275,501 research outputs found
Breaking the law: the M_{bh}-M_{spheroid} mass relations for core-Sersic and Sersic galaxies
The popular log-linear relation between supermassive black hole mass, M_bh,
and the dynamical mass of the host spheroid, M_sph, is shown to require a
significant correction. Core galaxies, typically with M_bh > 2x10^8 M_Sun and
thought to be formed in dry merger events, are shown to be well described by a
linear relation for which the median black hole mass is 0.36% - roughly double
the old value of constancy. Of greater significance is that M_bh ~ (M_sph)^2
among the (non-pseudobulge) lower-mass systems: specifically, log[M_bh/M_Sun] =
(1.92+/-0.38)log[M_sph/7x10^{10}M_Sun] + (8.38+/-0.17). `Classical' spheroids
hosting a 10^6 M_Sun black hole will have M_bh/M_sph ~ 0.025%. These new
relations (i) bring consistency to the relation M_bh ~ sigma^5 and the fact
that L ~ sigma^x with exponent x equal to 5 and 2 for bright (M_B < -20.5 mag)
and faint spheroids, respectively, (ii) mimic the non-(log-linear) behavior in
the M_bh-(Sersic n) diagram, (iii) necessitate the existence of a previously
over-looked M_bh ~ L^{2.5} relation for Sersic (i.e.\ not core-Sersic)
galaxies, and (iv) resolve past conflicts (in mass prediction) with the
M_bh-sigma relation at the low-mass end. Furthermore, the bent nature of the
M_bh-M_sph relation for `classical' spheroids will have a host of important
implications that relate to (i) galaxy/black hole formation theories, (ii)
searches for the fundamental black hole scaling relation, (iii) black hole mass
predictions in other galaxies, (iv) alleged pseudobulge detections, (v)
estimates of the black hole mass function and mass density based on luminosity
functions, (vi) predictions for space-based gravitational wave detections,
(vii) connections with nuclear star cluster scaling relations, (viii)
evolutionary studies over different cosmic epochs, (ix) comparisons and
calibrations matching inactive black hole masses with low-mass AGN data, and
more.Comment: 4.5 pages plus reference
How non-linear scaling relations unify dwarf and giant elliptical galaxies
Dwarf elliptical galaxies are frequently excluded from bright galaxy samples
because they do not follow the same linear relations in diagrams involving
effective half light radii R_e or mean effective surface brightnesses _e.
However, using two linear relations which unite dwarf and bright elliptical
galaxies we explain how these lead to curved relations when one introduces
either the half light radius or the associated surface brightness. In
particular, the curved _e - R_e relation is derived here. This and other
previously misunderstood curved relations, once heralded as evidence for a
discontinuity between faint and bright elliptical galaxies at M_B ~ -18 mag,
actually support the unification of such galaxies as a single population whose
structure (i.e. stellar concentration) varies continuously with stellar
luminosity and mass.Comment: 4 pages including 2 figures, to appear in "A Universe of dwarf
galaxies", Conf. Proc. (Lyon, June 14-18, 2010
Oncolytic herpes viruses, chemotherapeutics, and other cancer drugs
Oncolytic viruses are emerging as a potential new way of treating cancers. They are selectively replication-competent viruses that propagate only in actively dividing tumor cells but not in normal cells and, as a result, destroy the tumor cells by consequence of lytic infection. At least six different oncolytic herpes simplex viruses (oHSVs) have undergone clinical trials worldwide to date, and they have demonstrated an excellent safety profile and intimations of efficacy. The first pivotal Phase III trial with an oHSV, talimogene laherparepvec (T-Vec [OncoVex<sup>GM-CSF</sup>]), is almost complete, with extremely positive early results reported. Intuitively, therapeutically beneficial interactions between oHSV and chemotherapeutic and targeted therapeutic drugs would be limited as the virus requires actively dividing cells for maximum replication efficiency and most anticancer agents are cytotoxic or cytostatic. However, combinations of such agents display a range of responses, with antagonistic, additive, or, perhaps most surprisingly, synergistic enhancement of antitumor activity. When synergistic interactions in cancer cell killing are observed, chemotherapy dose reductions that achieve the same overall efficacy may be possible, resulting in a valuable reduction of adverse side effects. Therefore, the combination of an oHSV with “standard-of-care” drugs makes a logical and reasonable approach to improved therapy, and the addition of a targeted oncolytic therapy with “standard-of-care” drugs merits further investigation, both preclinically and in the clinic. Numerous publications report such studies of oncolytic HSV in combination with other drugs, and we review their findings here. Viral interactions with cellular hosts are complex and frequently involve intracellular signaling networks, thus creating diverse opportunities for synergistic or additive combinations with many anticancer drugs. We discuss potential mechanisms that may lead to synergistic interactions
Recommended from our members
Screening For Trauma In the Foster Care Community
Children within the foster care community experience health disparities on a variety of levels, from physical and mental health conditions, developmental delay, and impaired social interactions. Many of these conditions can stem from the experience of trauma or adverse childhood events that color each component of their lives. For healthcare providers to be successful in the assessment and treatment of this community, an understanding of traumatic events and the delivery of trauma-informed care is essential. The complex needs of this community are such that the provision of healthcare must be specialized, multidimensional, and organized. The purpose of this project is to assist in the development of a clinic that specializes in the delivery of primary care to the foster care community, with a focus on screening and assessment for the experience of trauma. Children were screened for child trauma as well as for resiliency behaviors, and a tool for chart review was used to examine current health status and services. With the assistance of stakeholders, meticulous follow up on screening results, referrals and recommendations made ensured that no opportunities were missed to provide the highest quality care for this underserved community
Compactness results for immersions of prescribed Gaussian curvature I - analytic aspects
We extend recent results of Guan and Spruck, proving existence results for
constant Gaussian curvature hypersurfaces in Hadamard manifolds.Comment: New title. Previously, "Constant Gaussian Curvature Hypersurfaces in
Hadamard Manifolds". Mistakes corrected. Introduction revised to reflect
recent developments in the fiel
- …