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At least 73 records · Page 4Linked to original sources
PubMed2003

[Evaluation of radiation damage to the sperm DNA of radar operators].

OBJECTIVE: To evaluate the inflicted by radar electromagnetic radiation to the sperm DNA of radar operators. METHODS: Sperm concentration, viability, motility, sperm abnormality were determined by routine sperm analysis and sperm chromatin structure assay (SCSA) in the highly exposed group(n = 88), lowly exposed group(n = 143) and control group(n = 39). RESULTS: Sperm motility, viability of the highly exposed group reduced compared with that of the lowly exposed group and control group, while sperm abnormality increased. The COMP alpha reduction of the highly exposed group indicated that the highly exposed group had a medium fertility potential. The multifactor variable analysis showed that daily working time was a dangerous factor in sperm abnormality and abstinence time was a dangerous factor in the parameter of SCSA. CONCLUSIONS: Radar radiation inflicts damage to male reproduction system and it is important to take protective measures.

Adolescent↗
PubMed2005

Radar-based alert system to operate a sewerage network: relevance and operational effectiveness after several years of use.

Since January 2000, the sewerage network of a very urbanised catchment area in the Greater Nancy Urban Community has been operated according to the alarms generated in real time by a storm alert system using weather radar data. This alert system is based on an automatic identification of intense rain cells in the radar images. This paper presents the characteristics of this alert system and synthesises the main results of two complementary studies realised in 2002 in order to estimate the relevance and the operational effectiveness of the alert system. The first study consisted in an off-line analysis of almost 50,000 intense rain cells detected in four years of historical radar data. The second study was an analysis of the experience feedback after two years of operational use of this alert system. The results of these studies are discussed in function of the initial operational objectives.

Cities↗
PubMed1979

A study of the health status of radar workers.

The health status was examined of 322 radar workers with a history of occupational exposure in a microwave field from 5-10 years. The clinical findings were compared with a control group of 220 persons. There were no statistically significant differences in clinical and laboratory findings between exposed and control group. Only some subjective complaints were found more frequently in the exposed group than in the control. The authors' feeling is that subjective complaints in radar workers could not be ascribed only to the influence of microwaves because they could be due to other nonspecific harmful occupational factors. On the basis of the results of this work, the authors concluded that it is unlikely to expect marked harmful effects from microwaves in radar workers in normal working conditions.

Aerospace Medicine↗
PubMed1992

The rapid assessment of disease activity in rheumatology (radar) questionnaire. Validity and sensitivity to change of a patient self-report measure of joint count and clinical status.

OBJECTIVE: This study documents the measurement properties of a brief, self-administered questionnaire of disease signs and symptoms in patients with rheumatoid arthritis. METHODS: The Rapid Assessment of Disease Activity in Rheumatology (RADAR) questionnaire assesses joint pain/tenderness and clinical status. One hundred ninety-three pairs of RADAR forms were completed by 45 subjects and their assigned clinician evaluators. RESULTS: Subject-clinician agreement (intraclass correlation coefficients [ICC]) for joint pain/tenderness and clinical status ranged from 0.52 to 0.87 (P = 0.0001), with 83% greater than or equal to 0.65. The ICC for change in joint scores over 6 months was 0.83 (P = 0.0001). CONCLUSION: The 2-page RADAR questionnaire produces valid estimates of joint count and clinical status that are sensitive to change.

Adult↗
PubMed1995

Zebrafish Radar: a new member of the TGF-beta superfamily defines dorsal regions of the neural plate and the embryonic retina.

Proper development of metazoan embryos requires cell to cell communications. In many instances, these communications involve diffusible molecules, particularly members of the Transforming Growth Factor beta superfamily. In an effort to identify new members of this superfamily involved in the control of early zebrafish embryogenesis, we have isolated a gene, Radar, which appears to be conserved throughout vertebrate evolution and defines a new subfamily within the superfamily. Its pattern of expression suggests that Radar plays a role in the dorso-ventral polarity of the neural plate, blood islands formation, blood cells differentiation, the establishment of retinal dorso-ventral polarity and/or proper axonal retinotectal projections. Radar expression in ntl homozygous mutants indicates that notochord and hypochord development are intimately linked.

Amino Acid Sequence↗
PubMed2006

Titan Radar Mapper observations from Cassini's T3 fly-by.

Cassini's Titan Radar Mapper imaged the surface of Saturn's moon Titan on its February 2005 fly-by (denoted T3), collecting high-resolution synthetic-aperture radar and larger-scale radiometry and scatterometry data. These data provide the first definitive identification of impact craters on the surface of Titan, networks of fluvial channels and surficial dark streaks that may be longitudinal dunes. Here we describe this great diversity of landforms. We conclude that much of the surface thus far imaged by radar of the haze-shrouded Titan is very young, with persistent geologic activity.

