Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Radar”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1996

Disturbances in the soil: finding buried bodies and other evidence using ground penetrating radar.

Ground penetrating radar (GPR) is an efficient and effective means to search for buried evidence, whether it be a clandestine grave, formal burial, or certain missing articles from a crime scene. The procedures for GPR used by the U.S. Army Central Identification Laboratory, Hawaii (CILHI), are the result of several years of experimentation on a variety of ground surfaces in Hawaii, Southeast Asia and the mainland U.S. This remote sensing method does not usually provide direct information that there is a body or other specific object beneath the ground. Most of the time the GPR has been used to determine where a target object is not located. The key feature of GPR is that it can detect recent changes in shallow soil conditions caused by the disturbance of soil and the intrusion of different material. Using the methods described here, the investigator should be able to determine the precise metric grid coordinates for a subsurface disturbance, as well as the approximate size, the general shape, and the depth of the buried material. Success will vary with soil conditions. The conditions suitable or not practical for using GPR are summarized. This remote sensing technology can have wider use in crime scene investigations due to the recent introduction of more user-friendly software and more portable hardware.

Burial↗
PubMed1992

Do self-reported arthritis symptom (RADAR) and health status (AIMS2) data provide duplicative or complementary information?

This study assessed whether self-report measures of symptoms and functional health status provide unique outcome information, or whether functional status assessments primarily serve as a proxy for self-reported arthritis symptoms. Symptom scores of 138 individuals with rheumatoid arthritis (RA) collected with the Rapid Assessment of Disease Activity in Rheumatology (RADAR) measure were compared with same-day functional health scores collected with the recently revised Arthritis Impact Measurement Scales (AIMS2). Correlational and factor analyses revealed that self-assessed arthritis symptoms, physical function and work impact, psychological status, and social health each made independent contributions to outcome. Satisfaction with health status was shown not to be independent of symptoms, functional capacity, or psychological status. It is important to document that self-reported symptom and health status information, when collected concurrently, provides complementary rather than duplicative information.

Activities of Daily Living↗
PubMed2006

Clinical features and correlates of gemcitabine-associated lung injury: findings from the RADAR project.

BACKGROUND: Gemcitabine is a commonly used chemotherapeutic agent structurally and pharmacologically similar to cytarabine. Recently, instances of severe gemcitabine-associated lung injury have been reported. Herein, investigators affiliated with the Research on Adverse Drug Events and Reports (RADAR) pharmacovigilance program evaluated clinical characteristics of gemcitabine-associated severe acute lung injury from clinical trial reports, medical literature case reports, and spontaneous reports to the Food and Drug Administration (FDA) Adverse Event Reporting System (AERS). METHODS: Clinical data were obtained by reviewing adverse event case reports for gemcitabine-associated lung injury as reported in the medical literature and in the FDA AERS database. Upper limit estimates of ADE rate were derived from review of published clinical trials reporting gemcitabine-associated lung injury rates of 10% or higher. RESULTS: A total of 178 reports of gencitabine-associated lung injury were identified; in AERS, there were 55 cases from clinical trials and 92 spontaneous reports. A comprehensive search revealed 31 medical literature reports. Clinical features of gemcitabine-associated lung injury included dyspnea, fever, pulmonary infiltrate, and cough with recognition of toxicity occurring after a median duration of 48 (range, 1-529) days after initiation of gemcitabine. The taxanes, docetaxel and paclitaxel, were frequently reported as coadministered therapies. Eleven Phase II or Phase III clinical trials with 317 patients identified gemcitabine-associated lung injury rates of greater than 10%, with the highest rates (22% and 42%) being observed in Phase III clinical trials where Hodgkin disease patients were treated with a regimen that included gemcitabine and bleomycin. CONCLUSIONS: High rates of gemcitabine-associated severe lung injury were observed when gemcitabine was combined with other therapies known to also cause lung injury. Physicians should have a high index of suspicion for this toxicity and report the relevant clinical findings to the FDA's AERS.

Antimetabolites, Antineoplastic↗
PubMed2005

Hypersensitivity cases associated with drug-eluting coronary stents: a review of available cases from the Research on Adverse Drug Events and Reports (RADAR) project.

