The primordial deuterium abundance at z = 2.504 from a high signal-to-noise spectrum of Q1009+2956

The spectrum of the $z_{\rm em} = 2.63$ quasar Q1009+2956 has been observed extensively on the Keck telescope. The Lyman limit absorption system $z_{\rm abs} = 2.504$ was previously used to measure D/H by Burles & Tytler using a spectrum with signal to noise approximately 60 per pixel in the continuum near Ly {\alpha} at $z_{\rm abs} = 2.504$. The larger dataset now available combines to form an exceptionally high signal to noise spectrum, around 147 per pixel. Several heavy element absorption lines are detected in this LLS, providing strong constraints on the kinematic structure. We explore a suite of absorption system models and find that the deuterium feature is likely to be contaminated by weak interloping Ly {\alpha} absorption from a low column density H I cloud, reducing the expected D/H precision. We find D/H = $2.48^{+0.41}_{-0.35}\times10^{-5}$ for this system. Combining this new measurement with others from the literature and applying the method of Least Trimmed Squares to a statistical sample of 15 D/H measurements results in a "reliable" sample of 13 values. This sample yields a primordial deuterium abundance of (D/H)$_{\rm p} = (2.545 \pm 0.025)\times10^{-5}$. The corresponding mean baryonic density of the Universe is $\Omega_{\rm b}h^2 = 0.02174\pm0.00025$. The quasar absorption data is of the same precision as, and marginally inconsistent with, the 2015 CMB Planck (TT+lowP+lensing) measurement, $\Omega_{\rm b}h^2 = 0.02226\pm0.00023$. Further quasar and more precise nuclear data are required to establish whether this is a random fluctuation.Comment: accepted by MNRAS, 18 pages, 12 figures, 6 table

Power Allocation Games in Wireless Networks of Multi-antenna Terminals

We consider wireless networks that can be modeled by multiple access channels in which all the terminals are equipped with multiple antennas. The propagation model used to account for the effects of transmit and receive antenna correlations is the unitary-invariant-unitary model, which is one of the most general models available in the literature. In this context, we introduce and analyze two resource allocation games. In both games, the mobile stations selfishly choose their power allocation policies in order to maximize their individual uplink transmission rates; in particular they can ignore some specified centralized policies. In the first game considered, the base station implements successive interference cancellation (SIC) and each mobile station chooses his best space-time power allocation scheme; here, a coordination mechanism is used to indicate to the users the order in which the receiver applies SIC. In the second framework, the base station is assumed to implement single-user decoding. For these two games a thorough analysis of the Nash equilibrium is provided: the existence and uniqueness issues are addressed; the corresponding power allocation policies are determined by exploiting random matrix theory; the sum-rate efficiency of the equilibrium is studied analytically in the low and high signal-to-noise ratio regimes and by simulations in more typical scenarios. Simulations show that, in particular, the sum-rate efficiency is high for the type of systems investigated and the performance loss due to the use of the proposed suboptimum coordination mechanism is very small

Alien Registration- Dumont, Alphonse E. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29582/thumbnail.jp

A Wilderness Techscape: Land-Use Conflict, Work, and Recreation on the Central Klamath River

Land use has been a point of tension between rural residents, indigenous peoples, and environmentalists since the establishment of the first U.S. National Parks in 1872. Since then, the increased number of protected area designations and their unique restrictions has only increased the frequency and severity of these conflicts. The ‘No Monument’ movement in the Central Klamath River region embodies the core tensions between a variety of communities that intersect on a shared landscape. This thesis offers a qualitative analysis of the uses of different technologies (e.g. gold dredging, all-terrain vehicles, and iPhones) in rural areas along the Klamath River. By focusing on how some technologies gain acceptance while others are rejected by those with different interests, I argue that these practices reveal the cultural assumptions that shape ongoing land use conflicts. Such conflicts stem from inconsistencies in regulating technologies that “enhance” wilderness experiences for some and technologies that “degrade” wilderness experiences for others. Drawing on ideas from rural geography, political ecology, and science, technology, and society studies (STSS), I propose the notion of a techscape, a framework for viewing a landscape as a dynamic product of the technology that co-creates it. The techscape offers an alternative way of looking at a landscape that can highlight marginalized voices and illustrate the flaws with current land use restrictions

Characterization of the Microbial Associates of Nematodes Pathogenic to Myrmica rubra

Pristionchus entomophagus is a necromenic nematode commonly associated with dung beetles (Geotrupes spp.) in Europe. Recently, it has been found in Maine emerging from cadavers of M. rubra, an ant native to Europe that is currently established and pestiferous in Maine (Groden and Stack 2011). Laboratory assays inoculating M. rubra with these nematodes caused significant mortality. This study aimed to characterize the bacterial associates of P. entomophagus in order to further understand its pathogenic relationship with M. rubra. Bacterial samples were collected from the cuticle and gut of the nematodes, and the hemolymph of infected hosts. Single spore isolates were established, cultured, and identified using bacterial 16s rRNA gene sequencing. Following BLAST search comparisons of 24 isolate sequences that I obtained, I identified 14 species of bacteria associated with P. entomophagus and its infected hosts. All of these species have been reported as associated with nematodes, insects, the rhizosphere of plants, fungi, or soil. Three species in particular, Serratia marcescens, S. nematodiphila, and S. proteamaculans have all been directly linked to insect mortality in previous studies (Zhang et al. 2009, Nishiwaki et al. 2007, Al Own et al. 2011). Furthermore, S. proteamaculans was found in association with P. entomophagus in the United Kingdom. In comparing the bacterial isolates found in association with the hemolymph of infected hosts to isolates gathered from P. entomophagus, two species, Pseudomonas fluorescens and Delftia sp. were found in both the hemolymph and in association with the external surface of the nematode. The potential mechanism of pathogenicity employed by P. entomophagus is discussed based on the similarities and differences between the species isolated from the nematode and infected hosts

Alien Registration- Dumont, Paul E. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29340/thumbnail.jp

Systematic Errors in the Estimation of Black Hole Masses by Reverberation Mapping

The mass of the central black hole in many active galactic nuclei has been estimated on the basis of the assumption that the dynamics of the broad emission line gas are dominated by the gravity of the black hole. The most commonly-employed method is to estimate a characteristic size-scale $r_*$ from reverberation mapping experiments and combine it with a characteristic velocity $v_*$ taken from the line profiles; the inferred mass is then estimated by $r_* v_*^2/G$. We critically discuss the evidence supporting the assumption of gravitational dynamics and find that the arguments are still inconclusive. We then explore the range of possible systematic error if the assumption of gravitational dynamics is granted. Inclination relative to a flattened system may cause a systematic underestimate of the central mass by a factor $\sim (h/r)^2$, where $h/r$ is the aspect ratio of the flattening. The coupled effects of a broad radial emissivity distribution, an unknown angular radiation pattern of line emission, and sub-optimal sampling in the reverberation experiment can cause additional systematic errors as large as a factor of 3 or more in either direction.Comment: 19 pages, 4 figures, AASLaTeX, accepted by Ap