2,909 research outputs found
First results with the boloSource() algorithm: Photometry of faint standard stars observed by Herschel/PACS
The boloSource() algorithm is a tool to separate the signal of compact
sources from that of the diffuse background in the timeline of far-infrared
measurements performed by the PACS camera of the Herschel Space Observatory. An
important characteristic and quality indicator of this method is that how well
it can reproduce the flux of faint standard stars which have reliable flux
estimates. For this propose we selected a few calibrator targets and
constructed light curves by extracting point source flux for each repetition of
the measurements independently using standard aperture photometry methods.
These were compared with the light curves obtained using the boloSource()
method on the same dataset. The results indicate that boloSource() provides a
similar level of photometric accuracy and reproducibility as the usual flux
extraction and photometry methods. This new technique will be developed further
and also tested against other methods in more complex fields with the goal to
make it usable for large-scale studies in the future.Comment: 10 pages, 7 figures, 4 table
PACS photometer calibration block analysis
The absolute stability of the PACS bolometer response over the entire mission
lifetime without applying any corrections is about 0.5% (standard deviation) or
about 8% peak-to-peak. This fantastic stability allows us to calibrate all
scientific measurements by a fixed and time-independent response file, without
using any information from the PACS internal calibration sources. However, the
analysis of calibration block observations revealed clear correlations of the
internal source signals with the evaporator temperature and a signal drift
during the first half hour after the cooler recycling. These effects are small,
but can be seen in repeated measurements of standard stars. From our analysis
we established corrections for both effects which push the stability of the
PACS bolometer response to about 0.2% (stdev) or 2% in the blue, 3% in the
green and 5% in the red channel (peak-to-peak). After both corrections we still
see a correlation of the signals with PACS FPU temperatures, possibly caused by
parasitic heat influences via the Kevlar wires which connect the bolometers
with the PACS Focal Plane Unit. No aging effect or degradation of the
photometric system during the mission lifetime has been found.Comment: 15 pages, accepted for publication in Experimental Astronom
A general theory of intertemporal decision-making and the perception of time
Animals and humans make decisions based on their expected outcomes. Since
relevant outcomes are often delayed, perceiving delays and choosing between
earlier versus later rewards (intertemporal decision-making) is an essential
component of animal behavior. The myriad observations made in experiments
studying intertemporal decision-making and time perception have not yet been
rationalized within a single theory. Here we present a
theory-Training--Integrated Maximized Estimation of Reinforcement Rate
(TIMERR)--that explains a wide variety of behavioral observations made in
intertemporal decision-making and the perception of time. Our theory postulates
that animals make intertemporal choices to optimize expected reward rates over
a limited temporal window; this window includes a past integration interval
(over which experienced reward rate is estimated) and the expected delay to
future reward. Using this theory, we derive a mathematical expression for the
subjective representation of time. A unique contribution of our work is in
finding that the past integration interval directly determines the steepness of
temporal discounting and the nonlinearity of time perception. In so doing, our
theory provides a single framework to understand both intertemporal
decision-making and time perception.Comment: 37 pages, 4 main figures, 3 supplementary figure
"optimism Is a Strategy for Making a Better Future": A Systematic Review on the Associations of Dispositional Optimism with Health-Related Quality of Life in Cancer Patients
Cancer is a deadly disease that can lead to psychological suffering and decreased quality of life (QoL). Personality has been proven to have an effect on QoL and, in particular, Dispositional Optimism (DO) has been studied in relation to overcoming health crisis. The aim of this systematic review is to deepen the state of art of the relationship between QoL and DO in cancer patients. PubMed and Embase databases were systematically searched. Fifteen studies were included with a total of 5,249 cancer patients. All of the studies consider the relationship between DO and QoL, some studies analyze the correlation between the two variables and found a positive association. The majority of the studies investigate the predictive power of DO over QoL and most of them found DO to be predictive of a higher QoL. Results confirmed the association between DO and QoL in a sample of cancer patients. These results could influence the clinical practice as DO has been proven to have a beneficial effect on mental and physical health
Student interaction with the interplay tool
[EN] Among the priorities of the Polytechnic University of Valencia¿s Education Science Institute (ICE in
Spanish) is the training of university teachers, in which one of the subjects covered is the development
and application of technological resources to improve the teaching-learning process.
