Nanoscale surface metrology with a liquid crystal-based phase-shifting angular shearing interferometer.

In this Letter, a phase-shifting angular shearing interferometer has been proposed for the application in optical surface metrology (SM) by using a combination of a wedge-shaped liquid crystal (LC) cell and a polarization phase shifter. The demonstration of this angular shearing interferometer for step height measurement is accomplished with the help of a phase-shifting technique. Four phase-shifted interferograms produced by a geometrical phase shifter are subjected to a simplified Wiener deconvolution method, which resembles a simple analysis technique for shearing interferograms in comparison to alternative approaches. A simulation study has been conducted to validate the proposed technique. The experimental results show an accuracy of 5.56% for determining the step height, which also agrees with the results obtained by atomic force microscopy. Owing to the tunability of birefringence, the proposed LC-based angular shearing interferometry technique will be useful to control spatial resolution in optical metrology.

Plastic waste management during and post Covid19 pandemic: Challenges and strategies towards circular economy.

Global petroleum consumption suffered drastically as lockdowns were put in place to contain the Coronavirus Disease 2019 (COVID-19). As a result, oil costs dropped, making virgin plastics more cost-effective than recycled plastics. The usage of plastic has increased as a result of lifestyle modifications, cost-based incentives, and other factors, further obscuring the issue. The utilization of personal protective equipment (PPE) during the pandemic had resulted in a significant surge in the quantity of plastic waste. The plastic packaging industry achieved a revenue milestone of US$ 909.2 billion in 2021, boosting a compound annual growth rate of 5.5 %. The escalating dependence on plastics imposed additional pressure on waste management systems, which were proven to be ineffective and insufficient in addressing the issue. This situation exacerbated the problem and contributed to environmental pollution. Globally, 40 % of plastic waste ended up in landfills, 25 % was incinerated, 16 % was recycled, and the remaining 19 % infiltrated within the environment. By investing in circular technologies like feedstock recycling and enhancing infrastructural and environmental conditions, it expected to become viable to manage plastic waste flows during such a period of crisis. Investing in valorization strategies that transform plastic waste into value-added goods, such as fuels and building materials, receives a compelling macroeconomic signal when both plastic waste and plastic demand are on the rise. A robust circular economy can be accomplished by finalising the life cycle of plastic waste. The concept of Plastic Waste Footprint (PWF) aims to assess the environmental impact of plastic products throughout their intended usage period. In the midst of the emerging challenges in waste management during and post pandemic period, this research study has been conducted to explore the challenges and strategies associated with plastic waste in the environment.

Effect of CdSe/ZnS quantum dot dispersion on phase transitional behavior of 8OCB liquid crystal.

We report the effect on the phase transitional behavior of 8OCB liquid crystal (LC) doped with functionalized CdSe/ZnS quantum dots (QDs) in different concentrations. The temperature-dependent data of high-resolution optical birefringence and dielectric anisotropy are utilized to characterize the critical anomaly for both the isotropic-to-nematic (I-N) and nematic-to-smectic-A (N-SmA) phase transitions. The obtained results reveal that the order parameter exponent (ß) for the pure LC is found to be ß=0.249 and does not vary upon the inclusion of QDs in the pure matrix. It describes the weakly first-order characteristic of the I-N phase transition for all the studied samples, which falls within the limit of the tricritical hypothesis. Conversely, depending on the range of the N phase, we observed a nonuniversal nature of the specific heat capacity critical exponent (α^{'}) linked with the N-SmA phase transition for all the studied samples. A relative comparison was made amongst the α^{'} values extracted from both the anisotropy data, and further, a theoretical relationship is established with these exponent values. The coupling strength among the N and SmA order parameters is determined using the optical birefringence data and discussed from the perspective of mutual interaction between the LC-QDs ligands. The results signify that a strong ligand-ligand interaction between neighboring QDs effectively reduces the N range and slightly influences the N-SmA phase transition.

Liquid crystal based polarized low coherence interferometer for optical demodulation in sensors.

