Browsing by Author "Arvind Kumar Singh"

Now showing 1 - 20 of 27

A Fractional-Order Mathematical Model of Banana Xanthomonas Wilt Disease Using Caputo Derivatives
(Universal Wiser Publisher, 2024) A. Manickam; M. Kavitha; A. Benevatho Jaison; Arvind Kumar Singh
This article investigates a fractional-order mathematical model of Banana Xanthomonas Wilt disease while considering control measures using Caputo derivatives. The proposed model is numerically solved using the L1-based predictor-corrector method to explore the model’s dynamics in a particular time range. Stability and error analyses are performed to justify the efficiency of the scheme. The non-local nature of the Caputo fractional derivative, which includes memory effects in the system, is the main motivation for incorporating this derivative in the model. We obtain varieties in the model dynamics while checking various fractional order values. © 2024 A. Manickam, et al.
A Study on Dunaliella salina Under Selected Nutrient Manipulation with Reference to the Biomass, Lipid Content Along with Expression of ACCase and RuBisCO Genes
(Springer, 2023) Sk Riyazat Khadim; Abhishek Mohanta; Prabhakar Singh; Priyanka Maurya; Ankit Kumar Singh; Arvind Kumar Singh; Ravi Kumar Asthana
Energy crises and climate change attracted less-explored microalgae as renewable resources. Deficiencies of nitrogen and phosphorus are the most effective inducers of lipid accumulation in microalgae but at the cost of biomass productivity. Therefore, nitrogen, phosphorus, and carbon manipulation of the culture medium was adopted for maximizing lipid as well as biomass production in Dunaliella salina. Phosphate deficiency in combination with 1.25 mM KNO3 (1/8 of the basal) resulted in higher lipid content (341.1 mg g−1 dry cell weight, DCW), but lower biomass (13.12 mgL−1d−1 DCW). The addition of 10.00 mM NaHCO3 to such cultures enhanced not only lipid content to 1.17-fold but also biomass productivity to 2.25-fold. The increase in biomass may be correlated with the stress-ameliorating effects of bicarbonate augmentation which helped in maintaining the health of the cells, as reflected by robust photosynthetic performance. The two important enzymes, RuBisCO and ACCase were also monitored for their expressions. RuBisCO possesses large and small subunits (rbcL and rbcS) responsible for incorporation of CO2, and beta carboxyl transferase (accD) of the heteromeric ACCase is associated with the first and committed step of fatty acid biosynthesis. Enhanced biomass and lipid content in D. salina cells after NaHCO3 augmentation may be ascribed to 6.23-fold increase in the expression of accD and > 2.16-fold increase in rbcL and rbcS genes. Thus, the present work recommends a threshold level of nitrogen and bicarbonate in phosphate deficient D. salina cultures for simultaneously maximizing the biomass and lipid content. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Analysis of Nanoscale Short Channel Effects in Cylindrical Gate-All-Around Junctionless FETs and Performance Enhancement with GaAs and III–V Materials for Low-Power, High Frequency Applications
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Pooja Srivastava; Aditi Upadhyaya; Shekhar Yadav; C. M.S. Negi; Arvind Kumar Singh
With the advancement of the semiconductor industry into the sub-10 nm regime, high-performance, low-energy transistors have become important, and gate-all-around junctionless field-effect transistors (GAA-JLFETs) have been developed to meet the demands. Silicon (Si) is still the dominant semiconductor material, but other potential alternatives, such as gallium arsenide (GaAs), provide much higher electron mobility, improving the drive current and switching speed. In this study, our contributions include a comparative analysis of Si and GaAs-based cylindrical GAA-JLFETs, using threshold voltage behavior, electrostatic control, short channel effects, subthreshold slope, drain-induced barrier lowering, and leakage current as the metrics for performance evaluation. A comprehensive analytical modeling approach is employed, solving Poisson’s equation and utilizing numerical simulations to assess device characteristics using the ATLAS SILVACO tool under varying channel lengths and gate biases. Comparisons between Si and GaAs-based devices show what trade-offs exist and what the material engineering strategies are to use the advantages of GaAs while minimizing some disadvantages. The results of the study are a valuable contribution to the design and optimization of next-generation FET architectures, pointing the direction for enabling next-generation beyond CMOS technology. © 2025 by the authors.