Journal Article↗
PubMed2003

Valid assessment of the clinical features of depression by relatives appears to slip under the RADAR.

OBJECTIVE: We report on the development of an observational measure designed for completion by relatives, the Recent Appearance of Depression Assessed by Relatives (RADAR), and consider its validity. METHOD: One hundred and one patients with a current major depressive episode had a relative or close friend complete the RADAR, while psychiatrists and research assistants collected extensive data. RESULTS: Correlated against both patient self-report and psychiatrist-rated depression severity measures, RADAR scores evidenced poor validity overall. Recent Appearance of Depression Assessed by Relatives scores also failed to differentiate depressive subtypes, in that scores for patients with melancholic depression were not significantly higher than for those with non-melancholic depression. CONCLUSIONS: Results are consistent with previous findings of poor agreement between clinicians and corroborative witnesses in assessing clinical depressive features, and argue against reliance on corroborative witness reports.

Adult↗
PubMed2002

Multiple-return laser radar for three-dimensional imaging through obscurations.

A compact imaging laser radar was constructed and tested to investigate phenomenological issues in targeting, especially cases involving imaging through obscurations such as foliage and camouflage netting. The laser radar employs a Nd:YAG microchip laser that operates at a wavelength of 1.06 microm and produces pulses of 1.2-ns duration at a 3-kHz rate. The detector is a commercial indium gallium arsenide avalanche photodiode. A single computer controls the scanning mirrors and performs the digitization of the returning signal at 2 giga samples/s. A detailed description of the laser radar is presented as well as results from field experiments that examined its range accuracy capability and its ability to image a target through camouflage. Results of data collected from deciduous tree lines are also discussed to characterize the presence and quantity of multiple returns.

Journal Article↗
PubMed2002

Three-dimensional imaging laser radar with a photon-counting avalanche photodiode array and microchip laser.

We have developed a threedimensional imaging laser radar featuring 3-cm range resolution and single-photon sensitivity. This prototype direct-detection laser radar employs compact, all-solid-state technology for the laser and detector array. The source is a Nd:YAG microchip laser that is diode pumped, passively Q-switched, and frequency doubled. The detector is a gated, passively quenched, two-dimensional array of silicon avalanche photodiodes operating in Geigermode. After describing the system in detail, we present a three-dimensional image, derive performance characteristics, and discuss our plans for future imaging three-dimensional laser radars.

Journal Article↗
PubMed2005

Synthetic-aperture imaging laser radar: laboratory demonstration and signal processing.

The spatial resolution of a conventional imaging laser radar system is constrained by the diffraction limit of the telescope's aperture. We investigate a technique known as synthetic-aperture imaging laser radar (SAIL), which employs aperture synthesis with coherent laser radar to overcome the diffraction limit and achieve fine-resolution, long-range, two-dimensional imaging with modest aperture diameters. We detail our laboratory-scale SAIL testbed, digital signal-processing techniques, and image results. In particular, we report what we believe to be the first optical synthetic-aperture image of a fixed, diffusely scattering target with a moving aperture. A number of fine-resolution, well-focused SAIL images are shown, including both retroreflecting and diffuse scattering targets, with a comparison of resolution between real-aperture imaging and synthetic-aperture imaging. A general digital signal-processing solution to the laser waveform instability problem is described and demonstrated, involving both new algorithms and hardware elements. These algorithms are primarily data driven, without a priori knowledge of waveform and sensor position, representing a crucial step in developing a robust imaging system.

Journal Article↗
PubMed2004

Unification of radar phenomena as spacetime curvature: prediction and observation of an affine-phase effect.

The many properties of radar echoes and other radiative systems were recently described by Gabriel [J. Opt. Soc. Am. A 19, 946 (2002)] as lower-dimensional projections of simple forms in special relativity. A broader treatment including coherent phenomena is summarized, in which the phase properties of radar images and interferograms are also shown to have a simple unified structure. Their apparent complexity is a result of projection onto the lower dimension(s) of the observation. A predicted new property, locally scalable (affine) phase, is observed in a radar interferogram.

Journal Article↗
PubMed1999

[The radar chart method and its analysis as a comprehensive geriatric assessment system for elderly disabled patients].