The resolution of the measurement detection and sensitivity of a polarized low coherence interferometer (PLCI) can be pre-engineered by optimizing the key parameters of the birefringent wedge, which is rarely reported. In this work, we introduce a liquid crystal (LC) wedge in the PLCI and use it to demodulate Fabry-Perot (FP) cavity length. The birefringence property of the nematic LC is used to convert the optical path difference (OPD) of the sensor into a spatial distribution. This results in the production of localized interference fringe patterns. The formation of PLCI fringes and the related shift of the interferogram with a variation in the displacement of the FP displacement sensor is explained with reference to the OPD matching between an LC wedge and the FP cavity. The displacement value is demodulated from the obtained fringe pattern by tracking the centroid position of the fringe envelope and also considering the birefringence dispersion. An additional simulation study shows that the spatial position of the interferogram signal coupled with the dispersion coefficient is almost identical to the experimental data. The demodulated results from both the simulation and experimental investigations are found to be consistent with each other and closely agree with the actual cavity length. Further, the possibility to enhance the sensing resolution is examined by modulating the interferogram fringes using an electric field. Compared to birefringent crystals, the LC wedge presented here is found to be advantageous for high precision and tunability of the measurement range, which is useful for robust fiber optic sensing applications.

New distributional records of fireflies (Coleoptera, Lampyridae, Luciolinae) from two Eastern States of India with notes on their biology and an updated Indian checklist.

Background: The subfamily Luciolinae Lacordaire, 1857, a group of flashing fireflies, is composed of approximately 400 described species in the world. Though the taxonomy of this group has been fairly well established in Southeast (SE) Asia and the Australopacific Region, there is scope of gathering further information regarding taxonomic knowledge on this group from India. Until now, 32 Luciolinae species from nine genera have been reported from India, which is only about 8% (32 out of 400) of the world Luciolinae fauna. With this in mind, several faunistic surveys were conducted in Odisha and West Bengal States of India to explore the firefly fauna of the two States. New information: The faunistic surveys conducted in the Odisha and West Bengal States of India have revealed six new distributional records of Luciolinae firefly species belonging to the genera Abscondita Ballantyne, Lambkin & Fu 2013, Asymmetricata Ballantyne 2009, Pteroptyx Olivier 1902 and Sclerotia Ballantyne 2016 in the two States, earlier which were recorded from other States of India. Of the already recorded species, Abs.perplexa is recorded for the first time from both the States, whereas Abs.chinensis, Asy.ovalis and Scl.aquatilis present new records for Odisha State and Pt.malaccae and Scl.substriata for West Bengal State. The newly-recorded taxa are presented with their examined materials, diagnoses and brief biological notes. Some more distinguishing characters were added for the male genitalia of Abs.perplexa and Asy.ovalis. Further, a checklist of Luciolinae firefly species already recorded from India is also presented.

Determination of refractive indices for liquid crystals using a double transmission technique.

We report a new, to the best of our knowledge, approach to determine the refractive indices (RIs) of liquid crystal (LC) systems by considering a double transmission phenomenon of a light beam within the LC medium and the principle of the wedged-cell refractometer. This modified system delivers better spatial resolution of refracted beams in terms of well-resolved spots, compared to the single transmission of a beam in the conventional thin-prism method. The deviation angle obtained in this method is found to be comparatively greater than that of the thin-prism method. The higher values of deviation angle are described using a theoretical model and further experimentally demonstrated for the 5CB nematic LC compound. The variation of the principal RIs (no, ne), and hence the birefringence (Δn) with temperature as well as electric field is investigated for both transmission methods. A relative comparison is carried out between the simulated and standard values obtained from literature. The present technique provides a higher spatial beam resolution to determine the RIs and birefringence of LC systems, which can be very advantageous for different modern photonic applications based on beam shaping and steering.

Role of bioactive xenobiotics towards reproductive potential of Odontotermes longignathus through in silico study: An amalgamation of ecoinformatics and ecotechnological insights of termite mounds from a tropical forest, India.

