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Mercury pollution, with India ranked as the world's second-largest emitter, poses a critical environmental and public health challenge and underscores the need for rigorous research and effective mitigation strategies. Nanocellulose is derived from cellulose, the most abundant natural polymer on earth, and stands out as an excellent choice for mercury ion remediation due to its remarkable adsorption capacity, which is attributed to its high specific surface area and abundant functional groups, enabling efficient Hg(II) ion removal from contaminated water sources. This review paper investigates the compelling potential of nanocellulose as a scavenging tool for Hg(II) ion contamination. The comprehensive examination encompasses the fundamental attributes of nanocellulose, its diverse fabrication techniques, and the innovative development methods of nanocellulose-based nanocomposites. The paper further delves into the mechanisms that underlie Hg removal using nanocellulose, as well as the integration of nanocellulose in Hg detection methodologies, and also acknowledges the substantial challenges that lie ahead. This review aims to pave the way for sustainable solutions in mitigating Hg contamination using nanocellulose-based nanocomposites to address the global context of this environmental concern. [ABSTRACT FROM AUTHOR]

The invasive screening methods and the late stage diagnosis of colorectal carcinoma (CRC) are contributing for the devastative prognosis. The gradual shift of the disease pattern among younger generations requires the implementation of phytochemicals and traditional medicines. Arkeshwara rasa (AR) is a herb–mineral combination of Tamra bhasma/incinerated copper ashes and Dwigun Kajjali/mercury sulphide levigated with Calotropis procera leaf juice, Plumbago zeylanica root decoction and the decoction of three myrobalans (Terminalia chebula, Terminalia bellerica, Emblica Officinalis decoction)/Triphala decoction. The SW-480 cell line was checked for the cytotoxicity and the cell viability criteria with MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay. The acridine orange/ethidium bromide (AO/EtBr) assay revealed the depth of apoptosis affected cells in the fluorescent images. The FTIR analysis exhibited the graphical spectrum of functional groups within the compound AR. The IC50 from the 10−7 to 10−3 concentrations against SW-480 cells was 40.4 μg/mL. The staining of AO/EtBr was performed to visualize live and dead cells and it is evident from the result that number of apoptotic cells increases at increasing concentration of AR. The single bond with stretch vibrations of O–H and N–H are more concentrated in the 2,500–3,200 cm−1 and 3,700–4,000 cm−1 of the spectra whereas, the finger print region carries the O–H and S=O type peaks. The AR shows strong cyto-toxicity against the SW-480 cells by inducing apoptosis. It also modulates cellular metabolism with the involvement of functional groups which antagonizes the strong acids. Moreover, these effects need to be analyzed further based in the in vivo and various in vitro models. [ABSTRACT FROM AUTHOR]

A short-term field study was conducted to document the species diversity and abundance of ants in a deciduous forest in the South Western Ghats (Chinnar, Idukki, Kerala), India. In the present study, 22 species from 18 genera and 06 subfamilies of ants were recorded. The Myrmicinae subfamily had the most species (09), followed by Formicinae (07), Ponerinae (03), Dolichoderinae (01), Dorylinae (01), and Pseudomyrmicinae (01). The genus Camponotus had the most species (3), followed by Monomorium (2) and Pheidole (2), with the remaining genera each having one species. Camponotus compressus, Solenopsis geminata, and Oecophylla smaragdina were the three most common ant species, with Technomyrmex elatior, Leptogenys chinensis, and Odontomachus sp. being the least common (0.4%). The most abundant functional group of ants was the Tropical climate Specialists (6 species), followed by Opportunists and Generalised Myrmicinae (5 species each). Subordinate Camponotini (4 species), Specialist Predators (1 species), and Hot climate Specialists (1 species) were detected as other functional groups of ants in the study area. Overall, the study area holds good ant species diversity, which is even in composition. The present study provides useful information on the composition of the ant community in the South Western Ghats in India. [ABSTRACT FROM AUTHOR]

