455 research outputs found
Performance of \u3cem\u3eAcacia senegal\u3c/em\u3e L.: Untapped Wealth of Gum Arabic in Rangelands and Grasslands in Arid and Semi-Arid Region of India
Acacia senegal (Linn) Wild a member of Mimosaceae is a small tree of 3-6m in height with umbrella-shaped crown. It is a typical tree of Sahel in Africa from Senegal to red sea and essentially limited to the area between 110 and 160 North, with a wide range of rainfall 100 to 800mm. It spread widely in tropical Africa from Mozambique, Zambia to Somalia, Sudan, Ethiopia, Kenya, Tanzania and Nigeria, and in South Asia in India and Pakistan. In India it is a typical tree of arid regions with a low rainfall of 100-250mm. It is drought resistant and tolerates prolonged dry period of 10-11 months, with maximum temperature reaching 500C with strong winds, but susceptible to frost. It occurs mostly on sand stones and skeletal soils and widely distributed as interspersed species in most of the rangelands and grasslands in arid and semi-arid regions of India. Worldâs 90% gum Arabic is produced from Acacia senegal. The quality of gum is very superior as compared to gum from any other species of Acacia (Andreson, 1990). Nearly 90% of gum Arabic is produced by Republic of Sudan especially from (Kordafan). Production of gum Arabic is meagre in India, and contribution to the world production is negligible. The total annual output of gum Arabic is only 800 Mt compared to world production and consumption of 60,000-70,000 Mt. The domestic production is insufficient even for domestic consumption and more of it is imported from Sudan and Nigeria to meet India\u27s requirements. Gum exudes from cracks in bark of trees, mostly in the dry season. In Sudan the annual yields from young trees ranges from 188 to 2856 g (av. 0.9 kg), and from older trees, 379 to 6754 g (av. 2.0 kg). In India, however, the productivity is low varying from 175 to 550g tree-1 year-1. The main gum producing regions of India where natural as well as planted stands of A. senegal occur are in desert and arid region of Rajasthan, Gujarat, Haryana, and Punjab. The gum yield from various Acacia trees in their natural habitat is very poor.
In arid and semi-arid region of India, particularly in Rajasthan, Gujarat, Haryana, Punjab and Bundelkahand, there is a good scope for extending area for large- scale plantation for production of gum Arabic. The area covered under forest, barren and uncultivable, pasture, oren (temple lands) and community grazing land etc, can be used for commercial plantation of A. senegal. The arid zone of Western Rajasthan is prone to frequent drought and famine and cultivation of gum Arabic can provide livelihood security to desert dwellers. A farmer who has planted 100 trees/ ha at spacing of 10 x 10 m can harvest about 25kg gum assuming average yield of 250g per tree. This would generate revenue of Rs 10000 ha-1 year-1 if, gum is sold at a minimum price of Rs. 400 kg-1. In addition, systematic commercial plantation of Acacia senegal can also provide employment to millions of people towards various planting activities and gum collection. According to an estimate of FAO, gum collection sustains about 0.3 million people and has huge potential of employment.
