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La enfermedad de Hirayama es una rara mielopatía cervical mucho más frecuente en hombres jóvenes, que cursa con atrofia distal en los brazos como primer y principal síntoma. Es importante diferenciarla de las enfermedades de las motoneuronas porque su historia natural es distinta, con tendencia hacia la estabilización en menos de 5 años.

Positron annihilation lifetime and coincidence Doppler broadening measurements have been performed on ultra low carbon steel and Fe–Si alloys with different Si contents (from 3.32 up to 11.1 wt%) in the annealed state and after a deformation of 5% thickness reduction. It was seen that above 5.6 wt% Si the nature of the defects trapping the positron changes. This coincides with the concentration for the onset of long range D03 ordering in the Fe–Si alloys changing the nature of the dislocation structure. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We present far-infrared and submillimetre spectra of three carbon-rich evolved objects, AFGL 2688, AFGL 618 and NGC 7027. The spectra were obtained with the SPIRE Fourier-transform spectrometer on board the HerschelSpace Observatory, and cover wavelengths from 195–670 μm, a region of the electromagnetic spectrum hitherto difficult to study in detail. The far infrared spectra of these objects are rich and complex, and we measure over 150 lines in each object. Lines due to 18 different species are detected. We determine physical conditions from observations of the rotational lines of several molecules, and present initial large velocity gradient models for AFGL 618. We detect water in AFGL 2688 for the first time, and confirm its presence in AFGL 618 in both ortho and para forms. In addition, we report the detection of the J= 1–0 line of CH+in NGC 7027.

We present far-infrared and submillimetre spectra of three carbon-rich evolved objects, AFGL 2688, AFGL 618 and NGC 7027. The spectra were obtained with the SPIRE Fourier-transform spectrometer on board the HerschelSpace Observatory, and cover wavelengths from 195–670 μm, a region of the electromagnetic spectrum hitherto difficult to study in detail. The far infrared spectra of these objects are rich and complex, and we measure over 150 lines in each object. Lines due to 18 different species are detected. We determine physical conditions from observations of the rotational lines of several molecules, and present initial large velocity gradient models for AFGL 618. We detect water in AFGL 2688 for the first time, and confirm its presence in AFGL 618 in both ortho and para forms. In addition, we report the detection of the J= 1–0 line of CH+in NGC 7027.