15,786 research outputs found

    SINFONI's take on Star Formation, Molecular Gas, and Black Hole Masses in AGN

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    We present some preliminary (half-way) results on our adaptive optics spectroscopic survey of AGN at spatial scales down to 0.085arcsec. Most of the data were obtained with SINFONI which provides integral field capability at a spectral resolution of R~4000. The themes on which we focus in this contribution are: star formation around the AGN, the properties of the molecular gas and its relation to the torus, and the mass of the black hole.Comment: 5 pages, 2 figures. To appear in Science Perspectives for 3D Spectroscopy. ESO Astrophysics Symposia. Ed by M. Kissler-Patig, M. Roth and J. Wals

    Ecological and evolutionary processes at expanding range margins

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    Many animals are regarded as relatively sedentary and specialized in marginal parts of their geographical distributions. They are expected to be slow at colonizing new habitats. Despite this, the cool margins of many species' distributions have expanded rapidly in association with recent climate warming. We examined four insect species that have expanded their geographical ranges in Britain over the past 20 years. Here we report that two butterfly species have increased the variety of habitat types that they can colonize, and that two bush cricket species show increased fractions of longer-winged (dispersive) individuals in recently founded populations. Both ecological and evolutionary processes are probably responsible for these changes. Increased habitat breadth and dispersal tendencies have resulted in about 3- to 15-fold increases in expansion rates, allowing these insects to cross habitat disjunctions that would have represented major or complete barriers to dispersal before the expansions started. The emergence of dispersive phenotypes will increase the speed at which species invade new environments, and probably underlies the responses of many species to both past and future climate change

    Affine maps of density matrices

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    For quantum systems described by finite matrices, linear and affine maps of matrices are shown to provide equivalent descriptions of evolution of density matrices for a subsystem caused by unitary Hamiltonian evolution in a larger system; an affine map can be replaced by a linear map, and a linear map can be replaced by an affine map. There may be significant advantage in using an affine map. The linear map is generally not completely positive, but the linear part of an equivalent affine map can be chosen to be completely positive and related in the simplest possible way to the unitary Hamiltonian evolution in the larger system.Comment: 4 pages, title changed, sentence added, reference update

    Laboratory Accident Liability: Academic and Industrial

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    Educational institutions are not expected to be insurers of a student\u27s safety; however, schools must exercise that degree of care required to avoid a negligent disregard of the potential dangers inherent in academic chemical experimentation. Industry must likewise exert due care to avoid unnecessary exposure of the industrial chemist to unreasonable dangers. Injuries sustained in the industrial research laboratory may be recoverable under workmen\u27s compensation statutes or under tort law. The industrial chemist assumes a limited risk, but he does not assume the perils of his employer\u27s negligence

    The supermassive black hole in NGC4486a detected with SINFONI at the VLT

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    The near-infrared integral field spectrograph SINFONI at the ESO VLT opens a new window for the study of central supermassive black holes. With a near-IR spatial resolution similar to HST optical and the ability to penetrate dust it provides the possibility to explore the low-mass end of the M-sigma relation (sigma<120km/s) where so far very few black hole masses were measured with stellar dynamics. With SINFONI we observed the central region of the low-luminosity elliptical galaxy NGC4486a at a spatial resolution of ~0.1arcsec in the K band. The stellar kinematics was measured with a maximum penalised likelihood method considering the region around the CO absorption band heads. We determined a black hole mass of M_BH=1.25^{+0.75}_{-0.79} x 10^7 M_sun (90% C.L.) using the Schwarzschild orbit superposition method including the full 2-dimensional spatial information. This mass agrees with the predictions of the M-sigma relation, strengthening its validity at the lower sigma end.Comment: 7 pages, 7 figures. Accepted by MNRA

    Prospective relationships between body weight and physical activity: an observational analysis from the NAVIGATOR study