Assessment of feeding hydroponic fodder on growth and reproduction performance in Black Bengal goat
(Springer Science and Business Media B.V., 2024) Shailendra Kumar Rajak; Arvind Kumar Singh; Abhishek Kumar Singh; Asish Rai; Anshu Gangwar
This study aimed to evaluate the effects of hydroponic fodder on the growth and reproductive performance of Black Bengal goats in East Champaran, Bihar, during the years 2020-21 and 2021-22. A total of 24 goats were randomly assigned to four groups: Control (C) with extensive grazing, gram straw, concentrate feed, and green fodder; Treatment 1 (T1) receiving C + 300 g/day of wheat hydroponic fodder; Treatment 2 (T2) with 300 g/day of maize hydroponic fodder alone; and Treatment 3 (T3) receiving C + a combination of 150 g/day of wheat and 150 g/day of maize hydroponic fodder. Each group comprised 6 animals. The nutrient composition analysis revealed that wheat hydroponic fodder had significantly higher (P < 0.05) levels of dry matter, crude protein, and lignin, whereas maize contained higher nitrogen-free extract, crude fiber, ether extract, and ash. In terms of growth performance, T3 showed the highest body weight gain and daily weight gain, outperforming T2, T1, and the control group (P < 0.05). Though differences between T2 and T3 were not significant (P > 0.05) across both years, T3 consistently exhibited better performance. Reproductive performance indicators, such as age at puberty, age of first kidding, and kid mortality rates, were significantly lower (P < 0.05) in T3, T1, and the control group compared to T2. However, there were no significant differences (P > 0.05) between T2 and T3 in these parameters. T3 also showed the highest kidding size and birth weight of kids (P < 0.05), followed by T2, T1, and the control group. The cost of feed per kilogram of body weight gain was lowest in T3, followed by T2, T1, and the control. In conclusion, the combination of maize and wheat hydroponic fodder (T3) resulted in better growth and reproductive performance compared to feeding maize or wheat hydroponic fodder alone. Furthermore, this feeding strategy reduced the cost per kilogram of live weight gain, indicating its potential for enhancing the sustainability and profitability of goat farming systems in the region. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
Collocation Technique Based on Chebyshev Polynomial to Solve Lane-Emden-Fowler Boundary Value Problem
(Universal Wiser Publisher, 2025) Shabanam Kumari; Arvind Kumar Singh; Utsav Gupta
We present an innovative technique to find numerical solutions of the Lane-Emden-Fowler singular-type BVPs which plays a crucial role in comprehending a wide range of physical phenomena. The core concept of this technique is based on transforming the differential equation into the Fredholm integral equation, then it is converted into system of linear or nonlinear algebraic equations by utilizing the collocation technique based on Chebyshev polynomials. Subsequently, we employ an iterative numerical method, such as the Newton’s method, for solving the system to get the approximate solution. Error analysis is included which helps to assess the accuracy of the obtained solutions and provides insights into the reliability of the numerical results. Furthermore, we have also considered various examples to demonstrate the applicability of the collocation technique based on Chebyshev polynomials and compared with the existing results. © 2025 Arvind Kumar Singh, et al.
Collocation Technique Based on Chebyshev Polynomials to Solve Emden–Fowler-Type Singular Boundary Value Problems with Derivative Dependence
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Shabanam Kumari; Arvind Kumar Singh; Utsav Gupta
In this work, an innovative technique is presented to solve Emden–Fowler-type singular boundary value problems (SBVPs) with derivative dependence. These types of problems have significant applications in applied mathematics and astrophysics. Initially, the differential equation is transformed into a Fredholm integral equation, which is then converted into a system of nonlinear equations using the collocation technique based on Chebyshev polynomials. Subsequently, an iterative numerical approach, such as Newton’s method, is employed on the system of nonlinear equations to obtain an approximate solution. Error analysis is included to assess the accuracy of the obtained solutions and provide insights into the reliability of the numerical results. Furthermore, we graphically compare the residual errors of the current method to the previously established method for various examples. © 2024 by the authors.