The current study used phytoplankton functional groups (FGs) to assess the impact of barrages on the ecological function of subtropical river Ganga. A total of 101 phytoplankton species were identified, including 20 phytoplankton FGs with MP and D having the highest prevalence rates of more than 50%. Other FGs with higher occurrence rates, such as N, A, and J, displayed seasonal and spatial advantages on occasion, indicating the randomness of exogenous influx from catchment areas. Based on phytoplankton FGs similarities, a non-metric multidimensional scaling analysis (NMDS) revealed geographical and seasonal discrepancies. The higher concentration of chemical components in Kanpur was linked to decreased water discharged from preceding reservoirs, resulting in a highly polluted stretch in terms of spatial variation, according to our findings. During the monsoon season, however, the diluting process caused by precipitation and surface runoff significantly improved water quality. As a result, we hypothesized that a sequence of barrages alters the hydrological characteristics of cascading reservoirs, which was related to spatial and seasonal fluctuation in FG diversity and phytoplankton FGs could be useful bioindicators of water quality. In conclusion, the phytoplankton FGs approach is useful for identifying the geographical and seasonal aspects of aquatic ecosystems that are heavily influenced by human activities, but its sensitivity to changes in spatial and seasonal water quality warrants more exploration. [ABSTRACT FROM AUTHOR]

A pioneering study on phytoplankton marker pigments, by adopting the HPLC-CHEMTAX analytical approach, was carried out in one of the major shellfish harvesting estuaries (Ashtamudi estuary—AE) on the southwest coast of India and also its adjacent nearshore waters (< 20 m depth) to study the dynamics of phytoplankton functional groups (PFGs). The AE, in general, appeared to be warm (> 29 °C) during the non-monsoon seasons, along with the prevalence of higher salinity (> 25) and NH4-N (> 5 µM) levels. However, during the summer monsoon (SM), the prevailing substantial river influx converted the AE into a low salinity (< 10) dominated system, provided with enhanced levels of NO3-N (4.6–12.6 µM) and PO4-P (0.2–1.4 µM), specifically on its upper reaches. The dissolved inorganic nitrogen (DIN) in the AE was mainly comprised of ammonium (NH4-N), approximately up to ~ 81.8% of the DIN, regardless of seasons, which signifies the eutrophic state of the estuary, the upstream sampling locations, in particular. Concerning the phytoplankton community, a pronounced spatio-temporal variation in chlorophyll a biomass was discernible in the AE, with an exceptional increase (6.4–12.1 mg m−3) during the SIM period. The prevalence of a conspicuous increase in chlorophyll a (av. > 5 mg m−3) along with enhanced zeaxanthin (av. > 1.5 mg m−3) recorded in the AE during the non-monsoon (specifically SIM period) season apparently signified the characteristic governance of cyanobacterial community. During the SM period, the estuary sustained more or less similar concentrations of certain marker pigments, i.e. alloxanthin, zeaxanthin, fucoxanthin and chl b, which representing the co-occurrence of cryptophytes, cyanobacteria, diatoms and chlorophytes, respectively. In contrast, the nearshore waters, wherein enhanced nitrate (NO3-N) and phosphate (PO4-P) levels prevailed, irrespective of seasons, sustained dominance of fucoxanthin over other marker pigments, which indicated the numerical supremacy of diatoms. The CHEMTAX analysis, adopted for estimating the chlorophyll a equivalents of various PFGs, corroborated the supremacy of cyanobacterial derived chlorophyll a in the estuary, and it was conspicuous during the non-monsoonal seasonal periods. Even though the estuary has shown remarkable spatio-temporal hydrographic inconsistencies, that variability was not much operative in generating extreme changes in the nutrient components and subsequent phytoplankton community compositions. From the conspicuous increase in N:P and Si:P ratios, resulting mainly from the low levels of P, it can be concluded that the AE has been a P-limited system for phytoplankton growth (especially for large-sized phytoplankton, e.g. diatoms and dinoflagellates), mainly during the non-monsoonal seasonal periods. Perhaps, this P-limitation, along with the prevalence of warm water column and enhanced NH4-N levels, could be the potential causes of the preponderance of cyanobacterial populations in the AE. [ABSTRACT FROM AUTHOR]