OBJECTIVES: We undertook the review of all available cases of hypersensitivity reactions after placement of a drug-eluting stent (DES) and classified potential causes. BACKGROUND: Six months after the approval of the first DES, the Food and Drug Administration (FDA) reported 50 hypersensitivity reactions after stent placement but later concluded these were due to concomitantly prescribed medications such as clopidogrel. Nevertheless, the FDA continued to receive reports of hypersensitivity. METHODS: Reports available from April 2003 through December 2004 for hypersensitivity-like reactions associated with the sirolimus-eluting stent (CYPHER, Cordis Corp., Miami Lakes, Florida) and paclitaxel-eluting stent (TAXUS, Boston Scientific Corp., Natick, Massachusetts) were reviewed. Sources of reports included the FDA's adverse-device-event database, the published literature, and investigators from the Research on Adverse Drug/Device events And Reports (RADAR) project. Causality was assessed using standardized World Health Organization criteria. RESULTS: Of 5,783 reports identified for the DES in the FDA database, 262 unique events included hypersensitivity symptoms. Of these reports, 2 were certainly and 39 unlikely caused by clopidogrel and 1 was certainly, 9 probably, and 13 unlikely caused by the DES. From all sources, we identified 17 distinct cases that were probably or certainly caused by the stent, of which 9 had symptoms that lasted longer than four weeks. Four autopsies confirmed intrastent eosinophilic inflammation, thrombosis, and lack of intimal healing. CONCLUSIONS: The FDA reports and autopsy findings suggest that DES may be a cause of systemic and intrastent hypersensitivity reactions that, in some cases, have been associated with late thrombosis and death.

Coronary Vessels↗
PubMed2006

Gemtuzumab ozogamicin-associated sinusoidal obstructive syndrome (SOS): an overview from the research on adverse drug events and reports (RADAR) project.

Gemtuzumab ozogamicin (GO) was approved for marketing in 2000 by the United States Food and Drug Administration (FDA) for older patients with relapsed acute myeloid leukemia (AML). Four months later, 14 phase II clinical trial participants who received novel GO-containing combination chemotherapy regimens developed an unexpected hepatic toxicity termed sinusoidal obstructive syndrome (SOS) or hepatic veno-occlusive disease (VOD). Investigators associated with the Research on Adverse Drug Events and Reports (RADAR) project reviewed safety reports for GO included in reports of clinical trials and observational studies, interim reports from an FDA mandated Prospective Observational Registry, and the Food and Drug Administration's Adverse Event Reporting System. Medline searches provided incidence estimates of GO-associated SOS and comparative rates of SOS without GO. SOS is characterized by hyperbilirubinemia, painful hepatomegaly, ascites, and sudden weight gain developing at a median of 10 days following GO administration for patients who did not undergo an allogeneic SCT procedure and 13 days following an allogeneic SCT for patients who had previously received GO. Among adult AML patients who received GO in clinical trials, SOS incidence was 3% at doses < or =6 mg/m(2) if administered as monotherapy or in combination with non-hepatotoxic agents versus 28% if administered with thioguanine and 15% when administered as monotherapy at a dose of 9 mg/m(2). Observational studies identified SOS rates between 15% and 40% if an SCT is performed within 3 months of GO administration. The FDA mandated Prospective Observational Registry of patients who receive care at 60 medical centers has identified GO-associated SOS rates of 14% if an SCT is performed and 9% otherwise. Caution is advised when administering GO in routine clinical practice, particularly if administered with other hepatotoxic agents, at doses and schedules more intensive than those approved by the FDA, or within 3 months of a SCT procedure.

Acute Disease↗
PubMed1999

A case study for wintertime observation of atmospheric particulates by an eye-safe laser radar.

Atmospheric particulates were monitored on a typical high concentration day in early winter in Osaka, Japan, using a compact and portable eye-safe laser radar system. The height of mixing layer was about 0.4 km at 8:00 and gradually increased to 0.8 km at 14:00. The development of the layer was in inverse proportion to the decrease of particulates near the ground surface. Analysis of particulates collected with high-volume air samplers showed that concentrations of elemental carbon (EC), lead and ammonium ion near the surface decreased significantly from morning to midday, while concentrations of sulfate, nitrate, sodium and calcium ions were almost constant. The results obtained in the preliminary study suggest that anthropogenic particulates such as EC and lead are on the rise with development of mixing layer from morning to midday.

