Browsing by Author "Ashutosh Kumar Singh"

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A global review of rubber plantations: Impacts on ecosystem functions, mitigations, future directions, and policies for sustainable cultivation
(Elsevier B.V., 2021) Ashutosh Kumar Singh; Wenjie Liu; Sissou Zakari; Junen Wu; Bin Yang; Xiao Jin Jiang; Xiai Zhu; Xin Zou; Wanjun Zhang; Chunfeng Chen; Rishikesh Singh; Arun Jyoti Nath
The growing global need for latex is driving rubber plantation (RP) expansion since the last century, with >2 Mha of cultivation area being established in the last decade. Southeast Asia is the hotspot for rubber cultivation at other land-use costs. Although rubber cultivation has improved the economic status of farmers, it has altered the habitat's ecology and ecosystem functions (EF). However, studies on the impacts of RP on EF are limited, and a clear overview is not available. To bridge this gap, we conducted an inclusive review of the EF of RP, including soil carbon storage, aboveground biomass (AGB) and belowground biomass (BGB), litter production and decomposition, respiration, and biodiversity (plants, animals, soil fauna, and microbes). We compared the EF in RP (monoculture) with those in forests because the conversion of forests to RP is prevalent in the tropics and because most RP studies used forests as reference ecosystems. We found RP generally have lower EF than forests. The impacts of RP on some EF are more severe (e.g., AGB, BGB, and plant diversity), causing decreases of >55%, and the effects are consistently negative irrespective of plantation age. However, including agroforestry or polyculture, integrated pest management, cover cropping, mulching, and composting can improve the EF in RP to some extent. We highlighted research gaps, particularly substantial research gaps concerning the influence of plant diversity treatments (i.e., agroforestry) performed in RP on EF. Additionally, more empirical data on the significance of spatial and temporal levels are required, such as how the impact on EF could vary with climate and RP age, as we showed some examples where EF differs spatially and temporally. More importantly, further research on plantation management to offset EF losses is needed. Finally, we emphasized knowledge gaps and suggested future directions and policies for improving EF in RP. © 2021 Elsevier B.V.
Advancement of Single-Cell Sequencing in Medulloblastoma
(Humana Press Inc., 2022) Deepanshu Verma; Namyashree Nayak; Ashuthosh Singh; Ashutosh Kumar Singh; Neha Garg
Single-cell sequencing is a promising attempt to investigate the genomic, transcriptomic, and multiomic level of individual cell in the larger population of cells. The outward evolution of the technique from a manual method to the automation of single-cell sequencing is cogent. Lately, single-cell sequencing is widely used in various fields of science and has applications in neurobiology, immunity, cancer, microbiology, reproduction, and digestion. This chapter introduces the reader to the details of single-cell sequencing, currently used in several small-scale and commercial platforms. The advancement of single-cell sequencing in brain cancer sheds light on questions unanswered so far in the field of oncology. © 2022, The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.
Butea monosperma: a leguminous species for sustainable forestry programmes
(Springer Science and Business Media B.V., 2021) Apurva Rai; Vimal Chandra Pandey; Ashutosh Kumar Singh; Nandita Ghoshal; Nandita Singh
Forestry and greening programs in urban area are faced due to lack of awareness about multiple roles/benefits of trees, especially their role in drought proofing, prevention of soil and water run-off, degraded land restoration, livelihood security and sustainable development. In this regard, Butea monosperma (Lam.) Taubert, a medium-sized legume tree species, has gained much importance because of its multipurpose usage and well adaptability to forestry programs. We have documented the importance of Butea monosperma by surveys and compared with available literature. During the exhaustive surveys, 250 locals were interviewed between 2014 and 2016. We recorded maximum information of Butea monosperma viz. botanical description, traditional knowledge, commercial status, medicinal values and ecological importance. Globally, a reduction in its distribution has categorized it as an endangered species; the main reasons are overexploitation and inadequate awareness. Thus, the present paper deals with the beneficial uses and effectiveness of Butea monosperma for urban forestry and greening which could lead to generate interest in rising demand and value to broaden the scope for conservation, value addition and identification of multipurpose species. © 2020, Springer Nature B.V.