The present research study has evaluated the roles of different naturally occurring compounds in termite mounds of Odontotermes longignathus (GenBank Id: MZ542727.1) which facilitate to promote higher population growth of termites and subsequent biodegradation. The study has also monitored the change in physicochemical parameters along with the trend of biodegradation of complex organic carbon-based compounds like lignin, polysaccharides etc. and nitrogenous compounds from two different types of termite mounds such as developing (T1) and developed (T2) mounds. The GC MS profiling of mound samples have revealed the occurrence of different humic acids like organic materials in both T1 and T2 mound samples. Both the termite mounds have demonstrated a high population density as T1 (23.67 ± 1.56) individuals and T2 (43.51 ± 2.36) individuals per 0.1 kg of mound materials. Such observations have prompted to undertake molecular docking experiments which revealed that different molecules interact at low binding affinity with hormone receptors involved in moulting, spermatogenesis and oogenesis of termite like Adamantane carboxylate (EcR: -7.6 Kcal/mol; BTB-KLHL10: -6.2 Kcal/mol; USP-LBD: -7.3 Kcal/mol; VgR: -6.8 Kcal/mol), Benzene dicarboxylic acid (EcR: -5.5 Kcal/mol; BTB-KLHL10: -5.1 Kcal/mol; USP-LBD: -5.4 Kcal/mol; VgR: -5.6 Kcal/mol), Hexadecanol (EcR: -6.0 Kcal/mol; BTB-KLHL10: -4.4 Kcal/mol; USP-LBD: -6.9 Kcal/mol; VgR: -6.0 Kcal/mol), oxirane (EcR: -5.3 Kcal/mol; BTB-KLHL10: -4.9 Kcal/mol; USP-LBD: -5.2 Kcal/mol; VgR: -5.3 Kcal/mol) and tocopherol (EcR: -8.0 Kcal/mol; BTB-KLHL10: -5.4 Kcal/mol; USP-LBD: -7.6 Kcal/mol; VgR: -7.0 Kcal/mol). Such spontaneous ligand binding phenomenon coupled with high population density of termites have established the significance of different bioactive xenobiotics in achieving high reproductive potential of termites which in turn facilitate the process of biodegradation and enhance the nutrient enrichment in the soils of tropical deciduous forest.

GPU Accelerated Drug Application on Signaling Pathways Containing Multiple Faults Using Boolean Networks.

Cell growth is governed by the flow of information from growth factors to transcription factors. This flow involves protein-protein interactions known as a signaling pathway, which triggers the cell division. The biological network in the presence of malfunctions leads to a rapid cell division without any necessary input conditions. The effect of these malfunctions or faults can be observed if it is simulated explicitly in the Boolean derivative of the biological networks. The consequences thus produced can be nullified to a large extent, with the application of a reduced combination of drugs. This paper provides an insight into the behavior of the signaling pathway in the presence of multiple concurrent malfunctions. First, we simulate the behavior of malfunctions in the Boolean networks. Next, we apply the drug therapy to reduce the effects of malfunctions. In our approach, we introduce a parameter called probabilistic_score, which identifies the reduced drug combinations without prior knowledge of the malfunctions, and it is more beneficial in realistic cancerous conditions. The combinations of different custom drug inhibition points are chosen to produce more efficient results than known drugs. Our approach is significantly faster as GPU acceleration has been carried out during modeling the multiple faults/malfunctions in the Boolean networks.

Optimization of heavy metal (lead) remedial activities of fungi Aspergillus penicillioides (F12) through extra cellular polymeric substances.

