Color--Luminosity Relations for the Resolved Hot Stellar Populations in the Centers of M 31 and M 32

We present Faint Object Camera (FOC) ultraviolet images of the central 14x14'' of Messier 31 and Messier 32. The hot stellar population detected in the composite UV spectra of these nearby galaxies is partially resolved into individual stars, and their individual colors and apparent magnitudes are measured. We detect 433 stars in M 31 and 138 stars in M 32, down to detection limits of m_F275W = 25.5 mag and m_F175W = 24.5 mag. We investigate the luminosity functions of the sources, their spatial distribution, their color-magnitude diagrams, and their total integrated far-UV flux. Although M 32 has a weaker UV upturn than M 31, the luminosity functions and color-magnitude diagrams of M 31 and M 32 are surprisingly similar, and are inconsistent with a majority contribution from any of the following: PAGB stars more massive than 0.56 Msun, main sequence stars, or blue stragglers. Both the the luminosity functions and color-magnitude diagrams are consistent with a dominant population of stars that have evolved from the extreme horizontal branch (EHB) along tracks with masses between 0.47 and 0.53 Msun. These stars are well below the detection limits of our images while on the zero-age EHB, but become detectable while in the more luminous (but shorter) AGB-Manque' and post-early asymptotic giant branch (PEAGB) phases. The FOC observations require that only a only a very small fraction of the main sequence population (2% in M 31 and 0.5% in M 32) in these two galaxies evolve though the EHB and post-EHB phases, with the remainder evolving through bright PAGB evolution that is so rapid that few if any stars are expected in the small field of view covered by the FOC.Comment: 35 pages, Latex. 19 figures. To appear in ApJ. Uses emulateapj.sty and apjfonts.sty (included). Color plates distributed seperatedly: fig1.jpg and fig2.jp

Design of an RF-Dipole Crabbing Cavity System for the Electron-Ion Collider

The Electron-Ion Collider requires several crabbing systems to facilitate head-on collisions between electron and proton beams in increasing the luminosity at the interaction point. One of the critical rf systems is the 197 MHz crabbing system that will be used in crabbing the proton beam. Many factors such as the low operating frequency, large transverse voltage requirement, tight longitudinal and transverse impedance thresholds, and limited beam line space makes the crabbing cavity design challenging. The rf-dipole cavity design is considered as one of the crabbing cavity options for the 197 MHz crabbing system. The cavity is designed including the HOM couplers, FPC and other ancillaries. This paper presents the detailed electromagnetic design, mechanical analysis, and conceptual cryomodule design of the crabbing system

Extragalactic Fields Optimized for Adaptive Optics

In this paper we present the coordinates of 67 55' x 55' patches of sky which have the rare combination of both high stellar surface density (>0.5 arcmin^{-2} with 13<R<16.5 mag) and low extinction (E(B-V)<0.1). These fields are ideal for adaptive-optics based follow-up of extragalactic targets. One region of sky, situated near Baade's Window, contains most of the patches we have identified. Our optimal field, centered at RA: 7h24m3s, Dec: -1deg27'15", has an additional advantage of being accessible from both hemispheres. We propose a figure of merit for quantifying real-world adaptive optics performance, and use this to analyze the performance of multi-conjugate adaptive optics in these fields. We also compare our results to those that would be obtained in existing deep fields. In some cases adaptive optics observations undertaken in the fields given in this paper would be orders of magnitude more efficient than equivalent observations undertaken in existing deep fields.Comment: 28 pages, 15 figures, 1 table; accepted for publication in PAS

Assessment of modulated hot wire method for thermophysical characterization of fluid and solid matrices charged with (nano)particle inclusions

Recently we reported on simultaneous thermal conductivity k and thermal diffusivity a measurement of liquids and in particular of nanofluids in a configuration using an ac excited hot wire combined with lock-in detection of the third harmonic (3ω method) [1]. The conductive wire is used as both heater and sensor. The requirements for the asymptotic validity of the line heat source model are fulfilled at low modulation frequencies below a few Hz. The study of the relative sensitivity of signal amplitude and phase to changes in k and a indicates that there is an optimum frequency range for accurate and stable results. We extend by up to two decades the feasible frequency range for 3ω measurements by considering various more elaborate models for the heat transfer between the wire and the fluid. Finally we show that the same ac hot wire method can be applied to soft solid, composite materials. We measured the k enhancement of a poly(ethylene vinyl acetate) EVA polymer matrix charged with various fractions of graphite

