5,478 research outputs found

    Remote sensing in Iowa agriculture: Identification and classification of Iowa's crops, soils and forestry resources using ERTS-1 and complimentary underflight imagery

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    The author has identified the following significant results. Springtime ERTS-1 imagery covering pre-selected test sites in Iowa showed considerable detail with respect to broad soil and land use patterns. Additional imagery has been incorporated into a state mosaic. The mosaic was used as a base for soil association lines transferred from an existing map. The regions of greatest contrast are between the Clarion-Nicollet-Webster soil association area and adjacent areas. Landscape characteristics in this area result in land use patterns with a high percentage of pasture, hay, and timber. The soil association areas of the state that have patterns interpreted to be associated with intensive row crop production are: Moody, Galva-Primghar-Sac, Clarion-Nicollet-Webter, Tama-Muscatine, Dinsdale-Tama, Cresco-Lourdes, Clyde, Kenyon-Floyd-Clyde, and the Luton-Onawa-Salix area on the Missouri River floodplain. Forestland estimates have been attained for an area in central Iowa using wintertime ERTS-1 imagery. Visual analysis of multispectral, temporal imagery indicates that temporal analysis for cropland identification and acreage analyses procedures may be a very useful tool. Combinations of wintertime, springtime, and summertime ERTS-1 imagery separate most vegetation types. Timing can be critical depending upon crop development and harvesting times because of the dynamic nature of agricultural production

    Risk assessment and risk management of violent reoffending among prisoners

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    “The final publication is available at Springer via http://dx.doi.org/10.1016/j.eswa.2015.05.025”

    The Cataclysmic Variable CW 1045+525: A Secondary-Dominated Dwarf Nova?

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    We present spectroscopic and photometric observations of the cataclysmic variable CW 1045+525. Both the optical spectrum and the photometric lightcurve show a strong contribution of a K5V–M0V secondary. We derive an orbital period Porb = 0.271278(1) d by measuring the radial velocities of the absorption lines of the secondary. The period and spectral type of the secondary suggest a distance of 350–700 pc. There is evidence for additional sources of line- and continuum emission, but no direct evidence of an accretion disc. We discuss several scenarios for the nature of CW 1045+525 on the basis of our results, finding a dwarf nova classification to be the most probable, although not completely satisfying, explanation for the observed characteristics

    Thrombin exosite for fibrinogen recognition is partially accessible in prothrombin.

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    The procoagulant alpha-thrombin is produced by the proteolytic cleavages of a minimum of two peptide bonds Arg274-Thr275 and Arg323-Ile324 in prothrombin. The Arg323-Ile324 cleavage is required for the expression of the active site of thrombin (Morita, T., Iwanaga, S. Suzuki, T. (1976) J. Biochem. (Tokyo) 79, 1089-1108; Hibbard, L. S., Nesheim, M. E., and Mann, K. G. (1982) Biochemistry 21, 2285-2292). It is not yet clear to what extent the proteolytic events are responsible for exposing protein recognition exosites on thrombin. We employed high resolution NMR spectroscopy to examine interactions of prothrombin and thrombin with synthetic hirudin peptides targeted toward the fibrinogen recognition exosite of thrombin. The hirudin tail synthetic analogues (acetyl-Asp55-Phe-Glu-Glu-Ile-Pro-Glu-Glu-Tyr-Leu-Gln65/G ly65-OH) exhibited similar NMR relaxation enhancements (line broadening patterns and transferred nuclear Overhauser effects) with human prothrombin as with human alpha-thrombin, indicating that both proteins bind the peptide in a similar manner. The protein-induced relaxation enhancements are specific to the interaction of the hirudin peptides with the fibrinogen recognition exosite of thrombin since no significant effects were observed with either human serum albumin or with human gamma-thrombin, which has an impaired recognition exosite. The binding affinities were determined from NMR relaxation time measurements, which gave approximate Kd values of 500 microM an

    Nonlinear Magneto-Optical Response of ss- and dd-Wave Superconductors

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    The nonlinear magneto-optical response of ss- and dd-wave superconductors is discussed. We carry out the symmetry analysis of the nonlinear magneto-optical susceptibility in the superconducting state. Due to the surface sensitivity of the nonlinear optical response for systems with bulk inversion symmetry, we perform a group theoretical classification of the superconducting order parameter close to a surface. For the first time, the mixing of singlet and triplet pairing states induced by spin-orbit coupling is systematically taken into account. We show that the interference of singlet and triplet pairing states leads to an observable contribution of the nonlinear magneto-optical Kerr effect. This effect is not only sensitive to the anisotropy of the gap function but also to the symmetry itself. In view of the current discussion of the order parameter symmetry of High-Tc_c superconductors, results for a tetragonal system with bulk singlet pairing for various pairing symmetries are discussed.Comment: 21 pages (REVTeX) with 8 figures (Postscript

    Sexual behaviour in Britain: partnerships, practices, and HIV risk behaviours.

