Resolution-enhanced Mapping Spectrometer

A familiar mapping spectrometer implementation utilizes two dimensional detector arrays with spectral dispersion along one direction and spatial along the other. Spectral images are formed by spatially scanning across the scene (i.e., push-broom scanning). For imaging grating and prism spectrometers, the slit is perpendicular to the spatial scan direction. For spectrometers utilizing linearly variable focal-plane-mounted filters the spatial scan direction is perpendicular to the direction of spectral variation. These spectrometers share the common limitation that the number of spectral resolution elements is given by the number of pixels along the spectral (or dispersive) direction. Resolution enhancement by first passing the light input to the spectrometer through a scanned etalon or Michelson is discussed. Thus, while a detector element is scanned through a spatial resolution element of the scene, it is also temporally sampled. The analysis for all the pixels in the dispersive direction is addressed. Several specific examples are discussed. The alternate use of a Michelson for the same enhancement purpose is also discussed. Suitable for weight constrained deep space missions, hardware systems were developed including actuators, sensor, and electronics such that low-resolution etalons with performance required for implementation would weigh less than one pound

Trajectory Mapping and Applications to Data from the Upper Atmosphere Research Satellite

The problem of creating synoptic maps from asynoptically gathered trace gas data has prompted the development of a number of schemes. Most notable among these schemes are the Kalman filter, the Salby-Fourier technique, and constituent reconstruction. This paper explores a new technique called trajectory mapping. Trajectory mapping creates synoptic maps from asynoptically gathered data by advecting measurements backward or forward in time using analyzed wind fields. A significant portion of this work is devoted to an analysis of errors in synoptic trajectory maps associated with the calculation of individual parcel trajectories. In particular, we have considered (1) calculational errors; (2) uncertainties in the values and locations of constituent measurements, (3) errors incurred by neglecting diabatic effects, and (4) sensitivity to differences in wind field analyses. These studies reveal that the global fields derived from the advection of large numbers of measurements are relatively insensitive to the errors in the individual trajectories. The trajectory mapping technique has been successfully applied to a variety of problems. In this paper, the following two applications demonstrate the usefulness of the technique: an analysis of dynamical wave-breaking events and an examination of Upper Atmosphere Research Satellite data accuracy

Retinopathy of prematurity and its association with neonatal factors

Retinopathy of prematurity is considered as an important cause of blindness. This prospective study was undertaken to document the frequency and the associated factors of retinopathy of prematurity among 97 preterm newborn weighing <2000 g and/or with a gestation of <35 weeks. The first eye examination was performed by an ophthalmologist at 4 weeks of postnatal age for the infants born at ?30 weeks of gestation or birth weight ?1200 g and at 3 weeks of postnatal age for the infants <30 weeks of gestation or birth weight <1200 g. The overall incidence of retinopathy of prematurity was 23.7%. Premature newborn with retinopathy was having significant low mean birth weight (p=0.001) and the mean gestational age (p=<0.001) when compared with newborns without retinopathy of prematurity. Newborns with retinopathy of prematurity were requiring a longer duration of oxygen (p=0.005) than that of non-retinopathy of prematurity newborns. Logistic regression shows the duration of oxygen in the hospital and lower gestational age were independent risk factors of retinopathy of prematurity. Prematurity and longer duration of oxygen administration were the risk factors for the development of retinopathy of prematurity

Retinopathy of prematurity and its association with neonatal factors

Retinopathy of prematurity is considered as an important cause of blindness. This prospective study was undertaken to document the frequency and the associated factors of retinopathy of prematurity among 97 preterm newborn weighing <2000 g and/or with a gestation of <35 weeks. The first eye examination was performed by an ophthalmologist at 4 weeks of postnatal age for the infants born at ?30 weeks of gestation or birth weight ?1200 g and at 3 weeks of postnatal age for the infants <30 weeks of gestation or birth weight <1200 g. The overall incidence of retinopathy of prematurity was 23.7%. Premature newborn with retinopathy was having significant low mean birth weight (p=0.001) and the mean gestational age (p=<0.001) when compared with newborns without retinopathy of prematurity. Newborns with retinopathy of prematurity were requiring a longer duration of oxygen (p=0.005) than that of non-retinopathy of prematurity newborns. Logistic regression shows the duration of oxygen in the hospital and lower gestational age were independent risk factors of retinopathy of prematurity. Prematurity and longer duration of oxygen administration were the risk factors for the development of retinopathy of prematurity

An icteric newborn with bad obstetric history

This article has no abstract. The first 100 words appear below:A 34 week preterm baby was admitted with the complaints of respiratory distress soon after birth. The mother had bad obstetric history. She is having the fifth gravida with the first two alive and healthy who were born by the normal vaginal delivery at home. The third child was born with severe jaundice and was treated by exchange transfusion. Subsequently the baby developed bilirubin encephalopathy. Then the baby developed cerebral palsy and ultimately died due to aspiration pneumonia at the age of 2.5 years. Her first three pregnancies were not on any antenatal check-up by the health care provider due to poor socio-economic background and illiteracy