An Economic Comparison between Alternative Rice Farming Systems in Tanzania Using a Monte Carlo Simulation Approach

Tanzania is the second-largest producer of rice (Oryza sativa) in Eastern, Central, and Southern Africa after Madagascar. Unfortunately, the sector has been performing poorly due to many constraints, including poor agricultural practices and climate variability. In addressing the challenge, the government is making substantial investments to speed the agriculture transformation into a more modernized, commercial, and highly productive and profitable sector. Our objective was to apply a Monte Carlo simulation approach to assess the economic feasibility of alternative rice farming systems operating in Tanzania while considering risk analysis for decision-makers with different risk preferences to make better management decisions. The rice farming systems in this study comprise rice farms using traditional practices and those using some or all of the recommended system of rice intensification (SRI) practices. The overall results show 2% and zero probability of net cash income (NCI) being negative for partial and full SRI adopters, respectively. Meanwhile, farmers using local and improved seeds have 66% and 60% probability of NCI being negative, correspondingly. Rice farms which applied fertilizers in addition to improved seeds have a 21% probability of negative returns. Additionally, net income for rice farms using local seeds was slightly worthwhile when the transaction made during the harvesting period compared to farms applied improved varieties due to a relatively high price for local seeds. These results help to inform policymakers and agencies promoting food security and eradication of poverty on the benefits of encouraging improved rice farming practices in the country. Despite climate variability, in Tanzania, it is still possible for rice farmers to increase food production and income through the application of improved technologies, particularly SRI management practices, which have shown a promising future.Peer Reviewe

The star-forming core of Monoceros R2

Publisher's version/PDFThe central region of the Monoceros R2 molecular cloud has been studied using molecular line maps, maps in continuum emission, and an M-band (4.7 [micrometres]) absorption spectrum toward Mon R2 IRS 3. Maps were made in the emission lines CO (3-2) H[subscript 2]CO (5[subscript 1.5]-4[subscript 1.4), and HCN (4-3), all with a 14" beam size. CO (2-1) and [superscript 13]CO (3-2) spectra were obtained at a dozen positions. Maps of continuum emission were made at 1300 [micrometres] (25" resolution), 1100 [micrometres] (20" resolution), 800 [micrometres] (14" resolution), and 450 [micrometres] (14" resolution). The M-band spectrum of IRS 3 has a velocity resolution of 5.2 km s[superscript -1] and shows fundamental vibrational band absorption lines of CO and [superscript 13]CO over a range of rotational states. The CO map has numerous intensity peaks which, if interpreted as clumps, have masses from 0.1 to 3 M [subscript circled dot]. The large velocity dispersion of these structures implies that they cannot be gravitationally bound. The brightest CO-emitting gas shows no bipolar distribution with velocity. Diffuse CO-emitting gas with low velocities does have a generally bipolar distribution, but there are no collimated lobes pointing to a particular source. We conclude that the source (or sources) of the very extended Mon R2 outflow is (are) now inactive. The highest velocity gas is found toward the embedded young stellar object IRS 3, suggesting that IRS 3 is the source of a compact outflow, unresolved at our 14" resolution. The presence of blueshifted CO in the absorption spectrum supports the interpretation of IRS 3 as an outflow source. The H[subscript 2]CO and HCN maps demonstrate that much of the dense gas is distributed within three structures having different velocities. The fundamental band absorption lines of [superscript 13]CO show two gas temperatures in the line of sight to IRS 3. The colder (45 K) is identified as gas in the clump surrounding IRS 3, which is seen in emission lines of CO, H[subscript 2]CO, and HCN. The warmer (310 K) we interpret as gas very close to IRS 3. From the submillimeter continuum maps we identify 11 clumps whose masses lie in the range 3-10 M [subscript circled dot]. A clump that is prominent in the continuum maps but not in the molecular line maps is attributed to heated dust inside the compact H II region, where molecules have been destroyed

