23 research outputs found
Detection of DNA and Poly-L-Lysine using CVD Graphene-channel FET Biosensors
A graphene channel field-effect biosensor is demonstrated for detecting the
binding of double-stranded DNA and poly-l-lysine. Sensors consist of CVD
graphene transferred using a clean, etchant-free transfer method. The presence
of DNA and poly-l-lysine are detected by the conductance change of the graphene
transistor. A readily measured shift in the Dirac Voltage (the voltage at which
the graphenes resistance peaks) is observed after the graphene channel is
exposed to solutions containing DNA or poly-l-lysine. The Dirac voltage shift
is attributed to the binding/unbinding of charged molecules on the graphene
surface. The polarity of the response changes to positive direction with
poly-l-lysine and negative direction with DNA. This response results in
detection limits of 8 pM for 48.5 kbp DNA and 11 pM for poly-l-lysine. The
biosensors are easy to fabricate, reusable and are promising as sensors of a
wide variety of charged biomolecule
Role of ocean initial conditions to diminish dry bias in the seasonal prediction of Indian summer monsoon rainfall: A case study using climate forecast system
Coupled models tend to underestimate Indian summer monsoon (ISM) rainfall over most of the Indian subcontinent. Present study demonstrates that a part of dry bias is arising from the discrepancies in Oceanic Initial Conditions (OICs). Two hindcast experiments are carried out using Climate Forecast System (CFSv2) for summer monsoons of 2012-2014 in which two different OICs are utilized. With respect to first experiment (CTRL), second experiment (AcSAL) differs by two aspects: usage of high-resolution atmospheric forcing and assimilation of only ARGO observed temperature and salinity profiles for OICs. Assessment of OICs indicates that the quality of OICs is enhanced due to assimilation of actual salinity profiles. Analysis reveals that AcSAL experiment showed 10 reduction in the dry bias over the Indian land region during the ISM compared to CTRL. This improvement is consistently apparent in each month and is highest for June. The better representation of upper ocean thermal structure of tropical oceans at initial stage supports realistic upper ocean stability and mixing. Which in fact reduced the dominant cold bias over the ocean, feedback to air-sea interactions and land sea thermal contrast resulting better representation of monsoon circulation and moisture transport. This reduced bias of tropospheric moisture and temperature over the Indian land mass and also produced better tropospheric temperature gradient over land as well as ocean. These feedback processes reduced the dry bias in the ISM rainfall. Study concludes that initializing the coupled models with realistic OICs can reduce the underestimation of ISM rainfall prediction. © 2018. The Authors
Barriers to the Utilization of Dental Services in Udaipur, India
Objective: Regular home care and yearly dental check-ups are the best means of dental care. In spite of the information on dental care, many people fail to take these precautions. The objective of this study was to determine the barriers in regular dental care and home care and to assess their association with age, sex, education and income.Materials and Methods: A cross-sectional survey was conducted among 427 randomly selected individuals, 248 males and 179 females. Data were collected by a pre-tested, selfadministered 14 question questionnaire. The answer "very much" was scored as one, "to some degree" as two and "not at all" as three. The data was described and analyzed by frequency distribution and chi square test with P0.05), but females experienced higher dental fear (P<0.001). The younger age group had more visits within one year in comparison to the older. Increase in education, decreases the barriers for regular dental care. Income had a significantly negative correlation with dental visit (P=0.02).Conclusion: Our findings suggest that males believed in having regular dental care. Cost of the treatment also affected the dental visits, but the distance they had to travel to get the dental treatment was not much significant. Above all, felt need had a major impact on the dental visits
Tropical Indian Ocean response to the decay phase of El Nino in a coupled model and associated changes in south and east-Asian summer monsoon circulation and rainfall
This study investigates the response of tropical Indian Ocean (TIO) sea surface temperature (SST) to El Niño decay phase and its impacts on South and East Asian summer monsoon in the National Centers for Environmental Prediction Climate Forecast System version 2 free run. The TIO basin-wide warming induced by El Niño at its peak phase (winter; DJF) and next spring (MAM + 1) are reasonably well captured by the model but with weak magnitude. This TIO basin-wide SST warming persists until summer (JJA + 1) and exert strong impact on summer monsoon rainfall and circulation as revealed in the observations. However, TIO SST anomalies are very weak in the model during the El Niño decaying summers. Though El Niño decay is delayed by 2 months in the model, decay of TIO SST warming is faster than the observations. Anomalous latent heat loss from ocean and a feeble southern TIO Rossby waves associated with weak wind response to El Niño are mainly accountable for rapid decay of TIO SST warming by mid-summer in the model. This suggests that JJA + 1 TIO SST response to El Niño decay phase in the model is poorly represented. The model is able to capture the SST anomalies associated with the northwest Pacific anticyclone at the peak phase of El Niño but fail to maintain that during the decay phase in MAM + 1 and JJA + 1. It is found that precipitation and circulation anomalies associated with TIO SST warming over the South and East Asian regions are disorganized in the model during the decay phase of El Niño. Rainfall anomalies over the southwest TIO, west coast of India, northern flank of northwest Pacific anticyclone and over Japan in JJA + 1 are poorly represented by the model. Analysis of lower troposphere stream function and rotational wind component reveals that northwest Pacific anticyclone shifted far eastward to the date line in the model during JJA + 1 unlike in the observations. Anomalous divergence observed over the western TIO and convergence in the northwest Pacific are absent in the model during JJA + 1. Extension of anomalous tropospheric warming from TIO region to equatorial western Pacific is also very weak in the model due to poor representation of TIO SSTs and the subsequent absence of any Kelvin wave response. Anomalous Walker circulation persisted from DJF to JJA + 1 due to El Niño late decay in the model unlike in the observations. This is also found to be responsible for the redundant changes in SST, rainfall and circulation over the Indo-western Pacific in the model. This study demonstrates that it is essential to represent the decay phase of El Niño and the associated TIO response accurately to have realistic simulations of summer monsoon in the decaying year
Transport of aerosols into the UTLS and their impact on the Asian monsoon region as seen in a global model simulation
An eight-member ensemble of ECHAM5-HAMMOZ simulations for a boreal summer season is analysed to study the transport of aerosols in the upper troposphere and lower stratosphere (UTLS) during the Asian summer monsoon (ASM). The simulations show persistent maxima in black carbon, organic carbon, sulfate, and mineral dust aerosols within the anticyclone in the UTLS throughout the ASM (period from July to September), when convective activity over the Indian subcontinent is highest, indicating that boundary layer aerosol pollution is the source of this UTLS aerosol layer. The simulations identify deep convection and the associated heat-driven circulation over the southern flanks of the Himalayas as the dominant transport pathway of aerosols and water vapour into the tropical tropopause layer (TTL). Comparison of model simulations with and without aerosols indicates that anthropogenic aerosols are central to the formation of this transport pathway. Aerosols act to increase cloud ice, water vapour, and temperature in the model UTLS. Evidence of ASM transport of aerosols into the stratosphere is also found, in agreement with aerosol extinction measurements from the Halogen Occultation Experiment (HALOE) and Stratospheric Aerosol and Gas Experiment (SAGE) II. As suggested by the observations, aerosols are transported into the Southern Hemisphere around the tropical tropopause by large-scale mixing processes. Aerosol-induced circulation changes also include a weakening of the main branch of the Hadley circulation and a reduction of monsoon precipitation over India