Humans benefit from a variety of ecosystem services provided by seagrass meadows. However, seagrass conservation efforts appear to be insufficient, as evidenced by its low representation in marine protected areas around the world. Protecting seagrasses benefits not just the seagrass itself, but also the macro‐benthic invertebrate assemblages that dwell beside it and contribute indirectly to the various environmental services through their functions. Studies comparing seagrass‐associated invertebrate assemblages and functional trait composition within and outside marine protected areas are uncommon, so the current study compares invertebrate assemblages and functional trait composition from a marine protected area (Gulf of Mannar Marine National Park) and an adjacent non‐marine protected area (Palk Bay) along the southeast coast of India. The species richness (mean S = 83.3) and density (mean D = 6276.6) of seagrass‐associated macro‐molluscs were higher in marine protected areas than in non‐marine protected areas (mean S = 54.6, mean D = 5264.0), but not the species diversity (mean H′ = 2.1 for marine protected areas; mean H′ = 2.0 for non‐marine protected areas). Protected seagrass ecosystems, on the contrary, exhibited much higher species richness within functional groups (i.e., deposit feeders [mean S = 5.5], micro‐/macro‐grazers [21.7], predators [34.8], ectoparasites [2.1], and suspension feeders [19.3]), suggesting that the protection status supports functional redundancy. The study's findings reveal the importance of protection status in enhancing macro‐mollusc assemblages in seagrass ecosystems, which improves the ecosystem's resilience and function. [ABSTRACT FROM AUTHOR]

Coccolithophores contribute substantially to marine primary production as well as to particulate inorganic carbon (PIC) flux to the deep sea; however, there is no literature available so far from the Indian continental shelf on this functional group. We present here the first study describing the spatial variability and species composition of living coccolithophore communities from the north-western continental shelf waters (northeastern Arabian Sea) of India (SW monsoon; August 2018). We found a total of 18 species from 11 genera with Gephyrocapsa oceanica as the dominant coccolithophore. Florisphaera profunda, Calcidiscus leptoporus, Helicosphaera carteri and Umbilicosphaera sibogae were also observed in significant quantities in most of the stations. Cell abundances ranged from 0.3 to 85.6 × 103 l–1 with the maximum occurrence at the northernmost station. Coccolithophore diversity was comparatively higher in the southernmost region, while high dominance was noticed in the north. Redundancy analysis (RDA) revealed that nutrient availability was an important factor to modulate the distribution and abundance of coccolithophores. Gephyrocapsa oceanica was recorded in each station and showed a positive association with NO2– + NO3– levels, whereas F. profunda and U. sibogae were confined mostly to deepwater. Our study shows that a substantial number of coccolithophores are present in the shelf water and could be important as primary producers as well as for the carbon export flux. Further research attention to broaden our knowledge of the role of this functional group is warranted. [ABSTRACT FROM AUTHOR]

Industries are moving towards finding a natural source of functionally active constituents which is better and safer materials to fulfill customers' demand. Marine algae contain a huge variety of biologically active compounds and express a promising role in different applications. Hence, the present study was carried out to characterize different biochemicals from brown alga Sargassum tenerrimum by FTIR, GCMS, HRLCMS Q-TOF, and ICP AES technique. First, the macroalga was collected from the Beyt Dwarka sea site, the Western coast of Gujarat, India. In FTIR, different types of bioactive functional groups were characterized as accountable for different beneficial components whereas ethanolic and methanolic extracts of S. tenerrimum reported fourteen and nineteen different beneficial phyco compounds in GCMS analysis, respectively. In HRLCMS Q-TOF analysis, two compounds were found carbohydrate derivatives and fifty-nine different compounds were determined to be different types of phycocompounds. Additionally, in the ICP AES study, Silicon was found to be high up in amount whereas Copper remained the minimum among studied elements. Moreover, the HRLCMS-QTOF study of amino acids reported that Glutamic acid (132.13 nmol/mL) was found to be the highest whereas Isoleucine (0.70 nmol/mL) was found to be the least amidst measured twenty-one amino acids. Bioactive potentials of these compounds have been reported in many previous studies. The inclusion of macroalgae-derived constituents in different applications has been broadly rising due to their bioactive potentials. [ABSTRACT FROM AUTHOR]