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    Objectives: While bidirectional relationships exist between body weight and physical activity, direction of causality remains uncertain and previous studies have been limited by self-reported activity or weight and small sample size. We investigated the prospective relationships between weight and physical activity. Design: Observational analysis of data from the Nateglinide And Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) study, a double-blinded randomised clinical trial of nateglinide and valsartan, respectively. Setting Multinational study of 9306 participants. Participants: Participants with biochemically confirmed impaired glucose tolerance had annual measurements of both weight and step count using research grade pedometers, worn for 7 days consecutively. Along with randomisation to valsartan or placebo plus nateglinide or placebo, participants took part in a lifestyle modification programme. Outcome measures: Longitudinal regression using weight as response value and physical activity as predictor value was conducted, adjusted for baseline covariates. Analysis was then repeated with physical activity as response value and weight as predictor value. Only participants with a response value preceded by at least three annual response values were included. Results: Adequate data were available for 2811 (30%) of NAVIGATOR participants. Previous weight (χ2=16.8; p&lt;0.0001), but not change in weight (χ2=0.1; p=0.71) was inversely associated with subsequent step count, indicating lower subsequent levels of physical activity in heavier individuals. Change in step count (χ2=5.9; p=0.02) but not previous step count (χ2=0.9; p=0.34) was inversely associated with subsequent weight. However, in the context of trajectories already established for weight (χ2 for previous weight measurements 747.3; p&lt;0.0001) and physical activity (χ2 for previous step count 432.6; p&lt;0.0001), these effects were of limited clinical importance. Conclusions: While a prospective bidirectional relationship was observed between weight and physical activity, the magnitude of any effect was very small in the context of natural trajectories already established for these variables

    Nonlinear projective filtering in a data stream

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    We introduce a modified algorithm to perform nonlinear filtering of a time series by locally linear phase space projections. Unlike previous implementations, the algorithm can be used not only for a posteriori processing but includes the possibility to perform real time filtering in a data stream. The data base that represents the phase space structure generated by the data is updated dynamically. This also allows filtering of non-stationary signals and dynamic parameter adjustment. We discuss exemplary applications, including the real time extraction of the fetal electrocardiogram from abdominal recordings.Comment: 8 page

    The Impact Of Business Faculty Attire On Student Perceptions And Engagement

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    Certainly not a new phenomenon, professors continue to strive to discover the magic elixir that will cause all students to become active participants in the learning process. It seems logical that if students find a topic interesting or pertinent to their career objectives, they will tend to take a more active role in a course. Perhaps as reasonable to assume, if instructors are engaging and have the respect of the class, students will naturally put forth more effort to master the material.&nbsp; Prior studies have also shown that certain pedagogical devices and innovations, such as the usage of presentation technology, can positively impact student motivation. This study explored whether something as basic as the professor&rsquo;s attire could also have a motivating effect on student perceptions and behavior in a college classroom setting. This paper summarizes the results of a survey pertaining to faculty dress that was administered to students enrolled in selected business courses at a mid-sized Midwestern university. Students were asked their opinion of whether the professional or unprofessional dress of the instructor would conceivably impact their own learning and effort. The survey results show that, in general, students perceive professional dress positively, and adjust their behavior accordingly

    The Impact Of Instructor Attire On Student Perceptions Of Faculty Credibility And Their Own Resultant Behavior

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    Prior studies suggest that faculty members who are credible are more effective in the classroom in that they are evaluated more highly and their students achieve greater learning. This paper explores how the instructor&rsquo;s attire impacts his or her perceived credibility, and how the students&rsquo; corresponding perception of instructor credibility impacts the students&rsquo; self-described behavior.&nbsp; Questionnaires depicting instructors of both genders each wearing three different outfits, including casual, business casual and professional attire, are used to assess business student opinions regarding the academician&rsquo;s credibility and the students&rsquo; resultant effort and learning.&nbsp; The results indicate that faculty members can take comfort in that &nbsp;their level of preparation, knowledge and ability to prepare students for a career do impact their credibility in the eyes of the students, no matter their choice of attire.&nbsp; Instructor credibility, in turn, was found to have a significant positive relationship with all ten student effort and behavior variables that were examined.&nbsp; In particular, credibility had the most impact on the student&rsquo;s preparation for each class, attentiveness, appreciation for instructor effort, and respect for the instructor.&nbsp; Positive significant relationships were also found between credibility and student evaluations of both the class and the instructor.&nbsp

    Night-time lighting alters the composition of marine epifaunal communities

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    Marine benthic communities face multiple anthropogenic pressures that compromise the future of some of the most biodiverse and functionally important ecosystems in the world. Yet one of the pressures these ecosystems face, night-time lighting, remains unstudied. Light is an important cue in guiding the settlement of invertebrate larvae, and altering natural regimes of nocturnal illumination could modify patterns of recruitment among sessile epifauna. We present the first evidence of night-time lighting changing the composition of temperate epifaunal marine invertebrate communities. Illuminating settlement surfaces with white light-emitting diode lighting at night, to levels experienced by these communities locally, both inhibited and encouraged the colonization of 39% of the taxa analysed, including three sessile and two mobile species. Our results indicate that ecological light pollution from coastal development, shipping and offshore infrastructure could be changing the composition of marine epifaunal communities.European Research Council under the European Union's Seventh Framework programme (FP7/2007-2013
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