301 research outputs found
Spatial variation of the aftershock activity across the Kachchh Rift Basin and its seismotectonic implications
We analyzed 3365 relocated aftershocks with magnitude of completeness (Mc) ≥1.7 that occurred in the Kachchh Rift Basin (KRB) between August 2006 and December 2010. The analysis of the new aftershock catalogue has led to improved understanding of the subsurface structure and of the aftershock behaviour. We characterized aftershock behaviour in terms of a-value, b-value, spatial fractal dimension (D s ), and slip ratio (ratio of the slip that occurred on the primary fault and that of the total slip). The estimated b-value is 1.05, which indicates that the earthquake occurred due to active tectonics in the region. The three dimensional b-value mapping shows that a high b-value region is sandwiched around the 2001 Bhuj mainshock hypocenter at depths of 20–25 km between two low b-value zones above and below this depth range. The D s -value was estimated from the double-logarithmic plot of the correlation integral and distance between hypocenters, and is found to be 2.64 ± 0.01, which indicates random spatial distribution beneath the source zone in a two-dimensional plane associated with fluid-filled fractures. A slip ratio of about 0.23 reveals that more slip occurred on secondary fault systems in and around the 2001 Bhuj earhquake (Mw 7.6) source zone in KRB
CMB Telescopes and Optical Systems
The cosmic microwave background radiation (CMB) is now firmly established as
a fundamental and essential probe of the geometry, constituents, and birth of
the Universe. The CMB is a potent observable because it can be measured with
precision and accuracy. Just as importantly, theoretical models of the Universe
can predict the characteristics of the CMB to high accuracy, and those
predictions can be directly compared to observations. There are multiple
aspects associated with making a precise measurement. In this review, we focus
on optical components for the instrumentation used to measure the CMB
polarization and temperature anisotropy. We begin with an overview of general
considerations for CMB observations and discuss common concepts used in the
community. We next consider a variety of alternatives available for a designer
of a CMB telescope. Our discussion is guided by the ground and balloon-based
instruments that have been implemented over the years. In the same vein, we
compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the
South Pole Telescope (SPT). CMB interferometers are presented briefly. We
conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and
Planck, to demonstrate a remarkable evolution in design, sensitivity,
resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1:
Telescopes and Instrumentatio
Identification of micro satellite markers on chromosomes of bread wheat showing an association with karnal bunt resistance
A set of 104 wheat recombinant inbred lines developed from a cross between parents resistant (HD 29) and susceptible (WH 542) to karnal bunt (caused by Neovossia indica) were screened and used toidentify SSR markers linked with resistance to karnal bunt as these would allow indirect marker assisted selection of karnal bunt resistant genotypes. The two parents were analysed with 46 SSR primer pairs. Of these, 15 (32%) were found polymorphic between the two parental genotypes. Using these primer pairs, we carried out bulked segregate analysis on two bulked DNAs, one obtained by pooling DNA from 10 karnal bunt resistant recombinant inbred lines and the other similarly derived by pooling DNA from 10 karnal bunt susceptible recombinant inbred lines. Two molecular markers, Xgwm 337-1D and Xgwm 637-4A showed apparent linkage with resistance to karnal bunt. This was confirmed following selective genotyping of individual recombinant inbred lines included in the bulks. These markers may be useful in marker assisted selection for karnal bunt resistance in wheat
Conventional and Molecular Breeding Approaches for Biofortification of Pearl Millet
Pearl millet [Pennisetum glaucum (L.) R. Br.] is an essential diet of more than 90
million people in the semi-arid tropics of the world where droughts and low fertility
of soils cause frequent failures of other crops. It is an important nutri-rich grain
cereal in the drier regions of the world grown on 26 mha by millions of farmers
(IFAD 1999; Yadav and Rai 2013). This makes pearl millet the sixth most important
crop in the world and fourth most important food crop of the India, next to rice,
wheat, and maize with annual cultivation over an area of ~8 mha. Pearl millet is also
primary food crop in sub-Saharan Africa and is grown on 15 mha (Yadav and Rai
2013). The significant increase in productivity of pearl millet in India is attributed
to development and adoption of hybrids of early to medium duration maturity. More
than 120 diverse hybrids/varieties have been released till date for various production
environments. The heterosis breeding and improved crop management technologies
increased productivity substantially achieving higher increased production of