Heath-related quality of life in thyroid cancer patients following radioiodine ablation

<p>Abstract</p> <p>Background</p> <p>There is limited information about the medium to long-term health-related quality of life (QOL) in thyroid cancer patients after initial therapy and the existing studies suffer from limitations. The aim of the study was to assess the determinants of medium-term QOL after the initial therapy.</p> <p>Methods</p> <p>Following a total thyroidectomy, 88 thyroid cancer patients received either rhTSH or hypothyroid-assisted radioiodine ablation (RRA) using 3.7 GBq (100 mCi) of radioiodine. QOL evaluation of the patients using the validated Functional Assessment of Chronic Illness & Therapy (FACIT) was performed at the time of inclusion (t0) and later at the 9-month post-RRA (t1).</p> <p>Results</p> <p>83 patients were eligible for the final evaluation. Medium-term FACIT scores were not statistically different between t0 and t1 patients. All but one domain of the QOL score was similar between t0 and t1. Using a multivariate analysis, only age and immediate postoperative QOL scores were found to be determinants of the overall medium term 9-month QOL scores. Analysis showed that 'high QOL levels' (baseline and 9-month) and 'no depression', 'low anxiety levels', were associated with '<45yrs', 'men', 'partner', and 'rhTSH stimulation'.</p> <p>Conclusions</p> <p>The use of radioiodine ablation does not seem to affect the medium term QOL scores of patients. Medium-term QOL is mainly determined by pre-ablation QOL. The assessment of baseline QOL might be interesting to evaluate in order to adapt the treatment protocols, the preventive strategies, and medical information to patients for potentially improving their outcomes.</p

Rosetta-Alice Observations of Exospheric Hydrogen and Oxygen on Mars

The European Space Agency's Rosetta spacecraft, en route to a 2014 encounter with comet 67P/Churyumov-Gerasimenko, made a gravity assist swing-by of Mars on 25 February 2007, closest approach being at 01:54UT. The Alice instrument on board Rosetta, a lightweight far-ultraviolet imaging spectrograph optimized for in situ cometary spectroscopy in the 750-2000 A spectral band, was used to study the daytime Mars upper atmosphere including emissions from exospheric hydrogen and oxygen. Offset pointing, obtained five hours before closest approach, enabled us to detect and map the HI Lyman-alpha and Lyman-beta emissions from exospheric hydrogen out beyond 30,000 km from the planet's center. These data are fit with a Chamberlain exospheric model from which we derive the hydrogen density at the 200 km exobase and the H escape flux. The results are comparable to those found from the the Ultraviolet Spectrometer experiment on the Mariner 6 and 7 fly-bys of Mars in 1969. Atomic oxygen emission at 1304 A is detected at altitudes of 400 to 1000 km above the limb during limb scans shortly after closest approach. However, the derived oxygen scale height is not consistent with recent models of oxygen escape based on the production of suprathermal oxygen atoms by the dissociative recombination of O2+.Comment: 17 pages, 8 figures, accepted for publication in Icaru

Low-frequency gravitational-wave science with eLISA/NGO

We review the expected science performance of the New Gravitational-Wave Observatory (NGO, a.k.a. eLISA), a mission under study by the European Space Agency for launch in the early 2020s. eLISA will survey the low-frequency gravitational-wave sky (from 0.1 mHz to 1 Hz), detecting and characterizing a broad variety of systems and events throughout the Universe, including the coalescences of massive black holes brought together by galaxy mergers; the inspirals of stellar-mass black holes and compact stars into central galactic black holes; several millions of ultracompact binaries, both detached and mass transferring, in the Galaxy; and possibly unforeseen sources such as the relic gravitational-wave radiation from the early Universe. eLISA's high signal-to-noise measurements will provide new insight into the structure and history of the Universe, and they will test general relativity in its strong-field dynamical regime.Comment: 20 pages, 8 figures, proceedings of the 9th Amaldi Conference on Gravitational Waves. Final journal version. For a longer exposition of the eLISA science case, see http://arxiv.org/abs/1201.362