1,297 research outputs found
Minactivin expression in human monocyte and macrophage populations
Adherent monolayer cultures of human blood monocytes, peritoneal macrophages, bone marrow macrophages, and colonic mucosa macrophages were examined for their ability to produce and secrete minactivin, a specific inactivator of urokinase-type plasminogen activator. All except colonic mucosa macrophages produced and secreted appreciable amounts of minactivin, but only blood monocytes were stimulated by muramyl dipeptide (adjuvant peptide) to increase production. The minactivin from each of these populations could be shown to preferentially inhibit urokinase-type plasminogen activator and not trypsin, plasmin, or 'tissue'-type plasminogen activator (HPA66). A plasminogen-activating enzyme present in monocyte cultures appeared unaffected by the presence of minactivin and could be shown to be regulated independently by dexamethasone
Comment on "Evidence for Neutrinoless Double Beta Decay"
We comment on the recent claim for the experimental observation of
neutrinoless double-beta decay. We discuss several limitations in the analysis
provided in that paper and conclude that there is no basis for the presented
claim.Comment: A comment written to Modern Physics Letters A. 4 pages, no figures.
Updated version, accepted for publicatio
First E region observations of mesoscale neutral wind interaction with auroral arcs
We report the first observations of E region neutral wind fields and their interaction with auroral arcs at mesoscale spatial resolution during geomagnetically quiet conditions at Mawson, Antarctica. This was achieved by using a scanning Doppler imager, which can observe thermospheric neutral line-of-sight winds and temperatures simultaneously over a wide field of view. In two cases, the background E region wind field was perpendicular to an auroral arc, which when it appeared caused the wind direction within âŒ50 km of the arc to rotate parallel along the arc, reverting to the background flow direction when the arc disappeared. This was observed under both westward and eastward plasma convection. The wind rotations occurred within 7â16 min. In one case, as an auroral arc propagated from the horizon toward the local zenith, the background E region wind field became significantly weaker but remained unaffected where the arc had not passed through. We demonstrate through modeling that these effects cannot be explained by height changes in the emission layer. The most likely explanation seems to be the greatly enhanced ion drag associated with the increased plasma density and localized ionospheric electric field associated with auroral arcs. In all cases, the F region neutral wind appeared less affected by the auroral arc, although its presence is clear in the data
Chemical carcinogenicity revisited 2: Current knowledge of carcinogenesis shows that categorization as a carcinogen or non-carcinogen is not scientifically credible
Abstract Developments in the understanding of the etiology of cancer have undermined the 1970s concept that chemicals are either "carcinogens" or "non-carcinogens". The capacity to induce cancer should not be classified in an inflexible binary manner as present (carcinogen) or absent (non-carcinogen). Chemicals may induce cancer by three categories of mode of action: direct interaction with DNA or DNA replication including DNA repair and epigenetics; receptor-mediated induction of cell division; and non-specific induction of cell division. The long-term rodent bioassay is neither appropriate nor efficient to evaluate carcinogenic potential for humans and to inform risk management decisions. It is of questionable predicitiveness, expensive, time consuming, and uses hundreds of animals. Although it has been embedded in practice for over 50 years, it has only been used to evaluate less than 5% of chemicals that are in use. Furthermore, it is not reproducible because of the probabilisitic nature of the process it is evaluating combined with dose limiting toxicity, dose selection, and study design. The modes of action that lead to the induction of tumors are already considered under other hazardous property categories in classification (Mutagenicity/Genotoxicity and Target Organ Toxicity); a separate category for Carcinogenicity is not required and provides no additional public health protection
Project 8 Phase III Design Concept
We present a working concept for Phase III of the Project 8 experiment,
aiming to achieve a neutrino mass sensitivity of ( C.L.)
using a large volume of molecular tritium and a phased antenna array. The
detection system is discussed in detail.Comment: 3 pages, 3 figures, Proceedings of Neutrino 2016, XXVII International
Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, U
- âŠ