Carbon Storage and Carbon Dioxide Sequestration by Urban Tree Cover: Case Study From Varanasi, India
(Springer, 2022) Ashutosh Kumar Singh; Vivek Kumar Nair; Hema Singh; Rohit Kumar Mishra; J.S. Singh
Increasing number of urban settlements is a major contributor to global climate change and has resulted into rising sea level, increasing the frequency of floods and droughts and ultimately decreasing human well-being. Urban areas are likely to account for 68 per cent of the world’s population by 2050, which will result in extensive environmental degradation and ecological destruction. They are considered the major source of carbon emissions because anthropogenic activities such as the heating of domestic spaces and vehicular emissions are concentrated in urban areas. Tree populations in urban areas have a tremendous potential to mitigate emissions through carbon sequestration. However, only a few studies on the quantification of carbon stock in urban vegetation are so far available. There is therefore an urgent need to quantify the amount of sequestered carbon in urban tree cover for better monitoring and management of regional carbon stock. In the present study, we explore the potential of carbon dioxide sequestration in trees at a few sites in the heavily populated city of Varanasi. Our study shows that the carbon stock in both above-ground and below-ground biomass in different sites averaged 1901 metric tonnes of carbon per hectare, with carbon dioxide sequestration of 6977 tonnes per hectare. This indicates that urban tree plantations have a significant potential to sequester anthropogenic carbon locally at source and to stock it in their biomass for long periods of time. Some key recommendations regarding the expansion of urban green cover and the planting of fast-growing native species are offered, in order to enhance carbon dioxide sequestration. © 2022, The National Academy of Sciences, India.
Contribution of glomalin to dissolve organic carbon under different land uses and seasonality in dry tropics
(Academic Press, 2017) Ashutosh Kumar Singh; Apurva Rai; Vivek Pandey; Nandita Singh
Glomalin related soil protein (GRSP) is a hydrophobic glycoprotein that is significant for soil organic carbon (SOC) persistence and sequestration, owing to its large contribution to SOC pool and long turnover time. However, the contribution of GRSP to dissolve OC (DOC) leach from soil is not yet comprehensively explored, though it could have implication in understanding SOC dynamics. We, therefore, aim to measure the contribution of GRSP to DOC, in a range of land uses and climatic seasons in the dry tropical ecosystem. Our results demonstrated that a significant proportion of GRSP (water soluble GRSP; WS-GRSP) leached with DOC (7.9–21.9 mg kg-1), which accounts for 0.2–0.23% of soils total GRSP (T-GRSP). Forest exhibited significantly higher WS-GRSP and DOC leaching than fallow and agriculture. WS-GRSP and DOC accumulations were higher in the dry season (summer and winter) than in rainy. The extent of seasonal variations was higher in forest than in other two land uses, indicating the role of vegetation and biological activity in soil dissolve organic matter (DOM) dynamics. The regression analysis among WS-GRSP, T-GRSP, DOC and SOC prove that the accumulations and leaching of GRSP and other soil OM (SOM) depend on similar factors. The ratio of WS-GRSP-C to DOC was higher in agriculture soil than in forest and fallow, likely a consequence of altered soil chemistry, and organic matter quantity and quality due to soil management practices. Multivariate analysis reflects a strong linkage among GRSP and SOC storage and leaching, soil nutrients (nitrogen and phosphorus) and other important soil properties (pH and bulk density), suggesting that improving GRSP and other SOM status is an urgent need for the both SOC sequestration and soil health in dry tropical agro-ecosystems. © 2017 Elsevier Ltd
Effect of elevated CO2 on litter functional traits, mass loss and nutrient release of two subtropical species in free air carbon enrichment facility
(Elsevier B.V., 2020) Apurva Rai; Ashutosh Kumar Singh; Nandita Singh; Nandita Ghoshal