Wastewater imposes a great threat to any ecosystem across the world, especially the aquatic one because of the different anthropogenic activities of human beings. The present study emphasizes the optimization of ecological parameters [pH, time (h) and temperature (°C)] employing Box-Behnken design (BBD) to achieve better bio-adsorption of a selected heavy metal [lead (Pb II)] from the wastewater through an extracellular polymeric substance (EPS) of a benthic fungus, Aspergillus penicillioides (F12) (MN210327). The relevant statistical analysis (ANOVA) has enabled to record of the optimized bio-adsorption (73.14 %) of lead (Pb II) by fungal EPS at pH (8.85) and temperature (32 °C) for a duration of 5.74 h. Besides that, at the concentration of 0.5 mg/L of EPS, the flocculating rate was noted to be highest (88.4 %) in kaolin clay and the 50 % emulsifying activity. This investigation has also opened up new vistas on the possibility of the development of an alternative method of eco-sustainable bioremediation of heavy metals by fungal EPS on an industrial scale.

Succession of enzymes and microbial biomarkers in the process of vermicomposting: An insight towards valorization of toxic paper mill wastes using Perionyx excavatus (Oligochaeta; Perrier, 1872).

PURPOSE: Main insight of the study was to evaluate the potential of Perionyx excavatus, an indigenous earthworm of India towards bioconversion of toxic paper mill wastes. The study had considered a comprehensive study over succession of different enzymes and microbial biomasses alongside removal of heavy metals to reflect the qualitative enrichment of the toxic waste through valorisation procedure. METHODS: The process of vermicomposting was performed using ratio of paper mill sludge: cow dung: straw as 5:4:1 and Perionyx excavatus for a period of 60 days. Qualitative enrichment was considered through detailed evaluation of physicochemical parameters and succession of 19 enzymes using API ZYM technology. Heavy metal loads in terms of Zn, Cr, Cu, Pb along with bioaccumulation factor (BAF) were considered to establish functional role of earthworm in bioremediation. Microbial succession was measured in terms of PLFA biomarkers. RESULTS: Enzymatic enrichment of different isozymes of esterase, aminopeptidase and glycosyl hydrolase were found in the vermicompost. A significant reduction of heavy metals was noticed in vermicomposting of primary sludge as Zn > Pb > Cr > Cu and secondary sludge as Zn > Pb > Cu > Cr. An increase in density of Gram positive bacterial and fungal populations was found at the end phase of vermicomposting process which supports maturity of vermicompost. CONCLUSION: Presence of different enzyme activities, reduction of heavy metal loads along with rise of eukaryotic PLFA markers, had illustrated the efficiency of vermicomposting as a valorisation procedure in the qualitative enrichment of toxic organic paper mill sludge.

An efficient module-less synthesis approach for Digital Microfluidic Biochip.

Digital Microfluidic Biochips (DMFBs) will require error-free synthesis techniques which can function at much higher speed while implementing on real-time systems and capable of tackling more complex assay operations. Until now various bio-assays are successfully implemented based on different mixing modules present on such lab-on-chips. In present work, the concept of such dedicated virtual modules has been eliminated and a novel module-less-synthesis (MLS) method is proposed for accomplishing high-performance bio-protocols. Various shift-patterns (movements) of the micro-droplets are identified to accomplish entire mixing in lesser time compared to earlier module-based synthesis methods. We have also computed the percentage of mixing accomplishment for each directional-shift of the mixer-droplet. However, path congestion problem and operational errors are inevitable in MLS approach. Hence, the path congestion and washing problem in MLS is addressed by tweaking the earlier MLS approach and a new modified-MLS (MMLS) method is proposed. Finally, washing optimization technique on MMLS method is also given. Different real-life bio assays like PCR, IVD are tested with the proposed technique as well as synthetic benchmarks (hard test benches) are also incorporated in the experiments. For both kind of benchmarks synthesis performance improved with bioassay completion time ( T max ) significantly reduced compared to existing synthesis approaches on DMFB platform.

Measurement of visco-elastic properties in a binary system of hockey stick-shaped and calamitic mesogens.

