22 research outputs found
Basis Pursuit Receiver Function
Receiver functions (RFs) are derived by deconvolution of the horizontal (radial or transverse) component of ground motion from the vertical component, which segregates the PS phases. Many methods have been proposed to employ deconvolution in frequency as well as in time domain. These methods vary in their approaches to impose regularization that addresses the stability problem. Here, we present application of a new time-domain deconvolution technique called basis pursuit deconvolution (BPD) that has recently been applied to seismic exploration data. Unlike conventional deconvolution methods, the BPD uses an L1 norm constraint on model reflectivity to impose sparsity. In addition, it uses an overcomplete wedge dictionary based on a dipole reflectivity series to define model constraints, which can achieve higher resolution than that obtained by the traditional methods. We demonstrate successful application of BPD based RF estimation from synthetic data for a crustal model with a near-surface thin layer of thickness 5, 7, 10, and 15 km. The BPD can resolve these thin layers better with much improved signal-to-noise ratio than the conventional methods. Finally, we demonstrate application of the BPD receiver function (BPRF) method to a field dataset from Kutch, India, where near-surface sedimentary layers are known to be present. The BPRFs are able to resolve reflections from these layers very well.Jackson Chair funds at the Jackson School of Geosciences, University of Texas, AustinCouncil of Scientific and Industrial Research twelfth five year plan project at the Council of Scientific and Industrial Research National Geophysical Research Institute (CSIR-NGRI), HyderabadInstitute for Geophysic
Counterion Effects on Nano-confined Metal-Drug-DNA Complexes
We have explored morphology of DNA molecules bound with Cu-complexes of
piroxicam molecules, a non-steroidal anti-inflammatory drug (NSAID), under
one-dimensional confinement of thin films and have studied the effect of
counterions present in a buffer. X-ray reflectivity at and away from the Cu K
absorption edge and atomic force microscopy studies reveal that confinement
segregates the drug molecules preferentially in a top layer of the DNA film,
and counterions enhance this segregation
Eco-psychiatry and Environmental Conservation: Study from Sundarban Delta, India
Aims This study attempts to examine the extent and impact of human-animal conflicts visa-vis psychosocial stressors and mental health of affected people in two villages adjacent to Sundarban Reserve Forest (SRF) in the Gosaba Block, West Bengal, India. Methods Door to door household survey for incidents of human-animal conflicts, Focus Group Discussions, In-depth Interviews, Case studies, Community Mental health clinics and participatory observation. Results A total of 3084 households covering a population of 16,999 were surveyed. 32.8% people live on forest-based occupation. During the last 15 years 111 persons (male 83, female 28) became victims of animal attacks, viz, Tiger (82%), Crocodile (10.8%) and Shark (7.2%) of which 73.9% died. In 94.5% cases the conflict took place in and around the SRF during livelihood activities. Tracking of 66 widows, resulted from these conflicts, showed that majority of them (51.%) are either disabled or in a very poor health condition, 40.9% are in extreme economic stress and only 10.6% remarried. 1 widow committed suicide and 3 attempted suicide. A total of 178 persons (male 82, female 96) attended the community mental health clinics. Maximum cases were Major Depressive Disorder (14.6%), followed by Somatoform Pain Disorder (14.0%), Post Traumatic Stress Disorder-animal attack related (9.6%) and Adjustment Disorder (9%). 11.2% cases had history of deliberate self-harm attempt, of which 55% used pesticides. Conclusions Improvement of quality of life of this deltaic population by appropriate income generation and proper bio-forest management are the key factors to save their life as well as the mangrove environment of the Sundarban region
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A Review and Evaluation of Planetary Boundary Layer Parameterizations in Hurricane Weather Research and Forecasting Model Using Idealized Simulations and Observations
This paper reviews the evolution of planetary boundary layer (PBL) parameterization schemes that have been used in the operational version of the Hurricane Weather Research and Forecasting (HWRF) model since 2011. Idealized simulations are then used to evaluate the effects of different PBL schemes on hurricane structure and intensity. The original Global Forecast System (GFS) PBL scheme in the 2011 version of HWRF produces the weakest storm, while a modified GFS scheme using a wind-speed dependent parameterization of vertical eddy diffusivity (Km) produces the strongest storm. The subsequent version of the hybrid eddy diffusivity and mass flux scheme (EDMF) used in HWRF also produces a strong storm, similar to the version using the wind-speed dependent Km. Both the intensity change rate and maximum intensity of the simulated storms vary with different PBL schemes, mainly due to differences in the parameterization of Km. The smaller the Km in the PBL scheme, the faster a storm tends to intensify. Differences in hurricane PBL height, convergence, inflow angle, warm-core structure, distribution of deep convection, and agradient force in these simulations are also examined. Compared to dropsonde and Doppler radar composites, improvements in the kinematic structure are found in simulations using the wind-speed dependent Km and modified EDMF schemes relative to those with earlier versions of the PBL schemes in HWRF. However, the upper boundary layer in all simulations is much cooler and drier than that in dropsonde observations. This model deficiency needs to be considered and corrected in future model physics upgrades.</div