Litter degradation influences nutrient cycling in the ecosystem. The present study is focused on the rate of leaf litter degradation in the evergreen forests of Pampadum Shola National Park, southern Western Ghats, India. Three different in-situ experiments which started in November (post-monsoon), March (pre-monsoon) and June (monsoon season) were carried out and the litter bag method was used for degradation study. The carbon dioxide evolution rate was also assessed using soil respirometer. The degradation pattern of the major polymers in leaf litter was in the order cellulose > hemicellulose > lignin. The litter degradation rate was high in the initial stages of decomposition than in the successive stages. The identification of major phytochemical compounds and functional groups present in the initial stage and at the end of the experiment were detected using GC–MS and ATR-FTIR respectively. Certain phytochemical compounds and functional groups which were present in the initial stage were degraded and a few daughter compounds were formed at the end of the experiment. The results indicate that the litter degradation and CO2 evolution rate are high in the evergreen forest of Pampadum Shola National Park. [ABSTRACT FROM AUTHOR]

The nutritional composition and functional groups of the edible portion of the most often utilized cuttlefish, Sepia pharaonis of Puducherry coastal waters, India was evaluated. Moisture is the basic component of the mantle with 82.45±0.15% followed by a good source of 14.5±0.1% protein. The ash, lipid, and carbohydrates were found less than 1%. The energetic value of the mantle of cuttlefish S. pharaonis is calculated as 6.06 KJ/g. Na and K were found in considerable quantities of 2772 and 3247 mg/kg respectively and the Na/K ratio (0.85) was less than 1. The amount of Zn, Mn, B, Al, Sr, and As was found to be relatively high when compared to a low or insignificant level of Cu, Mo, Se, Cr, Ni, Pb, and Hg. The fatty acid profile analysis revealed that it contains 71.67% saturated fatty acids,17.87% polyunsaturated fatty acids and 10.38% monounsaturated fatty acids. In all three types, the C16:0 palmitic acid (40.29%), C18:0 stearic acid (16.54%), and C22:6 docosahexaenoic acid (13.52%) represented as the dominant fatty acids. The FT-IR analysis disclosed the presence of various functional groups belonging to protein, lipids, and polysaccharides. Thus, the present study proved that the cuttlefish S pharaonisis considered as a potential nutraceutical and the right choice of food for greater and wider human consumption. [ABSTRACT FROM AUTHOR]

A central question of community ecology is to understand how the interplay between processes of the Neutral Theory (e.g., immigration and ecological drift) and niche‐based processes (e.g., environmental filtering, intra‐ and interspecific density dependence) shape species diversity in competitive communities. The articulation between these two categories of mechanisms can be studied through the lens of the intermediate organizational level of "functional groups" (FGs), defined as clusters of species with similar traits. Indeed, FGs stress ecological differences among species and are thus likely to unravel non‐neutral interactions within communities. Here we presented a novel approach to explore how FGs affect species coexistence by comparing species and functional diversity patterns. Our framework considers the Neutral Theory as a mechanistic null hypothesis. It assesses how much the functional diversity deviates from species diversity in communities, and compares this deviation, called the "average functional deviation," to a neutral baseline. We showed that the average functional deviation can indicate reduced negative density dependence or environmental filtering among FGs. We validated our framework using simulations illustrating the two situations. We further analyzed tropical tree communities in Western Ghats, India. Our analysis of the average functional deviation revealed environmental filtering between deciduous and evergreen FGs along a broad rainfall gradient. By contrast, we did not find clear evidence for reduced density dependence among FGs. We predict that applying our approach to new case studies where environmental gradients are milder and FGs are more clearly associated to resource partitioning should reveal the missing pattern of reduced density dependence among FGs. [ABSTRACT FROM AUTHOR]

