Browsing by Author "S.S. Singh"

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Annual variation of plasma melatonin following pinealectomy and melatonin administration in Indian tropical rodent, Funambulus pennanti
(2004) C. Haldar; S. Sharma; S.S. Singh
Pinealectomy (Px) and melatonin (Mel) administration is known for its effect on reproductive and behavioural rhythms. To date no report is available to suggest the effect of Px and Mel administration on the annual variations of plasma Mel itself in any tropical seasonally breeding rodent. We report here that a statistically significant annual oscillation of Mel existed in sham operated control squirrel, F. pennanti. The exact peak value of Mel was noted some time in November (∼13th ± 8 days), which was certainly due to short photoperiod and low ambient temperature. Px decreased the melatonin level most significantly. Mel injection to Px squirrel entrained the phase of Mel, though the amplitude was not completely achieved but had a peak melatonin concentration in January (∼2 months phase delay). Exogenous Mel administration to sham operated squirrel decreased amplitude of melatonin during the months of March-July leading to early gonadal regression but could not alter the amplitude of Mel in November and December, while the peak value was phase delayed by ∼2 months (January). We may suggest, therefore, that the pineal gland of this squirrel is essential for maintaining its own rhythm, which is an adaptive significance of this tropical rodent for the perpetuation of the species. © VSP 2004.
Athermal physiological effects of microwaves on a cynobacterium Nostoc muscorum: evidence for EM-memory bits in water
(Kluwer Academic Publishers, 1994) S.P. Singh; Subas Rai; A.K. Rai; S.P. Tiwari; S.S. Singh; Samarketu; J. Abraham
Athermal physiological effects of continuous wave and modulated microwaves were studied on a cynobacterium Nostoc muscorum. The study shows that different microwave frequencies in continuous wave and modulated modes produced significantly different physiological effects on the algae. Water-mediated bioeffects further present additional proof that water has the capability to remember the imposed electromagnetic field characteristics for an extended period of time. © 1994 IFMBE.
Attenuation of metal toxicity by frankial siderophores
(2010) A. Singh; S.S. Singh; P.C. Pandey; A.K. Mishra
In order to investigate the role of frankial siderophores in minimizing metal toxicity, Frankia strains were grown at different concentrations of Mg2+, Cu2+, and Zn2+. Growth was observed up to 500 mmol L-1 Mg2+, 10 μ mol L-1 Cu2+, and 10 μmolL-1 Zn2+ while the maxima were at 200 μmol L-1 Mg2+, 1 μmol L-1 Cu2+, and 1 μmol L-1 Zn2+. The siderophore production was increased up to 500 μmol L-1 Mg2+, 10 μmol L-1 Cu2+, 100 μmol L-1 (hydroxamate type), and 200 μmol L-1 (catecholate type) Zn2+ while maximum production was found at Mg2+ (200 μmol L-1), Cu2+ (10 μmol L-1), and Zn2+ (10 μ molL-1). The results suggested that the growth was protected at higher concentrations of Mg2+ (up to 500 μmol L-1), Cu2+ (10 μ molL-1), and Zn2+ (10 μ mol L-1), possibly due to enhanced siderophore production. Thus, siderophores minimize the metal-induced inhibition of growth in Frankia, likely due to regulation of nutritional imbalances and metabolic processes during adaptation towards metal stress and/or metal toxicity. © 2010 Taylor & Francis.
