4,072 research outputs found
The Bitter Truth About Sugar and Willpower: The Limited Evidential Value of the Glucose Model of Ego Depletion
This work was supported by European Research Council Grant 283849 (to N. Gold) under the European Unionâs Seventh Framework Programme (FP/2007â2013)
Native architecture of the Chlamydomonas chloroplast revealed by in situ cryo-electron tomography
Chloroplast function is orchestrated by the organelle's intricate architecture. By combining cryo-focused ion beam milling of vitreous Chlamydomonas cells with cryo-electron tomography, we acquired three-dimensional structures of the chloroplast in its native state within the cell. Chloroplast envelope inner membrane invaginations were frequently found in close association with thylakoid tips, and the tips of multiple thylakoid stacks converged at dynamic sites on the chloroplast envelope, implicating lipid transport in thylakoid biogenesis. Subtomogram averaging and nearest neighbor analysis revealed that RuBisCO complexes were hexagonally packed within the pyrenoid, with similar to 15 nm between their centers. Thylakoid stacks and the pyrenoid were connected by cylindrical pyrenoid tubules, physically bridging the sites of light-dependent photosynthesis and light-independent carbon fixation. Multiple parallel minitubules were bundled within each pyrenoid tubule, possibly serving as conduits for the targeted one-dimensional diffusion of small molecules such as ATP and sugars between the chloroplast stroma and the pyrenoid matrix
Alignment and preliminary outcomes of an ELT-size instrument to a very large telescope: LINC-NIRVANA at LBT
LINC-NIRVANA (LN) is a high resolution, near infrared imager that uses a
multiple field-of-view, layer-oriented, multi-conjugate AO system, consisting
of four multi-pyramid wavefront sensors (two for each arm of the Large
Binocular Telescope, each conjugated to a different altitude). The system
employs up to 40 star probes, looking at up to 20 natural guide stars
simultaneously. Its final goal is to perform Fizeau interferometric imaging,
thereby achieving ELT-like spatial resolution (22.8 m baseline resolution). For
this reason, LN is also equipped with a fringe tracker, a beam combiner and a
NIR science camera, for a total of more than 250 optical components and an
overall size of approximately 6x4x4.5 meters. This paper describes the
tradeoffs evaluated in order to achieve the alignment of the system to the
telescope. We note that LN is comparable in size to planned ELT
instrumentation. The impact of such alignment strategies will be compared and
the selected procedure, where the LBT telescope is, in fact, aligned to the
instrument, will be described. Furthermore, results coming from early
night-time commissioning of the system will be presented.Comment: 8 pages, 6 pages, AO4ELT5 Proceedings, 201
Television exposure, consumer culture values, and lower well-being among preadolescent children: the mediating role of consumer-focused coping strategies
Previous research has linked materialism to lower wellâbeing in children, and recent findings suggest that this link is heightened among those exposed to high levels of advertising. One proposal is that children may be pursuing consumer culture ideals (CCIs) â orienting to material possessions and physical appearance â as a maladaptive coping strategy for dealing with underlying distress. The present work offers the first direct evaluation of this theoretically plausible hypothesis. In Study 1, higher scores on our measure of consumerâfocused coping (CFC) not only predicted lower wellâbeing in a sample of 109 9â to 11âyearâolds, but also served as mediator in the indirect link between the number of hours spent watching television and lower wellâbeing. Study 2 tested our expanded model of these processes in a sample of 380 9â to 11âyearâolds. Specifically, structural equation modelling revealed that frequency of watching commercial (advertisingârich) television in particular predicted greater CFC. This, in turn, predicted greater endorsement of CCIs, which then predicted lower wellâbeing. Implications for theoretical models and educational interventions are discussed
Misanthropic Person Memory when the Need to Self-Enhance is Absent
This research examined the role that the removal of the need or ability to self-enhance can play in the misanthropic processing of attributed behavioral information (i.e., remembering best negative, internally attributed behaviors and positive externally attributed behaviors). Experiment 1demonstrated that removing a personâs need to self-enhance by increasing his or her self-esteem eliminated misanthropic memory, whereas misanthropy was preserved for control participants and perceivers who had experienced a decrease in self-esteem. Furthermore, controlling for participantsâ self-evaluations eliminated the memory pattern differences between the two experimental conditions. Experiment 2 demonstrated that canceling the ability to self-enhance by having perceivers form an impression of themselves eliminated the misanthropy effect. However, the misanthropy effect was replicated when perceivers learned about an unknown other. The results were discussed with regard to the situations and factors that can increase or reduce the need to self-enhance and their implications for social information processing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68679/2/10.1177_0146167299025002011.pd
The SNAPSHOT study protocol : SNAcking, Physical activity, Self-regulation, and Heart rate Over Time
Peer reviewedPublisher PD
The Complexity of Computing Minimal Unidirectional Covering Sets
Given a binary dominance relation on a set of alternatives, a common thread
in the social sciences is to identify subsets of alternatives that satisfy
certain notions of stability. Examples can be found in areas as diverse as
voting theory, game theory, and argumentation theory. Brandt and Fischer [BF08]
proved that it is NP-hard to decide whether an alternative is contained in some
inclusion-minimal upward or downward covering set. For both problems, we raise
this lower bound to the Theta_{2}^{p} level of the polynomial hierarchy and
provide a Sigma_{2}^{p} upper bound. Relatedly, we show that a variety of other
natural problems regarding minimal or minimum-size covering sets are hard or
complete for either of NP, coNP, and Theta_{2}^{p}. An important consequence of
our results is that neither minimal upward nor minimal downward covering sets
(even when guaranteed to exist) can be computed in polynomial time unless P=NP.
This sharply contrasts with Brandt and Fischer's result that minimal
bidirectional covering sets (i.e., sets that are both minimal upward and
minimal downward covering sets) are polynomial-time computable.Comment: 27 pages, 7 figure
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