Analyses immunoélectrophorétiques des fractions protéiques du sérum humain séparées par électrophorèse en gel d'amidon

Summary Human plasma components, separated by starch gel electrophoresis, are eluted and concentrated by lyophilisation. Immuno-electrophoretic analysis shows that certain of these fractions are immunologically heterogenous. The authors point out that this immunological criterium should be used before employing an eluted fraction, even if it appears electrophoretically homogenous.      

Accelerated synaptic transmission in nucleus ventralis-postero-lateralis during deep sleep

Conclusion It is clear that during deep sleep the response evoked in the somatosensory cortex of the cat by shocks to the cutaneous nerve or medial lemniscus is not only higher² but has a shorter latency as well. Our experiments demonstrate that this decrease in latency occurs during transmission through the nucleus VPL. No change in synaptic transmission time was observed in nuclei gracilis and cuneatus or in the cortex itself.

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Riassunto La latenza delle risposte evocate nella corteccia somatica sia da stimolazione cutanea che del lemnisco mediale diminuisce significativamente con 1'aumentare della profondità del sonno. Tale fenomeno è dovuto ad una accelerata trasmissione degli impulsi ascendenti a livello del nucleo ventro-postero-laterale del talamo.

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Parts of these results have been presented at a meeting of the Società italiana di Biologia sperimentale, held in Genoa on February 12, 1965.     

Birth of a relativistic outflow in the unusual γ-ray transient Swift J164449.3+573451

Active galactic nuclei, which are powered by long-term accretion onto central supermassive black holes, produce relativistic jets with lifetimes of at least one million years, and the observation of the birth of such a jet is therefore unlikely. Transient accretion onto a supermassive black hole, for example through the tidal disruption of a stray star, thus offers a rare opportunity to study the birth of a relativistic jet. On 25 March 2011, an unusual transient source (Swift J164449.3+573451) was found, potentially representing such an accretion event. Here we report observations spanning centimetre to millimetre wavelengths and covering the first month of evolution of a luminous radio transient associated with Swift J164449.3+573451. The radio transient coincides with the nucleus of an inactive galaxy. We conclude that we are seeing a newly formed relativistic outflow, launched by transient accretion onto a million-solar-mass black hole. A relativistic outflow is not predicted in this situation, but we show that the tidal disruption of a star naturally explains the observed high-energy properties and radio luminosity and the inferred rate of such events. The weaker beaming in the radio-frequency spectrum relative to γ-rays or X-rays suggests that radio searches may uncover similar events out to redshifts of z?≈?6.     

Mitochondrial point mutations do not limit the natural lifespan of mice

Whether mitochondrial mutations cause mammalian aging, or are merely correlated with it, is an area of intense debate. Here, we use a new, highly sensitive assay to redefine the relationship between mitochondrial mutations and age. We measured the in vivo rate of change of the mitochondrial genome at a single-base pair level in mice, and we demonstrate that the mutation frequency in mouse mitochondria is more than ten times lower than previously reported. Although we observed an 11-fold increase in mitochondrial point mutations with age, we report that a mitochondrial mutator mouse was able to sustain a 500-fold higher mutation burden than normal mice, without any obvious features of rapidly accelerated aging. Thus, our results strongly indicate that mitochondrial mutations do not limit the lifespan of wild-type mice.