Identity of the 'true' Micraspis discolor (Fabricius) (Coleoptera, Coccinellidae) with illustrated diagnostic notes on other Micraspis spp. in Indian paddy fields.

Micraspis discolor (Fabricius, 1798) (Coleoptera: Coccinellidae), a widely studied complex of externally similar species, is known to be distributed in all the major rice growing countries of the Oriental region. It consists of disjunct populations that have been treated as a single taxonomic entity, but these are not conspecific and show disparities in their morphology. In this paper, we establish the identity of the true M. discolor based on Fabricius's type material from Tamil Nadu, Southern India, and redescribe it with illustrations of the diagnostic characters and the life stages. A lectotype is designated for M. discolor from Fabricius's type material (lectotype designation). Coccinella tenuilinea Walker, 1859, a sympatric species closely related to M. discolor and omitted from Korschefsky's World Catalogue of Coccinellidae, is transferred to Micraspis (new combination) and a lectotype is designated for it. It is found to be the most predominant species in South India and redescribed with illustrations of the genitalia and the life stages. COI sequences of M. discolor, M. tenuilinea and M. yasumatsui Sasaji based on the material collected in India are given. Phylogenetic analysis of the COI sequences of Indian M. discolor and other Asian 'M. discolor' sequences confirm that the Indian M. discolor is a distinct species and all Micraspis spp. from South and southeast Asian countries not matching the true M. discolor described here need to be re-examined and renamed if necessary. Brief illustrated accounts of other Micraspis spp. known from the paddy ecosystems of India are also given. Alesia guerini Mulsant, 1850, currently placed in Micraspis, is transferred to Oenopia Mulsant (new combination) and Coelophora walteri Sicard, 1913 is a new junior synonym of O. guerini (new synonym).

Assessment of Out of Pocket Expenditure and associated factors for availing COVID-19 vaccination by the beneficiaries in Bengaluru: South India

BackgroundGovernment of India has introduced COVID 19 vaccination in Jan 2021. There are no studies on out of pocket expenditure in COVID-19 vaccination in India, hence this study was undertaken to estimate the out of pocket expenditure for availing COVID 19 vaccine, to assess the factors associated with out of pocket expenditure for COVID vaccination and adverse events following immunisation. MethodsThis is a cross-sectional study conducted during Sep 2021-Dec 2021 of a medical college. A total of 438 study subjects above 18 years fulfilling inclusion and exclusion criteria were studied using probability proportional to population size. Data was collected using interview method by pre-tested semi structured proforma and analysed using descriptive & inferential statistics. ResultsThe mean direct cost in Government vaccination centre was 3.24{+/-} 6.74 INR, indirect cost 809.10{+/-}1076.35 INR, total cost was 812.34 {+/-}1079.49 INR.The mean direct cost in private vaccination centre was 1446.9{+/-}1845.65 INR, indirect cost 1140{+/-}1398 INR and total cost was 2586.90{+/-}2241.54 INR. The mean total cost was OOPE for COVID 19 vaccination was 852.80 {+/-}1128.512 INR, out of which direct cost was only 36.17({+/-}359.20). The higher mean OOPE was found in loss of wages 670.02 INR. The factors associated with higher out of pocket expenditure was type of vaccine (P=0.031, OR=2.141, 95% CI=1.07-4.24) occupation of the study subject (P=0.000, OR=2.043, 95% CI= 1.37-3.03), reported stress following vaccination (P= 0.018, OR=1.72, 95%CI=1.098-2.703), adverse event within 48hrs (P=0.006, OR=2.125, 95% CI= 1.248-3.62), received any medication for adverse event (P=0.041, OR= 1.721, 95% CI= 1.022-2.84) ConclusionMajority of the study subjects utilized public facility. The higher mean out of pocket expenditure was for indirect cost loss of wages. This study shows that type of vaccine, occupation of the study subject and adverse event within 48 hrs, had 2 times higher out of pocket expenditure compared to other factors. Among the AEFI, fever was the most common, followed by pain at the injection site and myalgia.

Immature stages, host plants and natural enemies of Henosepilachna implicata (Mulsant) (Coleoptera: Coccinellidae) with DNA sequence data and a new synonym and notes on some Indian species of Epilachnini.

