C^+ distribution around S1 in rho Ophiuchi

We analyze a [C II] 158 micron map obtained with the L2 GREAT receiver on SOFIA of the emission/reflection nebula illuminated by the early B star S1 in the rho-OphA cloud core. This data set has been complemented with maps of CO(3-2), 13CO(3-2) and C18O(3-2), observed as a part of the JCMT Gould Belt Survey, with archival HCO^+(4-3) JCMT data, as well as with [O I] 63 and 145 micron imaging with Herschel/PACS. The [C II] emission is completely dominated by the strong PDR emission from the nebula surrounding S1 expanding into the dense Oph A molecular cloud west and south of S1. The [C II] emission is significantly blue shifted relative to the CO spectra and also relative to the systemic velocity, particularly in the northwestern part of the nebula. The [C II] lines are broader towards the center of the S1 nebula and narrower towards the PDR shell. The [C II] lines are strongly self-absorbed over an extended region in the S1 PDR. Based on the strength of the [13C II] F = 2-1 hyperfine component, [C II] is significantly optically thick over most of the nebula. CO and 13CO(3-2) spectra are strongly self-absorbed, while C18O(3-2) is single peaked and centered in the middle of the self-absorption. We have used a simple two-layer LTE model to characterize the background and foreground cloud contributing to the [C II] emission. From this analysis we estimate the extinction due to the foreground cloud to be ~9.9 mag, which is slightly less than the reddening estimated towards S1. Since some of the hot gas in the PDR is not traced by low J CO emission, this result appears quite plausible. Using a plane parallel PDR model with the observed [OI(145)]/[C II] brightness ratio and an estimated FUV intensity of 3100-5000 G0 suggests that the density of the [C II] emitting gas is ~3-4x10^3 cm^-3.Comment: Accepted for publication in Astronomy & Astrophysic

Tyranny of the College of Physicians.

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Evaporation of a Kerr black hole by emission of scalar and higher spin particles

We study the evolution of an evaporating rotating black hole, described by the Kerr metric, which is emitting either solely massless scalar particles or a mixture of massless scalar and nonzero spin particles. Allowing the hole to radiate scalar particles increases the mass loss rate and decreases the angular momentum loss rate relative to a black hole which is radiating nonzero spin particles. The presence of scalar radiation can cause the evaporating hole to asymptotically approach a state which is described by a nonzero value of $a_* \equiv a / M$. This is contrary to the conventional view of black hole evaporation, wherein all black holes spin down more rapidly than they lose mass. A hole emitting solely scalar radiation will approach a final asymptotic state described by $a_* \simeq 0.555$. A black hole that is emitting scalar particles and a canonical set of nonzero spin particles (3 species of neutrinos, a single photon species, and a single graviton species) will asymptotically approach a nonzero value of $a_*$ only if there are at least 32 massless scalar fields. We also calculate the lifetime of a primordial black hole that formed with a value of the rotation parameter $a_{*}$, the minimum initial mass of a primordial black hole that is seen today with a rotation parameter $a_{*}$, and the entropy of a black hole that is emitting scalar or higher spin particles.Comment: 22 pages, 13 figures, RevTeX format; added clearer descriptions for variables, added journal referenc

Extremal Problems for Roman Domination

A Roman dominating function of a graph G is a labeling f: V(G) →{0,1,2} such that every vertex with a label 0 has a neighbor with label 2. The Roman domination number γR(G) of G is the minimum of ∑ʋϵV(G)f(v) over such functions. Let G be a connected n-vertex graph. We prove that γR(G) ≤ 4n/5, and we characterize the graphs achieving equality. We obtain sharp upper and lower bounds for γR(G) + γR(Ḡ) and γR(G)γR(Ḡ), improving known results for domination number. We prove that γR(G) ≤ 8n/11 when ᵟ(G) ≥ 2 and n ≥ 9, and this is sharp

Phosphoregulation on mitochondria: Integration of cell and organelle responses

Mitochondria are highly integrated organelles that are crucial to cell adaptation and mitigating adverse physiology. Recent studies demonstrate that fundamental signal transduction pathways incorporate mitochondrial substrates into their biological programs. Reversible phosphorylation is emerging as a useful mechanism to modulate mitochondrial function in accordance with cellular changes. Critical serine/threonine protein kinases, such as the c‐Jun N‐terminal kinase (JNK), protein kinase A (PKA), PTEN‐induced kinase‐1 (PINK1), and AMP‐dependent protein kinase (AMPK), readily translocate to the outer mitochondrial membrane (OMM), the interface of mitochondria‐cell communication. OMM protein kinases phosphorylate diverse mitochondrial substrates that have discrete effects on organelle dynamics, protein import, respiratory complex activity, antioxidant capacity, and apoptosis. OMM phosphorylation events can be tempered through the actions of local protein phosphatases, such as mitogen‐activated protein kinase phosphatase‐1 (MKP‐1) and protein phosphatase 2A (PP2A), to regulate the extent and duration of signaling. The central mediators of OMM signal transduction are the scaffold proteins because the relative abundance of these accessory proteins determines the magnitude and duration of a signaling event on the mitochondrial surface, which dictates the biological outcome of a local signal transduction pathway. The concentrations of scaffold proteins, such as A‐kinase anchoring proteins (AKAPs) and Sab (or SH3 binding protein 5—SH3BP5), have been shown to influence neuronal survival and vulnerability, respectively, in models of Parkinson\u27s disease (PD), highlighting the importance of OMM signaling to health and disease. Despite recent progress, much remains to be discovered concerning the mechanisms of OMM signaling. Nonetheless, enhancing beneficial OMM signaling events and inhibiting detrimental protein‐protein interactions on the mitochondrial surface may represent highly selective approaches to restore mitochondrial health and homeostasis and mitigate organelle dysfunction in conditions such as PD

Spatial Graphs with Local Knots

It is shown that for any locally knotted edge of a 3-connected graph in $S^3$, there is a ball that contains all of the local knots of that edge and is unique up to an isotopy setwise fixing the graph. This result is applied to the study of topological symmetry groups of graphs embedded in $S^3$.Comment: 20 pages, 3 figures; in v. 2 the proof of Theorem 1 has been clarified, and other minor revisions have been mad

Nutrient composition of the produce of the Broadbalk continuous wheat experiment I. Changes over seventy years

RESP-325

Nutrient composition of the produce of the Broadbalk continuous wheat experiment II. Changes occurring during one season's growth

RESP-325