457 research outputs found
BVR photometry of the resolved dwarf galaxy Ho IX
We present BVR CCD photometry down to limiting magnitude B=23.5 mag for 232
starlike objects and 11 diffuse objects in a 5.4' x 5.4' field of Ho IX. The
galaxy is a gas-rich irregular dwarf galaxy possibly very close to M 81, which
makes it especially interesting in the context of the evolution of satellite
galaxies and the accretion of dwarf galaxies. Investigations of Ho IX were
hampered by relatively large contradictions in the magnitude scale between
earlier studies. With our new photometry we resolved these discrepancies. The
color magnitude diagram (CMD) of Ho IX is fairly typical of a star-forming
dwarf irregular, consistent with earlier results. Distance estimates from our
new CMD are consistent with Ho IX being very close to M 81 and therefore being
a definite member of the M 81 group, apparently in very close physical
proximity to M 81.Comment: 9 pages, 8 figures, uses aa.cls, A&A in pres
The EU Emissions Trading System and Climate Policy towards 2050: Real incentives to reduce emissions and drive innovation? CEPS Special Reports, 12 January 2011
With the EU Emissions Trading System (ETS) now entering in its seventh year of operation, this report takes stock of the largest multi-sector greenhouse gas trading scheme in the world. It reviews the experiences of the pilot phase from 2005-07, assesses the adjustments introduced in the second phase (2008-12) and looks ahead to the radical changes that will come into effect in the third phase starting in 2013. The assessment is based on a literature review of recently published ex-post analyses and ex-ante studies and draws as well on our own calculations. It investigates the main controversies surrounding the EU ETS, such as its environmental effectiveness, economic rents, windfall profits and fairness, the role of CDM and JI and its impact of on industrial competitiveness. It also evaluates the scheme’s ability to promote innovation and low-carbon technology deployment. Finally, the study addresses the fundamental question of whether the ETS has lived up to its promise to “promote reductions of greenhouse gas emissions in a cost-effective and economically efficient manner”, and if not, what are the prospects of its doing so in the future and what additional changes will be required
Next generation, secure cloud-based pan-European information system for enhanced disaster awareness
Information management in disaster situations is challenging, yet critical for efficient response and recovery. Today information flows are difficult to establish, partial, redundant, overly complex or insecure, besides the interoperability between heterogeneous organisations is limited. This paper presents a novel system architecture that enables combining of several communication technologies in a secure manner. This supports creation of a pan-European 'Common Information Space' by rescue organizations that can enable more efficient and effective information management in disaster response. Moreover, this technology can be used for disaster preparedness (e.g., training, tutorials). The modular architecture is designed to consider future evolutions of technology by defining interfaces for the integration of new technologies and services
An open-access database of video stimuli for action observation research in neuroimaging settings: psychometric evaluation and motion characterization
Published on 25 September 2024Video presentation has become ubiquitous in paradigms investigating the neural and behavioral responses to observed actions. In spite of the great interest in uncovering the processing of observed bodily movements and actions in neuroscience and cognitive science, at present, no standardized set of video stimuli for action observation research in neuroimaging settings exists. To facilitate future action observation research, we developed an open-access database of 135 high-definition videos of a male actor performing object-oriented actions. Actions from 3 categories: kinematically natural and goal-intact (Normal), kinematically unnatural and goal-intact (How), or kinematically natural and goal-violating (What), directed toward 15 different objects were filmed from 3 angles. Psychometric evaluation of the database revealed high video recognition accuracy (Mean accuracy = 88.61 %) and substantial inter-rater agreement (Fleiss' Kappa = 0.702), establishing excellent validity and reliability. Videos' exact timing of motion onset was identified using a custom motion detection frame-differencing procedure. Based on its outcome, the videos were edited to assure that motion begins at the second frame of each video. The videos' timing of category recognition was also identified using a novel behavioral up-down staircase procedure. The identified timings can be incorporated in future experimental designs to counteract jittered stimulus onsets, thus vastly improving the sensitivity of neuroimaging experiments. All videos, their psychometric evaluations, and the timing of their frame of category recognition, as well as our custom programs for performing these evaluations on our, or on other similar video databases, are available at the Open Science Framework (https://osf.io/zexc4/).The author(s) declare financial support was received for the research, authorship, and/or publication of this article. CG was supported by an Aspirant Research Fellowship awarded by the Fonds de la Recherche Scientifique (F.R.S.-FNRS; Brussels, Belgium; grant 1.A.211.24F). SM was supported by an Aspirant Research Fellowship awarded by the F.R.S.-FNRS (Brussels, Belgium; grant FC 46249). The project was supported by grants of the Fonds de la Recherche Scientifique (F.R.S.-FNRS, Brussels, Belgium; grant MIS F.4504.21) and of the Brussels-Wallonia Federation (Collective Research Initiatives grant) awarded to MB