Effect of glucocorticoid and melatonin on immune function of an Indian tropical bird, Perdicula asiatica: An in Vivo and in Vitro study
(Biolife s.a.s., 2010) S.S. Singh; S.K. Yadav; C. Haldar
Inverse relationship between circulatory levels of glucocorticoids and melatonin has been reported for most of the vertebrates including human beings. We report the importance of glucocorticoid along with melatonin in avian immune regulation in an Indian tropical bird, Perdicula asiatica with in vivo and in vitro approach. Dexamethasone (30μg/bird/day) treatment of the male birds suppressed the immune activity as judged by the spleen activity (mass, anatomy), circulating total leukocyte, and lymphocyte count, blastogenic response, increased % apoptosis and cytokine (IL-2) production by splenocytes. Melatonin (25μg/100g B.wt./day) treatment increased the above-mentioned immune parameters whereas melatonin together with dexamethasone restored the suppressed immune parameters by dexamethasone to control level. In vitro melatonin (2.5 pM) supplementation to splenocyte cultures restored the dexamethasone (2 μM) suppressed splenocyte proliferation, % apoptosis and IL-2 production. Therefore, melatonin antagonized the suppressive effect of synthetic glucocorticoid on all immune parameters studied in vivo as well as in vitro. Furthermore, exogenous administration of dexamethasone and melatonin treatment altered the circulatory level of corticosterone and melatonin in an inverse manner. It is therefore, suggested that a hormonal trade-off between glucocorticoid and melatonin exists under in vivo and in vitro conditions, being involved in maintenance of the immune function of P. asiatica probably by involving cytokines i.e. IL-2 mediated pathway. Copyright © by Biolife, s.a.s.
Factors modulating alkaline phosphatase activity in the diazotrophic rice-field cyanobacterium, Anabaena oryzae
(2006) S.K. Singh; S.S. Singh; V.D. Pandey; A.K. Mishra
Alkaline phosphatases (APase), both phosphomonoesterase (PMEase) and phosphodiesterase (PDEase) were studied in the cyanobacterium Anabaena oryzae for their specific requirements of temperature, pH, micro- and macronutrients and their activities in the presence of salinity and heavy metal stress. The alkaline phosphatases (PMEase and PDEase) are quite stable enzymes and require a narrow range of pH (pH 10-10.2) and temperature (35-40°C) for their optimal activity. A pH of 10, 10.2 and 10.2 supported optimal activity of cellular PMEase, cellular PDEase and extracellular PMEase, respectively, whereas temperatures of 35, 38 and 40°C were required for their optimal activity. The requirement for Ca2+ and Mg2+ as macronutrients and the significance of the micronutrients Zn2+, Co2+, Fe 2+, Mn2+ and Cu2+ in APase activity in the cyanobacterium suggests nutritional regulation of enzyme activity in A. oryzae. The metals Pb2+, Cr6+ and Ni2+ severely inhibited APase activity, whereas the NaCl stress had a dual role, which was concentration dependent. NaCl stress at lower concentrations (≤20 mM) caused an increase in cellular PMEase activity while its higher concentration (>20 mM) favoured release of the extracellular PMEase. The decrease in cellular activity and an increase in extracellular activity suggest that the higher concentrations of salt stimulate the release of the enzyme. The data suggest that the cyanobacterium A. oryzae possess a potential application as biofertilizer in high salinity and alkaline (Ca2+-rich) soils because of its ability to release PO 4 3- enzymatically under these conditions. © Springer 2006.
Fingerprinting and phylogeny of some heterocystous cyanobacteria using short tandemly repeated repetitive and highly iterated palindrome sequences
(2013) E. Shukla; S.S. Singh; A.K. Mishr
The presence of repeated DNA, viz. short tandemly repeated repetitive (STRR) and highly iterated palindrome (HIP) sequences was used as a typing technique for assessing genetic variability and phylogenetic relatedness of heterocystous cyanobacteria. Primers analogous to the STRR and HIP sequences were used to generate specific fingerprints for the twelve heterocystous cyanobacterial strains and a dendrogram was constructed. STRRmod and HIPTG primers revealed 100% polymorphism and yielded almost identical patterns. Anabaena sp. PCC 7120 clustered with Nostoc muscorum with both primers. Primer STRRmod supported the heterogeneity between Nostoc and Anabaena but HIPTG placed these two genera distinctly apart. STRRmod and HIPTG revealed that the members of the two orders were intermixed and thus suggesting a monophyletic origin of heterocystous cyanobacteria. © 2013 Pleiades Publishing, Ltd.