Ecopsychosocial Aspects of HumanâTiger Conflict: An Ethnographic Study of Tiger Widows of Sundarban Delta, India
Aims Humanâtiger conflict (HTC) is a serious public health issue in Sundarban Reserve Forest, India. HTC is a continued concern for the significant mortality and morbidity of both human and tiger population. This is the first comprehensive report on Sundarban tigerâhuman conflicts and its impact on widows whose husbands were killed by tigers. The study attempts to explore the situation analysis of HTC and the aftermath of the incident including bereavement and coping, the cultural stigma related to being killed by a tiger and the consequent discrimination, deprivation, and social rejection, and the impact on the mental health of the tiger-widows. Methods This is a three-phase ethnographic research with a mix of quantitative and qualitative methods. In the first phase, a door-to-door village survey (3,084 households) was carried out in two villages of Sundarban, which are adjacent to the Reserve Forest, in which the incidents of human-animal conflicts and the 65 tiger-widows identified were documented. In the second phase, the 65 tiger-widows were studied to explore the ecodemography of tiger attacks and tiger-widows alongside the stigma issue by using a stigma questionnaire ( n = 49). The stigma burden was compared with normal widows ( n = 21) and snake-bite widows ( n = 18). In the third phase, the psychosocial and cultural dimensions related to tiger attacks were studied by using in-depth interviews (IDI) of the tiger-widows, focus-group discussions (FGD), and participatory mapping in the community. Clinical examinations of the mental health of the widows were also carried out in this phase. Results The mean age of the 65 widows was 43.49 ± 9.58 years. Of this, 12.3% of the widows had remarried and only 4.6% of the widows were literate. In all, 67.2% of all tiger attacks occurred as a result of illegal forest entry. The main livelihood of the former husbands of the widows were 43.8% wood cutting, 28.1% fishing, 10.9% crab catching, 9.4% tiger prawn seed (juvenile prawn), and 4.7% honey collection. The maximum number of attacks took place in the months of December (24.6%) and November (13.9%). The majority of incidences happened during the morning hours (47.7%) of the day. Of the cases, 86.1% were attacked while the person was engaged in livelihood activity. In all, 57.4% widows are recorded as living âbelow the poverty lineâ. Currently, 45.5% widows earn their living by laboring work followed by forest-based livelihood activities (30%) and begging (5.2%). Tiger-widows differed significantly ( P < 0.001) from both normal and snake-bite widows on all stigma cluster scores and the total score. Of the tiger-widows, 44% were shown to be suffering from some designated mental illness. IDIs and FGDs helped to unfold the cultural construct of stigma related to tiger-killing. This can be seen in how the tiger-widowsâ quality of life has been negatively impacted in the way their economic and social security, health, remarriage opportunities, and child upbringing is restricted, along with a multitude of posttrauma psychological scars, deprivation, abuse, and exploitation. Conclusions The study highlights the multitude of sufferings experienced by the tiger-widows including the issues of the gender aspect of HTC and the ecopsychiatric risk factors of tiger attacks combined with the background of local sociocultural beliefs and practices. It is well known that a similar problem also exists in Bangladesh Sundarban as well, in which case it may be that a strong and practical administrative strategy for sustainable alternative income generation and a balanced conservation policy with integrated participatory forest management may go to save both human and tiger. A community ecocultural mental health program involving all the stakeholders (community, gram panchayat, and forest department) and aiming to address and even eradicate the cultural stigma of tiger attack may help to reduce the stigma burden and socicultural discrimination currently experienced by the tiger-widows
Sensitivity of an Idealized Tropical Cyclone to the Configuration of the Global Forecast SystemâEddy Diffusivity Mass Flux Planetary Boundary Layer Scheme
The intensity and structure of simulated tropical cyclones (TCs) are known to be sensitive to the planetary boundary layer (PBL) parameterization in numerical weather prediction models. In this paper, we use an idealized version of the Hurricane Weather Research and Forecast system (HWRF) with constant sea-surface temperature (SST) to examine how the configuration of the PBL scheme used in the operational HWRF affects TC intensity change (including rapid intensification) and structure. The configuration changes explored in this study include disabling non-local vertical mixing, changing the coefficients in the stability functions for momentum and heat, and directly modifying the Prandtl number (Pr), which controls the ratio of momentum to heat and moisture exchange in the PBL. Relative to the control simulation, disabling non-local mixing produced a ~15% larger storm that intensified more gradually, while changing the coefficient values used in the stability functions had little effect. Varying Pr within the PBL had the greatest impact, with the largest Pr (~1.6 versus ~0.8) associated with more rapid intensification (~38 versus 29 m sâ1 per day) but a 5â10 m sâ1 weaker intensity after the initial period of strengthening. This seemingly paradoxical result is likely due to a decrease in the radius of maximum wind (~15 versus 20 km), but smaller enthalpy fluxes, in simulated storms with larger Pr. These results underscore the importance of measuring the vertical eddy diffusivities of momentum, heat, and moisture under high-wind, open-ocean conditions to reduce uncertainty in Pr in the TC PBL