Assessing the impact of increasing carbon dioxide (CO2) on nutrient cycling requires understanding of the relationship between the concentration of CO2 and litter dynamics. It is, therefore necessary to understand leaf litter traits in response to increased atmospheric CO2. Variations in plant litter chemistry under elevated carbon dioxide (e−CO2) are the critical factors in ecosystem feedback. Litter fall, litter substrate quality, nutrient flux and decay rate in two tropical tree of Tectona grandis (Teak) and Butea monosperma (Butea) were examined. Saplings were exposed to elevated CO2 treatment (e−CO2 -550 ppm) and ambient CO2 (a−CO2; - 395 ppm) in the FACE (Free air CO2 enrichment) facility in CSIR- National Botanical Research Institute in Indo-Gangetic plain region. Litter was analysed for concentrations of carbon (C), nitrogen (N), soluble sugars (SS), lipids, lignin, cellulose, hemi-cellulose (HC) and C-based defensive compounds; soluble phenolics (SP). Nutrient concentration in naturally senesced litter for Butea and Teak was significantly different in elevated and ambient rings. Elevated CO2 significantly increased C/N (+8.27 % and +21.94 %), lowered mean litter N concentration (–3.27 % and -12.15 %), and affected the concentrations of soluble sugars, soluble phenolic and lipids in leaf litter of Butea and Teak plantations, respectively. Increase in litter biomass production (+19.75 % and 22.84 %) for both the plants under e−CO2, resulted in significant increase in the flux of N, SS, SP and lipid in to the soil. Elevated CO2 increased cellulose (+18.21 %; 12.30 %), hemicellulose (+8.48 %; +10.18 %) and lignin inputs to soils (+35.22; +43.36 %) in Butea and Teak plantation respectively. The study indicated that changes in litter biomass production and litter substrate quality during exposure to e−CO2 could significantly alter the input of nitrogen, soluble phenolic, soluble sugars, lipids, cellulose, and lignin to soils, and so also the biogeochemical cycle of the prevailing ecosystem. © 2020
Erratum to: Outcomes and complications of fractures of distal radius (AO type B and C): Volar plating versus nonoperative treatment (Journal of Orthopaedic Science (2014) DOI: 10.1007/s00776-014-0560-0)
(Springer Tokyo, 2014) Himanshu Sharma; Ghanshyam Narayan Khare; Saurabh Singh; Arun Govindraj Ramaswamy; Vinay Kumaraswamy; Ashutosh Kumar Singh
[No abstract available]
Geomorphologic heterogeneity influences dry-season soil CO2 efflux by mediating soil biophysical variables in a tropical river valley
(Birkhauser Verlag AG, 2019) Rishikesh Singh; Ashutosh Kumar Singh; Shivam Singh; Pratap Srivastava; Hema Singh; Akhilesh Singh Raghubanshi
Riparian landscapes are characterized by heterogeneous geomorphological structures such as erosive and depositional habitats, and therefore, may have variable soil biophysical properties. The heterogeneity in geomorphological structures and related biophysical properties would exert spatial variations in the soil CO2 efflux (SCE). However, studies assessing the relative control of biophysical variables on the SCE under such complex landscapes of dry tropical ecosystems are limited. Therefore, we assessed the effect of heterogeneity in geomorphological structures on SCE, and identified the key biophysical variables governing SCE along the riparian landscapes. The SCE, soil organic C (SOC), microbial biomass C (MBC) and pH were found to vary significantly (P < 0.05) along riparian habitats, and SCE was found 73% higher at erosive than depositional habitats. SOC was found as a prominent regulator of SCE which alone explained about 80% of the variability in SCE. Moreover, soil moisture, fine particles, pH and MBC also showed strong control on SCE along riparian landscapes. Stepwise regression analysis revealed that after excluding SOC as a main variable, soil moisture explained 32% of the variability in SCE at overall landscape level whereas fine particles and MBC explained 78% and 23% of the variability in SCE at erosive and depositional habitats, respectively. Overall, results indicate that erosive habitats are the major source of SCE, and variation in biophysical variables is greatly affecting the SCE at these habitats. Therefore, further assessment of interactions of SCE, soil biophysical parameters and their regulatory components such as hydrology, vegetation and anthropogenic activities at micro—(site and land-use) as well as macro—(landscape) scales would help to understand the soil C dynamics along the heterogeneous riparian landscapes under climate change scenarios. © 2019, Springer Nature Switzerland AG.
Green infrastructure of cities: An overview
(Indian National Science Academy, 2020) Ashutosh Kumar Singh; Hema Singh; J.S. Singh
With growing urbanization cities are increasingly suffering due to the abundance of built-in spaces, concrete, mortar and tarmac, urban heat islands, increasing frequency of extreme heat events and climate change. The sustainable development goal 11, emphasizes on developing green infrastructure which could minimize the environmental footprint of the cities. In this paper, we discuss the role of green infrastructure in carbon sequestration, mitigating atmospheric pollution, moderating temperature and mitigating climate change, and management of storm water. We also discuss biodiversity of green infrastructure and the latter as habitat of organisms, and provide an overview of economic value of trees in the urban areas. © 2020 Indian National Science Academy. All rights reserved.