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    BACKGROUND: Sexual behaviour is a major determinant of sexual and reproductive health. We did a National Survey of Sexual Attitudes and Lifestyles (Natsal 2000) in 1999-2001 to provide population estimates of behaviour patterns and to compare them with estimates from 1990-91 (Natsal 1990). METHODS: We did a probability sample survey of men and women aged 16-44 years who were resident in Britain, using computer-assisted interviews. Results were compared with data from respondents in Natsal 1990. FINDINGS: We interviewed 11161 respondents (4762 men, 6399 women). Patterns of heterosexual and homosexual partnership varied substantially by age, residence in Greater London, and marital status. In the past 5 years, mean numbers of heterosexual partners were 3.8 (SD 8.2) for men, and 2.4 (SD 4.6) for women; 2.6% (95% CI 2.2-3.1) of both men and women reported homosexual partnerships; and 4.3% (95% CI 3.7-5.0) of men reported paying for sex. In the past year, mean number of new partners varied from 2.04 (SD 8.4) for single men aged 25-34 years to 0.05 (SD 0.3) for married women aged 35-44 years. Prevalence of many reported behaviours had risen compared with data from Natsal 1990. Benefits of greater condom use were offset by increases in reported partners. Changes between surveys were generally greater for women than men and for respondents outside London. INTERPRETATION: Our study provides updated estimates of sexual behaviour patterns. The increased reporting of risky sexual behaviours is consistent with changing cohabitation patterns and rising incidence of sexually transmitted infections. Observed differences between Natsal 1990 and Natsal 2000 are likely to result from a combination of true change and greater willingness to report sensitive behaviours in Natsal 2000 due to improved survey methodology and more tolerant social attitudes

    Experimental Evidence for the Effect of Small Wind Turbine Proximity and Operation on Bird and Bat Activity

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    The development of renewable energy technologies such as wind turbines forms a vital part of strategies to reduce greenhouse gas emissions worldwide. Although large wind farms generate the majority of wind energy, the small wind turbine (SWT, units generating <50 kW) sector is growing rapidly. In spite of evidence of effects of large wind farms on birds and bats, effects of SWTs on wildlife have not been studied and are likely to be different due to their potential siting in a wider range of habitats. We present the first study to quantify the effects of SWTs on birds and bats. Using a field experiment, we show that bird activity is similar in two distance bands surrounding a sample of SWTs (between 6-18 m hub height) and is not affected by SWT operation at the fine scale studied. At shorter distances from operating turbines (0-5 m), bat activity (measured as the probability of a bat "pass" per hour) decreases from 84% (71-91%) to 28% (11-54%) as wind speed increases from 0 to 14 m/s. This effect is weaker at greater distances (20-25 m) from operating turbines (activity decreases from 80% (65-89%) to 59% (32-81%)), and absent when they are braked. We conclude that bats avoid operating SWTs but that this effect diminishes within 20 m. Such displacement effects may have important consequences especially in landscapes where suitable habitat is limiting. Planning guidance for SWTs is currently lacking. Based on our results we recommend that they are sited at least 20 m away from potentially valuable bat habitat

    On calculating the lengths of water waves.

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    A discussion is given of the physical approximations used in obtaining water wave dispersion relations, which relate wave length and height, period, water depth and current. Several known explicit approximations for the wave length are presented, all of which ignore effects of wave height and current. These are compared and are shown to model the usual linear dispersion relation rather more accurately than it describes the physical problem. A simple approximation is obtained: in terms of wave period T, depth d and gravitational acceleration g, which is exact in the limits of short and long waves, and in the intermediate range has an accuracy always better than 1.7%. Explicit approximations which include the effects of current are presented, plus an algorithm based on Newton's method which converges to engineering accuracy in one evaluation, and requires the specification of a value of current, which is a useful reminder that one is obtaining an approximate solution to an approximate problem, and no great effort should go into refining methods or solutions
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