Combating unemployment through skill development
(Vilnius University Press, 2020) Arvind Kumar Singh; Pushkar Kumar Singh; Arvind Kumar Misra
In this paper, we propose and analyze a nonlinear mathematical model to study the effect of skill development on unemployment. We assume that government promulgates different levels of skill development programs for unemployed persons through which two different categories of skilled persons, namely, the low-skilled and the highly-skilled persons, are coming out and the highly-skilled persons are able to create vacancies. The model is studied using stability theory of nonlinear differential equations. We find analytically that there exists a unique positive equilibrium point of the proposed model system under some conditions. Also, the resulting equilibrium is locally as well as globally stable under certain conditions. The effective use of implemented policies to control unemployment by providing skills to unemployed persons and the new vacancies created by highly-skilled persons are identified by using optimal control analysis. Finally, numerical simulation is carried out to support analytical findings. © 2020 Authors. Published by Vilnius University Press.
Conservation Agriculture for Soil Health and Carbon Sequestration in the Indian Himalayan Region
(Springer Singapore, 2023) Ashish Rai; Sumit Tripathi; Ayush Bahuguna; Sumit Rai; Jitendra Rajput; Anshu Gangwar; Rajeev Kumar Srivastava; Arvind Kumar Singh; Satish Kumar Singh; Dibyanshu Shekhar; Rahul Mishra; Eetela Sathyanarayana; Supriya Pandey
Mountains the most significant agro-ecosystems that directly or indirectly support human life. The areas surrounding the hills are abundant in biodiversity and have enormous potential for sustaining Indian agriculture. It has been widely recognised that the ecological fragility and sensitivity of the Himalayas to climatic aberrations, topography, peculiar geographical features, and some of the particular identified problems, which may be soil loss, runoff, steep slopes, acidity of soils, and loss of soil nutrients, form it a very distinct region as opposed to plains in terms of socioeconomic situation. Conventional agriculture was one of the best aspects of food production during the green revolution and after India gained its independence for securing food and nutrition through intensive agricultural practices, but on the flip side, it has simultaneous effects on resource degradation and soil biodiversity. The need for food and fodder, an ever-growing population, the preservation of soil biodiversity, declining soil health, climate change, the use of unbalanced fertilisers, and decreased farm profitability all call for a paradigm shift in the agriculture sector. On the other hand, increasing the intensity of the hillside agriculture system without implementing any conservation measures greatly increases the likelihood of disastrous conditions. Conservation agriculture has long been known to improve soil health and sustain agricultural production systems by reducing environmental footprints. Between the atmosphere and the lithosphere, numerous biological and physical processes are regulated by soils. An integral aspect of soil that promotes agricultural sustainability is soil health. However, each measurement of a specific soil health parameter is always tied to a unique set of circumstances. A fundamental concern in maintaining soil health to feed an expanding population is resource conservation. Climate change is a topic of discussion on a worldwide scale in the current globalisation context. The greenhouse effect is best for life but only up to a point beyond which it becomes dangerous. Due to urbanisation, changes in land use, cropping patterns, and other factors, human influences on climate change go beyond the range of natural fluctuation. Climate change in the soil system is significantly influenced by carbon regulation in the soil. The rate of organic matter decomposition is accelerated by an increase in mean annual temperature, which affects aggregate stability, water storage capacity, and nutrient balance— all of which are crucial for healthy soil structure, soil fertility, productivity, and sustainability. In actuality, soil bacteria break down organic materials, but a change in temperature regime may change the microbial population. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.
Electronic information resource optimisation in academic libraries: A comparative study on licensing provision of commercial publisher
(Defence Scientific Information and Documentation Centre, 2018) Arvind Kumar Singh; Bhaskar Mukherjee
Electronic information resources are increasingly become an important component of the collection-building activities of libraries. This paper attempts to understand how far the licenses of commercial publishers support resource optimisation in general and what other important issues that are usually ignored by publishers, knowingly or unknowingly, but are essential for better resource optimisation. Five international publishers namely Elsevier, EBSCO, Sage, Springer, and Taylor & Francis were identified and analysed their agreements that are available in public domain with some model agreements like Liblicense model and model license developed by John Cox Associate. Study indicates that core part of the negotiations still remain price, IP access, display, ILL/document supply, etc. while important issues like perpetual access, archiving, self-archiving, copy of individual articles and share the same for non-commercial use by authorised users were minor issues of the contract. Furthermore, most of the obligations of the publishers that are identified as core issues in Liblicense model are also absent in commercial publishers’ license. A greater awareness of this to library managers is essential. They must be acquainted with the clause of the license agreement of commercial publishers and must negotiate to that extent so that the access should be uninterrupted. © 2018, DESIDOC.