Journal Article↗
PubMed1999

A neural network for enhancing boundaries and surfaces in synthetic aperture radar images.

A neural network system for boundary segmentation and surface representation, inspired by a new local-circuit model of visual processing in the cerebral cortex, is used to enhance images of range data gathered by a synthetic aperture radar (SAR) sensor. Boundary segmentation is accomplished by an improved Boundary Contour System (BCS) model which completes coherent boundaries that retain their sensitivity to image contrasts and locations. A Feature Contour System (FCS) model compensates for local contrast variations and uses the compensated signals to diffusively fill-in surface regions within the BCS boundaries. Image noise pixels that are not supported by BCS boundaries are hereby eliminated. More generally, BCS/FCS processing normalizes input dynamic range, reduces noise, and enhances contrasts between surface regions. BCS/FCS processing hereby makes structures such as motor vehicles, roads, and buildings more salient to human observers than in original imagery. The new BCS model improves image enhancement with significant reductions in processing time and complexity over previous BCS applications. The new system also outperforms several established techniques for image enhancement.

Journal Article↗
PubMed1970

Observations of clear air turbulence by high power radar.

Clear air turbulence is a hazard to aviation and is thought to have important effects on atmospheric dynamics. This article describes the structure and evolution of clear air turbulence at high altitudes as revealed by a high power radar and vertical soundings of wind and temperature.

Journal Article↗
PubMed2000

Widespread uplift and 'trapdoor' faulting on Galápagos volcanoes observed with radar interferometry.

Volcanic uplift, caused by the accumulation of magma in subsurface reservoirs, is a common precursor to eruptions. But, for some volcanoes, uplift of metres or more has not yet led to an eruption. Here we present displacement maps of volcanoes in the Galápagos Islands, constructed using satellite radar interferometry, that might help explain this dichotomy. We show that all but one of the seven volcanoes on the islands of Isabela and Fernandina deformed during 1992-99. Cerro Azul and Fernandina erupted during the observation period and show evidence of inflation, co-eruptive deflation and shallow dyke intrusion. In contrast, the largest volcano, Sierra Negra, has not erupted, yet exhibits spatially and temporally variable deformation, with a maximum uplift of 2.7 m between 1992 and 1999, which can be modelled by a shallow inflating sill. Inflation during 1997-98, however, was accompanied by 'trapdoor' faulting on a steeply dipping fracture system within the caldera. Repeated trapdoor faulting over geological time has formed an arcuate intra-caldera ridge within Sierra Negra and may have acted to relax stresses above the magma chamber, inhibiting summit eruptions. Similar processes may help explain large uplift unaccompanied by eruptive activity at other volcanoes.

Journal Article↗
PubMed2006

MARSIS radar sounder evidence of buried basins in the northern lowlands of Mars.

A hemispheric dichotomy on Mars is marked by the sharp contrast between the sparsely cratered northern lowland plains and the heavily cratered southern highlands. Mechanisms proposed to remove ancient crust or form younger lowland crust include one or more giant impacts, subcrustal transport by mantle convection, the generation of thinner crust by plate tectonics, and mantle overturn following solidification of an early magma ocean. The age of the northern lowland crust is a significant constraint on these models. The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instrument on the European Space Agency's Mars Express spacecraft is providing new constraints on the martian subsurface. Here we show evidence of buried impact basins ranging in diameter from about 130 km to 470 km found over approximately 14 per cent of the northern lowlands. The number of detected buried basins >200 km in diameter indicates that the lowland crust is ancient, dating back to the Early Noachian epoch. This crater density is a lower limit because of the likelihood that not all buried basins in the area surveyed by MARSIS have been detected. An Early Noachian age for the lowland crust has been previously suggested on the basis of a large number of quasi-circular topographic depressions interpreted to be evidence of buried basins. Only a few of these depressions in the area surveyed by MARSIS, however, correlate with the detected subsurface echoes. On the basis of the MARSIS data, we conclude that the northern lowland crust is at least as old as the oldest exposed highland crust. This suggests that the crustal dichotomy formed early in the geologic evolution of Mars.