Highlighting the compound risk of COVID-19 and environmental pollutants using geospatial technology
(Nature Research, 2021) Ram Kumar Singh; Martin Drews; Manuel De la Sen; Prashant Kumar Srivastava; Bambang H. Trisasongko; Manoj Kumar; Manish Kumar Pandey; Akash Anand; S.S. Singh; A.K. Pandey; Manmohan Dobriyal; Meenu Rani; Pavan Kumar
The new COVID-19 coronavirus disease has emerged as a global threat and not just to human health but also the global economy. Due to the pandemic, most countries affected have therefore imposed periods of full or partial lockdowns to restrict community transmission. This has had the welcome but unexpected side effect that existing levels of atmospheric pollutants, particularly in cities, have temporarily declined. As found by several authors, air quality can inherently exacerbate the risks linked to respiratory diseases, including COVID-19. In this study, we explore patterns of air pollution for ten of the most affected countries in the world, in the context of the 2020 development of the COVID-19 pandemic. We find that the concentrations of some of the principal atmospheric pollutants were temporarily reduced during the extensive lockdowns in the spring. Secondly, we show that the seasonality of the atmospheric pollutants is not significantly affected by these temporary changes, indicating that observed variations in COVID-19 conditions are likely to be linked to air quality. On this background, we confirm that air pollution may be a good predictor for the local and national severity of COVID-19 infections. © 2021, The Author(s).
Long-term melatonin administration attenuates low-LET γ-radiation- induced lymphatic tissue injury during the reproductively active and inactive phases of Indian palm squirrels (Funambulus pennanti)
(2010) S. Sharma; C. Haldar; S.K. Chaube; T. Laxmi; S.S. Singh
A comparative analysis of low linear energy transfer (LET) γ-radiationinduced damage in the lymphatic tissue of a tropical seasonal breeder, Indian palm squirrel (Funambulus pennanti), during its reproductively active phase (RAP) and inactive phase (RIP) was performed with simultaneous investigation of the effects of long-term melatonin pre-treatment (100 mg/100 g body weight). A total of 120 squirrels (60 during RAP and 60 during RIP) were divided into 12 groups and sacrificed at 4, 24, 48, 72 and 168 h following 5 Gy c-radiation exposure; control groups were excluded fromexposure. Total leukocyte count and absolute lymphocyte count (ALC) and melatonin only of peripheral blood, stimulation index, thiobarbituric-acid-reactive substances (TBARS) level, superoxide dismutase (SOD) activity, and the apoptotic index of spleen as analysed by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labelling (TUNEL) noted at observed time-points were significantly reduced in melatonin pre-treated groups during RAP and RIP. Long-term melatonin pretreatment mitigated radiation-induced alterations more prominently during RIP, as assessed by ALC, TBARS, SOD, TUNEL and caspase-3 activity, at some time-points. Our results demonstrate an inhibitory role of melatonin on caspase-3 activity in splenocytes during RAP and RIP following γ-radiation-induced caspase-mediated apoptosis. Hence, we propose that melatonin might preserve the viability of immune cells of a seasonal breeder against background radiation, which is constantly present in the environment. © 2010 The British Institute of Radiology.
Magnetobiological effects on a cyanobacterium, anabaena doliolum
(Informa Healthcare, 1994) S.S. Singh; S.P. Tiwari; J. Abraham; S. Rai; Ashwani K. Rai
Exposure time and magnetic-pole-dependent physiological response of a cyanobacterium, Anabaena doliolumwere studied by exposing the samples to two poles [north (N) and south (S)] of a 0.3 Tesla permanent magnet for 1-6 h. Study revealed that both magnetic poles, N and S, produce different effects, depending on the length of exposure. However, physiological response of the cyanobacterium to N + S mixtures was significantly different from the response to either of the poles, N or S, suggesting a change in structural chemistry of the water or nutrient solution responsible for the magnetobiological effects. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.
