Quantum Informational Dark Energy: Dark energy from forgetting

We suggest that dark energy has a quantum informational origin. Landauer's principle associated with the erasure of quantum information at a cosmic horizon implies the non-zero vacuum energy having effective negative pressure. Assuming the holographic principle, the minimum free energy condition, and the Gibbons-Hawking temperature for the cosmic event horizon we obtain the holographic dark energy with the parameter $d\simeq 1$, which is consistent with the current observational data. It is also shown that both the entanglement energy and the horizon energy can be related to Landauer's principle.Comment: revtex,8 pages, 2 figures more detailed arguments adde

Analysis of the Consistency of a Mixed Integer Programming-based Multi-Category Constrained Discriminant Model

Classification is concerned with the development of rules for the allocation of observations to groups, and is a fundamental problem in machine learning. Much of previous work on classification models investigates two-group discrimination. Multi-category classification is less-often considered due to the tendency of generalizations of two-group models to produce misclassification rates that are higher than desirable. Indeed, producing “good” two-group classification rules is a challenging task for some applications, and producing good multi-category rules is generally more difficult. Additionally, even when the “optimal” classification rule is known, inter-group misclassification rates may be higher than tolerable for a given classification model. We investigate properties of a mixed-integer programming based multi-category classification model that allows for the pre-specification of limits on inter-group misclassification rates. The mechanism by which the limits are satisfied is the use of a reserved judgment region, an artificial category into which observations are placed whose attributes do not sufficiently indicate membership to any particular group. The method is shown to be a consistent estimator of a classification rule with misclassification limits, and performance on simulated and real-world data is demonstrated

A Polyhedral Approach to the Multi-Layer Crossing Minimization Problem

We study the multi-layer crossing minimization problem from a polyhedral point of view. After the introduction of an integer programming formulation of the multi-layer crossing minimization problem, we examine the 2-layer case and derive several classes of facets of the associated polytope. Preliminary computational results for 2- and 3-layer instances indicate, that the usage of the corresponding facet-defining inequalities in a branch-and-cut approach may only lead to a practically useful algorithm, if deeper polyhedral studies are conducted

The first international workshop on the role and impact of mathematics in medicine: a collective account

The First International Workshop on The Role and Impact of Mathematics in Medicine (RIMM) convened in Paris in June 2010. A broad range of researchers discussed the difficulties, challenges and opportunities faced by those wishing to see mathematical methods contribute to improved medical outcomes. Finding mechanisms for inter- disciplinary meetings, developing a common language, staying focused on the medical problem at hand, deriving realistic mathematical solutions, obtainin

The Fine Line Between Normal and Starburst Galaxies

Recent literature suggests that there are two modes through which galaxies grow their stellar mass - a normal mode characterized by quasi-steady star formation, and a highly efficient starburst mode possibly triggered by stochastic events such as galaxy mergers. While these differences are established for extreme cases, the population of galaxies in-between these two regimes is poorly studied and it is not clear where the transition between these two modes of star formation occurs. We utilize ALMA observations of the CO J=3-2 line luminosity in a sample of 20 infrared luminous galaxies that lie in the intermediate range between normal and starburst galaxies at z ~ 0.25-0.6 in the COSMOS field to examine the gas content and star formation efficiency of these galaxies. We compare these quantities to the galaxies' deviation from the well-studied "main sequence" correlation between star formation rate and stellar mass (MS) and find that at log($SFR/SFR_{MS}$) < 0.6, a galaxy's distance to the main sequence is mostly driven by increased gas content, and not a more efficient star formation process.Comment: 21 pages, 10 figure

Complex Radio Spectral Energy Distributions in Luminous and Ultraluminous Infrared Galaxies

We use the Expanded Very Large Array to image radio continuum emission from local luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) in 1 GHz windows centered at 4.7, 7.2, 29, and 36 GHz. This allows us to probe the integrated radio spectral energy distribution (SED) of the most energetic galaxies in the local universe. The 4-8 GHz flux densities agree well with previous measurements. They yield spectral indices \alpha \approx -0.67 (where F_\nu \propto \nu^\alpha) with \pm 0.15 (1\sigma) scatter, typical of nonthermal (synchrotron) emission from star-forming galaxies. The contrast of our 4-8 GHz data with literature 1.5 and 8.4 GHz flux densities gives further evidence for curvature of the radio SED of U/LIRGs. The SED appears flatter near \sim 1 GHz than near \sim 6 GHz, suggesting significant optical depth effects at the lower frequencies. The high frequency (28-37 GHz) flux densities are low compared to extrapolations from the 4-8 GHz data. We confirm and extend to higher frequency a previously observed deficit of high frequency radio emission for luminous starburst galaxies.Comment: 7 pages, 3 figures, 1 table, accepted for publication in the EVLA Special Issue of ApJ Letter

Induction of Alloantigen-specific Anergy in Human Peripheral Blood Mononuclear Cells by Alloantigen Stimulation with Co-stimulatory Signal Blockade

