Atmospheric ammonia (NH3) is an alkaline gas and a prominent constituent of the nitrogen cycle that adversely affects ecosystems at higher concentrations. It is a pollutant, which influences all ...three spheres such as haze formation in the atmosphere, soil acidification in the lithosphere, and eutrophication in water bodies. Atmospheric NH3 reacts with sulfur (SOx) and nitrogen (NOx) oxides to form aerosols, which eventually affect human health and climate. Here, we present the seasonal and inter-annual variability of atmospheric NH3 over India in 2008–2016 using the IASI (Infrared Atmospheric Sounding Interferometer) satellite observations. We find that Indo-Gangetic Plains (IGP) is one of the largest and rapidly growing NH3 hotspots of the world, with a growth rate of +1.2% yr−1 in summer (June–August: Kharif season), due to intense agricultural activities and presence of many fertilizer industries there. However, our analyses show insignificant decreasing trends in annual NH3 of about −0.8% yr−1 in all India, about −0.4% yr−1 in IGP, and −1.0% yr−1 in the rest of India. Ammonia is positively correlated with total fertilizer consumption (r = 0.75) and temperature (r = 0.5) since high temperature favors volatilization, and is anti-correlated with total precipitation (r = from −0.2, but −0.8 in the Rabi season: October–February) as wet deposition helps removal of atmospheric NH3. This study, henceforth, suggests the need for better fertilization practices and viable strategies to curb emissions, to alleviate the adverse health effects and negative impacts on the ecosystem in the region. On the other hand, the overall decreasing trend in atmospheric NH3 over India shows the positive actions, and commitment to the national missions and action plans to reduce atmospheric pollution and changes in climate.
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•A detailed analysis of atmospheric NH3 over India using satellite observations•Intense agriculture and numerous fertilizer plants make the Indo-Gangetic Plain (IGP) as one of the largest NH3 hotspots of the world.•There is a decreasing trend in annual atmospheric NH3 over India in accordance with the national missions and action plans.•The IGP still shows an increasing trend in NH3 during the monsoon/Kharif season.
Summary Ever since the discovery of rapid eye movement sleep (REMS), studies have been undertaken to understand its necessity, function and mechanism of action on normal physiological processes as ...well as in pathological conditions. In this review, first, we briefly surveyed the literature which led us to hypothesise REMS maintains brain excitability. Thereafter, we present evidence from in vivo and in vitro studies tracing behavioural to cellular to molecular pathways showing REMS deprivation (REMSD) increases noradrenalin level in the brain, which stimulates neuronal Na–K ATPase, the key factor for maintaining neuronal excitability, the fundamental property of a neuron for executing brain functions; we also show for the first time the role of glia in maintaining ionic homeostasis in the brain. As REMSD exerts a global effect on most of the physiological processes regulated by the brain, we propose that REMS possibly serves a housekeeping function in the brain. Finally, subject to confirmation from clinical studies, based on the results reviewed here, it is being proposed that the subjects suffering from REMS loss may be effectively treated by reducing either noradrenalin level or Na–K ATPase activity in the brain.
Recent work showed that the temporal growth of the novel coronavirus disease (COVID-19) follows a sub-exponential power-law scaling whenever effective control interventions are in place. Taking this ...into consideration, we present a new phenomenological logistic model that is well-suited for such power-law epidemic growth.
We empirically develop the logistic growth model using simple scaling arguments, known boundary conditions and a comparison with available data from four countries, Belgium, China, Denmark and Germany, where (arguably) effective containment measures were put in place during the first wave of the pandemic. A non-linear least-squares minimization algorithm is used to map the parameter space and make optimal predictions.
Unlike other logistic growth models, our presented model is shown to consistently make accurate predictions of peak heights, peak locations and cumulative saturation values for incomplete epidemic growth curves. We further show that the power-law growth model also works reasonably well when containment and lock down strategies are not as stringent as they were during the first wave of infections in 2020. On the basis of this agreement, the model was used to forecast COVID-19 fatalities for the third wave in South Africa, which was in progress during the time of this work.
We anticipate that our presented model will be useful for a similar forecasting of COVID-19 induced infections/deaths in other regions as well as other cases of infectious disease outbreaks, particularly when power-law scaling is observed.