Magnetobiological effects on a cyanobacterium, Anabaena doliolum
(1994) S.S. Singh; S.P. Tiwari; J. Abraham; S. Rai; A.K. Rai
[No abstract available]
Multi-level impacts of the COVID-19 lockdown on agricultural systems in India: The case of Uttar Pradesh
(Elsevier Ltd, 2021) Pavan Kumar; S.S. Singh; A.K. Pandey; Ram Kumar Singh; Prashant Kumar Srivastava; Manoj Kumar; Shantanu Kumar Dubey; Uma Sah; Rajiv Nandan; Susheel Kumar Singh; Priyanshi Agrawal; Akanksha Kushwaha; Meenu Rani; Jayanta Kumar Biswas; Martin Drews
When on March 24, 2020 the Government of India ordered a complete lockdown of the country as a response to the COVID-19 pandemic, it had serious unwanted implications for farmers and the supply chains for agricultural produce. This was magnified by the fact that, as typically in developing countries, India's economy is strongly based on farming, industrialization of its agricultural systems being only modest. This paper reports on the various consequences of the COVID-19 lockdown for farming systems in India, including the economy, taking into account the associated emergency responses of state and national governments. Combining quantitative and qualitative sources of information with a focus on the Indian state of Uttar Pradesh, including expert elicitation and a survey of farmers, the paper identifies and analyzes the different factors that contributed to the severe disruption of farming systems and the agricultural sector as a whole following the lockdown. Among other issues, our study finds that the lack of migrant labor in some regions and a surplus of workers in others greatly affected the April harvest, leading to a decline in agricultural wages in some communities and an increase in others, as well as to critical losses of produce. Moreover, the partial closure of rural markets and procurement options, combined with the insufficient supply of products, led to shortages of food supplies and dramatically increased prices, which particularly affected urban dwellers and the poor. We argue that the lessons learned from the COVID-19 crisis could fuel the development of new sustainable agro-policies and decision-making in response not only to future pandemics but also to the sustainable development of agricultural systems in India and in developing countries in general. © 2020 Elsevier Ltd
Pulmonary embolism in rheumatic heart disease
(1973) A.N. Rai; S.S. Singh; A.P. Pandey
Pulmonary embolism is a known complication of phlebothrombosis affecting venous system of legs, pelvis and abdomen. Smith et al. (1965) reported that the commonest site of thrombus formation is leg veins (46%), followed by right atrium (38%), inferior vena cava (19%), pelvic veins (16%) and right ventricle (4%), in the order of frequency. Though pulmonary embolism may occur in apparently healthy individuals (Homan, 1943 and Short, 1952), heart disease patients are more at risk (Carlotti et al., 1947, Short, 1952, Byrne, 1960, Sasahara et al., 1967). Sasahara et al. (1967) found that 69% of their cases of pulmonary embolism had cardiac disease, 21% of whom had rheumatic mitral disease. In an earlier study by Sasahara (1965), 50% of the cases of pulmonary embolism were found to have rheumatic heart disease. The present work was undertaken in order to study different aspects of pulmonary embolism in rheumatic heart disease.
Ultraviolet radiation stress: Molecular and physiological adaptations in trees
(Springer Netherlands, 2006) S.S. Singh; Pankaj Kumar; Ashwani K. Rai
The ozone layer acts like a giant sunshade, protecting forests and other life forms on the Earth's surface from much of the Sun's harmful ultraviolet radiation. The depletion in stratospheric ozone layer due to anthropogenically released pollutants such as CFCs during the last few decades has resulted in increased UV radiation at ground level. UV radiation (100-400 nm) consists of UV-C (100-280 nm), UV-B (280-315 nm) and UV-A (315-400 nm) radiations. Out of these three, UV-B radiation has a disproportionately large photobiological effect on forest tree species. Enhanced UV radiation affects the tree species by modifying both their biological and biochemical environment. Damage may occur in a number of ways including the direct destruction of genetic material DNA at molecular level, disruption of membranes and other cell structure and generation of highly reactive chemicals known as "free radicals". It also inhibits various physiological processes including photosynthesis, nutrient assimilation, chlorophyll and protein synthesis, which results into reduced growth and development of the tree as a whole. Enhanced UV radiation especially UV-B radiation leads to several biochemical changes in the plants and synthesize secondary metabolites (condensed tannins, phenolics, flavonoids etc.) in the leaves and other parts of the plant. These secondary metabolites are synthesized as an adaptive mechanism in trees against enhanced UV radiation and have UV-absorbing properties. It reduces the insect herbivory, several viral and fungal diseases of a tree. Elevated CO2 concentration ameliorates the damaging effects of UV radiation, whereas, drought in combination to enhanced UV radiation has inhibitory effect on plant growth and development. The inhibitory effects of enhanced UV radiation on the tree growth and development are more pronounced in the trees grown at the higher altitudes and at the equator as compared to the trees grown at lower altitude and at higher latitude. Trees undergo several changes to overcome the damaging effects of increased UV radiation by expressing new genes, synthesizing UV-absorbing compounds (secondary metabolites) and reactive oxygen scavenging enzymes. These processes in combination lead to morphological changes and thereby trees are able to tolerate UV radiation stress. © 2006 Springer. All Rights Reserved.