9.80 mt in 2016–2017 from 2.60 mt in 1950–1951 in spite of declined of area under
the crop by 20–30% over last two decades (Yadav et al. 2012)
Variety Dhanashakti (Pearlmillet)
Dhanashakti is identified by its major
distinguishing features such as large, globular and dark
grey grains; compact to semi-compact and cylindricallanceolate
panicles with shining outer surfaces of the
grains; purple pigmentation of the glumes, mixed
anther colour (mostly purple and some cream colour);
anthocyanin pigmentation of the first leaf sheath; and
mixed node pigmentation (mostly purple, but some
green). These characteristics are similar to those of
the ICTP 8203
Fighting malaria in Madhya Pradesh (Central India): Are we loosing the battle?
Malaria control in Madhya Pradesh is complex because of vast tracts of forest with tribal settlement. Fifty four million individuals of various ethnic origins, accounting for 8% of the total population of India, contributed 30% of total malaria cases, 60% of total falciparum cases and 50% of malaria deaths in the country. Ambitious goals to control tribal malaria by launching "Enhanced Malaria Control Project" (EMCP) by the National Vector Borne Disease Control Programme (NVBDCP), with the World Bank assistance, became effective in September 1997 in eight north Indian states. Under EMCP, the programme used a broader mix of new interventions, i.e. insecticide-treated bed nets, spraying houses with effective residual insecticides, use of larvivorous fishes, rapid diagnostic tests for prompt diagnosis, treatment of the sick with effective radical treatment and increased public awareness and IEC. However, the challenge is to scale up these services
Increasing the potential for malaria elimination by targeting zoophilic vectors
Countries in the Asia Pacific region aim to eliminate malaria by 2030. A cornerstone of malaria elimination is the effective management of Anopheles mosquito vectors. Current control tools such as insecticide treated nets or indoor residual sprays target mosquitoes in human dwellings. We find in a high transmission region in India, malaria vector populations show a high propensity to feed on livestock (cattle) and rest in outdoor structures such as cattle shelters. We also find evidence for a shift in vector species complex towards increased zoophilic behavior in recent years. Using a malaria transmission model we demonstrate that in such regions dominated by zoophilic vectors, existing vector control tactics will be insufficient to achieve elimination, even if maximized. However, by increasing mortality in the zoophilic cycle, the elimination threshold can be reached. Current national vector control policy in India restricts use of residual insecticide sprays to domestic dwellings. Our study suggests substantial benefits of extending the approach to treatment of cattle sheds, or deploying other tactics that target zoophilic behavior. Optimizing use of existing tools will be essential to achieving the ambitious 2030 elimination target
Genomic Approaches to Enhance Stress Tolerance for Productivity Improvements in Pearl Millet
Pearl millet [Pennisetum glaucum (L.) R. Br.], the sixth most important cereal crop (after rice, wheat, maize, barley, and sorghum), is grown as a grain and stover crop by the small holder farmers in the harshest cropping environments of the arid and semiarid tropical regions of sub-Saharan Africa and South Asia. Millet is grown on ~31 million hectares globally with India in South Asia; Nigeria, Niger, Burkina Faso, and Mali in western and central Africa; and Sudan, Uganda, and Tanzania in Eastern Africa as the major producers. Pearl millet provides food and nutritional security to more than 500 million of the world’s poorest and most nutritionally insecure people. Global pearl millet production has increased over the past 15 years, primarily due to availability of improved genetics and adoption of hybrids in India and expanding area under pearl millet production in West Africa. Pearl millet production is challenged by various biotic and abiotic stresses resulting in a significant reduction in yields. The genomics research in pearl millet lagged behind because of multiple reasons in the past. However, in the recent past, several efforts were initiated in genomic research resulting into a generation of large amounts of genomic resources and information including recently published sequence of the reference genome and re-sequencing of almost 1000 lines representing the global diversity. This chapter reviews the advances made in generating the genetic and genomics resources in pearl millet and their interventions in improving the stress tolerance to improve the productivity of this very important climate-smart nutri-cereal
Genetic variation and diversity of pearl millet [Pennisetum glaucum (L.)] genotypes assessed for millet head miner, Heliocheilus albipunctella resistance, in West Africa
Pearl millet (Pennisetum glaucum L.), the
major source of minerals and dietary energy for people
living in the semi-arid regions of Sahel, is regularly
damaged by millet head miner, Heliocheilus albipunctella.