Integration of Acacia senegal in traditional grazing grounds such as orens and gochars, systematically raised silvopastoral systems and other agroforestry landuse for production of gum Arabic can be a profitable proposition. It will not only provide alternative livelihood options to local people but also increase economic viability and sustainability grasslands and pastures. In consideration of wide variations in gum production in respect to sites, annual rainfall and geographical locations, it imperative to study growth performance of A. senegal in different eco-regions and develop site specific models for optimizing production of gum Arabic. This study is a part of research efforts being made at Central Agroforestry Research Institute, Jhansi, which is one of the co-ordinating centres in the ICAR-network project on Natural Resin and Gums headquartered at Indian Institute of Natural Resin and Gums, Ranchi. The main objective is to develope suitable agroforestry models based on gums and resins yielding trees for Bundelkhand region. This paper presents growth performance of A. senegal in semi-arid region of Bundelkhand, Central India
Carbon Modeling of Agroforestry Systems at Farmersâ Field in Indo-Gangetic Plains of India
The Indian Green revolution region âIndo-Gangetic Plainâ (IGP) comprises of four agro-climatic zones namely lower, middle, upper, and trans gangetic plains covering West Bengal, Bihar, Uttar Pradesh, Delhi, Uttarakhand, Chandigarh, Haryana, Punjab, and some part of Rajasthan state. It covers 169 districts with total geographical area of 43.70 million ha. The Indo-Gangetic plains are one of the most populous regions with its area covering nearly 13% of the total geographical area of the country. It produces about 50% of the total food grains to feed 40% of the population. The continuous cropping of rice-wheat system has degraded the soil health dramatically over the years. Hence, the incorporation of trees in agriculture would be a better option to improve the soil as well as livelihood of the farmers in IGP.
Agriculture is the major enterprise of the region that is most vulnerable to climate changes particularly owing to the inadequacy of resources with the smallholder farmers. While, agroforestry has the potential to play a significant role in mitigating the atmospheric accumulation of greenhouse gases (GHG), it also helps smallholder farmers adapt to the changes. These are the reasons for recognizing agroforestry as a viable alternative to prevent and mitigate climate change (Ram Newaj et al., 2014). A considerable proportion of agroforestry area located in IGP and some of the promising tree species like Populus deltoides, Eucalyptus tereticornis, Melia azadirach, Mangifera indica, Dalbergia sissoo, and Acacia nilotica are very common in the farmerâs fields. Keeping this in view, the field survey was carried out to estimate the carbon sequestration potential at a farmerâs field in IGP
ERP evidence suggests executive dysfunction in ecstasy polydrug users
Background: Deficits in executive functions such as access to semantic/long-term memory have been shown in ecstasy users in previous research. Equally, there have been many reports of equivocal findings in this area. The current study sought to further investigate behavioural and electro-physiological measures of this executive function in ecstasy users.
Method: Twenty ecstasyâpolydrug users, 20 non-ecstasyâpolydrug users and 20 drug-naĂŻve controls were recruited. Participants completed background questionnaires about their drug use, sleep quality, fluid intelligence and mood state. Each individual also completed a semantic retrieval task whilst 64 channel Electroencephalography (EEG) measures were recorded.
Results: Analysis of Variance (ANOVA) revealed no between-group differences in behavioural performance on the task. Mixed ANOVA on event-related potential (ERP) components P2, N2 and P3 revealed significant between-group differences in the N2 component. Subsequent exploratory univariate ANOVAs on the N2 component revealed marginally significant between-group differences, generally showing greater negativity at occipito-parietal electrodes in ecstasy users compared to drug-naĂŻve controls. Despite absence of behavioural differences, differences in N2 magnitude are evidence of abnormal executive functioning in ecstasyâpolydrug users
On recognizing and formulating mathematical problems
When mathematics is used to help people cope with real-life situations, a three-stage intellectual process is involved. First, a person becomes aware of a problem-situation which stimulates him to generate a problem-statement, a verbal story-problem. This may be in writing, expressed orally, or merely thought and evidenced by other behavior. Second, he transforms the verbal problem-statement into a mathematical formulation. Third, he analyzes this mathematically stated problem into subproblems to which the solution is more immediate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43864/1/11251_2004_Article_BF00052419.pd
