroparetics. Predominant pain has at least as great an impact on disease severity and quality of life as predominant nausea/vomiting.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97520/1/nmo12091.pd

Baseline features and differences in 48 week clinical outcomes in patients with gastroparesis and type 1 vs type 2 diabetes

BackgroundIn studies of diabetic gastroparesis, patients with type 1 and type 2 diabetes mellitus (T1DM, T2DM) are often combined for analyses. We compared gastroparesis severity, healthcare utilization, psychological function, and quality of life in T1DM vs T2DM gastroparesis patients.MethodsQuestionnaire, laboratory, and scintigraphy data from patients with gastroparesis and T1DM and T2DM from seven centers of the National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium Registry were compared at enrollment and after 48 weeks. Multiple regression models assessed baseline and followâ up differences between diabetes subtypes.Key ResultsAt baseline, T1DM patients (N = 78) had slower gastric emptying, more hospitalizations, more gastric stimulator implantations, higher hemoglobin A1c (HbA1c), and more anxiety vs T2DM patients (N = 59). Independent discriminators of patients with T1DM vs T2DM included worse gastroesophageal reflux disease, less bloating, more peripheral neuropathy, and fewer comorbidities (p â ¤ 0.05). On followâ up, gastrointestinal (GI) symptom scores decreased only in T2DM (p < 0.05), but not in T1DM patients who reported greater prokinetic, proton pump inhibitor, anxiolytic, and gastric stimulator usage over 48 weeks (p â ¤ 0.03). Gastrointestinal symptoms at baseline and 48 weeks with both subtypes were not associated with HbA1c, peripheral neuropathy, psychological factors, or quality of life.Conclusions & InferencesBaseline symptoms were similar in T1DM and T2DM patients, even though T1DM patients had worse gastric emptying delays and higher HbA1c suggesting other factors mediate symptom severity. Symptom scores at 48 weeks decreased in T2DM, but not T1DM patients, despite increased medical and surgical treatment utilization by T1DM patients. Defining causes of different outcomes in diabetic gastroparesis warrants further investigation.This study defined similarities and differences in gastroparesis severity, healthcare utilization, psychological function, and quality of life in patients with type 1 (T1DM) and type 2 (T2DM) diabetes mellitus and gastroparesis. At baseline enrollment, T1DM patients had higher hemoglobin A1c levels and more severe emptying delays, but the severity of GI symptoms was similar to those of patients with T2DM and gastroparesis. After 48 weeks of followâ up, gastroparesis symptom scores significantly decreased in T2DM patients but not in T1DM patients despite increased use of prokinetic, acid suppressant, anxiolytic, and gastric electrical stimulation therapy in the T1DM group.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/122408/1/nmo12800.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122408/2/nmo12800_am.pd

Early satiety and postprandial fullness in gastroparesis correlate with gastroparesis severity, gastric emptying, and water load testing

BackgroundEarly satiety (ES) and postprandial fullness (PPF) are often present in gastroparesis, but the importance of these symptoms in gastroparesis has not been well‐described. The aims were: (i) Characterize ES and PPF in patients with gastroparesis. (ii) Assess relationships of ES and PPF with etiology of gastroparesis, quality of life, body weight, gastric emptying, and water load testing.MethodsGastroparetic patients filled out questionnaires assessing symptoms (PAGI‐SYM) and quality of life (PAGI‐QOL, SF‐36v2). Patients underwent gastric emptying scintigraphy and water load testing.Key Results198 patients with gastroparesis (134 IG, 64 DG) were evaluated. Early satiety was severe or very severe in 50% of patients. Postprandial fullness was severe or very severe in 60% of patients. Severity scores for ES and PPF were similar between idiopathic and diabetic gastroparesis. Increasing severity of ES and PPF were associated with other gastroparesis symptoms including nausea/vomiting, satiety/early fullness, bloating, and upper abdominal pain and GERD subscores. Increasing severity of ES and PPF were associated with increasing gastroparesis severity, decreased BMI, decreased quality of life from PAGI‐QOL and SF‐36 physical health. Increasing severity of ES and PPF were associated with increasing gastric retention of a solid meal and decreased volume during water load test.Conclusions & InferencesEarly satiety and PPF are commonly severe symptoms in both diabetic and idiopathic gastroparesis. Early satiety and PPF severity are associated with other gastroparesis symptom severities, body weight, quality of life, gastric emptying, and water load testing. Thus, ES and PPF are important symptoms characterizing gastroparesis. ClinicalTrials.gov number: NCT NCT01696747.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136370/1/nmo12981_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136370/2/nmo12981.pd