Fitness differences due to allelic variation at Esterase-4 locus in Drosophila ananassae
(Springer India, 2017) Kavita Krishnamoorti; Arvind Kumar Singh
Esterases are known to play essential role in metabolism, reproductive physiology and behaviour of Drosophila. Esterases are highly polymorphic enzymes in Drosophila, but the polymorphism of these enzymes is not well studied in Drosophila ananassae. Recent studies on esterase polymorphism in D. ananassae revealed that Est-4 locus comprises Est-4 active and Est-4 null alleles depending on enzymatic activity. For the in vivo functional characterization of this locus, homozygous lines of genotypes Est-4 active and Est-4 null were derived from the flies collected from Gangtok, Sikkim, in 2006. Mating propensity, mating pattern, fecundity, fertility and productivity of female, life span and triglycerides level were investigated in the flies bearing either Est-4 active or Est-4 null genotypes. Results showed that mating occurred randomly with nonsignificant difference in mating propensity between Est-4 active and Est-4 null flies. However, a significant difference in fecundity and strong dependency between genotypes and the rate of fertility was found. The median values of progeny produced per female were 24 and 20 for Est-4 active and Est-4 null genotypes, respectively. The life span assay showed a significant difference in the survivorship between the two genotypes. Triglycerides level was higher in Esterase-4 active larval haemolymph as well as in mature flies’ homogenate than that of Esterase-4 null. Thus, Esterase-4 locus of D. ananassae has its role in fecundity, fertility and productivity of female, life span control and lipid metabolism. © 2017, Indian Academy of Sciences.
Gallium Nitride Channel-Based Junctionless Transistors for Futuristics Power Electronics Energy Applications
(Springer Science and Business Media Deutschland GmbH, 2025) Pooja Srivastava; Aditi Upadhyaya; Shekhar Yadav; C. M.S. Negi; Arvind Kumar Singh
An investigation on cylindrical gate-all-around Junctionless Field Effect Transistors (JLFETs) with no gradients in doping concentration and non-availability of junctions has been conducted. The findings indicate that the suggested device provides a unique architecture that significantly enhances transistor performance while being less vulnerable to short-channel effects (SCEs). Specifically designed for power electronics applications, the Atlas 3D device simulator has been utilized to analyze the performance of the proposed JLFET. Gallium Nitride (GaN) III-V compound semiconductors are used in this study to examine the electrical performance of a JLFET. Comparing the III-V JLFET to other circuit topologies, the simulations showed a favorable subthreshold slope and a lower drain-induced barrier lowering (DIBL). The subthreshold slope is approximately 63 mV/dec, which is extremely near the ideal 60 mV/dec and exhibits a low DIBL of approximately 30 mV/V. According to simulations and experimental evidence, GaN-based JLFETs have a higher power efficiency than silicon-based devices. The potential use of GaN-based JLFET as a cutting-edge substitute for advanced energy applications is covered in this research. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
Genetic structuring of Drosophila bipectinata in Indian natural populations based on the distribution of cosmopolitan inversions
(Springer, 2021) Gurvachan Singh; Arvind Kumar Singh
Genetic differentiation among different natural populations of a species depends upon the environmental factors and the evolutionary forces that operate on them. In this study, seven Indian natural populations of D. bipectinata, two from north and five from south India, have been studied for their chromosomal inversion polymorphism. A total of nine paracentric autosomal inversions were recorded from these seven places but only three of them, present on the 2L, 2R and 3L were found to be cosmopolitan in distribution. In all the populations, the frequency of standard gene arrangement was found to be high than their respective cosmopolitan inversion gene arrangement. The average heterozygosity (Ho) of cosmopolitan inversions increases from north to south. There is a latitudinal cline in the distribution of three cosmopolitan inversion arrangements because their frequency increases with the decreasing latitude, i.e. from north to south India. A comparison of the genetic profile of two north Indian and five south Indian natural populations of D. bipectinata reveals the role of natural selection as well as bottleneck effect in the genetic structuring of these populations which may be due to their varying ecological conditions to which they are constantly encountered. Further, the presence of all kinds of paracentric inversions in individual populations was analysed following Poisson distribution to see whether these inversions occur randomly in natural populations or not and the results indicate that north Indian populations show the random occurrence of these inversions than the populations derived from the south. © 2021, Indian Academy of Sciences.
