Elephantoloemus indicus Austen, 1930 (Diptera: Calliphoridae) as the cause of cutaneous myiasis in captive Indian elephants from Assam, India

Elephantoloemus indicus Austen, 1930, a dipteran calliphorid fly is known to cause by its larval stage obligatory cutaneous myiasis in Indian subspecies of Asian elephants (Elephas maximus indicus Cuvier, 1798) in Myanmar and Thailand. The present study was undertaken on morphological identification of some specimens of fly larvae which were recovered from the warbles detected on the skin of captive Indian elephants at the Nameri National Park and Kaziranga National Park both situated in the state of Assam, India. The larval specimens were whitish to creamy white in colour and body conformation varied from cylindrical to barrel shaped depending on their measured size (Av 6.12 ± 0.28 × 2.35 ± 0.12 mm). Microscopic examination of processed larvae revealed presence of numerous single pointed spines uniformly distributed on entire body surface, well developed mouth hooks and cephalopharyngeal skeleton at the anterior end and posterior spiracles each with lightly sclerotized peritreme enclosing three short and straight respiratory slits. Based on geographical distribution of the fly, host relation, larval parasitism and morphological characters, the larvae were determined as of the genus Elephantoloemus which is represented by E. indicus as the only species described so far. This finding seems to be the first record in India after its report from Myanmar and Thailand.

Low reflectance of carbon nanotube and nanoscroll-based thin film coatings: a case study

Research on carbon material-based thin films with low light reflectance has received significant attention for the development of high absorber coatings for stray light control applications. Herein, we report a method for the successful fabrication of stable thin films comprised of carbon nanotubes (CNTs) and nanoscrolls (CNS) on an aluminium (Al) substrate, which exhibited low reflectance of the order of 2-3% in the visible and near-infrared (NIR) spectral bands. Changes in the structural and chemical composition of pristine single-walled carbon nanotube (SWCNT) samples were analyzed after each processing step. Spectroscopy, microscopy and microstructural studies demonstrated emergence of CNS and multi-walled carbon nanotubes (MWCNTs) due to the sequential chemical processing of the sample. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) studies revealed the formation of CNS via curling and folding of graphene sheets. Microstructural investigations including SEM and atomic force microscopy (AFM) confirmed the presence of microcavities and pores on the surface of the film. These cavities and pores significantly contribute to the observed low reflectance value of CNTs, CNS compound films by trapping the incident light. Fundamental space environmental simulation tests (SEST) were performed on the coated films, that showed promising results with reflectance values almost unaltered in the visible and NIR spectral bands, demonstrating the durability of these films as potential candidates to be used in extreme space environmental conditions. This study describes the preparation, characterization, and testing of blended CNT and CNS coatings for low-light scattering applications.

Structural stability of coplanar 1T-2H superlattice MoS2 under high energy electron beam

Coplanar heterojunctions composed of van der Waals layered materials with different structural polymorphs have drawn immense interest recently due to low contact resistance and high carrier injection rate owing to low Schottky barrier height. Present research has largely focused on efficient exfoliation of these layered materials and their restacking to achieve better performances. We present here a microwave assisted easy, fast and efficient route to induce high concentration of metallic 1T phase in the original 2H matrix of exfoliated MoS₂ layers and thus facilitating the formation of a 1T-2H coplanar superlattice phase. High resolution transmission electron microscopy (HRTEM) investigations reveal formation of highly crystalline 1T-2H hybridized structure with sharp interface and disclose the evidence of surface ripplocations within the same exfoliated layer of MoS₂. In this work, the structural stability of 1T-2H superlattice phase during HRTEM measurements under an electron beam of energy 300 keV is reported. This structural stability could be either associated to the change in electronic configuration due to induction of the restacked hybridized phase with 1T- and 2H-regions or to the formation of the surface ripplocations. Surface ripplocations can act as an additional source of scattering centers to the electron beam and also it is possible that a pulse train of propagating ripplocations can sweep out the defects via interaction from specific areas of MoS₂ sheets.

Microbial profile of the vitreous aspirates in culture proven exogenous endophthalmitis: A 10-year retrospective study

PURPOSE

To describe the microbiological profile and clinical outcome in the eyes with culture-proven exogenous endophthalmitis.