Green infrastructure of Varanasi, an ancient city of India
(Springer, 2025) Ashutosh Kumar Singh; Jamuna Sharan Singh; Hema N. Singh; Rohit Kumar Mishra
Trees are an essential component of the urban green infrastructure (UGI) as they mitigate the negative impacts of urbanisation on human well-being. However, little is known about the richness, density, and botanical composition of the green infrastructure, particularly in places like Varanasi city of Uttar Pradesh with rapid and unplanned rate of urbanization. This study assessed the tree species richness, density, and composition patterns at eight sites in Varanasi city, encompassing rural, sub-urban, peri-urban, and urban areas with varying green cover. A total of 189 trees were recorded, belonging to 46 species, 39 genera, and 23 families. Of these 85% were native, while 15% were exotic. The densities of exotic species were higher in Sarnath and Indane Gas Plant (IGP) campuses. Seven species were common to all sites (Ficus religiosa L., F. benghalensis L., Eucalyptus globulus Labill., Syzigium cumini L., Mangifera indica L., Azadirachta indica A. Juss, and Artocarpus heterophyllus Lam). Flower-yielding species were maximum at the IGP campus site, whereas fruit and fodder yielding species occupied the Banaras Hindu University (BHU) site. The Jaccard similarity index was high between peri-urban Sarnath and Ramnagar sites. Tree biomass, carbon storage, and carbon sequestration were higher in the Banaras Locomotive Works (BLW) site as compared to other sites. Our findings imply that in order to improve the ecological quality of urban areas, citizens and city managers should develop endemic heterogeneous green infrastructure by selecting fast-growing and those that potentially will develop a higher girth class. © International Society for Tropical Ecology 2025.
Long-term follow up of single-stage anterior cruciate ligament reconstruction and high tibial osteotomy and its relation with posterior tibial slope
(Springer Verlag, 2016) G.R. Arun; Vinay Kumaraswamy; David Rajan; K. Vinodh; Ashutosh Kumar Singh; Pradeep Kumar; Karthik Chandrasekaran; Sahanand Santosh; Chandan Kishore
Background: Open-wedge high tibial osteotomy is considered to be an effective treatment for medial compartmental osteoarthritis. It is generally admitted that tibial slope increases after open-wedge high tibial osteotomy and decreases after closing-wedge high tibial osteotomy. Young patients with anterior cruciate ligament (ACL) deficiency along with medial compartment osteoarthritis need a combined procedure of ACL reconstruction along with high tibial osteotomy to regain physiological knee kinematics and to avoid chondral damage. Materials and methods: We retrospectively analysed data from 30 patients who underwent arthroscopic ACL reconstruction along with medial opening-wedge osteotomy from Jan 2004 to June 2012 with a minimum follow up of 2 years. The pre-operative and post-operative posterior tibial slopes were measured. Functional outcome was analysed using clinico-radiological criteria, IKDC scoring and Lysholm score. Results: Post-operative patients improved both clinically and functionally. The patients who had posterior tibial slope >5° decrease, compared to patients who had less <5° decrease, had better functional scores (IKDC and Lysholm score), which was statistically significant (p < 0.05). Conclusion: Our study has shown that decreasing the tibial slope >5° compared to pre-operative value has functionally favourable effect on the reconstructed ACL graft and outcome. It is known that increasing slope causes an anterior shift in tibial resting position that is accentuated under axial loads. This suggests that decreasing tibial slope may be protective in an ACL deficient knee. Hence by placing the tricortical graft posterior to midline in the opening wedge reduces the posterior tibial slope and thereby reduces the stress on the graft leading to better functional outcome. © 2015, Springer-Verlag Berlin Heidelberg.
Monitoring of Sea Level Variations Using GNSS Technology
(CRC Press, 2025) Ashutosh Kumar Singh; Abhay Kumar Singh
In recent years the study of climate change, as it relates to hazard mitigation in coastal regions, relies heavily on sea level variations. This chapter assesses the use of Global Navigation Satellite Systems (GNSSs) for remote sensing of sea surface variations and demonstrates the possibility of measuring absolute sea level variations brought on by tsunamis, significant storm surges, etc., which is crucial for mitigating coastal hazards. © 2025 selection and editorial matter, Dileep Kumar Gupta and Abhay Kumar Singh; individual chapters, the contributors.
