First Lattice Study of the NN-P11(1440)P_{11}(1440) Transition Form Factors

Experiments at Jefferson Laboratory, MIT-Bates, LEGS, Mainz, Bonn, GRAAL, and Spring-8 offer new opportunities to understand in detail how nucleon resonance ($N^*$) properties emerge from the nonperturbative aspects of QCD. Preliminary data from CLAS collaboration, which cover a large range of photon virtuality $Q^2$ show interesting behavior with respect to $Q^2$ dependence: in the region $Q^2 \le 1.5 {GeV}^2$, both the transverse amplitude, $A_{1/2}(Q^2)$, and the longitudinal amplitude, $S_{1/2}(Q^2)$, decrease rapidly. In this work, we attempt to use first-principles lattice QCD (for the first time) to provide a model-independent study of the Roper-nucleon transition form factor.Comment: 4 pages, 2 figures, double colum

Solving Einstein's Equations With Dual Coordinate Frames

A method is introduced for solving Einstein's equations using two distinct coordinate systems. The coordinate basis vectors associated with one system are used to project out components of the metric and other fields, in analogy with the way fields are projected onto an orthonormal tetrad basis. These field components are then determined as functions of a second independent coordinate system. The transformation to the second coordinate system can be thought of as a mapping from the original ``inertial'' coordinate system to the computational domain. This dual-coordinate method is used to perform stable numerical evolutions of a black-hole spacetime using the generalized harmonic form of Einstein's equations in coordinates that rotate with respect to the inertial frame at infinity; such evolutions are found to be generically unstable using a single rotating coordinate frame. The dual-coordinate method is also used here to evolve binary black-hole spacetimes for several orbits. The great flexibility of this method allows comoving coordinates to be adjusted with a feedback control system that keeps the excision boundaries of the holes within their respective apparent horizons.Comment: Updated to agree with published versio

Beyond the Mean Field Approximation for Spin Glasses

We study the d-dimensional random Ising model using a Bethe-Peierls approximation in the framework of the replica method. We take into account the correct interaction only inside replicated clusters of spins. Our ansatz is that the interaction of the borders of the clusters with the external world can be described via an effective interaction among replicas. The Bethe-Peierls model is mapped into a single Ising model with a random gaussian field, whose strength (related to the effective coupling between two replicas) is determined via a self-consistency equation. This allows us to obtain analytic estimates of the internal energy and of the critical temperature in d dimensions.Comment: plane TeX file,19 pages. 3 figures may be requested to Paladin at axscaq.aquila.infn.i

Rotational Grazing Increases Wool and Lamb Production from Phalaris-Subterranean Clover Pastures in South Eastern Australia

Wool and lamb production from different grazing systems was compared in a Mediterranean environment near Hamilton in southeastern Australia. The grazing systems were based on combinations of fertiliser inputs and grazing methods that could promote the growth and persistence of phalaris (Phalaris aquatica) and increase animal production compared to ‘typical’ unimproved pastures. In the first 2 years of this experiment, the most productive systems more than doubled ewe stocking rate and wool production, and more than trebled lamb production per hectare, compared to ‘typical’ unimproved pasture, low fertility, set-stocked systems. The change to a well fertilised phalaris/subterranean clover (Trifolium subterraneum) pasture system accounted for 50-80% of these gains in productivity per hectare, with additional benefits from applying extra phosphorus (P) fertiliser and rotational grazing. These results show the potential for producers to adopt simple changes in management practices that can significantly increase wool and lamb production in southeastern Australia

The Spectral Types of White Dwarfs in Messier 4

We present the spectra of 24 white dwarfs in the direction of the globular cluster Messier 4 obtained with the Keck/LRIS and Gemini/GMOS spectrographs. Determining the spectral types of the stars in this sample, we find 24 type DA and 0 type DB (i.e., atmospheres dominated by hydrogen and helium respectively). Assuming the ratio of DA/DB observed in the field with effective temperature between 15,000 - 25,000 K, i.e., 4.2:1, holds for the cluster environment, the chance of finding no DBs in our sample due simply to statistical fluctuations is only 6 X 10^(-3). The spectral types of the ~100 white dwarfs previously identified in open clusters indicate that DB formation is strongly suppressed in that environment. Furthermore, all the ~10 white dwarfs previously identified in other globular clusters are exclusively type DA. In the context of these two facts, this finding suggests that DB formation is suppressed in the cluster environment in general. Though no satisfactory explanation for this phenomenon exists, we discuss several possibilities.Comment: Accepted for Publication in Astrophys. J. 11 pages including 4 figures and 2 tables (journal format

