855 research outputs found
A photometric study of the hot exoplanet WASP-19b
Context: When the planet transits its host star, it is possible to measure
the planetary radius and (with radial velocity data) the planet mass. For the
study of planetary atmospheres, it is essential to obtain transit and
occultation measurements at multiple wavelengths.
Aims: We aim to characterize the transiting hot Jupiter WASP-19b by deriving
accurate and precise planetary parameters from a dedicated observing campaign
of transits and occultations.
Methods: We have obtained a total of 14 transit lightcurves in the r'-Gunn,
IC, z'-Gunn and I+z' filters and 10 occultation lightcurves in z'-Gunn using
EulerCam on the Euler-Swiss telescope and TRAPPIST. We have also obtained one
lightcurve through the narrow-band NB1190 filter of HAWK-I on the VLT measuring
an occultation at 1.19 micron. We have performed a global MCMC analysis of all
new data together with some archive data in order to refine the planetary
parameters and measure the occultation depths in z'-band and at 1.19 micron.
Results: We measure a planetary radius of R_p = 1.376 (+/-0.046) R_j, a
planetary mass of M_p = 1.165 (+/-0.068) M_j, and find a very low eccentricity
of e = 0.0077 (+/-0.0068), compatible with a circular orbit. We have detected
the z'-band occultation at 3 sigma significance and measure it to be dF_z'= 352
(+/-116) ppm, more than a factor of 2 smaller than previously published. The
occultation at 1.19 micron is only marginally constrained at dF_1190 = 1711
(+/-745) ppm.
Conclusions: We have shown that the detection of occultations in the visible
is within reach even for 1m class telescopes if a considerable number of
individual events are observed. Our results suggest an oxygen-dominated
atmosphere of WASP-19b, making the planet an interesting test case for
oxygen-rich planets without temperature inversion.Comment: Published in Astronomy & Astrophysics. 11 pages, 11 figures, 4 table
Engagement of families in ICU from the nursing staff perspective
Background:
Family engagement in intensive care units (ICU) is proposed as a way to increase active partnership with patients and move away from paternalism (Burns et al 2018). Family engagement and family-centred care are closely linked to improve the quality of care. The term and practice of ‘family engagement’ is complex but Burns et al (2018) viewed patient and family engagement as a way to achieve family centred care. Promoting family engagement within the ICU setting is recognised as more challenging to nursing practice because of the added emotional aspects for families of acutely ill patients (Brown et al 2015).
This research was part of an international collaboration supported by the Family Care in Acute and Critical Illness Research Cluster which is supported by the International Family Nursing Association. This presentation will focus on the findings of the UK aspect of the research.
Research Question:
How do nurses from one English setting describe their nursing engagement with families of adults admitted in intensive care units?
Methods:
A social ecological approach (Bronfenbrenner, 1979) was used for this study. Social ecology acknowledges that families are complex groups that interact with other people and their world to provide meaning.
Data were collected including demographic information, individual semi-structured qualitative interviews which were transcribed, and a questionnaire ‘Factors That Influence Family Engagement (QFIFE)’ (Hetland, Hickman, McAndrew, & Daly, 2017).
One intensive care unit in the South East of England was used for this study. Permanent members of the nursing team were invited to participate. Analysis was undertaken using a statistic package (SPSS version 21) for questionnaire data and a content analysis approach for qualitative data.
Ethical approval was gained from the University and Gray Area Project approval from the healthcare organisation.
Results:
Seven participants completed all aspects of the data collection. All participants rated that family engagement was important. Engagement varied depending of the acuity of the patient with nurses deciding the level of family engagement at a particular point in the patient journey. As the patients’ illness stabilised the involvement of the family was promoted. The family engagement role can be described as observers, encouragers, supporter or active participants in patient care. Staff were particularly concerned about maintaining the safety of the patient during any family activities and developing good communication.
Initial analysis suggests that nurses regulate family engagement to ensure safety of patients and to promote recovery. Families need encouragement from ICU nurses to engage in a meaningful way. Building rapport and setting boundaries are skills needed by nurses and families value explanation of care.