Intra- and interspecific comparison of protein polymorphism to establish genetic differentiation in two sympatric species of Drosophila: D. bipectinata and D. malerkotliana
(Springer Science and Business Media Deutschland GmbH, 2022) Gurvachan Singh; Arvind Kumar Singh
Drosophila bipectinata species complex includes four monophyletic closely related sympatric species with perfect reproductive isolation in natural conditions. Among these, two species, i.e., D. bipectinata and D. malerkotliana are known to be more prevalent in their occurrence all along their distribution area of Oriental–Australian regions. Genetic characteristics of these two species have been studied by earlier researchers mainly by focusing on their chromosomal polymorphism to gain knowledge pertaining to their evolutionary trend. The present work is one step farther, as we considered isozyme variants of three polymorphic enzymes to envisage genetic differentiation among the different natural populations of these two species, along with, a comparative perusal of their certain population genetic parameters. Natural populations of these two species were sampled from eight places aligned on the north–south axis of India and were subjected to isozyme analysis. The collection of both species and the geographical locations were kept same to avoid the effect of temporal or seasonal factors on the distribution of their allelic frequency. The results of this study clearly indicate that there is intraspecific genetic structuring among the populations of both the species with a distinct steady increase in the level of heterozygosity from north to south. The evolutionary tree in the form of dendrogram depicts two genetically differentiated groups of natural populations, one for north and other for South India. Most essential aspect that has been noticed through this study is the evolutionary trend of these two sympatric species being largely similar all along the north–south axis of India. © 2022, King Abdulaziz City for Science and Technology.
Investigation of Short Channel Effects in Al0.30Ga0.60As Channel-Based Junctionless Cylindrical Gate-All-Around FET for Low Power Applications
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Pooja Srivastava; Aditi Upadhyaya; Shekhar Yadav; C. M.S. Negi; Arvind Kumar Singh
In this work, a cylindrical gate-all-around junctionless field effect transistor (JLFET) was investigated. Junctions and doping concentration gradients are unavailable in JLFET. According to the results, the suggested device has a novel architecture that significantly enhances transistor performance while exhibiting a decreased vulnerability to short-channel effects (SCEs). The Atlas 3D device simulator has been used to analyze the proposed JLFET’s performance, especially for low-power applications for different channel lengths ranging from 10 nm to 60 nm with Al0.30Ga0.60As as III-V materials. The comparative simulated study has been based on various performance parameters, including subthreshold slope (SS), drain-induced barrier lowering (DIBL), transconductance, threshold voltage, and ION to IOFF ratio. The results of the simulations demonstrated that the III-V JLFET exhibited a favorable SS and decreased DIBL compared to other circuit topologies. In the suggested study, gallium arsenide (GaAs) and its compound materials have demonstrated a strong correlation between the SS and DIBL values. The SS is approximately 63 mV/dec, extremely near the ideal 60 mV/dec value. Gallium arsenide (GaAs) and aluminum gallium arsenide (AlGaAs) exhibit DIBL of approximately 30 mV/V and an SS value of around 64 mV/dec. © 2025 by the authors.