Neural Mechanisms of Interference Control in Working Memory: Effects of Interference Expectancy and Fluid Intelligence
A critical aspect of executive control is the ability to limit the adverse effects of interference. Previous studies have shown activation of left ventrolateral prefrontal cortex after the onset of interference, suggesting that interference may be resolved in a reactive manner. However, we suggest that interference control may also operate in a proactive manner to prevent effects of interference. The current study investigated the temporal dynamics of interference control by varying two factors - interference expectancy and fluid intelligence (gF) - that could influence whether interference control operates proactively versus reactively.A modified version of the recent negatives task was utilized. Interference expectancy was manipulated across task blocks by changing the proportion of recent negative (interference) trials versus recent positive (facilitation) trials. Furthermore, we explored whether gF affected the tendency to utilize specific interference control mechanisms. When interference expectancy was low, activity in lateral prefrontal cortex replicated prior results showing a reactive control pattern (i.e., interference-sensitivity during probe period). In contrast, when interference expectancy was high, bilateral prefrontal cortex activation was more indicative of proactive control mechanisms (interference-related effects prior to the probe period). Additional results suggested that the proactive control pattern was more evident in high gF individuals, whereas the reactive control pattern was more evident in low gF individuals.The results suggest the presence of two neural mechanisms of interference control, with the differential expression of these mechanisms modulated by both experimental (e.g., expectancy effects) and individual difference (e.g., gF) factors
The mind's eye, looking inward? In search of executive control in internal attention shifting
In studies of mental counting, participants are faster to increment a count that was just incremented (no-switch trial) than to increment a different count (switch trial). Investigators have attributed the effect to a shift in the internal focus of attention on switch trials. Here we report evidence for other bottom-up and top-down contributions. Two stimuli were mapped to each of two counts. The no-switch facilitation was greater when stimuli repeated than when they were different. Event-related potential (ERP) activity associated with repetitions was anterior to that associated with switching. Runs of no-switch trials elicited faster responses and frontal ERP activity. Runs of switches and large counts both elicited slow responses and reduced P300 amplitudes. Bottom-up processes may include priming on no-switch trials and conflict on switch trials. Top-down processes may control conflict, subvocal rehearsal, and the contents of working memory.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73572/1/1469-8986.00059.pd
The Function and Organization of Lateral Prefrontal Cortex: A Test of Competing Hypotheses
The present experiment tested three hypotheses regarding the function and organization of lateral prefrontal cortex (PFC). The first account (the information cascade hypothesis) suggests that the anterior-posterior organization of lateral PFC is based on the timing with which cue stimuli reduce uncertainty in the action selection process. The second account (the levels-of-abstraction hypothesis) suggests that the anterior-posterior organization of lateral PFC is based on the degree of abstraction of the task goals. The current study began by investigating these two hypotheses, and identified several areas of lateral PFC that were predicted to be active by both the information cascade and levels-of-abstraction accounts. However, the pattern of activation across experimental conditions was inconsistent with both theoretical accounts. Specifically, an anterior area of mid-dorsolateral PFC exhibited sensitivity to experimental conditions that, according to both accounts, should have selectively engaged only posterior areas of PFC. We therefore investigated a third possible account (the adaptive context maintenance hypothesis) that postulates that both posterior and anterior regions of PFC are reliably engaged in task conditions requiring active maintenance of contextual information, with the temporal dynamics of activity in these regions flexibly tracking the duration of maintenance demands. Activity patterns in lateral PFC were consistent with this third hypothesis: regions across lateral PFC exhibited transient activation when contextual information had to be updated and maintained in a trial-by-trial manner, but sustained activation when contextual information had to be maintained over a series of trials. These findings prompt a reconceptualization of current views regarding the anterior-posterior organization of lateral PFC, but do support other findings regarding the active maintenance role of lateral PFC in sequential working memory paradigms
