The ISO-LWS map of the Serpens cloud core. II. The line spectra

We present spectrophotometric ISO imaging with the LWS and the CAM-CVF of the Serpens molecular cloud core. The LWS map is centred on the far infrared and submillimetre source SMM1 and its size is 8' x 8'. The fine structure line emission in [OI] and [CII] is extended and can be successfully modelled to originate in a PDR with G_0 = 15 and n(H2) about 10^4 - 10^5 cm^-3. Extended emission is also observed in the rotational line emission of H2O and high-J CO. However, lack of sufficient angular resolution prevents us from excluding the possibility that the emssion regions of these lines are point like, which could be linked to the embedded objects SMM9 and SMM4. Toward the Class0 source SMM1, the LWS observations reveal, in addition to fine structure line emission, a rich spectrum of molecular lines. The sub-thermally excited and optically thick CO, H2O and OH lines are tracing an about 10^3 AU source with temperatures higher than 300 K and densities above 10^6 cm^-3. We show that geometry is of concern for the correct interpretation of the data and based on 2D-radiative transfer modelling of the disk/torus around SMM1, which successfully reproduces the entire observed SED and the observed line profiles of CO isotopomers, we can exclude the disk to be the source of the LWS-molecular line emission. The CAM-CVF permits us to see a region of rotational H2 emission. This H2 gas has a temperature of 10^3 K, which suggests that the heating of the gas is achieved through relatively slow shocks. Although we are not able to establish any firm conclusion regarding the detailed nature of the shock waves, our observations of the molecular line emission from SMM1 can be explainable in terms of an admixture of J-shocks and of C-shocks.Comment: 20 pages, 20 figures, accepted for publication in A&

Evaluation methods among corporate travel managers

This study examined whether corporate travel planners performed any kind of evaluation among their clients and in that case what that evaluation revealed about the different air lines\u27 performance. A questionnaire was sent out to 100 members of National Business Travel Association (NBTA) all over the U.S. In this questionnaire the respondents were asked to answer 10 questions about if and how the evaluated the performance of the airlines. In the survey, 25% of the respondents said that they did not perform any evaluation at all. The most commonly used evaluation method was to hand-out questionnaires which was used by 37.5%. Focus groups were used by 11% of the respondents as an evaluation method. When asked why they did not perform focus groups 40% said it was too time consuming. None of the respondents indicated that it was too expensive or that they did not have the knowledge. When conducting focus groups the most commonly used method was to pick out participators from a frequent flier list provided by the airlines. The top issued brought up in their evaluation whether they used focus groups or any other kind of evaluation method, was arrival time of the airlines. The highest rated U. S carrier was USAir followed by United and the highest rated transatlantic carrier was British Airways followed by SAS

Visualization, Exploration and Data Analysis of Complex Astrophysical Data

In this paper we show how advanced visualization tools can help the researcher in investigating and extracting information from data. The focus is on VisIVO, a novel open source graphics application, which blends high performance multidimensional visualization techniques and up-to-date technologies to cooperate with other applications and to access remote, distributed data archives. VisIVO supports the standards defined by the International Virtual Observatory Alliance in order to make it interoperable with VO data repositories. The paper describes the basic technical details and features of the software and it dedicates a large section to show how VisIVO can be used in several scientific cases.Comment: 32 pages, 15 figures, accepted by PAS

Progenitors of Long Gamma-ray Bursts

Pinpointing the progenitors of long duration gamma-ray bursts (LGRBs) remains an extremely important question, although it is now clear that at least a fraction of LGRBs originate in the core collapse of massive stars in type Ic supernovae, the pathways to the production of these stars, and their initial masses, remain uncertain. Rotation is thought to be vital in the creation of LGRBs, and it is likely that black hole creation is also necessary. We suggest that these two constraints can be met if the GRB progenitors are very massive stars (>20 solar masses) and are formed in tight binary systems. Using simple models we compare the predictions of this scenario with observations and find that the location of GRBs on their host galaxies are suggestive of main-sequence masses in excess of 20 solar masses, while 50% of the known compact binary systems may have been sufficiently close to have had the necessary rotation rates for GRB creation. Thus, massive stars in compact binaries are a likely channel for at least some fraction of LGRBs.Comment: To appear in "Gamma-ray bursts: Prospects for GLAST", AIP Conference proceedings 906, Editors M. Axelsson and F Ryd

Use of net cages for fish farming in swedish conditions

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Qubits from Number States and Bell Inequalities for Number Measurements

Bell inequalities for number measurements are derived via the observation that the bits of the number indexing a number state are proper qubits. Violations of these inequalities are obtained from the output state of the nondegenerate optical parametric amplifier.Comment: revtex4, 7 pages, v2: results identical but extended presentation, v3: published versio

β- and α-Cell Dysfunction in Subjects Developing Impaired Glucose Tolerance: Outcome of a 12-Year Prospective Study in Postmenopausal Caucasian Women

OBJECTIVE— This study assessed insulin and glucagon secretion in relation to insulin sensitivity in Caucasian women who develop impaired glucose tolerance (IGT) versus those who maintain normal glucose tolerance (NGT) over a 12-year period

Benchmarking of Carrier Phase Recovery Circuits for M-QAM Coherent Systems

We benchmark blind carrier phase recovery DSP circuits in terms of SNR penalty, power dissipation, latency, area usage, and cycle slip probability, to identify optimal implementations for 16, 64, and 256QAM