Outcomes and complications of fractures of distal radius (AO type B and C): Volar plating versus nonoperative treatment
(Springer Tokyo, 2014) Himanshu Sharma; Ghanshyam Narayan Khare; Saurabh Singh; Arun Govindraj Ramaswamy; Vinay Kumaraswamy; Ashutosh Kumar Singh
Objectives: Management of AO type B and C fractures of the distal radius is controversial. This study compares outcomes and complications of AO type B and C fractures of the distal radius treated with volar locked plating and nonoperative methods. Materials and methods: Sixty-four patients with fractures of the distal radius (AO type B and C) were included in this study, according to inclusion criteria, and were allocated to the volar plating group or nonoperative group by alternate randomization: 32 patients with odd numbers went into the nonoperative group and the other 32 with even numbers went into the volar plating group. Patients in the nonoperative group were managed with closed reduction of the fracture and plaster cast application under an image intensifier. Those in the volar plating group were managed by open reduction and fixation with a volar locked plate. Preoperative and postoperative serial clinico-radiological follow-up was done. The range of movement, grip strength, functional outcome scores and radiological parameters were compared. Student's t-test was used for statistical analysis with significance at p < 0.05. Results: Range of movement and functional scores were significantly (p < 0.001) better in the volar plating group, but the difference in ulnar variance and radial and ulnar deviation was insignificant as compared to the nonoperative group. At 24 months follow-up, the nonoperative group had significantly more cases with malunion, articular incongruity and osteoarthritis. Conclusion: In cases of AO type B or C fractures of the distal radius, volar locked plating provides anatomical stable fixation and early mobilization with better clinico-radiological outcome as compared to conservative treatment. © 2014 The Japanese Orthopaedic Association.
Palaeoceanographic and palaeoclimatic history of ODP site 763A (Exmouth Plateau), southeast Indian Ocean: 2.2 Ma record of planktic foraminifera
(2006) Devesh K. Sinha; Ashutosh Kumar Singh; Manish Tiwari
The western margin of Australia is unique in being the only eastern boundary region undergoing no upwelling as the poleward flowing Leeuwin Current (LC) nullifies the equatorward-driven wind-induced circulation. The principal forcing mechanism of the Leeuwin Current is the alongshore pressure gradients and associated zonal geostrophic flows along the West Australian margin. Based on planktic foraminiferal census counts and stable isotopic analysis of a surface-dwelling planktic foraminifera, Globigerinoides sacculifer, we show that during the Quaternary there have been five intervals when this eastern boundary region behaved in an opposite manner and the margin experienced extensive upwelling due to weakening of the LC and dominance of equatorward wind-driven circulation, causing offshore Ekman transport. These events occurred at 2.22, 1.83, 0.68, 0.45 and 0.04 Ma and have been named here as PL-1 to PL-5 in ascending stratigraphic order. We demonstrate here that the previous two events, PL-1 and PL-2, occurred due to ENSO-induced changes in the Western Pacific Warm Pool, while the last three events, PL-3, PL-4, and PL-5, occurred due to reduced Indonesian throughflow as a result of lowered sea level caused by ice volume expansion. We envisage here that these periods must be those of reduced net heat input to the Indian Ocean from the Pacific via Indonesian Seaway and thus should have an effect on sea surface temperature of the Indian Ocean and Indian monsoon.
Plant diversity in cities: Call for assessment and conservation
(Indian Academy of Sciences, 2018) Ashutosh Kumar Singh; Hema Singh; J.S. Singh
Urbanization destroys natural habitats, displaces native ecosystems and results in regional extinction of native species. Urbanization is also argued to cause homogenization during which native species are replaced with non-native species. Negative impact of urbanization on ecosystems and biodiversity is usually focused upon while the fact that high levels of biodiversity may flourish inside cities are frequently ignored. Cities comprise a mixture of remnants of the pre-existing urban habitats and new urban habitats. The remaining fragments of natural landscapes, and other vegetation areas constitute the green infrastructure supporting the biological diversity of cities. Several biotopes such as lawns, hedges, parklands and street trees occur in the cities. In the cities ambient temperatures are higher than those of the surrounding rural areas, exhibiting the phenomenon of urban heat island. Urban vegetation experiences longer growing seasons and exhibits earlier greening than vegetation in the surrounding rural areas. Trees comprise the natural capital assets for cities as they provide immense benefits and ecosystem services for the wellbeing of city dwellers, although there are some disservices also. Studies on urban vegetation are very few in the tropics and particularly in India. In this article we review several aspects of plant diversity in cities in order to sensitize scientists, city managers and lay public to the need for more research on socioeconomic benefits and costs of city vegetation and to augment the vegetation within cities through conservation. © 2018, Current Science Association.
