310 research outputs found
Pioneering Metallurgy: The origins of iron and steel making in the Southern Indian subcontinent Telangana Field Survey Interim Report 2011
A chapter from this report ("From the macroscopic to the microscopic: some scientific insights") is in ORE: http://hdl.handle.net/10871/17744British Council UKIER
Underwater Navigation using Pseudolite
Using pseudolite or pseudo satellite, a proven technology for ground and space applications for the augmentation of GPS, is proposed for underwater navigation. Global positioning systems (GPS) like positioning for underwater system, needs minimum of four pseudolite-ranging signals for pseudo-range and accumulated delta range measurements. Using four such measurements and using the models of underwater attenuation and delays, the navigation solution can be found. However, for application where the one-way ranging does not give good accuracy, alternative algorithms based upon the bi-directional and self-difference ranging is proposed using selfcalibrated pseudolite array algorithm. The hardware configuration is proposed for pseudolite transceiver for making the self-calibrated array. The pseudolite array, fixed or moored under the sea, can give position fixing similar to GPS for underwater applications.Defence Science Journal, 2011, 61(4), pp.331-336, DOI:http://dx.doi.org/10.14429/dsj.61.108
Modelling and Simulation of Pseudolite-based Navigation: A GPS-independent Radio Navigation System
The use of global positioning system (GPS) for precision guidance of weapons is being questioned due to its vulnerability of jamming and spoofing for non-military code users. In this paper a novel approach is proposed for guidance of weapons where use of GPS or other civilian Satellite-based navigation system is threatened. The proposed approach is modelled and simulated using SIMULINK for realistic trajectories and scenario. The results of simulation are validated with the actual GPS data
Urinary System anomalies at birth
Background: Congenital anomalies of urinary system are common and are found in 3-4% of population, and lethal urinary anomalies account for 10% of termination of pregnancy.Methods: A study was done to know the incidence of congenital anomalies at birth for the period of 4 months from May 99 - Sept 99 at Cheluvamba hospital attached to Mysore medical college. Congenital anomalies in the still births, live births and aborted fetuses >20 weeks were studied along with the case history and ultrasound reports. Aborted fetuses and still born babies were collected for autopsy after the consent of parents. These babies were fixed in 10% formalin and autopsy was done after fixing, and anomalies were noted.Results: Total births during study period were 3000. There were 61 babies with congenital anomalies and 6 babies had anomalies of urinary system. Among the urinary system anomalies 1 baby had bilateral renal agenesis, 1 baby had unilateral renal agenesis with anophthalmia (Fraser syndrome), 2 babies had Multicystic dysplastic kidney disease (MCDK) and 1 live baby had hydronephrosis due to obstruction at pelvi ureteric junction, and 1 live female baby had polycystic kidneys.Conclusion: Incidence of urinary system anomalies in the present study was 2 per 1000 births. U/S detection of urinary anomalies varies with period of gestation, amniotic fluid volume and visualisation of urinary bladder. Autopsy helps to detect renal agenesis.
Healthcare costs and utilization for Medicare beneficiaries with Alzheimer\u27s
BACKGROUND: Alzheimer\u27s disease (AD) is a neurodegenerative disorder incurring significant social and economic costs. This study uses a US administrative claims database to evaluate the effect of AD on direct healthcare costs and utilization, and to identify the most common reasons for AD patients\u27 emergency room (ER) visits and inpatient admissions.
METHODS: Demographically matched cohorts age 65 and over with comprehensive medical and pharmacy claims from the 2003-2004 MEDSTAT MarketScan Medicare Supplemental and Coordination of Benefits (COB) Database were examined: 1) 25,109 individuals with an AD diagnosis or a filled prescription for an exclusively AD treatment; and 2) 75,327 matched controls. Illness burden for each person was measured using Diagnostic Cost Groups (DCGs), a comprehensive morbidity assessment system. Cost distributions and reasons for ER visits and inpatient admissions in 2004 were compared for both cohorts. Regression was used to quantify the marginal contribution of AD to health care costs and utilization, and the most common reasons for ER and inpatient admissions, using DCGs to control for overall illness burden.