METHODS

A retrospective analysis of 495 eyes diagnosed as exogenous endophthalmitis was performed over a period of 10 years. In all, aseptically collected aqueous and vitreous aspirates were cultured for bacteria and fungus using standard microbiological techniques. Gram-stain and KOH preparation of the specimens were also performed. The antibiotic susceptibility testing for bacterial isolates was performed by Kirby-Bauer disk diffusion method. The treatment was modified according to the antibiotic sensitivity profile. The final clinical ocular condition was divided into improved, stable or deteriorated.

RESULTS

Of 148 culture-proven endophthalmitis eyes, 137 (92.57%) were referred from elsewhere, and 11 (7.43%) belonged to our institute. Aetiologically, 76 (51.35%) eyes were post-cataract surgery, 61 (41.22%) were post-traumatic, 5 (3.38%) eyes post-intravitreal anti-vascular endothelial growth factor injection, 5 associated with corneal diseases and 1 bleb-related endophthalmitis. In 31 (20.95%) eyes, primary intravitreal antibiotics were given outside. The cultures revealed monomicrobial growth in 92.57% (n = 137) and polymicrobial growth in 7.43% (n = 11). Among the bacteria (n = 121, 81.76%), Pseudomonas species dominated overall (n = 32, 27.11%) and post-operative (n = 26, 38.23%) endophthalmitis group. Staphylococcus epidermidis (n = 14, 28%) was prominent in post-traumatic endophthalmitis group. Ninety-two percent (n = 108 isolates) of bacteria were sensitive to vancomycin. In 78 (52.7%) eyes, the clinical ocular condition improved or remained stable while deteriorated in 51 (34.46%).

CONCLUSION

A bacterial predominance was observed among causative organisms of exogenous endophthalmitis with Pseudomonas species being the most common. The appropriate surgical intervention improved or stabilised the visual acuity in nearly 50% eyes.

Gastrointestinal nematode larvae in the grazing land of cattle in Guwahati, Assam

Aim:

To know the prevalence of gastrointestinal nematode larvae (L₃) in the grazing land of cattle in Guwahati, Kamrup district, Assam.

Materials and Methods:

Pastures were collected and examined for the presence of nematode larvae (L₃) from six localities of Guwahati at monthly interval from August 2012 to July 2013. The counted larvae were then expressed as per kg dry matter of herbage (L₃/kg DM).

Results:

Examination of pastures revealed presence of nematode larvae (L₃) in pastures throughout the year which varied from 4.5 L₃/kg DM in January to a maximum of 106.33 L₃/kg DM in August. The L₃ of Haemonchus contortus, Trichostrongylus spp., Oesophagostomum spp., Cooperia spp., and Mecistocirrus spp. were recovered from pastures. The average pasture larval burden (PLB) was 34.75±3.48 L₃/kg DM. Season-wise PLB revealed the presence of 23.89±3.01, 67.54±5.41, 26.67±1.92, and 7.28±0.89 L₃/kg DM during pre-monsoon, monsoon, post-monsoon, and winter seasons, respectively. Monsoon season has significant (p<0.05) effect on PLB. However, analysis of variance of different locations with respect to season revealed that there was no significant difference but season-wise it was highly significant (p<0.01). Pearson correlation of environmental variables (temperature, relative humidity, and rainfall) with PLB revealed correlation was statistically significant with rainfall (p<0.05).

Conclusion:

This study reveals the presence of five nematode larvae (L₃) in the pastures of Guwahati, Assam throughout the year, statistically significant during monsoon season.

Emergence of oriental theileriosis in cattle and its transmission through Rhipicephalus (Boophilus) microplus in Assam, India

Aim:

The aim of the present study was to investigate the presence of Theileria in blood samples of crossbred and indigenous adult cows raised under unorganized small scale farming system in a Babesia and Anaplasma endemic geographical area from Assam, India and to see its transmission through Rhipicephalus (Boophilus) microplus ticks.

Materials and Methods:

For the present study, 57 clinical cases of cattle suspected to be of hemoparasitic infections were taken into consideration. The parasites were identified based on morphology in giemsa stained blood smear followed by polymerase chain reaction (PCR). Sera samples were tested for T. annulata antibodies in plate and Dot-ELISA. PCR was also conducted in eggs of Rhipicephalus (Boophilus) microplus tick collected from a Theileria orientalis positive animal.