Variation in soil nutrient availability can influence the functional traits and performance of tree species in a forested landscape. We tested this hypothesis by studying the variations in leaf-traits, and N- and P-resorption efficiencies of a few evergreen (Myrica esculenta, Rhododendron arboretum and Lithocarpus dealbatus) and deciduous (Quercus griffithii, Engelhardtia spicata and Lyonia ovalifolia) tree species growing in montane subtropical old-growth and regenerating forests of Meghalaya, northeast India, varying in their soil characteristics. Trees of the old-growth forest stand, having greater soil total N and P, proved to be much efficient in their foliar nutrient resorption (mean = 42.0% for N and mean = 82.1% for P) and showed higher leaf nutritional quality compared to the regenerating forest stand. Deciduous species had greater N-resorption efficiencies (45.3–49.7%) than the evergreen species (23.6–56.9%) in the old-growth stand. However, in the regenerating stand, the evergreen species were better at resorbing both N (30.6–55.9%) and P (67.9–76.4%) from their leaves than the deciduous species (23.2–40.9% for N and 33.2–52.0% for P). Overall, phosphorus was the limiting nutrient for growth in both the functional groups, with relatively low concentrations in the soils of the two forest stands. The evergreen and deciduous trees in the old-growth forest are found to tightly conserve nutrients with higher leaf N and P concentrations and higher N- and P- resorption efficiencies than the regenerating forest stand. The study clearly indicates that soil fertility has profound effect on the internal nutrient cycling of evergreen and deciduous tree species. [ABSTRACT FROM AUTHOR]

Results of National Gas Hydrate Program-02 (NGHP-02) expedition have confirmed the resource potential of sand-hosted gas hydrate accumulations in the deep offshore of Krishna-Godavari Basin (KG Basin). NGHP-02 has identified two types of gas hydrate accumulations: one is thick, layer-type units developed in sand-rich facies at depths of a few 100 m below sea floor (mbsf), and the other, fracture type unit of variable thickness at shallow depths. Fracture-type and Layer-type gas hydrates were observed in Areas B, C, and E in the KG Basin as defined under NGHP-02. The importance of each type of gas hydrate occurrence as discovered during NGHP-02 has led to the need for microbial profiling. Different classes of microbes, anaerobic fermentative microbes (AFM), methanotrophs and sulphate reducing bacteria (SRB) were studied to understand the microbial system for biogenic gas generation in sedimentary sequences encountered in eight core holes (4 in Area B, 3 in Area C and 1 in Area E) as established during NGHP-02. This study reveals the availability of highest concentration of methane generating microbes that are closely associated with high total organic carbon (TOC) content in the identified gas hydrate bearing sedimentary units cored in each borehole. The presence of microbial consortia for methane generation through both processes, of reduction of CO 2 and fermentation of formate/acetate has been confirmed. Stratigraphic correlation between drill sites have also been generated to better understand the spatial relationship of various microbial processes. An observation from the study, is that the entire late Miocene age sediments has potential to generate biogenic gas in Holes NGHP-02-05B, −17B, −22B and −23B. Late to early Pleistocene age sediments are showing methane generating activity in Holes NGHP-02-01C, −08B and −09B, while early Pleistocene to late Pliocene age sediments contains methane generating microbes in Holes NGHP-02-05B, −17B, −19B, −22B and −23B. The existence of methane generating biogenic microbial system in Areas B, C and E of KG Basin has been confirmed. • Highest content of methane generating microbes are available in identified gas hydrate zones across the studied wells having high TOC content. • Both acetoclastic and hydrogenotropic methanogenesis. • Entire late Miocene age sediments has potential to generate biogenic gas in holes 05, 17, 22 and 23. • Late to early Pleistocene age sediments are showing methane producing activity in hole 01, 08 and 09. • Early Pleistocene to late Pliocene age sediments houses methanogenic microbes in hole 05, 17, 19, 22 and 23. [ABSTRACT FROM AUTHOR]