Temperature variation of the splay elastic modulus (K11) and rotational viscosity ([Formula: see text]) have been measured throughout the entire nematic (N phase of a binary liquid crystal system comprising of host calamitic compound, 4'-octyloxy-4-cyanobiphenyl (8OCB) and small amount of a hockey stick-shaped mesogen, 4-(3-decyloxyphenyliminomethyl) phenyl 4-decyloxycinnamate (SF7). Two different structural conformations play a significant role in the phase behavior leading to a noticeable shrinkage in the nematic width. During cooling in the nematic phase, both K11 and [Formula: see text] enhance monotonically and divulge an evidence of pretransitional fluctuation near the Smectic-A (Sm-A) transition. With increase in the dopant concentration, the slope of the temperature-dependent K11 and [Formula: see text] becomes uniformly steeper. The observed variations are explained in accordance with the formation of smectic-like clusters in the nematic phase. A representative model of the smectic-like clusters in the nematic phase is presented. However, the obtained values of [Formula: see text] have found to be between that of conventional calamitics and typical bent-core mesogens. Measurement of the temperature-dependent orientational order parameter (〈P2〉 ) and activation energy (Ea) has also been carried out for all the studied mixtures, exhibiting a small augmentation due to the addition of a hockey stick-shaped compound. This indicates an enhancement in intermolecular packing within the mixtures which further influences the molecular motions.

Attachment and antimicrobial susceptibility of bacterial associates of zooplanktonic copepod: Lesson for environmental safety.

The present study emphasizes on the antimicrobial susceptibility of different bacterial strains isolated from the external body surface of a commonly found zooplanktonic copepod (Heliodiaptomus viduus, Gurney, 1916) inhabiting both in fresh and brackish water bodies of Midnapore (West and East) Districts, West Bengal, India. Out of 62 bacterial isolated strains, 38 isolates were identified as Gram-positive while the remaining 24 isolates were found to be Gram-negative. Antimicrobial properties of all those bacterial strains were determined by Vitek 2 compact system using minimum inhibitory concentration (MIC) values. All isolated bacterial strains had exhibited differential susceptibilities against some selected antibiotics. Field Emission Scanning Electron Microscope (FE-SEM) analysis revealed the considerable association of bacteria on the cuticular body parts of the studied zooplankton. The outcomes of the present research are expected to enable health professionals in identifying two major problems -1) bacterial association with zooplankton which is so far mostly considered as a novel source of food for fish in aquatic ecosystems. 2) Selection of antibiotics as treatment measure because of the pathogenic effects of zooplankton associated bacteria on human being. This unattended arena of research is also supposed to evoke a new dimension not only because of bacteria-zooplankton interactions but also on undertaking of judicious strategies to find out proper ways and means to make the surface water suitable for the utilization by the common peoples (minimising bacterial contamination) in the context of human health and environmental safety.

Assessment of qualitative enrichment of organic paper mill wastes through vermicomposting: humification factor and time of maturity.

The process of bioconversion of solid organic wastes through vermicomposting justifies the environmental message for sustainability such as reduce, recycle and reuse of wastes. In the present study, wastes derived from two different types of paper mill sludge (primary and secondary), was used for their bioconversion through the vermicomposting process using an indigenous species of earthworm (Perionyx excavatus). The maturity and stability stage of vermicompost production was assessed using FT-IR, GC-MS and TG analyses. During vermicomposting, different biochemical functional groups present in the wastes have shown differential chemical alteration and turnover as revealed by FT-IR spectroscopy. This study has also confirmed the trend of biodegradation of complex substances like lignin, cellulose, proteins etc. and thereby demonstrates the extent of mineralization. TG spectral analysis had revealed a mass loss of 80% and 71% in vermicompost produced from primary and secondary sludge respectively. GC-MS studies have also shown the presence of several humic acids like octadecanoic acid, heptadecanoic acid etc. in the decomposing substances demonstrating as an indicator of the maturity of products. This was further confirmed by the decrease of humification index which focuses the combined action of both earthworms and microbes in the degradation of organic wastes. The present study has highlighted the role of an indigenous earthworm in converting specific industrial wastes especially by recording the point of maturation using humic acids an indicator of the quality of decomposing of wastes following several instrumental applications.