Results:

PCR amplified 1124, 776, and 160 bp DNA fragments of B. bigemina (64.91%), T. orientalis (21.05%) and A. marginale (14.03%), respectively. This assay further conducted in 12 T. orientalis positive blood samples with primers of Buffeli, Chitose, and Ikeda variants of T. orientalis showed 3 samples positive to Ikeda type and none for Buffeli and Chitose. Babesia bovis and Theileria annulata specific primers also did not amplify any fragment during the PCR assay of the blood samples. Further, all sera samples tested negative to T. annulata antibodies in Plate and Dot-ELISA. PCR conducted in eggs of R (B).microplus tick collected from a T. orientalis positive animal revealed presence of the parasite DNA. Gradual improvement in physical condition leading to complete recovery in 10 out of 12 T. orientalis infected clinical cases treated with buparvaquone(at 2.5mg/kg.b.wt I/M) was the feedback obtained from field veterinarians and the cattle owners.

Conclusion:

The present investigation represents the first report of occurrence of T. orientalis in cattle of Assam with involvement of pathogenic Ikeda strain in clinical outbreaks and its possible natural transmission by R (B). microplus through the transovarian mode.

Larvicidal activity of few select indigenous plants of North East India against disease vector mosquitoes (Diptera: Culicidae)

Mosquitoes are the vectors of several life threatening diseases like dengue, malaria, Japanese encephalitis and lymphatic filariasis, which are widely present in the north-eastern states of India. Investigations on five local plants of north-east India, selected on the basis of their use by indigenous communities as fish poison, were carried out to study their mosquito larvicidal potential against Anopheles stephensi (malaria vector), Stegomyia aegypti (dengue vector) and Culex quinquefasciatus (lymphatic filariasis vector) mosquitoes. Crude Petroleum ether extracts of the roots of three plants viz. Derris elliptica, Linostoma decandrum and Croton tiglium were found to have remarkable larvicidal activity; D. elliptica extract was the most effective and with LC50 value of 0.307 μg/ml its activity was superior to propoxur, the standard synthetic larvicide. Half-life of larvicidal activity of D. elliptica and L. decandrum extracts ranged from 2-4 days.

Human consumption of rumen flukes of cattle in India

The practice of eating rumen flukes of cattle by a section of people living in Meghalaya, a north eastern State of India, is reported in this communication. Economically backward, some rural people belonging to Khasi, Jaintia, Garo, and Karbi tribes of Christian and Nepali communities who eat beef are accustomed to consuming cooked flukes during breakfast, meals, and also along with rice beer or alcohol. Inspection of the rumens of cattle during slaughter indicated a prevalence of flukes belonging to Cotylophoron, Paramphistomum, Calicophoron, Gastrothylax, and Fischoederius genera in 74% cases, and their collection from rumen ranged approximately from 50 g to 600 g. Biochemical analysis of flukes found 12.60% total protein, 0.78% fat, and 0.87% ash on fresh weight basis. High prevalence of flukes, easy visualization in rumen, their bulk collection, presence of nutritive value, absence of any ill effect, and lack of imminent danger of transmissibility are believed to be the rationales influencing their consumption by people. It is suggested that dietary benefits obtained from flukes might contribute to the energy transfer and inclusion in the food web.

Genetic population structure of the malaria vector Anopheles baimaii in north-east India using mitochondrial DNA

BACKGROUND

Anopheles baimaii is a primary vector of human malaria in the forest settings of Southeast Asia including the north-eastern region of India. Here, the genetic population structure and the basic population genetic parameters of An. baimaii in north-east India were estimated using DNA sequences of the mitochondrial cytochrome oxidase sub unit II (COII) gene.

METHODS

Anopheles baimaii were collected from 26 geo-referenced locations across the seven north-east Indian states and the COII gene was sequenced from 176 individuals across these sites. Fifty-seven COII sequences of An. baimaii from six locations in Bangladesh, Myanmar and Thailand from a previous study were added to this dataset. Altogether, 233 sequences were grouped into eight population groups, to facilitate analyses of genetic diversity, population structure and population history.

RESULTS

A star-shaped median joining haplotype network, unimodal mismatch distribution and significantly negative neutrality tests indicated population expansion in An. baimaii with the start of expansion estimated to be ~0.243 million years before present (MYBP) in north-east India. The populations of An. baimaii from north-east India had the highest haplotype and nucleotide diversity with all other populations having a subset of this diversity, likely as the result of range expansion from north-east India. The north-east Indian populations were genetically distinct from those in Bangladesh, Myanmar and Thailand, indicating that mountains, such as the Arakan mountain range between north-east India and Myanmar, are a significant barrier to gene flow. Within north-east India, there was no genetic differentiation among populations with the exception of the Central 2 population in the Barail hills area that was significantly differentiated from other populations.