The ICE¿s Educational and Multimedia Resources Bureau (GREM in Spanish) has developed the
InterPLAY teaching tool to promote changes that make it necessary to re-invent the teaching process,
in which the teachers take on an innovative role and create conditions for the students to acquire new
knowledge, experience and elements that generate analytical, reflective and acquisition processes.
Apart from being a teaching video, InterPLAY allows the teacher to introduce information (recordings,
videos, questions, images, files, graphs, embedded web pages, etc) and construct it in a way to suit
teaching criteria, facilitate the students¿ learning, and especially generate interaction with the contents.
There are clear standards for the correct use of the teaching resource in the subject [2]. It must be
relevant, up-to-date and realistic, as well as have high image and audio quality, and of course assist in
learning the contents to be studied. Both its design and production, the resource¿s foundation, and
experimentation and evaluation are creatively and dynamically inserted into the teaching-learning
process and can be used as a tool to develop competencies and skills in the students, who are
benefitted by playing a more active learning role, making education more accessible and dynamic [3],
This paper describes the characteristics of the practical formative sessions, which use an experiential
method for teachers to learn to design their own teaching resources using InterPLAY [4]. The
participants were teachers who give different engineering degree subjects, including master¿s degree
courses. We also give an analysis of the evaluations given in the participants¿ responses to the
questionnaire specially composed for this purpose at the end of the last two courses. These
considered the evaluations as regards the didactic use of the tool, with an analysis of its impact on the
learning process, its degree of interest, and the difficulties encountered in the tool¿s different
applications, both from the teachers¿ and students¿ point of view. Using InterPLAY is a constant
incentive for teachers to give more thought to their teaching methods.Rios, JG.; Garcia, E.; Marton Lluch, I. (2020). Student interaction with the interplay tool. IATED Academy. 4513-4520. https://doi.org/10.21125/edulearn.2020.1190S4513452
Comet C/2013 A1 (Siding Spring) as seen with the Herschel Space Observatory
The thermal emission of comet C/2013 A1 (Siding Spring) was observed on March
31, 2013, at a heliocentric distance of 6.48 au using the PACS photometer
camera of the Herschel Space Observatory. The comet was clearly active, showing
a coma that could be traced to a distance of 10", i.e. 50000 km. Analysis of
the radial intensity profiles of the coma provided dust mass and dust
production rate; the derived grain size distribution characteristics indicate
an overabundance of large grains in the thermal emission. We estimate that
activity started about 6 months before these observations, at a heliocentric
distance of 8 au.Comment: 4 pages, 3 figures + a one-page Appendix with 2 figures, accepted for
publication in Astronomy & Astrophysics (Letter
The Polyamine Binding Site in Inward Rectifier K+ Channels
Strongly inwardly rectifying potassium channels exhibit potent and steeply voltage-dependent block by intracellular polyamines. To locate the polyamine binding site, we have examined the effects of polyamine blockade on the rate of MTSEA modification of cysteine residues strategically substituted in the pore of a strongly rectifying Kir channel (Kir6.2[N160D]). Spermine only protected cysteines substituted at a deep location in the pore, between the “rectification controller” residue (N160D in Kir6.2, D172 in Kir2.1) and the selectivity filter, against MTSEA modification. In contrast, blockade with a longer synthetic polyamine (CGC-11179) also protected cysteines substituted at sites closer to the cytoplasmic entrance of the channel. Modification of a cysteine at the entrance to the inner cavity (169C) was unaffected by either spermine or CGC-11179, and spermine was clearly “locked” into the inner cavity (i.e., exhibited a dramatically slower exit rate) following modification of this residue. These data provide physical constraints on the spermine binding site, demonstrating that spermine stably binds at a deep site beyond the “rectification controller” residue, near the extracellular entrance to the channel
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