Journal Article↗
PubMed1994

Analytic inversion in synthetic aperture radar.

A method of processing synthetic aperture radar signals that avoids some of the approximations currently in use that appear to be responsible for severe phase distortions is described. As a practical matter, this method requires N3 numerical operations, as opposed to the N2 ln N currently the case, but N3 is now easily managed, for N in the range of interest.

Journal Article↗
PubMed2003

Fractal radar scattering from soil.

A general technique is developed to retrieve the fractal dimension of self-similar soils through microwave (radar) scattering. The technique is based on a mathematical model relating the fractal dimensions of the georadargram to that of the scattering structure. Clear and different fractal signatures have been observed over four geosystems (soils and sediments) compared in this work.

Journal Article↗
PubMed2004

A novel method to prevent secondary exposure of medical and rescue personnel to toxic materials under biochemical hazard conditions using microwave radar and infrared thermography.

In order to prevent secondary exposure of medical personnel to toxic materials under biochemical hazard conditions, we performed a noncontact determination of exposure to toxic conditions via 1215-MHz microwave radar and thermography. A toxic condition was induced by intravenous administration of lipopolysaccharide (LPS) in rabbits. The exposure to LPS was determined by linear discriminant analysis using non-contact derived variables.

Animals↗
PubMed2004

Quantitative statistical assessment of conditional models for synthetic aperture radar.

Many applications of object recognition in the presence of pose uncertainty rely on statistical models-conditioned on pose-for observations. The image statistics of three-dimensional (3-D) objects are often assumed to belong to a family of distributions with unknown model parameters that vary with one or more continuous-valued pose parameters. Many methods for statistical model assessment, for example the tests of Kolmogorov-Smirnov and K. Pearson, require that all model parameters be fully specified or that sample sizes be large. Assessing pose-dependent models from a finite number of observations over a variety of poses can violate these requirements. However, a large number of small samples, corresponding to unique combinations of object, pose, and pixel location, are often available. We develop methods for model testing which assume a large number of small samples and apply them to the comparison of three models for synthetic aperture radar images of 3-D objects with varying pose. Each model is directly related to the Gaussian distribution and is assessed both in terms of goodness-of-fit and underlying model assumptions, such as independence, known mean, and homoscedasticity. Test results are presented in terms of the functional relationship between a given significance level and the percentage of samples that wold fail a test at that level.

Journal Article↗
PubMed2006

Babesiosis and blood transfusion: flying under the radar.

Infectious agents of disease continue to plague transfusion medicine as an increasing number of pathogens are described that pose a potential blood safety risk. While the recent focus has been on newly emerged agents, several well-established pathogens provide timely reminders that other agents continue to pose threats, but invariably 'fly under the radar', thereby failing to elicit adequate measures to prevent their transmission by blood transfusion. Perhaps foremost among this group of agents are the Babesia spp., which have been known to cause human disease, in the USA, for close to 40 years. B. microti, B. divergens and several Babesia-like agents are responsible for a growing number of human babesiosis infections. Concomitantly, in the USA, there has been a sharp rise in the number of transfusion-transmitted infections of Babesia spp., attributable almost exclusively to B. microti. Despite the obvious public health issues posed by Babesia spp., options for preventing their transmission by blood transfusion remain limited. However, recognition that the Babesia spp. are indeed an ongoing and expanding blood safety threat will probably prove instrumental in the development of viable interventions to limit transmission of these agents.

Animals↗
PubMed2003

Direct detection of the Yarkovsky effect by radar ranging to asteroid 6489 Golevka.

Radar ranging from Arecibo, Puerto Rico, to the 0.5-kilometer near-Earth asteroid 6489 Golevka unambiguously reveals a small nongravitational acceleration caused by the anisotropic thermal emission of absorbed sunlight. The magnitude of this perturbation, known as the Yarkovsky effect, is a function of the asteroid's mass and surface thermal characteristics. Direct detection of the Yarkovsky effect on asteroids will help constrain their physical properties, such as bulk density, and refine their orbital paths. Based on the strength of the detected perturbation, we estimate the bulk density of Golevka to be 2.7(+0.4)(-0.6) grams per cubic centimeter.

Journal Article↗