Impairments to Thermoregulation in the Elderly During Heat Exposure Events

Heat waves represent a public health risk to elderly people, and typically result in an increased rate of hospital admissions and deaths. Studies of thermoregulation in this cohort have generally focused on single elements such as sweating capacity. Sweating capacity and skin blood flow reduce with age, reducing ability to dissipate heat. Perception of effort during heat exposure is emerging as an area that needs further investigation as the elderly appear to lack the ability to adequately perceive increased physiological strain during heat exposure. The role of the gut and endotoxemia in heat stress has received attention in young adults, while the elderly population has been neglected. This shortcoming offers another potential avenue for identifying effective integrated health interventions to reduce heat illnesses. Increasing numbers of elderly individuals in populations worldwide are likely to increase the incidence of heat wave-induced deaths if adequate interventions are not developed, evaluated, and implemented. In this narrative-style review we identify and discuss health-related interventions for reducing the impact of heat illnesses in the elderly

Polarized Redundant-Baseline Calibration for 21 cm Cosmology Without Adding Spectral Structure

21 cm cosmology is a promising new probe of the evolution of visible matter in our universe, especially during the poorly-constrained Cosmic Dawn and Epoch of Reionization. However, in order to separate the 21 cm signal from bright astrophysical foregrounds, we need an exquisite understanding of our telescopes so as to avoid adding spectral structure to spectrally-smooth foregrounds. One powerful calibration method relies on repeated simultaneous measurements of the same interferometric baseline to solve for the sky signal and for instrumental parameters simultaneously. However, certain degrees of freedom are not constrained by asserting internal consistency between redundant measurements. In this paper, we review the origin of these "degeneracies" of redundant-baseline calibration and demonstrate how they can source unwanted spectral structure in our measurement and show how to eliminate that additional, artificial structure. We also generalize redundant calibration to dual-polarization instruments, derive the degeneracy structure, and explore the unique challenges to calibration and preserving spectral smoothness presented by a polarized measurement.Comment: 12 pages, 3 figures, updated to match the published MNRAS versio

LPS-matured CD11c+ bone marrow-derived dendritic cells can initiate autoimmune pathology with minimal injection site inflammation

The pathogenesis of human autoimmune disorders is incompletely understood. This has led to the development of numerous murine models in which the pathogenesis of autoimmunity can be probed and the efficacy of novel therapies can be tested. One of the most widely-used murine models of autoimmunity is experimental autoimmune encephalomyelitis (EAE). To induce autoimmune pathology, mice are often immunized with an autoantigen alongside an adjuvant, typically complete Freund\u2019s adjuvant (CFA). Unfortunately, CFA causes significant inflammation at the site of administration. Despite the well-recognized complication of injection site inflammation, CFA with autoantigen immunization is widely used to induce central nervous system autoimmunity. We performed a literature review which allowed us to estimate that over 10,000 mice were immunized with CFA in published EAE studies in 2013. In this study, we demonstrated that subcutaneously administered myelin basic protein (MBP)-pulsed CD11c+ bone marrow-derived dendritic cells (BMDC) were as effective at inducing EAE as subcutaneously administered MBP plus CFA. Importantly, we also discovered that the CD11c+ BMDC caused significantly less injection site inflammation than MBP plus CFA immunization. This study demonstrated that the use of CD11c+ BMDC can enable the development of autopathogenic T-cells to be studied in vivo without the unwanted side-effects of long-lasting injection site inflammation. This model represents a significant refinement to existing EAE models and may lead to the improvement of the welfare of experimental mice used to study the development of autoimmunity in vivo

Eddington-Limited Accretion in z~2 WISE-selected Hot, Dust-Obscured Galaxies

Hot, Dust-Obscured Galaxies, or "Hot DOGs", are a rare, dusty, hyperluminous galaxy population discovered by the WISE mission. Predominantly at redshifts 2-3, they include the most luminous known galaxies in the universe. Their high luminosities likely come from accretion onto highly obscured super massive black holes (SMBHs). We have conducted a pilot survey to measure the SMBH masses of five z~2 Hot DOGs via broad H_alpha emission lines, using Keck/MOSFIRE and Gemini/FLAMINGOS-2. We detect broad H_alpha emission in all five Hot DOGs. We find substantial corresponding SMBH masses for these Hot DOGs (~ 10^{9} M_sun), and their derived Eddington ratios are close to unity. These z~2 Hot DOGs are the most luminous AGNs at given BH masses, suggesting they are accreting at the maximum rates for their BHs. A similar property is found for known z~6 quasars. Our results are consistent with scenarios in which Hot DOGs represent a transitional, high-accretion phase between obscured and unobscured quasars. Hot DOGs may mark a special evolutionary stage before the red quasar and optical quasar phases, and they may be present at other cosmic epochs.Comment: 15 pages, 9 figures. Accepted by Ap