Life stages of Henosepilachna implicata (Mulsant), an economically important species of Epilachnini in India, are documented and illustrated. Mitochondrial DNA sequence data is provided for the first time for H. implicata with additional details on its host plants, distribution, and natural enemies. Its similarities and differences with other common pestiferous Henosepilachna spp. in India such as H. vigintioctopunctata (F.), H. septima (Dieke) and H. pusillanima (Mulsant) are discussed. Epilachna circularis Korschefsky, 1933 is found to be conspecific with H. implicata and is reduced to a junior synonym of the latter (new synonym). Notes are given on the distribution and natural enemies of some other species of Epilachnini of the Indian region.

Population structure and genetic diversity of invasive Fall Armyworm after 2 years of introduction in India.

Fall Armyworm (FAW), Spodoptera frugiperda, is a polyphagous pest capable of feeding over 80 plant species and was indigenous to the Western Hemisphere. Within a span of 4 years, FAW has established itself throughout most of the regions in Africa and Asia causing significant losses in maize production. Owing to its revamped distribution range, it would be prudent to analyze the ensuing genetic changes and study the emerging phylogeographic patterns across the world. In this regard, we would like to provide a current snapshot of genetic diversity of FAW in India 2 years after the initial introduction and compare it with the worldwide diversity in order to trace the origins and evolutionary trajectories of FAW in India. We have investigated around 190 FAW samples from different regions in India for strain identity and polymorphism analysis on the basis of partial mitochondrial cytochrome oxidase I (COI) gene sequences. Apart from the ancestral rice and corn strain haplotype, our study demonstrates the presence of 14 more haplotypes unique to India at a haplotype diversity of 0.356. We were also able to record inter-strain hybrid haplotypes of rice and corn strains in India. Regional heterogeneity within Indian populations seems to be quite low representative of extensive migration of FAW within India. Distribution analysis of pairwise differences and rejection of neutrality tests suggest that the FAW population in India might be undergoing expansion. Our data is consistent with the findings suggesting a recent and common origin for invasive FAW populations in Asia and Africa, and does not indicate multiple introductions to India. This study reports the highest genetic diversity for Indian FAW populations to date and will be useful to track the subsequent evolution of FAW in India. The findings would have important ramifications for FAW behavior and composition throughout the world.

Coupling of Elementary Electronic Excitations: Drawing Parallels Between Excitons and Plasmons.

Recent advances in understanding the theoretical and experimental properties of excitons and plasmons have led to several technological breakthroughs. Though emerging from different schools of research, the parallels they possess both in their isolated and assembled forms are indeed interesting. Employing the larger framework of the dipolar coupling model, these aspects are discussed based on the excitonic transitions in chromophores and plasmonic resonances in noble metal nanostructures. The emergence of novel optical properties in linear, parallel, and helical assemblies of chromophores and nanostructures with varying separation distances, orientations, and interaction strengths of interacting dipolar components is discussed. The very high dipolar strengths of plasmonic transitions compared to the excitonic transitions, arising due to the collective nature of the electronic excitations in nanostructures, leads to the emergence of hot spots in plasmonically coupled assemblies. Correlations on the distance dependence of electric field with Raman signal enhancements have paved the way to the development of capillary tube-based plasmonic platforms for the detection of analytes.

Interlocked benzenes in triangular π-architectures: anchoring groups dictate ion binding and transmission.

Macrocyclic compounds like crown ethers, calixarenes, etc. are well explored in the literature as receptors for alkali metal ions. In most of these studies, the size of the macrocyclic cavity has evolved as the prominent determining criterion for the selective binding of various ions. However, approaches to systematically tailor the ion transport properties via the interplay of topological as well as electronic properties of the hosts are rarely addressed. Herein, we investigate the performance of [2.2.2]PCPs ([2.2.2]paracyclophane and [2.2.2]paracyclophene) and cyclohexaphenylene (CHP) as receptors for the alkali ions, Li+, Na+ and K+. The three macrocycles differ in terms of the groups (ethylene, vinylene and phenylene) anchoring the three benzene rings into triangular three-dimensional architectures, thereby providing opportunities for controlling the topological and the electronic features of the cavities. Based on electronic structure calculations, we predict that PCPs and CHP could be used in conjunction with dehydrobenzoannulenes that possess similar triangular π-architectures in two-dimensions to achieve selective ion transmission. Furthermore, an extended network of CHP, graphenylene, is shown for the first time to be potentially useful in energy storage applications in lithium ion batteries akin to graphyne and graphdiyne. The ion binding properties of graphenylenes would be rather interesting to investigate experimentally for energy applications, particularly in the context of the recent successful synthesis of one of the members of the graphenylene family. Overall, we have attempted to provide a unified description of the cationic interactions with 2D and 3D triangular π-architectures, describing the utility of materials like graphyne, graphdiyne and graphenylene for ion sensing and separation and energy storage applications.