In order to identify the plant-based resistance
sources for millet head miner along with high
grain Fe and Zn, we have screened forty pearl millet
genotypes, using an artificial infestation method.
Analysis of variance revealed significant differences
in the genotypes tested for head miner resistance. The
genotypes Gamoji, ICMP 177001, ICMP 177002,
ICMV 177003, ICMV IS 90311, LCIC9702, Souna 3,
ICMV IS 94206 and PE08043 exhibited antibiosis
resistance mechanism to Heliocheilus albipunctella
with appreciable agronomy and grain yield when
compared with the susceptible check ICMV IS 92222.
The genotypes Faringuero, ICMV 167005, ICMV IS
99001, Sadore local, SOSAT-C88, and ICMP 177004
exhibited tolerance to head miner damage with good
per se performance. The genotypes ICMP 177001,
ICMP 177002, ICMV 177003, and Moro exhibited
resistance to millet head miner and had consistent
grain Fe content across seasons (ranging from 44 to
70 ppm). Association between the head miner resistance
and morphological traits showed a positive and significant correlation of larval production index (%)
with head miner damage (r = 0.59**). Grain Fe and
Zn contents exhibited negative association with panicle
length and grain yield indicating proper care
should be taken in breeding for these traits. Hence, the
identified resistance sources can be effectively utilized
in breeding head miner resistant pearl millet OPV’s/
hybrids, with high grain yield including Fe and Zn
concentrations, to overcome the hunger and malnutrition
seen in populations living in the semi-arid tropics
Phytoremediation of heavy metal-contaminated sites: Eco-environmental concerns, field studies, sustainability issues and future prospects
Environmental contamination due to heavy metals (HMs) is of serious ecotoxicological concern worldwide because of their increasing use at industries. Due to non-biodegradable and persistent nature, HMs cause serious soil/water pollution and severe health hazards in living beings upon exposure. HMs can be genotoxic, carcinogenic, mutagenic, and teratogenic in nature even at low concentration. They may also act as endocrine disruptors and induce developmental as well as neurological disorders and thus, their removal from our natural environment is crucial for the rehabilitation of contaminated sites. To cope with HM pollution, phytoremediation has emerged as a low-cost and eco-sustainable solution to conventional physico-chemical cleanup methods that require high capital investment and labor alter soil properties and disturb soil microflora. Phytoremediation is a green technology wherein plants and associated microbes are used to remediate HM-contaminated sites to safeguard the environment and protect public health. Hence, in view of the above, the present paper aims to examine the feasibility of phytoremediation as a sustainable remediation technology for the management of metals-contaminated sites. Therefore, this paper provides an in-depth review on both the conventional and novel phytoremediation approaches, evaluate their efficacy to remove toxic metals from our natural environment, explore current scientific progresses, field experiences and sustainability issues and revise world over trends in phytoremediation research for its wider recognition and public acceptance as a sustainable remediation technology for the management of contaminated sites in 21st century
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