RESULTS: Compared with controls, the AD cohort had more co-morbid medical conditions, higher overall illness burden, and higher but less variable costs (10,369; Coefficient of variation = 181 vs. 324). Significant excess utilization was attributed to AD for inpatient services, pharmacy, ER visits, and home health care (all p \u3c 0.05). In particular, AD patients were far more likely to be hospitalized for infections, pneumonia and falls (hip fracture, syncope, collapse).
CONCLUSION: Patients with AD have significantly more co-morbid medical conditions and higher healthcare costs and utilization than demographically-matched Medicare beneficiaries. Even after adjusting for differences in co-morbidity, AD patients incur excess ER visits and inpatient admissions
Association of A1C with cardiovascular disease and metabolic syndrome in Asian Indians with normal glucose tolerance.
OBJECTIVE: This study examines the association of A1C with cardiovascular disease (CVD) risk factors, coronary artery disease (CAD), and metabolic syndrome in Asian Indians with normal glucose tolerance (NGT). RESEARCH DESIGN AND METHODS: This cross-sectional study recruited subjects from phase III of the Chennai Urban Rural Epidemiology Study (CURES), an epidemiological study in a representative population of Chennai (formerly Madras) in South India, conducted between January 2003 and June 2004. Included were 1,644 subjects with NGT, i.e., fasting plasma glucose <100 mg/dl (5.6 mmol/l) and 2-h postload plasma glucose <140 mg/dl (7.8 mmol/l). A1C was measured using the Biorad Variant machine. Metabolic syndrome was defined based on modified Adult Treatment Panel III guidelines. RESULTS: The mean +/- SD A1C value in the study cohort was 5.5 +/- 0.4%. A1C showed a significant association with BMI (beta = 0.017, P < 0.001), systolic (beta = 0.002, P = 0.028) and diastolic (beta = 0.202, P = 0.017) blood pressure, waist circumference (beta = 0.007, P < 0.001), serum cholesterol (beta = 0.002, P < 0.001), triglycerides (beta = 0.001, P < 0.001), LDL cholesterol (beta = 0.002, P < 0.001), fasting insulin (beta = 0.009, P < 0.001), and homeostasis model assessment of insulin resistance (beta = 0.047, P < 0.001) after adjusting for age and sex. Regression analysis showed that A1C had a strong association with metabolic syndrome that persisted after adjusting for age and sex (odds ratio [OR] 2.9 [95% CI 2.08-4.00]; P < 0.001). A1C also had a strong association with CAD (2.6 [1.23-5.63]; P = 0.01), but the significance was lost when adjusted for age and sex. CONCLUSIONS: There is a strong association of A1C with prevalent CVD risk factors in Asian-Indian subjects with NGT
Disparities in routine breast cancer screening for medicaid managed care members with a work-limiting disability
Objective: Examine disparities in routine mammography for women who qualify for Medicaid, because of a work-limiting disability.
Methods: Individual-level data were obtained for women enrolled in Massachusetts Medicaid Managed Care plans who met the 2007 Healthcare Effectiveness Data and Information Set (HEDIS) criteria for the breast cancer screening measure (n=35,171). Disability status was determined from Medicaid eligibility records. Mammography screening was modeled using multivariate logistic regression. Separate models for women with and without a disability were also estimated.