Conclusions:
Family engagement needs careful consideration about the amount and type of activities that are appropriate and safe for families to undertake at a particular point. However, family engagement is seen as positive contribution to the patient recovery journey. This international project will continue to compare and combine results across the world. Consideration of future initiatives to family engagement in ICU will be further outlined
Modeling an Evolutionary Conserved Circadian Cis-Element
Circadian oscillator networks rely on a transcriptional activator called CLOCK/CYCLE (CLK/CYC) in insects and CLOCK/BMAL1 or NPAS2/BMAL1 in mammals. Identifying the targets of this heterodimeric basic-helix-loop-helix (bHLH) transcription factor poses challenges and it has been difficult to decipher its specific sequence affinity beyond a canonical E-box motif, except perhaps for some flanking bases contributing weakly to the binding energy. Thus, no good computational model presently exists for predicting CLK/CYC, CLOCK/BMAL1, or NPAS2/BMAL1 targets. Here, we use a comparative genomics approach and first study the conservation properties of the best-known circadian enhancer: a 69-bp element upstream of the Drosophila melanogaster period gene. This fragment shows a signal involving the presence of two closely spaced E-box–like motifs, a configuration that we can also detect in the other four prominent CLK/CYC target genes in flies: timeless, vrille, Pdp1, and cwo. This allows for the training of a probabilistic sequence model that we test using functional genomics datasets. We find that the predicted sequences are overrepresented in promoters of genes induced in a recent study by a glucocorticoid receptor-CLK fusion protein. We then scanned the mouse genome with the fly model and found that many known CLOCK/BMAL1 targets harbor sequences matching our consensus. Moreover, the phase of predicted cyclers in liver agreed with known CLOCK/BMAL1 regulation. Taken together, we built a predictive model for CLK/CYC or CLOCK/BMAL1-bound cis-enhancers through the integration of comparative and functional genomics data. Finally, a deeper phylogenetic analysis reveals that the link between the CLOCK/BMAL1 complex and the circadian cis-element dates back to before insects and vertebrates diverged
Mid-term report for the CORE Organic II funded project. “Innovative cropping Practices to increase soil health of organic fruit tree orchards” BIO-INCROP
Activities performed in the first part of BIO-INCROP project concern five of the eight main objectives fixed in the project proposal. They are:
Evaluation of soil borne pest and pathogens involved in replant disease
Role of rhizospheric bacterial and fungal communities in plant health
Selection of naturally available resources to increase microbial diversity and biomass
Compost and organic amendments
Evaluation of biologically active formulates
The document reports main research results and shows main items of dissemination activity performed in the first part of the project
A New Analysis of the Exoplanet Hosting System HD 6434
The current goal of exoplanetary science is not only focused on detecting but
characterizing planetary systems in hopes of understanding how they formed,
evolved, and relate to the Solar System. The Transit Ephemeris Refinement and
Monitoring Survey (TERMS) combines both radial velocity (RV) and photometric
data in order to achieve unprecedented ground-based precision in the
fundamental properties of nearby, bright, exoplanet-hosting systems. Here we
discuss HD 6434 and its planet, HD 6434b, which has a M_p*sin(i) = 0.44 M_J
mass and orbits every 22.0170 days with an eccentricity of 0.146. We have
combined previously published RV data with new measurements to derive a
predicted transit duration of ~6 hrs, or 0.25 days, and a transit probability
of 4%. Additionally, we have photometrically observed the planetary system
using both the 0.9m and 1.0m telescopes at the Cerro Tololo Inter-American
Observatory, covering 75.4% of the predicted transit window. We reduced the
data using the automated TERMS Photometry Pipeline, developed to ensure
consistent and accurate results. We determine a dispositive null result for the
transit of HD 6434b, excluding the full transit to a depth of 0.9% and grazing
transit due to impact parameter limitations to a depth of 1.6%Comment: 9 pages, 5 figures, 3 tables, accepted to A
Nuclear spin relaxation rates in two-leg spin ladders
Using the transfer-matrix DMRG method, we study the nuclear spin relaxation
rate 1/T_1 in the two-leg s=1/2 ladder as function of the inter-chain
(J_{\perp}) and intra-chain (J_{|}) couplings. In particular, we separate the
q_y=0 and \pi contributions and show that the later contribute significantly to
the copper relaxation rate ^{63}(1/T_1) in the experimentally relevant coupling
and temperature range. We compare our results to both theoretical predictions
and experimental measures on ladder materials.Comment: Few modifications from the previous version 4 pages, 5 figures,
accepted for publication in PR
No planet for HD 166435
The G0V star HD166435 has been observed by the fiber-fed spectrograph ELODIE
as one of the targets in the large extra-solar planet survey that we are
conducting at the Observatory of Haute-Provence. We detected coherent,
low-amplitude, radial-velocity variations with a period of 3.7987days,
suggesting a possible close-in planetary companion. Subsequently, we initiated
a series of high-precision photometric observations to search for possible
planetary transits and an additional series of CaII H and K observations to
measure the level of surface magnetic activity and to look for possible
rotational modulation. Surprisingly, we found the star to be photometrically
variable and magnetically active. A detailed study of the phase stability of
the radial-velocity signal revealed that the radial-velocity variability
remains coherent only for durations of about 30days. Analysis of the time
variation of the spectroscopic line profiles using line bisectors revealed a
correlation between radial velocity and line-bisector orientation. All of these
observations, along with a one-quarter cycle phase shift between the
photometric and the radial-velocity variationss, are well explained by the
presence of dark photospheric spots on HD166435. We conclude that the
radial-velocity variations are not due to gravitational interaction with an
orbiting planet but, instead, originate from line-profile changes stemming from
star spots on the surface of the star. The quasi-coherence of the
radial-velocity signal over more than two years, which allowed a fair fit with
a binary model, makes the stability of this star unusual among other active
stars. It suggests a stable magnetic field orientation where spots are always
generated at about the same location on the surface of the star.Comment: 9 pages, 8 figures, Accepted for publication in A&
Extrasolar planets in stellar multiple systems
Analyzing exoplanets detected by radial velocity or transit observations, we
determine the multiplicity of exoplanet host stars in order to study the
influence of a stellar companion on the properties of planet candidates.
Matching the host stars of exoplanet candidates detected by radial velocity or
transit observations with online multiplicity catalogs in addition to a
literature search, 57 exoplanet host stars are identified having a stellar
companion. The resulting multiplicity rate of at least 12 percent for exoplanet
host stars is about four times smaller than the multiplicity of solar like
stars in general. The mass and the number of planets in stellar multiple
systems depend on the separation between their host star and its nearest
stellar companion, e.g. the planetary mass decreases with an increasing stellar
separation. We present an updated overview of exoplanet candidates in stellar
multiple systems, including 15 new systems (compared to the latest summary from
2009).Comment: 11 pages, 4 figures, appendix with 6 tables, accepted for publication
in A&
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