Galin N.,University College London |
Wingham D.J.,University College London |
Cullen R.,Vega Space Ltd. |
Fornari M.,New Technology Center |
And 2 more authors.
IEEE Transactions on Geoscience and Remote Sensing | Year: 2013
This paper describes the calibration of the CryoSat-2 interferometer, whose principal purpose is to accurately measure the height of the Antarctic and Greenland ice sheets. A sequence of CryoSat-2 data acquisitions over the tropical and midlatitude oceans were obtained between June and September 2010, from the SIRAL 'A' and redundant SIRAL 'B' radars operating in their 'SARIN' mode, during a sequence of satellite rolls between-0.6° and 0.4°. Using the arrival angle of the echo relative to the interferometer baseline, the attitude of the satellite determined by the star trackers, and estimates of the ocean surface across-track slope from the EGM08 geoid, we determined the errors in the interferometer estimate of surface slope as functions of the roll angle and ocean surface waveheight. These were found to be in close agreement with the theoretical description. The scale factor of the interferometric measurement of angle was determined to be 0.973 ± 0.002. We estimate the accuracy of the across-track slope measurement of the interferometer by applying this scale factor to the measured phase. In applying this scale factor to the measurements, the across-track slope of the marine geoid was obtained with an accuracy of 26 μrad at 10 km and 10 μrad at 1000 km. We conclude that the instrument performance considerably exceeds that needed for the accurate determination of height over the sloping surfaces of the continental ice sheets. The results also demonstrate that CryoSat-2 provides the first observations of the instantaneous vector gradient of the ocean surface, and that the normal-incidence interferometric configuration has a greater potential for the measurement of the ocean across-track slope than has been previously recognized. © 2012 IEEE.
Chaudhari R.S.,Institute of Chemical Technology |
Mankumare V.B.,Institute of Chemical Technology |
Shankaranarayanan J.,OmniActive Health Technologies Ltd. |
Shankaranarayanan J.,New Technology Center |
And 5 more authors.
PharmaNutrition | Year: 2014
Recent studies show that high intake of carotenoids is helpful in preventing bone loss in post-menopausal women. Carotenoids like β-cryptoxanthin increases calcium and phosphorus deposition in cultured osteoblasts. β-Cryptoxanthin is also reported to have anabolic property in cultured osteoblast cells. It can also inhibit bone resorption process. Paprika and its dietary products are rich in carotenoids like β-cryptoxanthin. Carotenoids from the paprika oleoresin are also reported to have very good bioavailability in humans. The present study was carried out to investigate the effect of β-cryptoxanthin rich paprika extract on animal model of ovariectomy induced bone loss. Treatment with the test drug was given for 6 weeks. The β-cryptoxanthin rich paprika extract significantly reduced urinary excretion of pyridinium crosslinks, indicating its probable anti-resorptive property. The mechanical strength and density of cancellous bones are significantly improved. Thus the paprika extract may have potential role as a sustainable nutritional approach to improving bone health in post-menopausal condition. © 2014 Elsevier B.V.
Hastie G.D.,University of St. Andrews |
Hastie G.D.,New Technology Center |
Donovan C.,University of St. Andrews |
Gotz T.,University of St. Andrews |
Janik V.M.,University of St. Andrews
Marine Pollution Bulletin | Year: 2014
The use of high frequency sonar is now commonplace in the marine environment. Most marine mammals rely on sound to navigate, and for detecting prey, and there is the potential that the acoustic signals of sonar could cause behavioral responses. To investigate this, we carried out behavioral response tests with grey seals to two sonar systems (200 and 375. kHz systems). Results showed that both systems had significant effects on the seals behavior; when the 200. kHz sonar was active, seals spent significantly more time hauled out and, although seals remained swimming during operation of the 375. kHz sonar, they were distributed further from the sonar. The results show that although peak sonar frequencies may be above marine mammal hearing ranges, high levels of sound can be produced within their hearing ranges that elicit behavioral responses; this has clear implications for the widespread use of sonar in the marine environment. © 2013 Elsevier Ltd.
King S.L.,New Technology Center |
King S.L.,University of St. Andrews |
Schick R.S.,University of St. Andrews |
Donovan C.,DMP Statistics |
And 5 more authors.
Methods in Ecology and Evolution | Year: 2015
Changes in natural patterns of animal behaviour and physiology resulting from anthropogenic disturbance may alter the conservation status of a population if they affect the ability of individuals to survive, breed or grow. However, information to forecast population-level consequences of such changes is often lacking. We developed an interim framework to assess the population consequences of disturbance when empirical information is sparse. We show how daily effects of disturbance, which are often straightforward to estimate, can be scaled to the disturbance duration and to multiple sources of disturbance. We used expert elicitation to estimate parameters that define how changes in individual behaviour or physiology affect vital rates and incorporated them into a stochastic population model. Model outputs can be used to evaluate cumulative impacts of disturbance over space and time. As an example, we forecast the potential effects of disturbance from offshore wind farm construction on the North Sea harbour porpoise (Phocoena phocoena) population. Synthesis and applications. The interim framework can be used to forecast the effects of disturbances from human activities on animal populations, to assess the effectiveness of mitigation measures and to identify priority areas for research that reduces uncertainty in population forecasts. The last two applications are likely to be important in situations where there is a risk of unacceptable change in a species' conservation status. The framework should, however, be augmented with empirical data as soon as these are available. © 2015 British Ecological Society.