Intercalation of HF, H2O, and NH3 Clusters within the Bilayers of Graphene and Graphene Oxide: Predictions from Coronene-Based Model Systems.

Understanding molecular interactions with monolayers and bilayers of graphene and its derivatized forms is very important because of their fundamental role in gas sensing and separation, gas storage, catalysis, etc. Herein, motivated by the recent realization of graphene-based sensors for the detection of single gas molecules, we use density functional theory to study the noncovalent interactions of molecules and molecular clusters with graphene, graphene oxide, and graphane, which are represented by coronene-based molecular model systems, C24H12 (coronene), C24OH12 (coroepoxide), and C24H36 (perhydrocoronene), respectively. The objective is to understand the structural and energetic changes that occur as a result of adsorption on monolayers and intercalation within bilayers. To begin with, the interactions of coronene, coroepoxide, and perhydrocoronene with a variety of small molecules like HF, HCl, HBr, H2O, H2S, NH3, and CH4 are studied. Subsequently, the binding of coronene and coroepoxide substrates with molecular clusters of HF, H2O, and NH3 is studied to understand the strength of adsorption on the substrates and the effect of substrates on hydrogen-bonding interactions within the molecular clusters. Further, bilayers of the model systems, namely, coronene-coronene, coronene-coroepoxide, and two configurations of coroepoxide-coroepoxide (one in which the oxygen atoms are facing each other and the other in which they do not face each other) are generated. The energetics for the nanoscale confinement or intercalation of the clusters within the bilayers along with the impact of the intercalation on the intermolecular hydrogen-bonding interactions are investigated. Our coronene-based model systems can provide a simple way of describing the rather complex events that occur in representative regions of graphene-based heterogeneous substrates.

Noble gas encapsulation into carbon nanotubes: predictions from analytical model and DFT studies.

The energetics for the interaction of the noble gas atoms with the carbon nanotubes (CNTs) are investigated using an analytical model and density functional theory calculations. Encapsulation of the noble gas atoms, He, Ne, Ar, Kr, and Xe into CNTs of various chiralities is studied in detail using an analytical model, developed earlier by Hill and co-workers. The constrained motion of the noble gas atoms along the axes of the CNTs as well as the off-axis motion are discussed. Analyses of the forces, interaction energies, acceptance and suction energies for the encapsulation enable us to predict the optimal CNTs that can encapsulate each of the noble gas atoms. We find that CNTs of radii 2.98 - 4.20 Å (chiral indices, (5,4), (6,4), (9,1), (6,6), and (9,3)) can efficiently encapsulate the He, Ne, Ar, Kr, and Xe atoms, respectively. Endohedral adsorption of all the noble gas atoms is preferred over exohedral adsorption on various CNTs. The results obtained using the analytical model are subsequently compared with the calculations performed with the dispersion-including density functional theory at the M06 - 2X level using a triple-zeta basis set and good qualitative agreement is found. The analytical model is however found to be computationally cheap as the equations can be numerically programmed and the results obtained in comparatively very less time.

Au nanorod quartets and Raman signal enhancement: towards the design of plasmonic platforms.

Quartets of Au nanorods were designed by combining the methodologies of lateral and longitudinal assemblies. A high electric field prevailing at the quartet junctions results in large enhancement in the Raman signals of molecules. FDTD simulations showed that the displacement of the lateral dimers in quartets expands the scope of hot spot distribution.

Host-guest interactions in the confined geometries formed from molecular aggregates of push-pull molecules.