CONCLUSIONS

The high genetic distinctiveness of the Central 2 population in the Barail hills area of the north-east India should be confirmed and its epidemiological significance further investigated. The lack of genetic population structure in the other north-east Indian populations likely reflects large population sizes of An. baimaii that, historically, were able to disperse through continuous forest habitats in the north-east India. Additional markers and analytical approaches are required to determine if recent deforestation is now preventing ongoing gene flow. Until such information is acquired, An. baimaii in north-east India should be treated as a single unit for the implementation of vector control measures.

Spatial distribution and r-DNA second internal transcribed spacer characterization of Anopheles dirus (Diptera: Culicidae) complex species in north-east India

The identity and distribution of the prevalent member species of the Anopheles dirus complex mosquitoes in the north-eastern region of India was investigated in a cross-sectional study. We altogether collected 267 individuals of An. dirus s.l. from 27 forested/forest fringed locations spread across the seven north-eastern states, identified the species using a ribosomal DNA (r-DNA) second internal transcribed spacer (ITS2) based allele specific polymerase chain reaction (ASPCR) method and sequenced the ITS2 locus in a sub set of mosquitoes. An. baimaii was identified as the main, almost exclusive (266/267), species of the Dirus complex throughout the north-east India with no intraspecific variation in the 479 base pair long ITS2 sequences in 59 of the 60 individuals sequenced. Ribosomal DNA of one individual from Assam state did not amplify in the ASPCR, possessed 786 base pair long ITS2 sequence and showed 99.7% similarity with the sequence of An. dirus species D (An. baimaii) from Yunnan province of China, later referred to as species X of the Dirus complex. These observations suggest the presence of another, possibly the new, species of the Dirus complex, sympatric with An. baimaii, in Assam warranting investigations on its distribution, biology and role in human malaria transmission in north-east India.

Evaluation of PermaNet 2.0 mosquito bednets against mosquitoes, including Anopheles minimus s.l., in India

Wash resistance and field bioefficacy of PermaNet 2.0 nets, long lasting insecticidal nets, against mosquitoes were evaluated in Assam, northeastern India. After repeated hand washings at 12-day intervals a decline in the mosquito killing ability of PermaNet nets was noted (trend chi2 38.9, p < 0.0001), yet these nets retained good insecticidal efficacy for up to 15 wash cycles, producing a 72.5% mean mortality of An. minimus 24 hours after a 3-minute exposure in World Health Organization cones after 15 washings. Significantly fewer (p < 0.001) mosquitoes were captured in self-baited landing collections in houses equipped with PermaNet nets than in houses using untreated nets in the case of culicines (p < 0.001) but not with anophelines, including An. minimus. The use of PermaNet nets resulted in noticeably fewer bites from Culex pseudovishnui (68.5%) and Cx. quinquefasciatus (70%). Blood-feeding inhibition of mosquitoes in deliberately torn PermaNet nets was seen, indicating a protective effect for those sleeping under these nets. No serious adverse effects of the PermaNet nets were reported by users.

Probing atomic migration in nanostructured multilayers: application of X-ray standing wave fields

X-ray standing wave fields, excited in periodic nanostructured multilayers during Bragg diffraction, have been used to probe atomic migration in multilayers. Ion beam induced migration of Fe impurity atoms from the C layers to the Pt layers in a Pt(Fe)/C(Fe) multilayer, where each layer is about 2 nm thick, has been detected. With a depth resolution better than 0.2 nm of this technique, the direction of Fe migration (here outward) and the change of Fe concentration in C (also Pt) layers have been determined. The results of such measurements are important for understanding the properties of multilayers, for example, the evolution of ferromagnetism in the present example [Dev, Microelectron. Eng. 83, 1721 (2006)10.1016/j.mee.2006.01.230].

Capsulorhexis in intumescent cataract

This technique of anterior capsulorhexis is for use in eyes with high intralenticular pressure and absence of red reflex as encountered in intumescent cataract. The initial steps of fashioning the anterior capsular flap and lens decompression are done under the microscope's high magnification and noncoaxial oblique illumination. Intralenticular pressure is controlled by filling the anterior chamber with a viscoelastic agent. Once the lens is decompressed, the capsulorhexis is completed with a capsule forceps and an endoilluminator is used as an oblique source of illumination. This technique allows controlled capsulorhexis in eyes with intumescent cataract.