Spectral Properties of Near-Earth Asteroids: Evidence for Sources of Ordinary Chondrite Meteorites

Although ordinary chondrite (OC) meteorites dominate observed falls, the identification of near-Earth and main-belt asteroid sources has remained elusive. Telescopic measurements of 35 near-Earth asteroids ( approximately3 kilometers in diameter) revealed six that have visible wavelength spectra similar to laboratory spectra of OC meteorites. Near-Earth asteroids were found to have spectral properties that span the range between the previously separated domains of OC meteorites and the most common (S class) asteroids, suggesting a link. This range of spectral properties could arise through a diversity of mineralogies and regolith particle sizes, as well as through a time-dependent surface weathering process.     

Inflammatory myofibroblastic tumour in the nasal cavity of a dog

A 4·5‐year‐old, female neutered Leonberger was presented with a 2‐month history of sneezing, nasal discharge and epistaxis. A presumptive diagnosis of nasal aspergillosis was made based on a suspected (fungal) granuloma on rhinoscopic examination and fungal hyphae on cytological examination. A poor response to targeted therapy was observed and computed tomography 16 months after initial presentation revealed a progressive, locally invasive mass lesion. Histopathological and immunohistochemical analysis of deep surgical biopsies revealed a spindle cell population and a plasma cell rich inflammatory infiltrate, with diffuse expression of vimentin, supporting a diagnosis of inflammatory myofibroblastic tumour. Complete resolution of the nasal discharge and reduced sneezing frequency was reported 9 months post‐surgical debridement via rhinotomy. To the authors’ knowledge, this is the first report of IMT in the nasal cavity of a dog. IMT should be considered when presented with a nasal mass lesion, particularly if histopathological features and clinical course are inconsistent.     

Semi-lethality in hybrid offspring of wheat

Summary Seven of the wheat crosses which were performed in 1954 and 1955 produced a uniform semi-lethal F₁. Among these were four combinations with the spring wheat Koga and two with the Turkish winter wheat Eskischir. The degree of withering in the F₁ appeared to be dependent on the variety with which Koga or Eskischir were combined. In the F₂ of the Koga crosses carried out in 1954 a 9 : 7 ratio of semi-lethals and normal plants was found. The almost continuous gradation in semi-lethality within the group of semi-lethal plants of every F₂ was conspicuous.The facts are explained as follows: Two complementary genes determine the semi-lethality as such, while modifying genes are responsible for the different degrees of semi-lethality of the different F₁'s and for the variation in degree of semi-lethality within every F₂. In the discussion this explanation is given in detail.It is pointed out that it is perhaps possible, with the aid of the phenomenon of semi-lethality, to discover or confirm relationships between species and/or varieties.Finally it is suggested that the rejection of F₁'s with withering symptoms is premature.