We have considered push-pull molecules, aminonitroacetylene and aminonitrodiacetylene (O2N-(C≡C)n-NH2; n = 1 and 2) as the basic units to design a series of molecular aggregates containing favorable hydrogen bonding interactions. Linear, closed, and stacked geometries of dimers, trimers, tetramers, and pentamers formed from these molecules are found to have very good stabilization energies due to the strong hydrogen bonding abilities of the terminal -NO2 and -NH2 groups. The closed hydrogen-bonded assemblies can act as supramolecular hosts for accommodating some molecules and ions as guests. We have been able to find substantial host-guest interaction energies for the complexes of the hydrogen-bonded closed assemblies with some highly reactive molecules like hexahydro-1,3,5-trinitro-s-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), pentafluoroethane (R-125), and difluoromethane (R-32). Further investigations on the interaction of the ions Li(+), Na(+), K(+), Mg(2+), Ca(2+), Al(3+), F(-), Cl(-), and Br(-) with the monomers as well as the oligomers reveal the formation of strong ion-σ complexes, unlike the conventional weak ion-π complexes found in similar acetylenic systems without the end groups. This opens up the possibility of tuning the nature of ionic interactions in π-systems by varying the terminal groups.

Rattling motion of alkali metal ions through the cavities of model compounds of graphyne and graphdiyne.

We study the passage of the alkali metal ions (Li(+), Na(+), and K(+)) through some conjugated carbon-based ring systems, starting from C12H6 and C24H12 (tribenzocyclyne; TBC), which serve as model compounds for graphyne to some of the higher analogues, C26H12, C28H12, and C30H12, the model systems for graphdiyne. The motion of the ions through cyclic carbon clusters, C12 and C14, is also investigated. The potential for the motion of the ions from one side of the ring to the other through the cavities of the molecules is a symmetric double well in most cases, while it is a rather flat potential in others, arising due to the free motion of the ions through the cavities. Electrostatic potential (ESP) analyses reveal that the ions bind to the ring systems at the most negative regions of ESP. The estimated energy barriers for the motion of Li(+) through C12H6 and C24H12 are 4.7 and 4.3 kcal mol(-1), respectively, and are comparable to the barrier for the classic case of umbrella-like inversion in ammonia. Transmission of Li(+) through C26H12, C28H12, C30H12, C12, and C14 rings is barrierless. We predict that the rattling motion of Li(+) through the model compounds of graphyne and graphdiyne should be experimentally observable. We also model the effectively one-dimensional motion of the ions through the rings using discrete variable representation (DVR) and calculate the energy levels of the complexes in the symmetric double well potentials. The molecular orbital analyses and the nuclear independent chemical shift (NICS) values for the rings suggest distinct trends based on the (4n + 2/4n) π electron count, leading us to propose two neutral complexes, (C12H6)Li2 and (C24H12)Li2, that are highly stable with binding energies of 400 and 356 kcal mol(-1), respectively.

Strength from weakness: opportunistic CH···O hydrogen bonds differentially dictate the conformational fate in solid and solution states.

We show that the CH···O hydrogen bond can be opportunistic to differentially dictate the conformation of cyclitols in solution and solid states. While several intermolecular CH···O stabilize the chair-conformation in the solid, single intramolecular CH···O stabilizes an otherwise unfavorable boat-conformation in solutions analogous to the boat-conformation of cis-1,4-cyclohexanediols by OH···O bonds.

Ag@SiO2 Core-Shell Nanostructures: Distance-Dependent Plasmon Coupling and SERS Investigation.

Enhancement of Raman signals of pyrene due to the enhanced electric fields on the surface of silver nanoparticles has been investigated by controlling the thickness of the silica shell. Dimeric nanostructures having well-defined gaps between two silver nanoparticles were prepared, and the gap size (d) was varied from 1.5 to 40 nm. The molecules trapped at the dimeric junctions showed higher Raman signal enhancements when the gap was less than 15 nm due to the presence of amplified electric field, in agreement with our theoretical studies. The experimental Raman enhancement factors at the hot spots follow a 1/d(n) dependence, with n = 1.5, in agreement with the recent theoretical studies by Schatz and co-workers. Experimental results presented here on the distance dependence of surface enhanced Raman spectroscopy (SERS) enhancement at the hot spots can provide insight on the design of newer plasmonic nanostructures with optimal nanogaps.

