A thermally stable {FeNO}(8) complex: properties and biological reactivity of reduced MNO systems

Reduced nitrogen oxide ligands such as NO−/HNO or nitroxyl participate in chemistry distinct from nitric oxide (NO). Nitroxyl has been proposed to form at heme centers to generate the Enemark–Feltham designated {FeNO}8 system. The synthesis of a thermally stable {FeNO}8 species namely, [Co(Cp*)2][Fe(LN4)(NO)] (3), housed in a heme-like ligand platform has been achieved by reduction of the corresponding {FeNO}7 complex, [Fe(LN4)(NO)] (1), with decamethylcobaltocene [Co(Cp*)2] in toluene. This complex readily reacts with metMb, resulting in formation of MbNO via reductive nitrosylation by the coordinated HNO/NO−, which can be inhibited with GSH. These results suggest that 3 could serve as a potential HNO therapeutic. Spectroscopic, theoretical, and structural comparisons are made to 1 and the {CoNO}8 complex, [Co(LN4)(NO)] (2), an isoelectronic analogue of 3

Toxicity of Cadmium in Soil-Plant-Human Continuum and Its Bioremediation Techniques

Cadmium (Cd) toxicity is highly detrimental for the human and largely originated from faulty industrial and agricultural practices. Cadmium toxicity can be observed in minute concentration and highly mobile in the soil–plant system and availability in soil is mainly governed by various physio-chemical properties of the soil. Cereals and vegetables cultivated in peri-urban areas, former mining and industrial areas accumulate Cd in toxic limit as they receive Cd from multiple ways. In general, when the total cadmium (Cd) concentration in soil exceeds 8 mg kg−1, or the bioavailable Cd concentration becomes >0.001 mg kg−1, or the Cd concentration in plant tissue reaches 3–30 mg kg−1 most plants exhibit visible Cd toxicity symptoms. The impacts of Cd toxicity are seed germination, growth, photosynthesis, stomata conductance, enzyme activities and alteration in mineral nutrition. The major source of Cd in human is food chain cycle and causes disorders like “itai-itai” disease, cancer, and nephrotoxicity. Cadmium harms kidney, liver, bone and reproductive body parts and may be fatal in serious condition. WHO recommended the tolerable monthly Cd intake are 25 μg kg−1 body weights and in drinking water Cd concentration should not exceed 3 μg L−1. It is hard to remove these potent and hazardous metals from the environment as they have long mean residence time but, can be converted into less toxic form through bioremediation. This chapter focuses on the effect of Cd toxicity in soil–plant-human continuum and its bioremediation techniques to mitigate the Cd- toxicity

HI 21cm Cosmology and the Bi-spectrum: Closure Diagnostics in Massively Redundant Interferometric Arrays

New massively redundant low frequency arrays allow for a novel investigation of closure relations in interferometry. We employ commissioning data from the Hydrogen Epoch of Reionization Array to investigate closure quantities in this densely packed grid array of 14m antennas operating at 100 MHz to 200 MHz. We investigate techniques that utilize closure phase spectra for redundant triads to estimate departures from redundancy for redundant baseline visibilities. We find a median absolute deviation from redundancy in closure phase across the observed frequency range of about 4.5deg. This value translates into a non-redundancy per visibility phase of about 2.6deg, using prototype electronics. The median absolute deviations from redundancy decrease with longer baselines. We show that closure phase spectra can be used to identify ill-behaved antennas in the array, independent of calibration. We investigate the temporal behavior of closure spectra. The Allan variance increases after a one minute stride time, due to passage of the sky through the primary beam of the transit telescope. However, the closure spectra repeat to well within the noise per measurement at corresponding local sidereal times (LST) from day to day. In future papers in this series we will develop the technique of using closure phase spectra in the search for the HI 21cm signal from cosmic reionization.Comment: 32 pages. 11 figures. Accepted to Radio Scienc

Effect of Biochar Application on Heavy Metal accumulation in Different Parts of Paddy Plant

Heavy metal contamination in agricultural field is a challenging aspect globally. Various methods are employed to address the issue; biochar among the most cost-effective and promising one. Our study encompasses biochar preparation from Parthenium, a noxious weed of agricultural field, and its subsequent modification using ferric chloride and orthophosphoric acid. Results revealed that more than 20% reduction of Pb, Cd and Ni in Rice roots under 5 and 7.5 t ha-1 biochar treatments. Moreover, greater than 30% reduction of abovementioned heavy metals in rice grains is also noted in 10 t ha-1 biochar application rates. So, it can be concluded from our study that biochar application to a metal contaminated soil can be a promising approach to reduce metal accumulation in different parts of rice and subsequently addressing the adverse effect of it in human body.&nbsp

Square-Antiprismatic Eight-Coordinate Complexes of Divalent First-Row Transition Metal Cations: A Density Functional Theory Exploration of the Electronic–Structural Landscape