[Display omitted] • Kimberlite emplacement at 1.1 Ga thermally perturbed the colder Archean geotherm. • Base of the Dharwar lithosphere underwent plume-induced plastic deformation. • Multiple metasomatic events at different time windows affected the lithospheric mantle. • Chromatographic flow of mantle melts plays a key role in lithospheric modification. Megacrysts are large monomineralic crystals with an unknown relationship with the host rock and hence of debatable origin. We present major and trace element chemistry of clinopyroxene (cpx) megacrysts from the ca. 1.1 Ga diamondiferous CC4 kimberlite pipe, Dharwar craton, southern India in order to understand their parentage and ambient lithospheric conditions. The megacrysts were classified into three groups based on their chemistry. Two Cr-poor (Group-I and III) and one Cr-rich (Group-II) populations were identified. The Group-I diopsides have low Al 2 O 3 , Na 2 O, and REE, and positive Zr and Hf anomalies similar to those from deep-seated sheared peridotites. The Group-II and III diopsides, have higher Al 2 O 3 and Na 2 O than the Group-I. The Group-II diopsides have elevated HREE and lower LREE than the Group-III. Thermobarometry indicates a pressure range of 56–67 Kbar for the Group-I samples, making them the deepest. The Group-II and the Group-III megacrysts appear to be shallower compared to the Group-I. Equilibrium melt composition calculated for all the three groups show a silicate-rich end member for the Group-I, whereas the Group-II samples show a carbonatitic equilibrium melt composition. Equilibrium melt composition of the Group-III megacrysts indicate elevated Nb, Zr, Hf, LREE, and HREE than that of natural basalt, carbonatite, and fresh kimberlite. Inter-element relations indicate that the Group-I and II are of metasomatic origin, whereas the Group-III samples suggest a fractionated history. Other trace element ratios indicate a deeper silicate and shallower carbonate melt related metasomatic overprint. [ABSTRACT FROM AUTHOR]

Soak-n-eat rice, a natural treasure of Eastern India, is popular rice based ethnic food item of the tribal peoples of Assam. In the present study, 22 low amylose containing glutinous Bora rice lines were explored for their unique 'ready-to-eat' properties, where physicochemical and molecular approach was used to investigate the science behind softness and finally the establishment of trait linked marker associated with this unique soft trait. Very low amylose content, pinholes in kernel, low final viscosity and detection of unique functional groups, made physicochemical properties of soft rice very distinct from normal rice. Polymorphic trait linked markers; a good number of SNPs in trait linked loci and down regulation of those loci during grain filling revealed the unique molecular basis of softness. RM190 is associated with amylose content and softness, confirmed as a trait linked marker by showing heterozygous band in hybrid lines with desired trait. This study may be the first holistic approach on soft rice for its unique soak-n-eat properties and developed hybrid lines may be the source of future environment friendly food. [ABSTRACT FROM AUTHOR]