Excitation energy transfer from a fluorophore to single-walled carbon nanotubes.

We study the process of electronic excitation energy transfer from a fluorophore to the electronic energy levels of a single-walled carbon nanotube. The matrix element for the energy transfer involves the Coulombic interaction between the transition densities on the donor and the acceptor. In the Forster approach, this is approximated as the interaction between the corresponding transition dipoles. For energy transfer from a dye to a nanotube, one can use the dipole approximation for the dye, but not for the nanotube. We have therefore calculated the rate using an approach that avoids the dipole approximation for the nanotube. We find that for the metallic nanotubes, the rate has an exponential dependence if the energy that is to be transferred, variant Planck's over 2piOmega is less than a threshold and a d(-5) dependence otherwise. The threshold is the minimum energy required for a transition other than the k(i, perpendicular)=0 and l=0 transition. Our numerical evaluation of the rate of energy transfer from the dye pyrene to a (5,5) carbon nanotube, which is metallic leads to a distance of approximately 165 A up to which energy transfer is appreciable. For the case of transfer to semiconducting carbon nanotubes, apart from the process of transfer to the electronic energy levels within the one electron picture, we also consider the possibility of energy transfer to the lowest possible excitonic state. Transfer to semiconducting carbon nanotubes is possible only if variant Planck's over 2piOmega > or = epsilon(g)-epsilon(b). The long range behavior of the rate of transfer has been found to have a d(-5) dependence if variant Planck's over 2piOmega > or = epsilon(g). But, when the emission energy of the fluorophore is in the range epsilon(g) > variant Planck's over 2piOmega > or = epsilon(g)-epsilon(b), the rate has an exponential dependence on the distance. For the case of transfer from pyrene to the semiconducting (6,4) carbon nanotube, energy transfer is found to be appreciable up to a distance of approximately 175 A.

Long range resonance energy transfer from a dye molecule to graphene has (distance)(-4) dependence.

In our previous report on resonance energy transfer from a dye molecule to graphene [J. Chem. Phys.129, 054703 (2008)], we had derived an expression for the rate of energy transfer from a dye to graphene. An integral in the expression for the rate was evaluated approximately. We found a Yuwaka-type dependence of the rate on the distance. We now present an exact evaluation of the integral involved, leading to very interesting results. For short distances (z<20 A), the present rate and the previous rate are in good agreement. For larger distances, the rate is found to have a z(-4) dependence on the distance, exactly. Thus we predict that for the case of pyrene on graphene, it is possible to observe fluorescence quenching up to a distance of 300 A. This is in sharp contrast to the traditional fluorescence resonance energy transfer where the quenching is observable only up to 100 A.

Resonance energy transfer from a dye molecule to graphene.

We study the distance dependence of the rate of resonance energy transfer from the excited state of a dye to the pi system of graphene. Using the tight-binding model for the pi system and the Dirac cone approximation, we obtain the analytic expression for the rate of energy transfer from an electronically excited dye to graphene. While in traditional fluorescence resonance energy transfer, the rate has a (distance)(-6) dependence, we find that the distance dependence in this case is quite different. Our calculation of rate in the case of the two dyes, pyrene and nile blue, shows that the distance dependence is Yukawa type. We have also studied the effect of doping on energy transfer to graphene. Doping does not modify the rate for electronic excitation energy transfer significantly. However, in the case of vibrational transfer, the rate is found to be increased by an order of magnitude due to doping. This can be attributed to the nonzero density of states at the Fermi level that results from doping.

Resonance energy transfer from a fluorescent dye molecule to plasmon and electron-hole excitations of a metal nanoparticle.

The authors study the distance dependence of the rate of electronic excitation energy transfer from a dye molecule to a metal nanoparticle. Using the spherical jellium model, they evaluate the rates corresponding to the excitation of l=1, 2, and 3 modes of the nanoparticle. The calculation takes into account both the electron-hole pair and the plasmon excitations of the nanoparticle. The rate follows conventional R(-6) dependence at large distances while small deviations from this behavior are observed at shorter distances. Within the framework of the jellium model, it is not possible to attribute the experimentally observed d(-4) dependence of the rate to energy transfer to plasmons or electron-hole pair excitations.