Allogeneic hematopoietic stem cell transplantation (AHSCT) offers the best chance of cure for many patients with congenital and acquired hematologic diseases. Unfortunately, transplantation of alloreactive donor T cells which recognize and damage healthy patient tissues can result in Graft-versus-Host Disease (GvHD)1. One challenge to successful AHSCT is the prevention of GvHD without associated impairment of the beneficial effects of donor T cells, particularly immune reconstitution and prevention of relapse. GvHD can be prevented by non-specific depletion of donor T cells from stem cell grafts or by administration of pharmacological immunosuppression. Unfortunately these approaches increase infection and disease relapse2-4. An alternative strategy is to selectively deplete alloreactive donor T cells after allostimulation by recipient antigen presenting cells (APC) before transplant. Early clinical trials of these allodepletion strategies improved immune reconstitution after HLA-mismatched HSCT without excess GvHD5, 6. However, some allodepletion techniques require specialized recipient APC production6, 7and some approaches may have off-target effects including depletion of donor pathogen-specific T cells8and CD4 T regulatory cells9.One alternative approach is the inactivation of alloreactive donor T cells via induction of alloantigen-specific hyporesponsiveness. This is achieved by stimulating donor cells with recipient APC while providing blockade of CD28-mediated co-stimulation signals10.This "alloanergization" approach reduces alloreactivity by 1-2 logs while preserving pathogen- and tumor-associated antigen T cell responses in vitro11. The strategy has been successfully employed in 2 completed and 1 ongoing clinical pilot studies in which alloanergized donor T cells were infused during or after HLA-mismatched HSCT resulting in rapid immune reconstitution, few infections and less severe acute and chronic GvHD than historical control recipients of unmanipulated HLA-mismatched transplantation12. Here we describe our current protocol for the generation of peripheral blood mononuclear cells (PBMC) which have been alloanergized to HLA-mismatched unrelated stimulator PBMC. Alloanergization is achieved by allostimulation in the presence of monoclonal antibodies to the ligands B7.1 and B7.1 to block CD28-mediated costimulation. This technique does not require the production of specialized stimulator APC and is simple to perform, requiring only a single and relatively brief ex vivo incubation step. As such, the approach can be easily standardized for clinical use to generate donor T cells with reduced alloreactivity but retaining pathogen-specific immunity for adoptive transfer in the setting of AHSCT to improve immune reconstitution without excessive GvHD

TWENTY-YEAR STATUS OF THE EASTERN MIGRATORY WHOOPING CRANE REINTRODUCTION

Since the 10-year status update in 2011, the first parent-reared whooping cranes (Grus americana) were released in the Eastern Migratory Population, the ultralight program (UL) ended, and cranes were released at new sites in eastern Wisconsin. During 2011-2020, 117 captive-reared whooping cranes were released; 75 costume-reared (35 in UL and 40 in the Direct Autumn Release program) and 42 parent-reared. There were no significant differences in 1- or 3-year survival rates based on rearing technique or release site. The population size remained at about 100 cranes during 2010-2018 but then decreased during 2018-2020 due to a reduced number of releases of captive-reared cranes and low recruitment. Predation remained the leading cause of death (54.1% of confirmed cases) for cases in which the cause of death could be determined, followed by impact trauma (18.8%), gunshot (10.5%), and disease (9.0%). The winter distribution shifted northward into more agricultural landscapes, with the majority of the population wintering in southern Indiana or northern Alabama. The summer distribution remained concentrated in Wisconsin, and breeding areas expanded into eastern Wisconsin. As a management response to nest abandonments caused by avian-feeding black flies (Simulium spp.), the first clutch of eggs was removed from nests at Necedah National Wildlife Refuge (i.e., forced renesting), which increased renesting rates from 42% to 79%. In total, 152 cranes were confirmed to have hatched in the wild, 27 of which survived to fledging. Two male whooping cranes nested with female sandhill cranes (Grus canadensis) and produced hybrid chicks. Three cranes were removed from the population due to using an active air strip on an Air National Guard base. As of April 2021, the estimated population size was 76 individuals (38 females, 36 males, and 2 of unknown sex), 16 of which were wild-hatched

LEGUS Discovery of a Light Echo Around Supernova 2012aw

We have discovered a luminous light echo around the normal Type II-Plateau Supernova (SN) 2012aw in Messier 95 (M95; NGC 3351), detected in images obtained approximately two years after explosion with the Wide Field Channel 3 on-board the Hubble Space Telescope (HST) by the Legacy ExtraGalactic Ultraviolet Survey (LEGUS). The multi-band observations span from the near-ultraviolet through the optical (F275W, F336W, F438W, F555W, and F814W). The apparent brightness of the echo at the time was ~21--22 mag in all of these bands. The echo appears circular, although less obviously as a ring, with an inhomogeneous surface brightness, in particular, a prominent enhanced brightness to the southeast. The SN itself was still detectable, particularly in the redder bands. We are able to model the light echo as the time-integrated SN light scattered off of diffuse interstellar dust in the SN environment. We have assumed that this dust is analogous to that in the Milky Way with R_V=3.1. The SN light curves that we consider also include models of the unobserved early burst of light from the SN shock breakout. Our analysis of the echo suggests that the distance from the SN to the scattering dust elements along the echo is ~45 pc. The implied visual extinction for the echo-producing dust is consistent with estimates made previously from the SN itself. Finally, our estimate of the SN brightness in F814W is fainter than that measured for the red supergiant star at the precise SN location in pre-SN images, possibly indicating that the star has vanished and confirming it as the likely SN progenitor.Comment: 10 pages, 9 figures, to appear in the Astrophysical Journa