In order to simply express the results of comprehensive geriatric assessment (CGA) for elderly disabled patients, we tried to develop a CGA system using a radar chart method in 50 patients (age 73-101, mean 85 +/- 5.4) admitted to our hospital during May 1997. Our clinical database for CGA included 7 major factors (diagnosis, mental function, physical function, nutritional state, complication, coronary risk factors, social background). Finally, the radar chart was made from the results of 6 scored factors other than diagnosis and the correlation was examined statistically between these factors. This study suggests that: (1) the radar chart method display of CGA is useful for all medical staff to understand the results of CGA for elderly disabled patients and the characteristic patterns of each disease, (2) because significant positive correlations were found between 3 factors (mental, physical, nutritional) in patients with cerebrovascular disease (CVD), a more global strategy for medical care planning, especially for treatment, nursing care and rehabilitation program is necessary in patients with CVD, (3) in patients with Alzheimer's disease (AD), significant positive correlation was found only between physical and nutritional factors; mental factors showed significant negative correlation only with the duration of morbidity and as a result, quality of life is a more important problem for planning care of patients with AD, (4) for elderly disabled patients, nutritional assessment and nutritional care planning are very important as well as mental and physical care planning.

Aged↗
PubMed1993

Doppler radar device as a useful tool to quantify the liveliness of the experimental animal.

The Doppler radar device which is described here is shown to be a reliable and accurate device to quantify the liveliness of an experimental rat. During recording the animal did not seem to be disturbed in any way by the device. It could stay in its normal cage, move freely, walk around and eat and drink ad libitum. Measurement did not require extra light, sound or other stimuli. Interpretation of the data was easy. The computer which samples the Doppler radar output signal generates activity curves which were easily interpreted for different ranges of vitality, varying between high liveliness and apnoea or cardiac arrest. The apparatus is low priced, and simple to build and use.

Animals↗
PubMed1992

Are radar detector users less safe than nonusers?

One hundred and seventy-four drivers who had purchased special insurance coverage during 1988-1989 for in-vehicle equipment that included a radar detector were compared to a similarly sized and sociodemographically stratified driver population random sample. It was found that the radar detector owners had significantly more accident claims and speeding convictions during the period 1986-1989 than those representing the general driver population.

Accidents, Traffic↗
PubMed1985

Doppler shift radar monitoring of activity of rats in a behavioural test situation.

The present study investigates the use of an activity monitoring system based upon Doppler shift radar for monitoring general activity of rats in a standard open field test situation. Significant positive correlations were found between the radar activity counts and the conventional lines crossed measure of activity. On the basis of these correlations it is suggested that this method of activity monitoring might be used in conjunction with other behavioural test situations. Further potential benefits of this activity monitoring system are discussed.

Animals↗
PubMedDate not supplied

Overview of independent component analysis technique with an application to synthetic aperture radar (SAR) imagery processing.

We present an overview of independent component analysis, an emerging signal processing technique based on neural networks, with the aim to provide an up-to-date survey of the theoretical streams in this discipline and of the current applications in the engineering area. We also focus on a particular application, dealing with a remote sensing technique based on synthetic aperture radar imagery processing: we briefly review the features and main applications of synthetic aperture radar and show how blind signal processing by neural networks may be advantageously employed to enhance the quality of remote sensing data.

Neural Networks, Computer↗
PubMed2003

Monitoring of landfill leachate dispersion using reflectance spectroscopy and ground-penetrating radar.

The utility of ground-penetrating radar and reflectance spectroscopy in the monitoring of landfill sites has been investigated. Strong correlations between red edge inflection position and chlorophyll and heavy metal concentrations have been demonstrated from grassland species affected by leachate contamination of the soil adjacent to the landfill test site. This study demonstrated that reflectance spectroscopy can identify vegetation affected by leachate-contaminated soil at a range of spatial resolutions. To identify the vegetation affected by leachate contamination, the spectroradiometer must have contiguous bands at sufficient spectral resolution over the critical wave range that measures chlorophyll absorption and the red edge (between 650 and 750 nm). The utility of ground-penetrating radar data to identify leachate escaping from breakout points in the contaminant wall has also been demonstrated. An integrated approach using these techniques, combined with field and borehole sampling and contaminant migration modeling, offers a possible cost-effective monitoring approach for landfill sites.

Chlorophyll↗
PubMed2003

Radar observations of the autumn migration of the beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) and other moths in northern China.

The autumn return migration of the beet armyworm Spodoptera exigua Hübner and other insects in northern China was observed with radar and with a simultaneously-operated searchlight trap and ground light-trap at a site in Langfang, near Beijing. The searchlight trap was found to be an efficient tool for trapping migrants and, operated alongside a ground light-trap, could distinguish migrant from locally-flying species. It was confirmed that S. exigua and some other species were high-altitude nocturnal windborne migrants during September and October in northern China. Maximum density of moths typically occurred below 500 m, and strong layering was often observed at about 200 m above ground level in airflows that would carry the moths towards the south. Descent of S. exigua in the vicinity of the radar site in late September was often associated with rain.

Animal Migration↗