This study is designed to determine the morphology, elemental composition, and identification of various minerals and functional groups in household dust in multiple locations in Dhanbad, India. Household dust samples were collected from different locations, and samples had been sieved for particle sizes of <75 μm for analysis. For indoor air quality, active PM sampling for each sampling site was done and concentrations of PM 10 , PM 2.5 , and PM 1 were observed in the range of 31–137, 23–82, and 17–52 μg/m3, respectively. The morphology (FESEM) and elemental analysis (EDX) confirmed the existence of particles with different shapes and compositions in different households. Spherical shape and chain-like structures are indicative of coal combustion inside houses. In contrast, irregular-shaped structures with sharp-edged and sheet-like structures suggest mineral-rich crustal dust in LPG-based houses. Also, soot agglomerates were found in houses nearby roadside from outside vehicular emissions. Energy-dispersive X-ray spectroscopy (EDX) confirmed the relative distribution of elements varied between households and reported that C, O, Mg, Ca, Al, and Si were the primary elements in dust samples collected from various households. The Fourier Transform Infrared (FTIR) peaks for functional groups at various wavelengths such as –C–H, –C C, –C O, –C-X indicates coal dust and their combustion whereas –NH 2 , –NH 4 +, –R-SO 3 − suggests the influence of walking, cleaning, and other household activities. X-ray diffraction (XRD) confirms that minerals such as calcite, vaterite, and quartz were found majorly in roadside houses whereas dolomite, quartz, and hematite were in other sites. [Display omitted] • Household dust is a significant environmental matrix in terms of human exposure. • Cooking and outdoor emissions were the most abundant sources of indoor PM concentrations. • FESEM-EDX revealed different types of particle shapes (spherical, chain/sheet-like) and elements (C, O, Mg, Ca, Al, Si). • Peaks were seen at various wavelengths for functional groups (–CH 3 , –COOH, –C O, –C-X, and –NH 2). • Calcite, dolomite, hematite, vaterite, and quartz were found in the household dust. [ABSTRACT FROM AUTHOR]

Humic acids (HA) and fulvic acids (FA) were extracted from tropical humid forest, tea garden, and field crop soils, and their chemical, potentiometric, and spectrophotometric properties were measured. There was less HA than FA in the cultivated soils. The HAs contained more carbon (C) and nitrogen (N) and had greater C/H ratios but lower O (oxygen)/H (hydrogen) ratios than FAs. Cultivated soils had greater total acidity than the forest soil generally because of both —COOH and phenolic-OH. Molecular weights of HA an FA, estimated from intrinsic viscosities, revealed that cultivation had reasonably reduced the molecular weights. The difference in pH (ΔpH) values, corresponding to three-fourths and one-fourth of the pH at final inflexion point showed that they were polyprotic. The longer time required for stability of greater pH of HAs was related to greater degree of stable coiling. The (E4/E6), in general, revealed a greater amount of aliphatic moiety rather than aromatic moiety. [ABSTRACT FROM PUBLISHER]

Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence. [ABSTRACT FROM AUTHOR]

1. Habitat fragmentation, anthropogenic disturbance and the introduction of invasive species are factors thought to structure ant assemblages. To understand responses of the ant community to changes in the environment, ants are commonly categorised into functional groups, a scheme developed and based on Australian ants. 2. Behaviourally dominant and aggressive ants of the dominant dolichoderinae functional group have been suggested to structure the ant assemblages in arid and semi-arid habitats of these regions. Given the limited geographical distribution of dominant dolichoderinae, it is crucial to determine the responses of the ant community to changes in the environment in their absence. 3. This study addresses this less studied aspect by considering the associations of ants of Western Ghats, India, with habitat, anthropogenic disturbance and introduced ants. We determined how ant functional groups respond to these factors in this region, where dominant dolichoderines are naturally absent, and whether responses are consistent with predictions derived from the ant functional group scheme. 4. This study provides new information on ant assemblages in a little-studied region. As in other parts of the world, ant assemblages in Western Ghats were strongly influenced by habitat and disturbance, with different functional groups associated with different habitats and levels of disturbance. 5. No functional group showed evidence of being influenced by the abundance of introduced species. In addition, predictions of negative interactions between functional groups were not supported. Our findings suggest that abiotic factors are universal determinants of ant assemblage structure, but that competitive interactions may not be. [ABSTRACT FROM AUTHOR]

