The influence of the phosphorus and calcium content of feeds on growth, feed conversion and slaughter quality, and on the chemical, mechanical and histological parameters of the bone tissue of pigs.

In a 2 X 4 factorial experiment on 96 individually housed pigs, 2 calcium/phosphorus ratios (1.3 and 1.9) and 4 phosphorus levels (0.4, 0.5, 0.6, 0.7% total P) were tested. The influence of the treatments on growth, feed conversion and slaughter quality was measured. The experiment showed the 1.3 Ca/P ratio to be more favourable than the 1.9 ratio. A P content of 0.6% was sufficient for good growth and favourable feed conversion. The quality of the bone tissue, for which the specific response resistance to distortion and breaking was used as a standard, was close to maximum when P in the feed was 0.6%. The strength of the whole bone, measured as the bending moment for distortion and breaking, was greatest when P was highest; mineralization of the bone also showed a further increase when the P content in the feed increased from 0.6 to 0.7%.During the experiment only a few cases of leg weakness were noted; these occurred throughout all the experimental treatments. On the basis of the results, the P and Ca requirements for optimal growth and feed conversion for the modern Dutch pig are 0.6% and 0.78%. More of these minerals in the feed may, however, increase deposition in the skeleton. (Abstract retrieved from CAB Abstracts by CABI’s permission

Data communication at the CERN computer centre

The growing interest for on-line computer service and process control at CERN decentralises certain computer activities. Small process computers, remote batch stations and user terminals are to be backed by a powerful central computer. The present data network is principally star shaped. At the centre of it is a CDC 6600-6500 computer combination. It has a front end CDC 3100 computer with a Hewlett Packard 2116 as multiplexer. Some details about the fast parallel connections between the CDC 3100 and the HP 2116B are given in the paper, as well as descriptions of some computer simulation techniques used to test the present systems. Finally some plans on a future network are given. (12 refs)

A reversion of an IL2RG mutation in combined immunodeficiency providing competitive advantage to the majority of CD8+ T cells

Mutations in the common gamma chain (γc, CD132, encoded by the IL2RG gene) can lead to B+T-NK-X-linked severe combined immunodeficiency, as a consequence of unresponsiveness to γc-cytokines such as interleukins-2, -7 and -15. Hypomorphic mutations in CD132 may cause combined immunodeficiencies with a variety of clinical presentations. We analyzed peripheral blood mononuclear cells of a 6-year-old boy with normal lymphocyte counts, who suffered from recurrent pneumonia and disseminated mollusca contagiosa. Since proliferative responses of T cells and NK cells to γc -cytokines were severely impaired, we performed IL2RG gene analysis, showing a heterozygous mutation in the presence of a single X-chromosome. Interestingly, an IL2RG reversion to normal predominated in both naïve and antigen-primed CD8+ T cells and increased over time. Only the revertant CD8+T cells showed normal expression of CD132 and the various CD8+T cell populations had a different T-cell receptor repertoire. Finally, a fraction of γδ+T cells and differentiated CD4+CD27-effector-memory T cells carried the reversion, whereas NK or B cells were repeatedly negative. In conclusion, in a patient with a novel IL2RG mutation, gene-reverted CD8+T cells accumulated over time. Our data indicate that selective outgrowth of particular T-cell subsets may occur following reversion at the level of committed T progenitor cells

Ratings and rankings: Voodoo or Science?

Composite indicators aggregate a set of variables using weights which are understood to reflect the variables' importance in the index. In this paper we propose to measure the importance of a given variable within existing composite indicators via Karl Pearson's `correlation ratio'; we call this measure `main effect'. Because socio-economic variables are heteroskedastic and correlated, (relative) nominal weights are hardly ever found to match (relative) main effects; we propose to summarize their discrepancy with a divergence measure. We further discuss to what extent the mapping from nominal weights to main effects can be inverted. This analysis is applied to five composite indicators, including the Human Development Index and two popular league tables of university performance. It is found that in many cases the declared importance of single indicators and their main effect are very different, and that the data correlation structure often prevents developers from obtaining the stated importance, even when modifying the nominal weights in the set of nonnegative numbers with unit sum.Comment: 28 pages, 7 figure