•Early COVID-19 data from the first wave of infections in 2020 showed sub-exponential power-law growth behavior.•The power-law scaling was attributed to effective containment and mitigation strategies, and reproduced reasonably well by two-dimensional random walk Monte Carlo simulations.•Here we empirically develop a new logistic growth model (LGM) that is well suited to describe such power-law growth.•The power-law model is compared with other LGMs. It is shown to be rather robust, making consistently accurate out-of-sample predictions for COVID-19 fatality data from five different countries.
Methane (CH4) is a prominent Greenhouse Gas (GHG) and its global atmospheric concentration has increased significantly since the year 2007. Anthropogenic CH4 emissions are projected to be 9390 ...million metric tonnes by 2020. Here, we present the long–term changes in atmospheric methane over India and suggest possible alternatives to reduce soil emissions from paddy fields. The increase in atmospheric CH4 concentrations from 2009 to 2020 in India is significant, about 0.0765 ppm/decade. The Indo-Gangetic Plains, Peninsular India and Central India show about 0.075, 0.076 and 0.074 ppm/decade, respectively, in 2009–2020. Seasonal variations in CH4 emissions depend mostly on agricultural activities and meteorology, and contribution during the agricultural intensive period of Kharif–Rabi (i.e., June–December) is substantial in this regard. The primary reason for agricultural soil emissions is the application of chemical fertilizers to improve crop yield. However, for rice farming, soil amendments involving stable forms of carbon can reduce GHG emissions and improve soil carbon status. High crop production in pot culture experiment resulted in lower potential yield–scaled GHG emissions in rice with biochar supplement. The human impact of global warming induced by agricultural activities could be reduced by using biochar as a natural solution.
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•Significant increase in methane concentration over India in last decade.•Shifting trends in biogenic sources of methane is observed over India.•Seasonal variation in methane concentration depends on agricultural activity.•Methane emissions from soil is modulated with the application of fertilizers.•Alternative organics like biochar may reduce potential soil emissions in paddy.
Highlights • Zebrafish sleep–wake cycles show a diurnal rhythm. • Constant light exposure deprives the fish of sleep. • Place preferences in fish sleep are associated with light conditions. • Sleep ...loss increased anxiety behavior in zebrafish. • Prazosin treatment prevented sleep deprivation-induced anxiety in zebrafish.
To stimulate poly-β-hydroxybutyrate (PHB) accumulation in Synechocystis sp. PCC 6803 by manipulating culture conditions. Stationary phase cultures of Synechocystis sp. PCC 6803 were subjected to N- ...and P-deficiency, chemoheterotrophy and limitations of gas-exchange. Enhanced PHB accumulation was observed under all the above conditions. However, interaction of P-deficiency with gas-exchange limitation (GEL) in the presence of exogenous carbon boosted PHB accumulation maximally. Combined effects of P-deficiency and GEL boosted PHB accumulation up to 38% (w/w) of dry cell weight (dcw) in Synechocystis sp. PCC 6803 in the presence of fructose and acetate. This value is about eightfold higher as compared with the accumulation under photoautotrophic growth condition. These results showed a good potential of Synechocystis sp. PCC 6803 in accumulating poly-β-hydroxybutyrate, an appropriate raw material for biodegradable and biocompatible plastic. Poly-β-hydroxybutyrate could be an important material for plastic and pharmaceutical industries.
The noradrenaline (NA) level in the brain is reduced during rapid eye movement sleep (REMS). However, upon REMS deprivation (REMSD) its level is elevated, which induces apoptosis and the degeneration ...of neurons in the brain. In contrast, isolated studies have reported that NA possesses an anti-oxidant property, while REMSD reduces lipid peroxidation (LP) and reactive oxygen species (ROS). We argued that an optimum level of NA is likely to play a physiologically beneficial role. To resolve the contradiction and for a better understanding of the role of NA in the brain, we estimated LP and ROS levels in synaptosomes prepared from the brains of control and REMS deprived rats with or without
treatment with either α1-adrenoceptor (AR) antagonist, prazosin (PRZ) or α2-AR agonist, clonidine (CLN). REMSD significantly reduced LP and ROS in synaptosomes; while the effect on LP was ameliorated by both PRZ and CLN; ROS was prevented by CLN only. Thereafter, we evaluated
the effects of NA, vitamin E (Vit E), vitamin C (Vit C), and desferrioxamine (DFX, iron chelator) in modulating hydrogen peroxide (H
O
)-induced LP and ROS in rat brain synaptosomes, Neuro2a, and C6 cells. We observed that NA prevented ROS generation by chelating iron (inhibiting a
reaction). Also, interestingly, a lower dose of NA protected the neurons and glia, while a higher dose damaged the neurons and glia. These
and
results are complementary and support our contention. Based on the findings, we propose that REMS maintains an optimum level of NA in the brain (an antioxidant compromised organ) to protect the latter from continuous oxidative onslaught.