We present here spectroscopic compositional analysis of brown carbon (BrC) and humic-like substances (HULIS) in the Indian context under varying conditions of source emissions and atmospheric processing. To this end, we study bulk water-soluble organic matter (WSOM), neutral- and acidic-HULIS (HULIS-n and HULIS-a), and high-polarity (HP)-WSOM collected in the eastern Indo-Gangetic Plain (IGP) with respect to UV–Vis, fluorescence, FT-IR, 1H NMR and 13C characteristics under three aerosol regimes: photochemistry-dominated summer, aged biomass burning (BB)-dominated post-monsoon, and fresh BB-dominated winter. Absorption coefficients (b abs_365 nm ; Mm−1) of WSOM and HULIS fractions increase by a factor of 2–9 during winter as compared to summer, with HULIS-n dominating total HULIS + HP-WSOM absorption (73–81%). Fluorophores in HULIS-n appear to contain near-similar levels of aromatic and unsaturated aliphatic conjugation across seasons, while HULIS-a exhibits distinctively smaller-chain structures in summer and post-monsoon. FT-IR spectra reveals, among others, strong signatures of aromatic phenols in winter WSOM suggesting a BB-related origin. 1H NMR-based source attribution coupled with back trajectory analysis indicate the presence of secondary and BB-related organic aerosol (SOA and BBOA) in the post-monsoon and winter, and marine-derived OA (MOA) in the summer, which is supported by 13C measurements. Overall, these observations uncover a complex interplay of emissions and atmospheric processing of carbonaceous aerosols in the IGP. Image 1 • Bulk BrC and HULIS fractions were enriched during biomass burning (BB) periods. • HULIS-n dominated (73–81%) the seasonal total HULIS + HP-WSOM absorption at 365 nm. • Polar functional groups from atmospheric photooxidation prevailed in summer. • Strong signatures of aromatic phenols were observed in BB-influenced samples. • Marine, secondary formation, and BB sources dominated seasonal organic aerosol. We use multiple spectroscopic approaches to characterize the sources and atmospheric processing of aerosol brown carbon and humic-like substances in the eastern Indo-Gangetic Plain, India. We find that secondary formation, marine and biomass burning sources constrain seasonal organic aerosol composition and its optical properties in this region. [ABSTRACT FROM AUTHOR]

This work investigates the absorption properties of soluble brown carbon (BrC), extracted in methanol and water, from ambient aerosol (PM 10) samples, collected over an urban background site in Mumbai, India. The diurnal variability was investigated in samples collected in the morning (7–11 a.m.) and afternoon (12–4 p.m.) periods. Absorption properties of BrC (in the 300–600-nm wavelength range) were measured in filter extracts of water-soluble organic carbon (WSOC) and methanol-soluble organic carbon (MSOC). WSOC and MSOC accounted for on average 52% and 77%, respectively, of the measured OC, potentially indicating unextracted BrC and rendering these values the lower bound. Compared with afternoon samples, the morning samples of MSOC and WSOC had increased BrC concentrations and absorption coefficients (b abs 365; 40%–65%). The correlation between b abs 365 and EC, ns-K+, and NO 3 − in the morning samples indicated contributions from primary sources, including both biomass and vehicular sources. The decreased b abs 365 in the afternoon samples was partly explained by mixing layer dilution, accompanied by a reduction in the concentrations of primary aerosol constituents. Furthermore, in the afternoon samples, 1HNMR spectroscopy revealed the presence of more oxidized functional groups and significantly higher OC/EC and WSOC/OC ratios, indicating the greater aging of afternoon aerosol. The MAC 365 (m2gC−1) for both WSOC and MSOC extracts decreased significantly by 20%–34% in the afternoon samples compared with the morning samples, indicating degradation in the absorption properties of the particles and potentially a change in the constituent BrC chromophores. Image 1 • Enhanced BrC levels & absorption, morning vis-à-vis afternoon, at urban Indian site. • Correlation between b abs 365& EC/ns-K+ implies primary source contribution in morning. • More oxidized functional groups, more aging found via 1HNMR, in afternoon. Compared with morning, BrC absorption of ambient aerosols decreased in the afternoon in Mumbai, India, with boundary layer dilution and change in emission sources being the influencing factors. Relatively higher OC/EC, WSOC/OC ratios and 1HNMR spectroscopy suggest the presence of more oxidized functional groups indicating greater aerosol aging in the afternoon. [ABSTRACT FROM AUTHOR]