Pseudochromadora benepapillata (Timm 1961) comb. n. (Desmodoridae: Nematoda): revision of its taxonomic status and distribution.

Metachromadora (Bradylaimoides) benepapillata, was first discovered from the coastal mangroves of Bangladesh by Timm (1961). This species was later synonymised with Pseudochromadora cazca, which was described from the Brazilian coast by Gerlach (1956). The present paper proposes to update the taxonomic status of the Timm's species as Pseudochromadora benepapillata comb. n. along with its distribution and comparative morphology. The major differences between P. cazca and P. benepapillata are found in the characteristics of the head capsule; length of cephalic sensilla; length and position of somatic setae; shape of amphideal fovea; shape of spicules and gubernaculum; number and morphology of copulatory and postcloacal thorns. The present report on the occurrence of this species along the eastern most coast of India extends its distribution from the eastern part of Bay of Bengal to its western part.

Antioxidant and Anticancer Roles of a Novel Strain of Bacillus anthracis Isolated from Vermicompost Prepared from Paper Mill Sludge.

Mass production of vermicompost using suitable species of earthworms and selecting target organic waste materials has appeared to be a great development in the realm of biotechnological research for the sustainable eco-management. Although, for the bioconversion of organic wastes to vermicompost, suitable earthworm species play major roles, a hoard of bacterial assemblages by virtue of production of different enzymes facilitate the process of vermicomposting. The present study has documented the roles of vermicompost associated bacteria in combating, preventing, and controlling of cancer so as to open a new vista not only in the field of vermitechnology but also on biomedical research. Earthworms' associated bacterial metabolic products having their unique physicochemical excellence have gained importance due to their roles as a facilitator of apoptosis (programed cell death in a MCF-7 cell line). The antioxidant and anticancer activities of ethyl acetate extracts' of vermicompost associated bacterium Bacillus anthracis were undertaken by antioxidant assay which revealed maximum DPPH radical scavenging effect (75.79 ± 5.41%) of the extracts' at 9 00 µg ml-1. Furthermore, the crude extracts obtained from the same bacteria were found to decrease the activity of SOD (superoxide dismutase) with the increase in doses. MTT assay showed potent cytotoxic activity against human breast adenocarcinoma cells (MCF-7) with the IC50 value of 46.64 ± 0.79 µg ml-1. It was further confirmed through Hoechst 33258 staining of nuclear fragmentation assay and DNA fragmentation analysis. Western blotting test has confirmed a downregulation of Akt upon application of crude extracts. Increase of SOD activity along with decrease of Akt level reflects that the mode of action is entirely PI-3K dependent. This study tends to indicate that B. anthracis isolated from vermicompost could be potentially explored for the development of new therapeutic agents, especially against cancer.

Biomonitoring role of some cellular markers during heat stress-induced changes in highly representative fresh water mollusc, Bellamya bengalensis: Implication in climate change and biological adaptation.

