Maximum Entropy Estimation of the Galactic Bulge Morphology via the VVV Red Clump

The abundance and narrow magnitude dispersion of Red Clump (RC) stars make them a popular candidate for mapping the morphology of the bulge region of the Milky Way. Using an estimate of the RC's intrinsic luminosity function, we extracted the three-dimensional density distribution of the RC from deep photometric catalogues of the VISTA Variables in the Via Lactea (VVV) survey. We used maximum entropy based deconvolution to extract the spatial distribution of the bulge from Ks-band star counts. We obtained our extrapolated non-parametric model of the bulge over the inner 40 by 40 degrees squared region of the Galactic centre. Our reconstruction also naturally matches onto a parametric fit to the bulge outside the VVV region and inpaints overcrowded and high extinction regions. We found a range of bulge properties consistent with other recent investigations based on the VVV data. In particular, we estimated the bulge mass to be in the range 13 to 17 billion solar masses, the X-component to be between 18% and 25% of the bulge mass, and the bulge angle with respect to the Sun-Galactic centre line to be between 18 and 32 degrees. Studies of the Fermi Large Area Telescope (LAT) gamma-ray Galactic centre excess suggests that the excess may be traced by Galactic bulge distributed sources. We applied our deconvolved density in a template fitting analysis of this Fermi-LAT GeV excess and found an improvement in the fit compared to previous parametric based templates.Comment: 25 pages, 27 figures, minor typo correcte

Non-Parametric Density Reconstruction of the Galactic Bulge Area using Red Clump Stars in the VVV Survey

Studies of the red clump giant population in the inner Milky Way suggest the Galactic bulge/bar has a boxy/peanut/X-shaped structure as predicted by its formation via a disc buckling instability. We used a non-parametric method of estimating the Galactic bulge morphology that is based on maximum entropy regularisation. This enabled us to extract the three-dimensional distribution of the red giant stars in the bulge from deep photometric catalogues of the VISTA Variables in the Via Lactea (VVV) survey. Our high-resolution reconstruction confirms the well-known boxy/peanut/X-shaped structure of the bulge. We also find spiral arm structures that extend to around three kpc in front of and behind the bulge and are on different sides of the bulge major axis. We show that the detection of these structures is robust to the uncertainties in the luminosity function.Comment: 12 pages, 8 figures, V4: MNRAS accepted versio

The dark side of organisations: A study of Psychopaths, Narcissists, Machiavellians, and Job Performance

This research study investigates the presence of the “dark triad” (DT: Machiavellianism, psychopathy, and narcissism) in organisations and its relationship with job performance. It poses three primary research questions: 1) What are the relationships between scores on dark triad personality measures and job performance? 2) Will age, tenure, and gender act as moderator variables? 3) What are the relationships between scores on the dark triad personality measures and Horney’s “global” factors? The principal research instrument used is the Hogan Development Survey (HDS). Comprising eleven scales, it is an inventory of dark personality traits designed to measure dysfunctional personality in normal populations. Two of the eleven scales, Bold and Mischievous were defined to capture the core characteristics of the narcissistic and psychopathic personalities respectively, as they might manifest themselves in organisational settings. The Bold and Mischievous scales are used to define all three scales in this research study (see table 3.6). Based on clinical definitions of personality disorders, the HDS is not designed to measure Machiavellianism with a specific scale construction since it is not a clinically defined personality disorder. The eleven scales of the HDS map to Horney’s (1950) global factors of “Moving Towards” people; “Moving Against” people and “Moving Away” from people as they relate to the preferred strategies of each member of the DT when interacting with others in the workplace. A review of the extant DT literature identified ten new hypotheses to be investigated. A quantitative research design was applied. Secondary data comprising a sample of 918 managers from a large US based retail chain store was analysed using a combination of ttests, correlations, bivariate and partial correlations. The ten hypotheses were analysed using a combination of bivariate and partial correlations. Hierarchical regression, and model testing through analysis of variance statistical techniques were used to assess the predictive power of each DT variables. The results show that all ten hypotheses were supported, with all three variables that comprise the DT (Psychopathy, narcissism, and Machiavellianism) negatively predicting job performance; and with age, gender and tenure acting as moderating variables. The psychopath and the narcissist show a strong preference to Move Against others in the workplace, whilst the Machiavellian shows a strong preference to Move Away from others. One of the major contributions to knowledge of this research is the finding that all three DT variables negatively and significantly predict job performance. This finding extends previous research which identified psychopathy and Machiavellianism as significant predictors. In addition, there is the compilation of a new scale for Machiavellianism comprising six scales of the HDS: Excitable, Skeptical, Reserved, Leisurely, Bold, and Mischievous. Along with this contribution, is the extension to the HDS measure of psychopathy (Mischievous) to include the Skeptical, Bold, Colorful and Imaginative scales. The same is true for the HDS measure of narcissism (Bold) with an extension to include the HDS scales of Cautious (Reversed), Bold, Mischievous, and Imaginative. A further contribution to knowledge is the identification of age, tenure, and gender as moderating variables of the effect of each the DT variables on job performance. The contribution to practice made by this research is in management selection and development. The HDS can now be applied as a single measure of the DT, particularly with regard to Machiavellianism, as the new scale obviates the need to apply separate DT scale measures. Finally, this research also contributes to the current debate relating to those researchers that consider the DT a single unified construct (lumpers) and those that argue for their distinctive differences (splitters). The results of this research support the “splitters” case for two pairs of the three DT personality scales (Machiavellianism and narcissism and psychopathy and Machiavellianism). Both pairs show high percentages of non-common variance