Trajectory mapping: A tool for validation of trace gas observations

We investigate the effectiveness of trajectory mapping(TM) as a data validation tool. TM combines a dynamical model of the atmosphere with trace gas observations to provide more statistically robust estimates of instrument performance over much broader geographic areas than traditional techniques are able to provide. We present four detailed case studies selected so that the traditional techniques are expected to work well. In each case the TM results are equivalent to or improve upon the measurement comparisons performed with traditional approaches. The TM results are statistically more robust than those achieved using traditional approaches since the TM comparisons occur over a much larger range of geophysical variability. In the first case study we compare ozone data from the Halogen Occultation Experiment (HALOE) with Microwave Limb Sounder(MLS). TM comparisons appear to introduce little to no error as compared to the traditional approach. In the second case study we compare ozone data from HALOE with that from the Stratospheric Aerosol and Gas Experiment TT(SAGE TT). TM results in differences of less than 5% as compared to the traditional approach at altitudes between 18 and 25 km and less than 10% at altitudes between 25 and 40 km.In the third case study we show that ozone profiles generated from HALOE data using TM compare well with profiles from five European ozonesondes. In the fourth case study we evaluate the precision of MLS H20 using TM and find typical precision uncertainties of 3-7% at most latitudes and altitudes. The TM results agree well with previous estimates but are the result of a global analysis of the data rather than an analysis in the limited latitude bands in which traditional approaches work. Finally, sensitivity studies using the MLS H20 data show the following: (1) a combination of forward and backward trajectory calculations minimize uncertainties in isentropic TM; (2) although the uncertainty of the technique increases with trajectory duration,TM calculations of up to 14 days can provide reliable information for use in data validation studies; (3) a correlation coincidence criterion of 400 km produces the best TM results under most circumstances; (4) TM performs well compared to (and sometimes better than) traditional approaches at all latitudes and in most seasons and; (5) TM introduces no statistically significant biases at altitudes between 22 and 40 km

Improving management of a mid-Atlantic coastal barrier island through assessment of habitat condition

AbstractTo achieve desired environmental outcomes, environmental condition and trends need to be rigorously measured and communicated to resource managers, scientists, and a broader general audience. However, there is often a disconnect between responsive ecosystem monitoring and decision making for strategic long-term management. This project demonstrates how historical monitoring data can be synthesized and used for future planning and decision making, thereby closing the management feedback cycle. This study linked disparate datasets, collected for a variety of purposes and across multiple temporal and spatial scales, in order to assess and quantify current habitat conditions. The results inform integrated resource management decision-making at Assateague Island National Seashore (Maryland and Virginia, USA) by using ecological reference conditions to identify monitoring needs, areas of high vulnerability, and areas with potential for improved management. The approach also provides a framework that can be applied in the future to assess the effectiveness of these management decisions on the condition of island habitats, and is a replicable demonstration of incorporating diverse monitoring datasets into an adaptive management cycle

Late-onset renal vein thrombosis: A case report and review of the literature

AbstractINTRODUCTIONRenal vein thrombosis, a rare complication of renal transplantation, often causes graft loss. Diagnosis includes ultrasound with Doppler, and it is often treated with anticoagulation or mechanical thrombectomy. Success is improved with early diagnosis and institution of treatment.PRESENTATION OF CASEWe report here the case of a 29 year-old female with sudden development of very late-onset renal vein thrombosis after simultaneous kidney pancreas transplant. This resolved initially with thrombectomy, stenting and anticoagulation, but thrombosis recurred, necessitating operative intervention. Intraoperatively the renal vein was discovered to be compressed by a large ovarian cyst.DISCUSSIONCompression of the renal vein by a lymphocele or hematoma is a known cause of thrombosis, but this is the first documented case of compression and thrombosis due to an ovarian cyst.CONCLUSIONEarly detection and treatment of renal vein thrombosis is paramount to restoring renal allograft function. Any woman of childbearing age may have thrombosis due to compression by an ovarian cyst, and screening for this possibility may improve long-term graft function in this population

Embedding Fiber Optic Sensors in Metal Components via Direct Energy Deposition

Fiber optics are useful as strain and temperature sensors in a variety of applications involving high-value parts. Embedding fiber optic sensors into end-use parts can allow for realtime strain and temperature monitoring of these parts in extreme conditions. Direct energy deposition processes have distinct advantages for producing parts in high-value embedded sensing applications, however, ensuring survival of the optical fiber during embedment is challenging. A method of fiber embedment using high-temperature ceramic adhesives is presented as a flexible method of embedding fiber optic sensors into end-use parts such as to preserve fiber transmission and sensor integrity. Example specimens are presented, and functionality of sensing capabilities is demonstrated.Mechanical Engineerin