Critique of Fermionic R\nuMDM and its Scalar Variants

We examine the stability of minimal dark matter (MDM) particle-candidates in the setup in which they participate in radiative neutrino (R\nu) masses. We first point out the existence of an additional renormalizable term in recently proposed R\nuMDM Lagrangian, which violates the claimed accidental Z_2 symmetry and spoils the stability of the fermionic MDM quintuplet component. We then explore the viability of R$\nu$MDM variants based on scalar MDM multiplets. There are ubiquitous super-renormalizable terms in the scalar potential which make these scalar multiplets unstable.Comment: 9 pages, 4 figures, corresponds to published versio

Growth of Neanderthal infants from Krapina (120-130 ka), Croatia

Modern humans have a slow and extended period of childhood growth but to what extent this ontogenetic pathway was present in Neanderthals is debated. Dental development, linked to the duration of somatic growth across modern primates, is the main source for information about growth and development in a variety of fossil primates, including humans. Studies of Neanderthal permanent teeth report a pace of development either similar to recent humans or relatively accelerated. Neanderthal milk teeth, which form and emerge before permanent teeth, provide an opportunity to determine which pattern was present at birth. Here we present a comparative study of the prenatal and early postnatal growth of five milk teeth from three Neanderthals (120,000-130,000 years ago) using virtual histology. Results reveal regions of their milk teeth formed quickly before birth, and over a relatively short period of time after birth. Tooth emergence commenced towards the earliest end of the eruption schedules displayed by extant human children. Advanced dental development is consistent with expectations for Neanderthal infant feeding