A new type of hybrid sterility was investigated in D. melanogaster . Matings between strain 27 males from Para Wirra, South Australia, and Canton-S females produce 70-80% fully sterile male and female progeny. Strain 27 males produce sterile progeny when crossed to females of other geographic origins, but produce fertile progeny when crossed to a second sympatric strain. The sterility is avoide...

By combining data from cosmic microwave background (CMB) experiments (including the recent BOOMERANG-2K2 results), large scale structure (LSS) and Lyman-α forest observations, we constrain the hypothesis of a fourth, sterile, massive neutrino. For the 3 massless + 1 massive neutrino case we bound the mass of the sterile neutrino to ms < 0.55eV at 95% c.l.. These results exclude at high signific...

The three massless active (doublet) neutrinos may mix with two heavy and one light sterile (singlet) neutrinos so that the induced masses and mixings among the former are able to explain the present data on atmospheric and solar neutrino oscillations. If the LSND result is also to be explained, one active neutrino mass eigenstate must mix with the light sterile neutrino. A specific model is pro...

Model-building issues raised by the prospect of light sterile neutrinos are discussed in a pedagogical way. I first review the näıve proposal that sterile neutrinos be identified with “right handed neutrinos”. A critical discussion of the simple expedient of adding three gauge singlet fermions to the usual minimal standard model matter content is followed by an examination of right handed neutr...

A simple model to accomodate light sterile neutrinos naturally with large mixing with the usual neutrinos has been proposed. The standard model gauge group is extended to include an SU(2)S gauge symmetry. Heavy triplet higgs scalars give small masses to the lefthanded neutrinos, while a heavy doublet higgs scalar give mixing with the sterile neutrinos of the same order of magnitude. The neutrin...

A new technique for sorting male and female mosquito larvae may lead to the use of sterile males in tackling malaria. Nigel Williams reports. the testicles of the male mosquitoes fluorescent, allowing the scientists to distinguish and easily separate them from females. The plan is to breed, sterilize and release millions of these male insects so they mate with females but produce no offspring. ...

Using a rabbit sterile peritonitis model, we compared the penetration of intravenously administered amikacin, gentamicin, and penicillin G into peritoneal exudate. Peritonitis was induced with sterile normal saline, and the peritoneal exudate contained 23,751 ± 3,039 granulocytes 8 h later. Antibiotics were administered intravenously 3 h after initiating peritonitis, and serum and peritoneal fl...

Neutrino masses are likely to be a manifestation of the right-handed, or sterile neutrinos. The number of sterile neutrinos and the scales of their Majorana masses are unknown. We explore theoretical arguments in favor of the high and low scale seesaw mechanisms, review the existing experimental results, and discuss the astrophysical hints regarding sterile neutrinos. 1. Sterile neutrinos in pa...

1 Cell Biology, IRCCS AOU San Martino IST, Genova, Italy 2 University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA 3 University of Massachusetts Medical School, Worcester, MA, USA 4 Institute of Innate Immunity, University of Bonn, Bonn, Germany 5 Vita Salute San Raffaele University, Milano, Italy 6 San Raffaele Scientific Institute, Milano, Italy *Correspondence: anna.rubartelli@hsanmar...

The study of immune responses in Drosophila has already yielded significant results with impacts on our understanding of vertebrate immunity, such as the characterization of the Toll receptor. Several recent papers have focused on the humoral response to damage signals rather than pathogens, particularly damage signals from tumour-like tissues generated by loss of cell polarity or chromosomal i...