The rediscovery of the putative ant social parasite Manica parasitica syn. nov. (Hymenoptera: Formicidae) reveals an unexpected endoparasite syndrome
Parasitism is ubiquitous across the tree of life, and parasites comprise approximately half of all animal species. Social insect colonies attract many pathogens, endo- and ectoparasites, and are exploited by social parasites, which usurp the social environment of their hosts for survival and reproduction. Exploitation by parasites and pathogens versus social parasites may cause similar behavioural and morphological modifications of the host. Ants possess two overlapping syndromes: the endo- and social parasite syndromes. We rediscovered two populations of the putative social parasite Manica parasitica in the Sierra Nevada, and tested the hypothesis that M. parasitica is an independently evolving social parasite. We evaluated traits used to discriminate M. parasitica from its host Manica bradleyi, and examined the morphology of M. parasitica in the context of ant parasitic syndromes. We find that M. parasitica is not a social parasite. Instead, M. parasitica represents cestode-infected M. bradleyi. We propose that M. parasitica should be regarded as a junior synonym of M. bradleyi. Our results emphasize that an integrative approach is essential for unravelling the complex life histories of social insects and their symbionts
Age-related changes in ultrasound-assessed muscle composition and postural stability
Published on 12 august 2024While the simultaneous degradation of muscle composition and postural stability in aging are independently highly investigated due to their association with fall risk, the interplay between the two has received little attention. Thus, the purpose of this study is to explore how age-related changes in muscle composition relate to postural stability. To that aim, we collected posturography measures and ultrasound images of the dominant Vastus Lateralis and Biceps Brachii from 32 young (18–35 year old) and 34 older (65–85 year old) participants. Muscle properties were quantified with echo-intensity and texture-based metrics derived from gray-level co-occurrence matrix analysis, and postural stability with the variability of the center of pressure during bipedal stance tasks. Ultrasound parameters revealed that young muscle possessed lower echo-intensity and higher homogeneity compared to the elderly. Echo-intensity and muscle thickness, and several texture-based parameters possessed outstanding young versus older classification performance. A canonical correlation analysis demonstrated a significant relationship between ultrasound and postural measures only within the young group (r = 0.53, p < 0.002), where those with ‘better’ muscle composition displayed larger postural sways. Our results indicate that, in older individuals, postural stability and muscle composition, two common fall risk factors, are unrelated. In view of this decoupling, both may contribute independently to fall risk. Furthermore, our data support the view that texture-based parameters provide a robust alternative to echo-intensity in providing markers of muscle composition.Scott Mongold was supported by an Aspirant research fellowship awarded by the F.R.S.-FNRS (F.R.S.-FNRS, Brussels, Belgium; grant FC 46249). Christian Georgiev was supported by an Aspirant research fellowship awarded by the F.R.S.-FNRS (F.R.S.-FNRS, Brussels, Belgium; grant 1.A.211.24F). Marc Vander Ghinst and Gilles Naeije were supported by the “Fonds Erasme pour la recherche médicale” (Brussels, Belgium). The project was supported by grants of the Fonds de la Recherche Scientifique (F.R.S.-FNRS, Brussels, Belgium; grant MIS F.4504.21), and of the Brussels-Wallonia Federation (Collective Research Initiatives grant) awarded to Mathieu Bourguignon
First-principles investigation of polytypic defects in InP
In this paper we study polytypic defects in Indium Phosphide (InP) using the complementary first-principles methods of density functional theory and non-equilibrium Greens functions. Specifically we study interfaces between the ground state Zincblende crystal structure and the meta-stable Wurtzite phase, with an emphasis on the rotational twin plane defect, which forms due to the polytypic nature of InP. We found that the transition of the band structure across the interface is anisotropic and lasts 7 nm (3.5 nm). Due to this, a crystal-phase quantum well would require a minimal width of 10 nm, which eliminates rotational twin planes as possible quantum wells. We also found that for conducting current, the interfaces increase conductivity along the defect-plane ([112¯]), whereas due to real growth limitations, despite the interfaces reducing conductivity across the defect-plane ([111]), we found that a high degree of polytypic defects are still desirable. This was argued to be the case, due to a higher fraction of Wurtzite segments in a highly phase-intermixed system
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