Density functional theory (in the form of the PW91, BP86, OLYP, and B3LYP exchange–correlation functionals) has been used to map out the low-energy states of a series of eight-coordinate square-antiprismatic (<i>D</i>₂<i>_d</i>) first-row transition metal complexes, involving Mn­(II), Fe­(II), Co­(II), Ni­(II), and Cu­(II), along with a pair of tetradentate N₄ ligands. Of the five complexes, the Mn­(II) and Fe­(II) complexes have been synthesized and characterized structurally and spectroscopically, whereas the other three are as yet unknown. Each N₄ ligand consists of a pair of terminal imidazole units linked by an <i>o</i>-phenylenediimine unit. The imidazole units are the strongest ligands in these complexes and dictate the spatial disposition of the metal three-dimensional orbitals. Thus, the d_{<i>x</i>²‑<i>y</i>²} orbital, whose lobes point directly at the coordinating imidazole nitrogens, has the highest orbital energy among the five d orbitals, whereas the d_<i>xy</i> orbital has the lowest orbital energy. In general, the following orbital ordering (in order of increasing orbital energy) was found to be operative: d_<i>xy</i> < d_<i>xz</i> = d_<i>yz</i> ≤ d_<i>z</i>² < d_{<i>x</i>²<i>‑y</i>²}. The square-antiprism geometry does not lead to large energy gaps between the d orbitals, which leads to an <i>S</i> = 2 ground state for the Fe­(II) complex. Nevertheless, the d_<i>xy</i> orbital has significantly lower energy relative to that of the d_<i>xz</i> and d_<i>yz</i> orbitals. Accordingly, the ground state of the Fe­(II) complex corresponds unambiguously to a d_<i>xy</i>²d_<i>xz</i>¹d_<i>yz</i>¹d_<i>z</i>²¹d_{<i>x</i>²‑<i>y</i>²}¹ electronic configuration. Unsurprisingly, the Mn­(II) complex has an <i>S</i> = 5/2 ground state and no low-energy d-d excited states within 1.0 eV of the ground state. The Co­(II) complex, on the other hand, has both a low-lying <i>S</i> = 1/2 state and multiple low-energy <i>S</i> = 3/2 states. Very long metal-nitrogen bonds are predicted for the Ni­(II) and Cu­(II) complexes; these bonds may be too fragile to survive in solution or in the solid state, and the complexes may therefore not be isolable. Overall, the different exchange–correlation functionals provided a qualitatively consistent and plausible picture of the low-energy d-d excited states of the complexes

Impact of STCR Based Nutrient Application on Dry Matter Accumulation, Partitioning of Potassium in Rice (Oryza sativa L.) and Potassium Fractions in Black Cotton Soil of Central India

Chemical fertilizers used by the majority of Indian farmers are based on a generalized recommendation that overlooks soil fertility and crop response. These broad recommendations frequently result in under- or over-fertilization, resulting in reduced productivity, efficiency, and environmental pollution. To address these issues, the STCR-target yield approach appears to be promising. However, the dynamics of potassium (K), an important primary essential nutrient, is not fully understood under STCR based approach. Therefore, our current study was aimed to profile the dynamics of potassium in rice parts and its different forms in vertisol. The present study was conducted at the soil science research farm of Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Madhya Pradesh, a part of AICRP on the effect of soil test and crop response based nutrient management on potassium partitioning in rice crop and its fractions in vertisol of Madhya Pradesh. The treatments comprised of T1 : Control (no fertilizer application); T2 : General recommended dose (120:60:40 N, P2O5 and K2O kg ha-1); T3 : Targeted Yield 50 q ha-1 (115:90:49 N, P2O5 and K2O kg ha-1);&nbsp; T4 : Targeted Yield 60 q ha-1 (157:125:70 N, P2O5 and K2O kg ha-1);&nbsp; T5 : Targeted Yield 50 q ha-1 with 5 t FYM ha-1 (115:90:49 N, P2O5 and K2O kg ha-1); and T6 : Targeted Yield 60 q ha-1&nbsp; with 5 t FYM ha-1 (157:125:70 N, P2O5 and K2O kg ha-1). Partitioning of K into different parts of rice was anlaysed and the result showed that T6 has a significant effect on it. Highest concentration of K in root, leaves, stem, panicle and grain (0.353, 1.730, 2.510, 0.441 and 0.275%, respectively) was found in T6. STCR based fertilizer with 5 tonnes FYM ha-1 application significantly influenced the different fractions of soil K and the maximum available potassium, which is present in the form of water-soluble, exchangeable, and non-exchangeable forms, equilibrium with each other, were also found to be maximum in treatment T6. The study based on STCR demonstrated that STCR based integrated use of fertilizers and manure for targeting yield can produce targeted yield without deteriorating soil fertility

Spatial variability of arsenic in Indo-Gangetic basin of Varanasi and itscancer risk assessment