Results: Although unadjusted breast cancer screening rates were roughly equal for women with and without disability, after adjusting for confounders disability status had a significant negative association with screening mammography (OR=0.74; p
Conclusion: Nationwide, rates of routine mammography for Medicaid managed care plans averaged below 50% in 2006. Given that a majority of eligible women served by Medicaid have disabilities, and studies have shown that women with disabilities are more likely to be diagnosed with late stage disease, a focus on improving rates of screening for women with disabilities is overdue
Australin: a chromosomal passenger protein required specifically for Drosophila melanogaster male meiosis
The chromosomal passenger complex (CPC), which is composed of conserved proteins aurora B, inner centromere protein (INCENP), survivin, and Borealin/DASRA, localizes to chromatin, kinetochores, microtubules, and the cell cortex in a cell cycle–dependent manner. The CPC is required for multiple aspects of cell division. Here we find that Drosophila melanogaster encodes two Borealin paralogues, Borealin-related (Borr) and Australin (Aust). Although Borr is a passenger in all mitotic tissues studied, it is specifically replaced by Aust for the two male meiotic divisions. We analyzed aust mutant spermatocytes to assess the effects of fully inactivating the Aust-dependent functions of the CPC. Our results indicate that Aust is required for sister chromatid cohesion, recruitment of the CPC to kinetochores, and chromosome alignment and segregation but not for meiotic histone phosphorylation or spindle formation. Furthermore, we show that the CPC is required earlier in cytokinesis than previously thought; cells lacking Aust do not initiate central spindle formation, accumulate anillin or actin at the cell equator, or undergo equatorial constriction
Searching for Oscillations with Extragalactic Neutrinos
We propose a novel approach for studying oscillations
with extragalactic neutrinos. Active Galactic Nuclei and Gamma Ray Bursts are
believed to be sources of ultrahigh energy muon neutrinos. With distances of
100 Mpc or more, they provide an unusually long baseline for possible detection
of with mixing parameters down to
eV, many orders of magnitude below the current accelerator
experiments. By solving the coupled transport equations, we show that
high-energy 's, as they propagate through the earth, cascade down in
energy, producing the enhancement of the incoming flux in the low
energy region, in contrast to the high-energy 's, which get absorbed.
For an AGN quasar model we find the flux to be a factor of 2 to 2.5
larger than the incoming flux in the energy range between GeV and
GeV, while for a GRB fireball model, the enhancement is 10%-27% in the same
energy range and for zero nadir angle. This enhancement decreases with larger
nadir angle, thus providing a novel way to search for appearance by
measuring the angular dependence of the muons. To illustrate how the cascade
effect and the final flux depend on the steepness of the incoming
, we show the energy and angular distributions for several generic
cases of the incoming tau neutrino flux, for n=1,2 and
3.6. We show that for the incoming flux that is not too steep, the signal for
the appearance of high-energy is the enhanced production of lower
energy and their distinctive angular dependence, due to the contribution
from the decay into just below the detector.Comment: 11 pages, including 4 color figure
Van der Waals Nanoantennas on Gold as Hosts for Hybrid Mie-Plasmonic Resonances
Dielectric nanoresonators have been shown to circumvent the heavy optical
losses associated with plasmonic devices, however they suffer from less
confined resonances. By constructing a hybrid system of both dielectric and
metallic materials, one can retain the low losses of dielectric resonances,
whilst gaining additional control over the tuning of the modes with the metal,
and achieving stronger mode confinement. In particular, multi-layered van der
Waals materials are emerging as promising candidates for integration with
metals owing to their weak attractive forces, which enable deposition onto such
substrates without the requirement of lattice matching. Here we use layered,
high refractive index WS exfoliated on gold, to fabricate and optically
characterize a hybrid nanoantenna-on-gold system. We experimentally observe a
hybridization of Mie resonances, Fabry-P\'erot modes, and surface
plasmon-polaritons launched from the nanoantennas into the substrate. We
achieve experimental quality factors of Mie-plasmonic modes of up to 20 times
that of Mie resonances in nanoantennas on silica, and observe signatures of a
supercavity mode with a Q factor of 263 28, resulting from strong mode
coupling between a higher-order anapole and Fabry-P\'erot-plasmonic mode. We
further simulate WS nanoantennas on gold with an hBN spacer, resulting in
calculated electric field enhancements exceeding 2600, and a Purcell factor of
713. Our results demonstrate dramatic changes in the optical response of
dielectric nanophotonic structures placed on gold, opening new possibilities
for nanophotonics and sensing with simple-to-fabricate devices.Comment: 21 + 11 pages, 5 + 7 figure
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