Variation in melatonin receptors (Mel 1a and Mel 1b) and androgen receptor (AR) expression in the spleen of a seasonally breeding bird, Perdicula asiatica
(2011) S.K. Yadav; C. Haldar; S.S. Singh
Daily variation in the peripheral level of melatonin plays a major role in integrating reproduction and environmental information for seasonally breeding birds. However, the variation in immunity and reproduction has never been assessed in any avian species on a 24h time scale. Therefore, to understand the relationship between immune function and reproductive phases in a seasonally breeding bird, Perdicula asiatica, the Indian jungle bush quail, we studied the daily variation of melatonin and testosterone levels along with expression of their receptors Mel 1a, Mel 1b, and androgen receptor in the spleen during the reproductively active phase. Immunocytochemistry for the melatonin receptors Mel 1a and Mel 1b presented a differential distribution pattern. Western blot of splenic protein suggested a daily rhythm of melatonin receptors, while acrophases for the two melatonin receptors Mel 1a and Mel 1b differed by 4h, suggesting that the expression of the receptors may peak at different times, causing more of either Mel 1a or Mel 1b to be available at a particular time to mediate function. The circulatory melatonin level correlated with percentage stimulation ratio of splenocytes and plasma interleukin-2 level, but did not correlate with testosterone or androgen receptor, suggesting that melatonin could be a major hormone imparting a time-of-day effect on the modulation of immune function in a seasonally breeding bird during the reproductively active phase. © 2011 Elsevier Ireland Ltd.
Westiellopsis tiwarii sp. nov., a New Cyanobacterium from North-East India Soils
(Pleiades Publishing, 2024) M. Parmar; T.P. Jaiswal; S. Bhattacharjee; S.S. Singh; A.K. Mishra
Abstract: In modern times, cyanobacterial identification, characterization, and classification have adopted a pragmatic polyphasic approach assigning equal weight to the ecological, morphological, physiological, and molecular parameters. The paucity of data on cyanobacterial diversity across unexplored regions resulted in poor taxonomic characterization of cyanobacteria. Hence, the poorly explored North-Eastern lower Himalayan region of India was targeted and a true-branched soil inhabiting cyanobacterial strain KFS2 was isolated. Along with habitat analysis, morphological and 16S-rRNA gene-based molecular characterization of the isolated strain have been performed. The complex cellular morphology, uni-seriate to multi-seriate main filaments and branches, along with the 16S rRNA gene sequence-based phylogeny indicated affiliation of this strain with the genus Westiellopsis. Furthermore, the strain KFS2 showed unique morphological features such as the multi-seriate base of lateral branches, the presence of both intercalary and terminal heterocytes in the main filaments along with the intercalary position of heterocytes in the lateral branches, and was found to form a separate node with the Westiellopsis clade having strong bootstrap support in the 16S-rRNA gene-based phylogeny. Moreover, comparative analysis of folded secondary structures of D1-D1' and box-B in the 16S-23S ITS region of the strain also exhibited striking differences with other members of the genus. Considering all the unique morphological and molecular characteristics of the strain KFS2, it was suggested to represent a new species of the genus Westiellopsis, with the name Westiellopsis tiwarii being proposed in accordance with the International Code of Nomenclature of algae, fungi, and plants. © Pleiades Publishing, Ltd. 2024. ISSN 0026-2617, Microbiology, 2024, Vol. 93, No. 4, pp. 399–409. Pleiades Publishing, Ltd., 2024.