Robust water repellent ZnO nanorod array by Swift Heavy Ion Irradiation: Effect of Electronic Excitation Induced Local Chemical State Modification
Tailoring the surface properties by varying the chemistry and roughness could be of interest for self-cleaning applications. We demonstrate the transformation of hydrophobic ZnO Nano rod (NR) array into superhydrophobic nature by changing the local chemical state and without altering the surface roughness by swift heavy ion (SHI) irradiation. The aligned ZnO NR arrays were irradiated using 150 MeV Ag ions with different fluences from 5E10 to 3E12 ions/cm2. The observed static water contact angles of ZnO NRs samples were 103° ± 3°, 152° ± 4°,161° ± 3°, 164° ± 2°, 167° ± 2°,154 ± 3° and 151° ± 2° for the pristine, ion fluencies of 1E11, 3E11, 5E11, 7E11, 1E12 and 3E12 ions cmâ2, respectively. The change in local surface chemistry via formation of surface oxygen related defects due to electronic excitations induced by ion irradiation determine the water dewetting properties. It is found that surface oxygen related defects could be tuned by varying the fluence of the SHIs. Durability tests show that the SHI induced surface oxygen-deficient ZnO NRs have the stable superhydrophobic behavior for more than a year
Comparison of Zotarolimus-Eluting and Sirolimus-Eluting Stents in Patients With Native Coronary Artery Disease A Randomized Controlled Trial
ObjectivesThis trial examined the relative clinical efficacy, angiographic outcomes, and safety of zotarolimus-eluting coronary stents (ZES) with a phosphorylcholine polymer versus sirolimus-eluting stents (SES).BackgroundWhether a cobalt-based alloy stent coated with the novel antiproliferative agent, zotarolimus, and a phosphorylcholine polymer may provide similar angiographic and clinical benefit compared with SES is undetermined.MethodsA prospective, multicenter, 3:1 randomized trial was conducted to evaluate the safety and efficacy of ZES (n = 323) relative to SES (n = 113) in 436 patients undergoing elective percutaneous revascularization of de novo native coronary lesions with reference vessel diameters between 2.5 mm and 3.5 mm and lesion length â„14 mm and â€27 mm. The primary end point was 8-month angiographic in-segment late lumen loss.ResultsAngiographic in-segment late lumen loss was significantly higher among patients treated with ZES compared with SES (0.34 ± 0.44 mm vs. 0.13 ± 0.32 mm, respectively; p < 0.001). In-hospital major adverse cardiac events were significantly lower among patients treated with ZES (0.6% vs. 3.5%, p = 0.04). In-segment binary angiographic restenosis was also higher in the ZES cohort (11.7% vs. 4.3%, p = 0.04). Total (clinically and non-clinically driven) target lesion revascularization rates at 9 months were 9.8% and 3.5% for the ZES and SES groups, respectively (p = 0.04). However, neither clinically driven target lesion revascularization (6.3% zotarolimus vs. 3.5% sirolimus, p = 0.34) nor target vessel failure (12.0% zotarolimus vs. 11.5% sirolimus, p = 1.0) differed significantly.ConclusionsCompared with SES, treatment with a phosphorylcholine polymer-based ZES is associated with significantly higher late lumen loss and binary restenosis at 8-month angiographic follow-up.(The Endeavor III CR; http://clinicaltrials.gov/ct/show/NCT00265668?order=1?
Mitigating losses: how scientific organisations can help address the impact of the COVID-19 pandemic on early-career researchers.
Scientific collaborations among nations to address common problems and to build international partnerships as part of science diplomacy is a well-established notion. The international flow of people and ideas has played an important role in the advancement of the 'Sciences' and the current pandemic scenario has drawn attention towards the genuine need for a stronger role of science diplomacy, science advice and science communication. In dealing with the COVID-19 pandemic, visible interactions across science, policy, science communication to the public and diplomacy worldwide have promptly emerged. These interactions have benefited primarily the disciplines of knowledge that are directly informing the pandemic response, while other scientific fields have been relegated. The effects of the COVID-19 pandemic on scientists of all disciplines and from all world regions are discussed here, with a focus on early-career researchers (ECRs), as a vulnerable population in the research system. Young academies and ECR-driven organisations could suggest ECR-powered solutions and actions that could have the potential to mitigate these effects on ECRs working on disciplines not related to the pandemic response. In relation with governments and other scientific organisations, they can have an impact on strengthening and creating fairer scientific systems for ECRs at the national, regional, and global level
- âŠ