The ADP/FS frame survey of Lake Kyoga and Lake Kwania

The report provides a summary of the frame survey results carried out in lakes Kyoga and Kwania in 1990. The ADP Fisheries Survey of Lake Kyoga is charged with a stock-assessment programme. The term stock-assessment is generally used to express the need of fisheries managers for knowledge on fish stocks which are allegedly over-exploited already. Stock-assessment can be very comprehensive, costly and time-consuming. Essentially however, investigations into exploited stocks and the fishery should provide viable answers to the questions of management at the shortest possible notice. Surveys should in any case provide indications concerning the rate of exploitation. That requires the execution of a catch assessment survey (CAS)

The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections

We present the final data release of observations of lambda 21-cm emission from Galactic neutral hydrogen over the entire sky, merging the Leiden/Dwingeloo Survey (LDS: Hartmann & Burton, 1997) of the sky north of delta = -30 deg with the Instituto Argentino de Radioastronomia Survey (IAR: Arnal et al., 2000, and Bajaja et al., 2005) of the sky south of delta = -25 deg. The angular resolution of the combined material is HPBW ~ 0.6 deg. The LSR velocity coverage spans the interval -450 km/s to +400 km/s, at a resolution of 1.3 km/s. The data were corrected for stray radiation at the Institute for Radioastronomy of the University of Bonn, refining the original correction applied to the LDS. The rms brightness-temperature noise of the merged database is 0.07 - 0.09 K. Residual errors in the profile wings due to defects in the correction for stray radiation are for most of the data below a level of 20 - 40 mK. It would be necessary to construct a telescope with a main beam efficiency of eta_{MB} > 99% to achieve the same accuracy. The merged and refined material entering the LAB Survey of Galactic HI is intended to be a general resource useful to a wide range of studies of the physical and structural characteristices of the Galactic interstellar environment. The LAB Survey is the most sensitive Milky Way HI survey to date, with the most extensive coverage both spatially and kinematically.Comment: 9 pages, 5 figures, accepted for publication by Astronomy & Astrophysic

Radio intensity and polarization distributions of quasars at three frequencies

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

Radio intensity and polarization distributions of quasars at three frequencies

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

Yellowing disease of 'family 41' sugar beet

In a preliminary note, Clinch, Loughnane and McKay describe a yellowing disease in a breeder's 'pure line' of sugar beet (family 41), which is transmissible through the seed and also by the aphis, Myzus persicœ. Recently, Clinch and Loughnane have published a paper2 on this disease with the title "Seed Transmission of Virus Yellows of Sugar Beet and the Existence of Strains of this Virus in Eire". This title is, in our opinion, misleading, for it suggests that sugar beet yellows virus is transmitted by seed. There is, on the contrary, much evidence that it is not, and though the yellowing of family 41 may be transmitted through the seed, there is nothing to show that the condition is caused by beet yellows virus

Geometrically non-linear behaviour of a bar with shear deformation

This article consists of two parts. The first part (section 2) deals with the bar without bending deformation, in which only shear deformation occurs. Such a bar may serve as a simplified model for the frame in a high-rise building. To investigate the properties required of the model we will look in more detail at the behaviour of a single storey taken out of the frame. The second part (section 3) deals with the bar in which both shear deformation and bending deformation occur. The influence of the shear rigidity on the buckling load of a simply supported bar is investigated.Civil Engineering and Geoscience