Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including microresonators. However, because of the increased acoustic radiative losses during direct liquid immersion of optomechanical devices, almost all published optomechanical experiments have been performed in solid phase. This paper discusses a recently introduced hollow microfluidic optomechanical resonator. Detailed methodology is provided to fabricate these ultra-high-Q microfluidic resonators, perform optomechanical testing, and measure radiation pressure-driven breathing mode and SBS-driven whispering gallery mode parametric vibrations. By confining liquids inside the capillary resonator, high mechanical- and optical- quality factors are simultaneously maintained.     

Priority based data gathering using multiple mobile sinks in cluster based UWSNs for oil pipeline leakage detection

Energy efficient and completely reliable data gathering in resource constrained sparse Underwater Wireless Sensor Networks (UWSNs) is challenging and requires dedicated routing techniques. Routing having mobility assistance employs a Mobile Sink (MS) or a mobile relay for data gathering. It mitigates transmission power consumption as well as relaying overhead. But multiple MSs should be deployed in order to reduce the load of a single MS. The visiting schedule of each MS should consider the priority of data, data gathering delay and buffer overflow of each sensor. In order to address these issues, a priority-based data gathering scheme using multiple MSs for clustered UWSN is proposed to help in pipeline leakage detection under the water. In this work, each MS is deployed in such a way so that it can move in both the directions i.e., top to bottom or bottom to top. When a Cluster Head (CH) receives critical data, it sends an emergency notification to the nearest MS via other CHs. Upon receiving the emergency notification, MS immediately visits that CH to gather the critical data (oil leakage).

     

Graphene-Based Plasmonic Sensor at THz Frequency with Photonic Spin Hall Effect Assisted by Magneto-optic Phenomenon

Plasmonics - Graphene monolayer of sub-nanometer thickness shows strong metallic and plasmonic behavior in terahertz (THz) frequency range. This plasmonic effect varies considerably when graphene...     

Sepsis triggered oxidative stress-inflammatory axis: the pathobiology of reprogramming in the normal sleep–wake cycle

Molecular and Cellular Biochemistry - In individuals with sepsis-related neurodegenerative illness, sleep and circadian rhythm disturbance are common. The alteration in genomic expression linked...     

Ecological variations in adult life table attributes of Aedes aegypti (L.) from the desert and coastal regions of India

The ecological variation in biological and adult life-table attributes of two populations of Aedes aegypti (Diptera: Culicidae) from the desert (Jodhpur) and coastal (Kolkata) regions of India are assessed to understand the reproductive and survival strategies. The results showed that females lived longer than males in both strains. The desert strain was more r-strategist because of its higher intrinsic rate of increase (r_m = 0.23), finite rate of increase (λ = 1.25), lower life expectancy of males (7.9 days) and females (14.4 days), mean generation time (T = 19.2 days) and doubling time (DT = 3.0 days). However, there was no difference in net reproductive rate (R₀) between the desert and coastal strains. The coastal strain showed a longer female life expectancy (22.0 days) than the desert strain (14.4 days). However, the fecundity (eggs/female/day) was lower in the coastal strain (11.4) than in the desert strain (15.1). Conclusively, the desert (Jodhpur) strain is adapted to a better r-strategy than the coastal (Kolkata) strain of Ae. aegypti, which might be helpful to flourish in harsh environmental conditions. This study may provide accurate predictions of Ae. aegypti population dynamics for vector management.     

Microbial diversity and composition in acidic sediments of freshwater finfish culture ponds fed with two types of feed: a metagenomic approach

Microbial community profile associated with acidic pond sediments (APS) (pH = 3·0–4·5) of freshwater finfish aquaculture ponds (n = 8) was investigated. Sediment DNA extracted from the eight APS were subjected to high-throughput sequencing of V3 and V4 regions which yielded 7236 operational taxonomic units (OTUs) at a similarity of 97%. Overall results showed higher proportion of bacterial OTUs than archaeal OTUs in all the APS. Euryarchaeota (23%), Proteobacteria (19%), Chloroflexi (17%), Crenarchaeota (5·3%), Bacteroidetes (4·8%), Nitrospirae (3·2%), Nanoarchaeaeota (3%) which together constituted 75% of the microbial diversity. At the genus level, there was high preponderance of methanogens namely Methanolinea (5·4%), Methanosaeta (4·5%) and methanotrops, Bathyarchaeota (5%) in APS. Moreover, the abundant phyla in the APS were not drastically affected by the administration of chicken slaughter waste (R-group ponds) and commercial fish feed (C-group ponds), since 67% of the OTUs generated remained common in the APS of both the groups of ponds. There was a minimal difference of 24–26% of OTUs between C-group and R-group ponds, suggesting the existence of a core microbial community in these ponds driven by acidic pH over the years. This study concludes that microbial diversity in pond sediment was influenced to a lesser extent by the addition of chicken slaughter waste but was majorly driven by acidic nature of the pond.     

Leaf fossils of Sabalites (Arecaceae) from the Oligocene of northern Vietnam and their paleoclimatic implications

Recent paleobotanical investigations in Vietnam provide a good opportunity to improve our understanding of the biodiversity and paleoclimatic conditions in the geological past of Southeast Asia. Palms (Arecaceae) are a diverse family of typical thermophilous plants with a relatively low tolerance for freezing. In this study, we describe well-preserved fossil palm leaves from the Oligocene Dong Ho Formation of Hoanh Bo Basin, northern Vietnam. Characters of the fossil leaves, such as a fan-shaped costapalmate lamina, an unarmed petiole, a costa slightly enlarged at the base that then tapers distally into the blade, and well-preserved amphistomatic leaves with cuticles, suggest that they represent a new fossil species, which we herein designate Sabalites colaniae A. Song, T. Su, T. V. Do et Z.K. Zhou sp. nov. Together with other paleontological and palaeoclimatic evidence, we conclude that a warm climate prevailed in northern Vietnam and nearby areas during the Oligocene.