Late Maastrichtian vegetation and palaeoclimate: Palynological inferences from the Deccan Volcanic Province of India
(Academic Press, 2022) Shreya Mishra; Sarvendra Pratap Singh; Mohammad Arif; Arvind Kumar Singh; Gaurav Srivastava; B.R. Ramesh; Vandana Prasad
Our understanding of the low latitude terrestrial climate of the late Maastrichtian is far from satisfactory. We have attempted to reconstruct the late Maastrichtian vegetation and climate of the Deccan Volcanic Province (DVP), central India. Palaeomagnetic results suggest that the Deccan lava flows were emplaced during the late Maastrichtian C29r magnetochron. Sedimentological studies reveal a swampy to shallow brackish lacustrine depositional setup in a warm and humid climate with low to moderate energy conditions. The floristic composition indicates an overall dominance of Arecaceae followed by Malvaceae and Ephedraceae. The vegetation prevailed under five palaeoecological associations viz., mangrove, coastal fringes, Tropical Rain Forests (TRFs), forest outliers and upland flora. The assemblage envelops taxa belonging to TRFs (54%), coastal (13%), tropical moist deciduous (13%), herbaceous (8%), mangrove (8%), and sub-tropical (4%) vegetation. The TRFs include taxa presently prevailing within the Western Ghats of India and in the TRFs of Africa. The Coexistence Approach (CA) analysis suggests a mean annual temperature of 24.5 ± 2.3 °C, cold month mean temperature of 18.5 ± 3.3 °C, warm month mean temperature of 27.5 ± 0.3 °C, mean annual precipitation of 1890.5 ± 208.5, precipitation during the wettest month 335 ± 15 mm, precipitation during the driest month 26 ± 7 and precipitation during the warmest month 111 ± 1. The inferred climatic conditions were apt for sustaining the high diversity within the close canopy multi-storeyed TRFs. The palaeoclimatic data also indicates a strong seasonality, and most likely, a monsoon type of climate during the late Maastrichtian of India. © 2021 Elsevier Ltd
Magnetostratigraphy and Sedimentology of Deccan Intertrappean Succession from Sagar, Central India: Insights into Palaeo-environment and End-Cretaceous Palaeogeography
(Geological Society of India, 2024) Sarvendra Pratap Singh; Arvind Kumar Singh; Mohammad Arif; Vandana Prasad; Mamilla Venkateshwarlu; Amiya Shankar Naik
The study of Deccan volcano-sedimentary successions is significant for understanding the palaeomagnetic correlation, eruption history and palaeoenvironmental conditions of the Central India during the Cretaceous-Paleogene (K-Pg) transition. In this study, we applied an integrated magnetostratigraphic and sedimentological approach to the Deccan Intertrappean Succession exposed at the Mothi Hill (Malwa Subprovince), Sagar, to provide palaeomagnetic age constraints for the lava flows, depositional environment and end-Cretaceous palaeogeography. Palaeo-magnetic data suggest that the lower and upper Trap lava flows associated with the Mothi Intertrappean deposits are not coeval, and they correspond to C29r and C29n magnetochrons, respectively, which points to the age duration of 66.3–65.1 Ma (late Maastrichtian-early Danian). The palaeomagnetic data also marks the presence of upper magnetic polarity transition (C29r/C29n) in the eastern part of the Malwa Subprovince, which indicates the occurrence of C30n-C29r-C29n magnetostratigraphic sequence for the Subprovince. The Malwa, eastern Mandla and Western Ghats Subprovinces can be palaeomagnetically correlated and are partly synchronous with each other. The Mothi Intertrappean deposition occurred in a low energy shallow water lacustrine setup with swampy to brackish depositional condition similar to shallow coastal lake type environment. The occurrence of such coastal type depositional environment at Sagar in the central part of India, points to the influence of temporary marine incursion and existence of marine pathway up to Central India, possibly through the western corridor of Narmada-Tapti rift zone during the late Maastrichtian-early Danian period. Moderate to intense chertification within the argillaceous limestone suggests post-depositional diagenetic modification and secondary silica generation due to interaction with silica enriched meteoric water diagenesis. © 2024 Geological Society of India, Bengaluru, India.
Major impact of global climate change in atmospheric, hydrospheric and lithospheric context
(Springer International Publishing, 2023) Monika Yadav; Hardik Giri Gosai; Gurudatta Singh; Abhilaksha Singh; Arvind Kumar Singh; Ravindra Pratap Singh; R.N. Jadeja
In this century, the rate of global climate change is rapid, and predicted to accelerate in upcoming generation, will significantly impact the Earth's ocean, biodiversity as well as atmosphere. In this chapter, we will discuss the published research on global climate change effects with respect to environmental compo-nents as well as biodiversity and wildlife. The nature is directly affected by climatic variation resulting in environmental refugees in the altered environment. The modifi-cation in growth rates and various physiological functions of plants and animals will be discussed in detail. The shifting in plant distribution patterns and animals with respect to increasing temperature also alters reproduction. Several indirect effects of temperature stress involve community change due to enhanced eutrophication and alteration in the intensity and frequency of extreme weather events. The coastal areas observe sea level rise effects in terms of variation in tides, enhanced water depth, alteration in movement of water, and increment of seawater intrusion into rivers and estuaries. Elevating the level of carbon dioxide in atmosphere directly increases the amount of CO2 in water of coastal regions. The increment of CO2 has a varied impact that changes with species and environmental circumstances. The effect of global climate change on freshwater ecosystems could be in terms of water quality, water quantity, habitat as well as aquatic biological assemblages. The iden-tification of thresholds and ecological triggers might be utilized for monitoring and improving the climate change-related impacts. The adverse effect of climate change in context with migratory species, challenges throughout their route, and alternation in the pattern have been discussed. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023. All rights reserved.