Owing to increasing concern of global climate-change, temperature rise is of great interest which can be primarily evaluated from the seasonal variations in some organisms. Aquatic environment can be extremely stressful to its inhabitants because most of them are poikilothermous. In the present study, attempt was made to evaluate the biological effects of oxidative-stress and adaptive/antioxidant capacities during temperature variations (36-40 °C for 24hrs to 72hrs) in Bellamya bengalensis both in environmental and laboratory conditions by testing some biomarkers like HSP70, catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH) and glutathione reductase (GR). The biomarker potency of the molecules and the anti-oxidative metabolic-network was postulated and extrapolated to find its resemblance to the climate-change associated organismal variations. In a natural and eco-restored environment in the Eastern part of India, 10-20 fold increases in CAT, SOD and HSP70 protein expressions (Western blot results) were noticed in Bellamya paralleling to their increased enzymatic activities (gel zymogram studies) due to the seasonal (summer versus winter) temperature variation. It is evident from the consecutive three years' study that this variation resulted in the unfavorable physico-chemical changes of water quality parameters like dissolved oxygen, biochemical oxygen demand, alkalinity and consequently decreased the animal density in summer. And that was revived due to their higher reproduction-rate in post rainy/winter season when temperature normalizes resulting in a restoration of favorable environment. In laboratory condition, the reduced GR and increased GPx indicated the oxidative damage as evident by higher tissue MDA level following to higher mortality. Changes in SOD and CAT activities suggest activation of physiological mechanism to scavenge the ROS produced during heat stress. However, when mortality increased at different time points (36 °C - 72 h and 38 °C - 72 h), these enzyme activities also decreased as they failed to save the tissues from ROS. The results suggest that temperature variation does alter the active oxygen metabolism by modulating antioxidant enzyme activities, which can be used as biomarker to detect sub-lethal effects of climate change-associated pollution. The parity in environmental and laboratory experimental results may justify this laboratory experiment as model heat-stress experiment and indicate temperature as a universal stressor which alone or in combination with other water parameters initiates a consistent adapting behavior. The Bellamya bengalensis being the highest faunal representative in its habitat may serve as a good bioindicator species.

Assessment of microbial roles in the bioconversion of paper mill sludge through vermicomposting.

PURPOSE: Main thrust of the present study is to determine the role of microbes in changing the proportion and turnover of nutrients such as carbon and nitrogen during vermicomposting of paper mill sludge through the assessment of ß-glucosidase and Leucine arylamidase activities. METHODS: The change in the ratio of Total Organic Carbon (TOC) and Total Kjeldahl Nitrogen (TKN) during sludge composting using paper mill sludge, cow dung, straw in the ratio of 5:4:1 have been determined alongside observing ß-glucosidase and Leucine arylamidase activities in different phases (0th, 30th and 60th days) of vermicomposting. The present study also assessed the bacterial assemblages in order to predict their role as major producers of these enzymes as estimated by Vitek 2 system. RESULTS: A declining trend of C/N ratio was observed which exhibited significant negative and positive correlations with the activity of ß-glucosidase and Leucine arylamidase respectively. Twenty-four strains were isolated under two genus Bacillus spp. and Lysinibacillus spp. which revealed differential sensitivity towards major carbon and nitrogen turnover mediating enzymes. CONCLUSION: Change in the activities of carbon and nitrogen turnover enzymes due to microbial growth and proliferation are the mediator for the change in C/N ratio.

Birefringence in the vicinity of the smectic-A to smectic-C phase transition: Crossover from XY critical to tricritical behavior.

High-resolution birefringence (Δn) measurements are carried out to probe the critical behavior at the smectic-A-smectic-C (Sm-A-Sm-C) phase transition in a binary system. The critical behavior of this transition is explored with the aid of a differential quotient extracted from the Δn values. The results obtained reveal that the Sm-A-Sm-C and nematic-smectic-A (N-Sm-A) transitions exhibit nonuniversal behaviors with effective exponents lying between the tricritical and three-dimensional XY values and follow two distinctly different curves with decreasing width of the Sm-A and N phases, respectively. The origin of such critical behavior is a unique feature for the respective phase transitions.

Cyathoshiva amaleshi gen. n. sp. n. (Nematoda: Cyatholaimidae) from the coast of India.

A new genus, Cyathoshiva, of free-living marine nematodes from the subfamily Cyatholaiminae (family Cyatholaimidae, order Chromadorida), is described from the Indian coast. The new genus differs from other known Cyatholaiminae genera in having a unique combination of morphological characters: buccal cavity with well-developed dorsal tooth and two subventral teeth, proximally unpaired gubernaculum and non-cup shaped supplements. The type species Cyathoshiva amaleshi gen. n. sp. n. is characterized by having multispiral amphids with 4.5 turns, punctated cuticle with a weak lateral differentiation, a conical tail, three supplements possessing both tubular and setoid parts, and a gubernaculum with a serrated and dentate distal end.