Sleep disorders are associated with cognitive impairment. Selective rapid eye movement sleep (REMS) deprivation (REMSD) alters several physiological processes and behaviors. By employing NGS platform ...we carried out transcriptomic analysis in brain samples of control rats and those exposed to REMSD. The expression of genes involved in chromatin assembly, methylation, learning, memory, regulation of synaptic transmission, neuronal plasticity and neurohypophysial hormone synthesis were altered. Increased transcription of BMP4, DBH and ATP1B2 genes after REMSD supports our earlier findings and hypothesis. Alteration in the transcripts encoding histone subtypes and important players in chromatin remodeling was observed. The mRNAs which transcribe neurotransmitters such as OXT, AVP, PMCH and LNPEP and two small non-coding RNAs, namely RMRP and BC1 were down regulated. At least some of these changes are likely to regulate REMS and may participate in the consequences of REMS loss. Thus, the findings of this study have identified key epigenetic regulators and neuronal plasticity genes associated to REMS and its loss. This analysis provides a background and opens up avenues for unraveling their specific roles in the complex behavioral network particularly in relation to sustained REMS-loss associated changes.
Abstract Pedunculopontine tegmentum (PPT) has GABA-ergic neurons and receives GABA-ergic projections from substantia nigra pars reticulata (SNrpr). Based on the recent studies from our and other ...laboratories, it was hypothesized that GABA in PPT promotes rapid eye movement (REM) sleep. In order to further study the role of GABA in PPT in REM sleep regulation, we microinjected GABA-A agonist, muscimol (200 nL, 3.5 mM), into the PPT. Muscimol in PPT significantly enhanced the amount of REM sleep by increasing the mean number of REM sleep bouts. Besides the local interneurons, GABA-ergic afferents from SNrpr are another source of GABA in PPT. In order to understand the contribution of GABA-ergic inputs from SNrpr into PPT for REM sleep regulation, SNrpr was electrically stimulated either alone or simultaneously along with the infusion of GABA-A antagonist, picrotoxin (200 nL, 0.86 mM), into the PPT. The experiment was designed with the premise that stimulation of SNrpr should increase GABA levels in PPT which should increase REM sleep comparable to that after muscimol microinjection in PPT. Further, the effect of stimulation of SNrpr on REM sleep should be antagonized by simultaneous infusion of picrotoxin into PPT. The electrical stimulation of SNrpr did not produce any significant change in sleep–wake states although it was sufficient to counter the effect of picrotoxin injection into the PPT. To overcome the limitations and confounds of electrical stimulation, SNrpr was pharmacologically stimulated by glutamate microinjection (200 nL, 5.34 mM). Infusion of glutamate into SNrpr enhanced REM sleep by increasing the mean number of REM sleep bouts, which was similar and comparable to the effect of muscimol injection into the PPT. The results confirm that GABA in PPT either from local neurons or from SNrpr promotes REM sleep.
Rapid eye movement sleep (REMS) is a unique phenomenon essential for maintaining normal physiological processes and is expressed at least in species higher in the evolution. The basic scaffold of the ...neuronal network responsible for REMS regulation is present in the brainstem, which may be directly or indirectly influenced by most other physiological processes. It is regulated by the neurons in the brainstem. Various manipulations including chemical, elec-trophysiological, lesion, stimulation, behavioral, ontogenic and deprivation studies have been designed to understand REMS genesis, maintenance, physiology and functional significance. Although each of these methods has its significance and limitations, deprivation studies have contributed significantly to the overall understanding of REMS. In this review, we discuss the advantages and limitations of various methods used for REMS deprivation (REMSD) to understand neural regulation and physiological significance of REMS. Among the deprivation strategies, the flowerpot method is by far the method of choice because it is simple and convenient, exploits physiological parameter (muscle atonia) for REMSD and allows conducting adequate controls to overcome experimental limitations as well as to rule out nonspecific effects. Notwithstanding, a major criticism that the flowerpot method faces is that of perceived stress experienced by the experimental animals. Nevertheless, we conclude that like most methods, particularly for in vivo behavioral studies, in spite of a few limitations, given the advantages described above, the flowerpot method is the best method of choice for REMSD studies.
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