Microbes and compost: an emerging role in climate resilience agriculture
(Elsevier, 2024) Ashish Rai; Rahul Mishra; Abhik Patra; Arvind Kumar Singh; Sachin Sharma; A. Arvind; Ayush Bahuguna; Sumit Rai; Jitendra Rajput; Anshu Gangwar; Shankar Jha; Sumit Kumar Tripathi; Rajeev Kumar Srivastava; Dibyanshu Shekhar; Satish Kumar Singh; Tejaswini Kapil; Ram Babu Sharma; Supriya Rai
Microbes and their metabolic activity are crucial for a healthy and functioning soil. The rhizosphere, where plant roots and microbes mingle, is a bustling hub for nutrient cycling, energy flow, and microbial activity. Sustainable farming prioritizes nurturing these rhizospheric processes. Biofertilizers, including symbiotic and nonsymbiotic microbial partnerships, plant growth-promoting microbes, and arbuscular mycorrhizal collaborations, all play diverse roles in soil health and plant growth. Some microbes like Pseudomonas spp., Bacillus spp., and Streptomyces spp. help convert insoluble phosphorus into plant available forms. Composting, is another sustainable process, transforms organic waste into valuable compost, a dual-action fertilizer and soil amendment. Microbes decompose organic matter in compost, turning it into a stable, plant-friendly material. This aerobic process breaks down easy-to-digest molecules, generating CO2 and more durable substances. Composting effectively manages organic waste, reusing nutrients, reducing volume and moisture, and breaking down harmful organics plus, intricate humic-like chemicals form, boosting soil health. Thus, understanding and nurturing the vibrant microbial world in the rhizosphere through sustainable practices like biofertilizers and composting is key to healthy soil and a thriving future for farming. © 2025 Elsevier Inc. All rights reserved.
Microsatellite polymorphism based genetic variation in two sympatric species of Drosophila: D. bipectinata and D. malerkotliana
(Elsevier Inc., 2024) Gurvachan Singh; Arvind Kumar Singh
Drosophila bipectinata and D. malerkotliana are found to be distributed all along the Oriental-Australian continents and have common phylogenetic descent. The genetic divergence of these two species have been studied by using genetic markers like chromosome inversions and allozyme variants to establish the extent of variation they have experienced since their speciation. In this study, microsatellite variations have been considered to observe the genetic differentiation among the seven natural populations of D. bipectinata and six populations of D. malerkotliana. Results pertaining to both the species indicate that the level of average heterozygosity increases from north to south. Distinct genetic differentiation has been observed between north and south populations of both the species giving an indication that north and south populations have undergone genetic structuring due to absence of gene flow between them and varying environmental conditions. Based on the frequencies of microsatellite variants of the two species, we have computed the level of variation between these two species. The analysis in this regard shows an almost similar trend of genetic variation being experienced by these two species which could be a kind of parallel evolution occurring due to similar ecological niches occupied by them and similar impact of evolutionary forces. © 2024 Elsevier Inc.
Modeling the effect of unemployment augmented industrialization on the control of unemployment
(Springer Science and Business Media B.V., 2023) Pushkar Kumar Singh; Kusum Lata; Arvind Kumar Singh; Arvind Kumar Misra
The increase in human population at large scale has given the birth to the problem of unemployment as industrialization has not taken place in the same proportion. Some developing countries are making efforts for sustainable industrial growth to overcome with this problem. To tackle this problem, in the present paper, we propose a nonlinear mathematical model to study the role of unemployment-dependent industrial growth (geared industrialization) on the control of unemployment. The study of the model is based on using the method of stability theory of differential equations. The study reveals that the sustainable growth of industrialization helps to control the problem of unemployment. Finally, certain numerical calculations have been carried out to support analytical findings. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.