Plant Invasion and Climate Change: An Overview on History, Impacts, and Management Practices
(Springer Nature, 2023) Ritturaj Singh; Ashutosh Kumar Singh; Prakash Rajak; Hema Singh
Species that implement new home ranges and then multiply, proliferate, and endure there at the cost of their surroundings are said to be alien species. Anthropogenic activities are one of the most important reasons for the unheard changes to the dispersion of the world biota. Invasion of plants (as well as animals) has been significantly expanded in the last few decades as a consequence of the quickly developing international trade and transportation. Among the primary causes of species extinction, invasive alien plant species (IAPS) are thought to affect social and economic conditions and ecological services through a variety of processes. The health of humans is also significantly impacted by alien species, both positively and negatively, but mostly negatively. A compre-hensive understanding of the dynamic mechanisms associated in the invasion procedure must be developed in order to establish an effective management strategy for invasive species. Changes in temperature and precipitation regimes and related processes are further accelerating the invasion success of several species and causing severe threat to the native ecosystems and their species composition. For avoiding severe cumulative effects of plant invasion and cli-mate change, it is essential to judicially handle unwanted alien species in native and foreign habitats. Direct monitoring of invasive alien species usually requires an integrated strategy comprising of the coordinated application of a number of techniques. In this chapter, emphasis has been given on understanding the impacts of invasive species on different ecological and socio-economic aspects, followed by outlining some prudent measures for their management in light of changing climate scenario. Several techniques that are accessible are often divided into three categories, viz. mechanical, chemical, and biocontrol techniques. Here, we conclude that using alien species in various value-added processes may be crucial in limiting their spread. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.
Response of low-latitude lower ionosphere during solar flare events over the complete solar cycle 24
(Akademiai Kiado ZRt., 2025) Gaurish S. Tripathi; Ashutosh Kumar Singh; Prashant Kumar Singh; Abhay Kumar Singh
The lower ionosphere of Earth is greatly impacted by solar flares. During a solar flare event, a sudden enhancement in X-ray flux leads to additional ionization, which increases electron density in the lower ionosphere. In this paper, we first investigated time the behaviour of lower ionosphere during solar flare events (SFE) over the complete solar cycle 24 during the years 2011 to 2018 by using amplitude measurement of very low frequency (VLF) waves and GOES 0.1–0.8 nm X-ray flux. The fixed frequency (19.8 kHz) VLF wave transmitted from the NWC-transmitter, Australia is observed at our low-latitude station Varanasi (geom. lat. 14o 55/ N, geom. long. 154o E), India. The amplitude enhancements associated with solar flares are characterised by the two traditional Wait parameters, virtual reflection height (H/ in km) and the sharpness factor (β in km− 1) i.e. electron density gradient. These empirically determined values of H/ and β were employed in Long Wave Propagation Capability (LWPC) to predict VLF amplitude perturbations induced by the solar flare throughout a wider frequency range than was observable. It is found that the sharpness factor increases with the increasing strength of solar flares, but the virtual reflection height decreases. These observations show a decrease in H/ from 78 km to 62 km and an increase in β from 0.34 km− 1 up to a ‘saturation’ level of 0.51 km− 1. A comparative study of these parameters during different phases of the solar cycle shows that during the rising phase of the solar cycle, β is found to be lower. In contrast, during the declining phase, its value is higher. Also, H/ decreases more during the decreasing phase of the cycle than during the rising phase. During the peak of the solar cycle, H/ and β values are found to lie between rising and decreasing phase values, although more dispersed. This indicates that the lower ionosphere behaves differently during different phases of the solar cycle. © Akadémiai Kiadó Zrt 2025.