REFLEXÕES SOBRE INTELIGÊNCIA

Este artigo intitulado "Reflexões sobre Inteligência", destinado aos alunos que iniciam seu curso de pedagogia, mostra as dificuldades que pedagogos e psicólogos educacionais têm com o conceito científico de inteligência. Apresenta, de uma maneira abreviada, uma amostra de testes de inteligência usados na Europa e nos Estados Unidos e, às vezes, com certas adaptações no Brasil. Mostra como classificar o tradicional conceito de Q.I e comenta, brevemente, as Múltiplas Inteligências" de Howard Gardner e a “Inteligência Emocional de Daniel Goleman

Improving the Limits of Detection of Low Background Alpha Emission Measurements

Alpha particle emission, even at extremely low levels, is a significant issue in the search for rare events (e.g., double beta decay, dark matter detection). Traditional measurement techniques require long counting times to measure low sample rates in the presence of much larger instrumental backgrounds. To address this, a commercially available instrument developed by XIA uses pulse shape analysis to discriminate alpha emissions produced by the sample from those produced by other surfaces of the instrument itself. Experience with this system has uncovered two residual sources of background: cosmogenics and radon emanation from internal components. A development program is underway to enhance the system and extend the pulse shape analysis technique further, so that these residual sources can be identified and rejected as well. In this paper, we review the theory of operation and pulse shape analysis techniques used in XIA`s alpha counter, and briefly explore data suggesting the origin of the residual background terms. We will then present our approach to enhance the system`s ability to identify and reject these terms. Finally, we will describe a prototype system that incorporates our concepts and demonstrates their feasibility.Comment: 8 pages, 13 figures, presented at LRT-201

Changes in fish assemblages following the establishment of a network of no-take marine reserves and partially-protected areas

Networks of no-take marine reserves and partially-protected areas (with limited fishing) are being increasingly promoted as a means of conserving biodiversity. We examined changes in fish assemblages across a network of marine reserves and two different types of partially-protected areas within a marine park over the first 5 years of its establishment. We used Baited Remote Underwater Video (BRUV) to quantify fish communities on rocky reefs at 20-40 m depth between 2008-2011. Each year, we sampled 12 sites in 6 no-take marine reserves and 12 sites in two types of partially-protected areas with contrasting levels of protection (n = 4 BRUV stations per site). Fish abundances were 38% greater across the network of marine reserves compared to the partially-protected areas, although not all individual reserves performed equally. Compliance actions were positively associated with marine reserve responses, while reserve size had no apparent relationship with reserve performance after 5 years. The richness and abundance of fishes did not consistently differ between the two types of partially-protected areas. There was, therefore, no evidence that the more regulated partially-protected areas had additional conservation benefits for reef fish assemblages. Overall, our results demonstrate conservation benefits to fish assemblages from a newly established network of temperate marine reserves. They also show that ecological monitoring can contribute to adaptive management of newly established marine reserve networks, but the extent of this contribution is limited by the rate of change in marine communities in response to protection

Scrutinizing pre- and post-device fabrication properties of atomic layer deposition WS₂ thin films

In this work, we investigate the physical and electrical properties of WS2 thin films grown by a plasma-enhanced atomic layer deposition process, both before and after device fabrication. The WS2 films were deposited on thermally oxidized silicon substrates using the W(NMe2)2(NtBu)2 precursor and a H2S plasma at 450 °C. The WS2 films were approximately 8 nm thick, measured from high-resolution cross-sectional transmission electron imaging, and generally exhibited the desired horizontal basal-plane orientation of the WS2 layers to the SiO2 surface. Hall analysis revealed a p-type behavior with a carrier concentration of 1.31 × 1017 cm−3. Temperature-dependent electrical analysis of circular transfer length method test structures, with Ni/Au contacts, yielded the activation energy (Ea) of both the specific contact resistivity and the WS2 resistivity as 100 and 91 meV, respectively. The similarity of these two values indicates that the characteristics of both are dominated by the temperature dependence of the WS2 hole concentration. Change in the material, such as in sheet resistance, due to device fabrication is attributed to the chemicals and thermal treatments associated with resist spinning and baking, ambient and UV exposure, metal deposition, and metal lift off for contact pad formation.</p

Synthesis of Large-Area Crystalline MoS2 by Sputter Deposition and Pulsed Laser Annealing

The wafer-scale synthesis of layered transitional metal dichalcogenides presenting good crystal quality and homogeneous coverage is a challenge for the development of next-generation electronic devices. This work explores a fairly unconventional growth method based on a two-step process consisting in sputter deposition of stochiometric MoS2 on Si/SiO2 substrates followed by nanosecond UV (248 nm) pulsed laser annealing. Large-scale 2H-MoS2 multi-layer films were successfully synthetized in a N2-rich atmosphere thanks to a fine-tuning of the laser annealing parameters by varying the number of laser pulses and their energy density. The identification of the optimal process led to the success in achieving a (002)-oriented nanocrystalline MoS2 film without performing post-sulfurization. It is noteworthy that the spatial and temporal confinement of laser annealing keeps the Si/SiO2 substrate temperature well below the back-end-of-line temperature limit of Si CMOS technology (770 K). The synthesis method described here can speed up the integration of large-area 2D materials with Si-based devices, paving the way for many important applications

Changing situational contexts present a constant challenge to software developers.

A software process can take many forms and its optimality demands that it should be harmonised with the needs of the given software development situational context. This theoretical proposition is reasonably clear. However, the finer details of the interaction between the software process and the factors of the situational context are much less obvious. In previously published research, the authors have elaborated a reference framework that identifies the factors of a situational context that affect the software process [1]. In this paper, we report on the application of our reference framework in an examination of the changing nature of software development situational contexts. Our corresponding study of fifteen software development companies indicates that certain factors appear more subject to change than others. This finding is a potentially important insight that can help us with the recurring challenge of adapting the software process to changing circumstances