Not AvailableThe Indo-Gangetic alluvium is prime region for intensive agricultural. In some areas of this region, groundwater is now becoming progressively polluted by contamination with poisonous substances like arsenic. Intensive irrigation with arsenic contaminated groundwater in dry spell results in the formation of As(III) which is more toxic. Thus groundwater quality assessment of Gangetic basin has becomeessential for its safer use. Therefore we undertook a study on the spatial variability of arsenic by collecting georeferred groundwater samples on-grid basis from various water sources like dug well, bore and handpumps covering the river bank region of Ganga basin. Water quality was investigated through determination pH, EC, TDS, salinity, Na, K, Ca, Mg, SAR, SSP, CO3, HCO3, RSC, Cl, As, Fe, Zn, Mn and Cu, etc. Results pointed severe As contamination in ground water of three sites of the study area. ARC GIS software is now able to process maps along with tabular data and compare them well, to provide the spatial visualization of information and using this tool, the Geographical Information System (GIS) of arsenic was developed. It was noticed from spatial maps that concentration of arsenic was more near the meandering points of Ganga.Not Availabl

Not Available

Not AvailableThe Indo-Gangetic alluvium is prime region for intensive agricultural. In some areas of this region, groundwater is now becoming progressively polluted by contamination with poisonous substances like arsenic. Intensive irrigation with arsenic contaminated ground water in dry spell results in the formation of As(III) which is more toxic. Thus groundwater quality assessment of Gangetic basin has become essential for its safer use. Therefore we under took study on the spatial variability of arsenic by collecting georeferred groundwater samples on grid basis from various water sources like dug well, bore and hand pumps covering the river bank region of Ganga basin. Water quality was investigated through determination pH, EC, TDS, salinity, Na, K, Ca, Mg, SAR, SSP, CO3, HCO3, RSC, Cl, As, Fe, Zn, Mn and Cu, etc. Results pointed severe As contamination in ground water of three sites of the study area. ARC GIS software is now able to process maps along with tabular data and compare them well, to provide the spatial visualization of information and using this tool, the Geographical Information System (GIS) of arsenic was developed. It was noticed from spatial maps that concentration of arsenic was more near the meandering points of Ganga.Not Availabl

Effect of Different Arsenic and Biochar Levels on Soil Microbial Population and Enzymatic Activity

Arsenic (As) poses a pervasive environmental contamination problem on a global scale. Human activities have significantly contributed to the extensive presence of arsenic (As) in soils. Recently, there has been growing interest in exploring the potential of biochar in addressing the issue of As-contaminated soils. This study focused on evaluating the effects of two types of biochar, namely straw biochar and iron-modified biochar, on the composition of soil microbial communities and enzymatic activity in soil contaminated with arsenic. After conducting a pot experiment for a duration of 9 months, the microbial communities and enzymatic activity were analyzed. Biochar refers to carbon-rich porous solids that are produced by heating biomasses under low oxygen conditions. These biochars are regarded as environmentally friendly sorbents that can be employed for the treatment of different types of arsenic contamination. The increased abundance of soil microbial populations and the enhanced enzymatic properties suggest that biochar fosters the richness and diversity of bacterial communities. Consequently, these improvements in the soil environment and biological quality highlight the potential of iron-modified biochar as an alternative agent for remediating arsenic-contaminated soils

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Not AvailablePresently, the world is suffering from the declining trend of crop yields globally, making food security a major challenge. The limited availability of arable land and water resources has made this challenge even bigger. Recent research-based studies depict that, in many developing countries, poor soil fertility, lower availability of mineral nutrients in soil, improper nutrient management, along with the lack of plant genotypes having high tolerance to nutrient deficiencies or toxicities are major constraints leading to food insecurity, malnutrition (i.e., micronutrient deficiencies), and degradation of ecosystem. It has been stated that 60% of our cultivated soils have growth-limiting problems with deficiencies and toxic-ities of available mineral nutrients. About 50% of the world population suffers from micronutrient de-ficiencies that make mineral nutrition studies a major promising area in meeting the global demand for sufficient food production with enhanced nutritional value. Integration of plant adaptation strategies in such soils using genetics and plant breeding and molecular biology is indispensable in developing plant genotypes with high genetic potential to acclimatize such nutrient-deficient and toxic soil conditions to translocate more micronutrients into edible plant parts such as cereal grains. Thus, plant nutrition research provides invaluable information, which is highly useful in elimination of these constraints, and leads to sustain the food security and well-being of humans without harming the environment. Keeping all these points in mind this chapter helps in understanding the mechanisms and strategies of plant in nutrient-deficient and toxic soil conditions. hysiological mechanisms and adaptation strategies of plants under nutrient deficiency and toxicity conditions. Available from: https://www.researchgate.net/publication/352055185_Physiological_mechanisms_and_adaptation_strategies_of_plants_under_nutrient_deficiency_and_toxicity_conditions [accessed Jun 12 2021].Not Availabl