Riparian land uses affect the dry season soil CO2 efflux under dry tropical ecosystems
(Elsevier B.V., 2017) Rishikesh Singh; Hema Singh; Shivam Singh; Talat Afreen; Shweta Upadhyay; Ashutosh Kumar Singh; Pratap Srivastava; Rahul Bhadouria; A.S. Raghubanshi
Riparian ecosystems are amongst the most vulnerable ecosystems of the world. The natural gradients and increasing human perturbations under these ecosystems can be explored for understanding the soil carbon (C) dynamics, especially soil carbon dioxide (CO2) efflux. However, studies on soil CO2 efflux and its governing variables under different land uses of dry tropical riparian ecosystems are limited. Therefore, the present study aimed (1) to assess the impact of riparian land use on soil CO2 efflux, and (2) to identify the key drivers of soil CO2 efflux along the river Ganga, Varanasi, India. The riparian land uses taken in this study were moist sandy flat (MSF), uncultivated sandy land (USL) and cultivated sandy land (CSL) depending upon their slope and distance from river body to upland, respectively. Soil CO2 efflux and other soil biophysical properties were measured at 54 locations distributed in six sites having these land uses, in dry season of 2014–15. Soil biophysical properties considered in this study were soil organic C, soil moisture, bulk density, porosity, fine particles, microbial biomass C and soil pH. Riparian land uses were found to have significant impact over soil CO2 efflux with a respective increase of 222, 424 and 63%, for MSF to USL, MSF to CSL, and USL to CSL land use transitions (P < 0.01), respectively. Similarly, the regulators of soil CO2 efflux varied with the land uses. It showed strong positive correlation with soil organic C (r = 0.81), fine particles (r = 0.64) and porosity (r = 0.61), whereas negative correlation with soil moisture (r = 0.61) and bulk density (r = 0.62) for overall dataset. However, soil organic C, fine particles, microbial biomass C and soil pH at MSF; soil organic C and microbial biomass C at USL; and soil moisture, porosity and microbial biomass C at CSL land uses were observed to regulate soil CO2 efflux. The findings revealed that riparian land uses have significant control over soil CO2 efflux and its biophysical regulators which have relative control over it. Soil organic C, soil moisture, fine particles, porosity and microbial biomass C were identified as prevalent regulators of soil CO2 efflux under dry seasons. Overall, the results indicate that the biophysical variables in addition to human interferences (CSL land use) have pronounced regulation over soil CO2 efflux in dry tropical riparian ecosystems. © 2017 Elsevier B.V.
The importance of Butea monosperma for the restoration of degraded lands
(Elsevier B.V., 2016) Apurva Rai; Ashutosh Kumar Singh; Vimal Chandra Pandey; Nandita Ghosal; Nandita Singh
The present study emphasized the importance of Butea monosperma (native tree species), not only as an ideal economic investment that can be utilized in many different manners but also as an species of enormous potential for restoration of degraded lands. Here, we evaluate the changes in chemical, microbial and enzymatic activities of rhizosphere soils (RS) of Butea and compared with bare lands (disturbed lands) to assess its ecological suitability for recovery. We collected 50 soil samples from Butea rhizosphere as well as from bare land soil. Soil pH and electrical conductivity (EC) were significantly lower in rhizospheric soils in comparison to bare land soils, while water holding capacity (WHC), organic carbon (OC), total nitrogen (N), available phosphorus (P), microbial biomass carbon (MBC), dehydrogenase, β-glucosidase and alkaline phosphatase activities were significantly higher in rhizospheric soil. Decrease in soil pH, EC and increases in soil nutrients, microbial biomass and soil enzyme activities suggests that Butea can be potential species to restore and enhance the biological activities of degraded lands and further to facilitate the vegetation establishment. However, further extensive research is required for better insights in this aspect. © 2016
The role of microRNA-21 in the onset and progression of cancer
(Future Medicine Ltd., 2021) Ashutosh Singh; Ashutosh Kumar Singh; Rajanish Giri; Dhruv Kumar; Rohit Sharma; Martin Valis; Kamil Kuca; Neha Garg
MicroRNAs (miRNAs), a class of small noncoding RNA, posttranscriptionally regulate the expression of genes. Aberrant expression of miRNA is reported in various types of cancer. Since the first report of oncomiR-21 involvement in the glioma, its upregulation was reported in multiple cancers and was allied with high oncogenic property. In addition to the downregulation of tumor suppressor genes, the miR-21 is also associated with cancer resistance to various chemotherapy. The recent research is appraising miR-21 as a promising cancer target and biomarker for early cancer detection. In this review, we briefly explain the biogenesis and regulation of miR-21 in cancer cells. Additionally, the review features the assorted genes/pathways regulated by the miR-21 in various cancer and cancer stem cells. © 2021 Newlands Press.