Skin diseases are common in exotic companion mammal medicine. Some of the diseases are infectious, with potential transmission towards the owners, while others have a metabolic etiology. A list of commonly found dermatologic conditions in exotic companion mammals can be found in Table 1. The approach to skin diseases in exotic companion mammals is similar to that of skin diseases in other compa...

Various generalizations of companion matrices to companion pencils are presented. Companion matrices link to monic polynomials, whereas companion pencils do not require monicity of the corresponding polynomial. In the classical companion pencil case (A,B) only the coefficient of the highest degree appears in B’s lower right corner. We will show, however, that all coefficients of the polynomial ...

We assume that if the sun has a companion, it has a period of 27 Myr corresponding to the periodicity seen in cometary impacts on earth. Based on this assumption, it is seen that the inner Lagrengian point of the interaction between the Sun and its companion is in the Oort cloud. From this we calculate the mass – distance relation for the companion. We then compute the expected apparent magnitu...