Sociedad de gananciales y herencia

Traballo fin de grao (UDC.DER). Dereito. Curso 2015/201

On the Automated and Objective Detection of Emission Lines in Faint-Object Spectroscopy

Modern spectroscopic surveys produce large spectroscopic databases, generally with sizes well beyond the scope of manual investigation. The need arises, therefore, for an automated line detection method with objective indicators for detection significance. In this paper, we present an automated and objective method for emission line detection in spectroscopic surveys and apply this technique to 1574 spectra, obtained with the Hectospec spectrograph on the MMT Observatory (MMTO), to detect Lyman alpha emitters near z ~ 2.7. The basic idea is to generate on-source (signal plus noise) and off-source (noise only) mock observations using Monte Carlo simulations, and calculate completeness and reliability values, (C, R), for each simulated signal. By comparing the detections from real data with the Monte Carlo results, we assign the completeness and reliability values to each real detection. From 1574 spectra, we obtain 881 raw detections and, by removing low reliability detections, we finalize 649 detections from an automated pipeline. Most of high completeness and reliability detections, (C, R) ~ (1.0, 1.0), are robust detections when visually inspected; the low C and R detections are also marginal on visual inspection. This method at detecting faint sources is dependent on the accuracy of the sky subtraction.Comment: 19 pages, 16 figures, submitted to MNRA

Spatially Resolved Gas Kinematics within a Lyα\alpha Nebula: Evidence for Large-scale Rotation

We use spatially extended measurements of Ly$\alpha$ as well as less optically thick emission lines from an $\approx$80 kpc Ly$\alpha$ nebula at $z\approx1.67$ to assess the role of resonant scattering and to disentangle kinematic signatures from Ly$\alpha$ radiative transfer effects. We find that the Ly$\alpha$, CIV, HeII, and CIII] emission lines all tell a similar story in this system, and that the kinematics are broadly consistent with large-scale rotation. First, the observed surface brightness profiles are similar in extent in all four lines, strongly favoring a picture in which the Ly$\alpha$ photons are produced in situ instead of being resonantly scattered from a central source. Second, we see low kinematic offsets between Ly$\alpha$ and the less optically thick HeII line ($\sim$100-200 km s$^{-1}$), providing further support for the argument that the Ly$\alpha$ and other emission lines are all being produced within the spatially extended gas. Finally, the full velocity field of the system shows coherent velocity shear in all emission lines: $\approx$500 km s$^{-1}$ over the central $\approx$50 kpc of the nebula. The kinematic profiles are broadly consistent with large-scale rotation in a gas disk that is at least partially stable against collapse. These observations suggest that the Ly$\alpha$ nebula represents accreting material that is illuminated by an offset, hidden AGN or distributed star formation, and that is undergoing rotation in a clumpy and turbulent gas disk. With an implied mass of M(<R=20 kpc)$\sim3\times10^{11}$ $M_{\odot}$, this system may represent the early formation of a large Milky Way mass galaxy or galaxy group.Comment: Accepted to ApJ; 25 pages in emulateapj format; 15 figures, 4 table

Level of accumulation of epoxy fatty acid in Arabidopsis thaliana expressing a linoleic acid Δ12-epoxygenase is influenced by the availability of the substrate linoleic acid

Arabidopsis thaliana (L.) Heynh. expressing the Crepis palaestina (L.) linoleic acid Δ12-epoxygenase in its developing seeds typically accumulates low levels of vernolic acid (12,13-epoxy-octadec-cis-9-enoic acid) in comparison to levels found in seeds of the native C. palaestina. In order to determine some of the factors limiting the accumulation of this unusual fatty acid, we have examined the effects of increasing the availability of linoleic acid (9cis, 12cis-octadecadienoic acid), the substrate of the Δ12-epoxygenase, on the quantity of epoxy fatty acids accumulating in transgenic A. thaliana. The addition of linoleic acid to liquid cultures of transgenic plants expressing the Δ12-epoxygenase under the control of the cauliflower mosaic virus35S promoter increased the amount of vernolic acid in vegetative tissues by 2.8-fold. In contrast, the addition to these cultures of linoelaidic acid (9trans, 12trans-octadecadienoic acid), which is not a substrate of the Δ12-epoxygenase, resulted in a slight decrease in vernolic acid accumulation. Expression of the Δ12-epoxygenase under the control of the napin promoter in the A. thaliana triple mutant fad3/fad7-1/fad8, which is deficient in the synthesis of tri-unsaturated fatty acids and has a 60% higher level of linoleic acid than the wild type, was found to increase the average vernolic acid content of the seeds by 55% compared to the expression of the Δ12-epoxygenase in a wild-type background. Together, these results reveal that the availability of linoleic acid is an important factor affecting the synthesis of epoxy fatty acid in transgenic plant

Being a bereaved parent : early bereavement experiences and perspectives on paediatric palliative care and bereavement services

La mort d'un enfant est considérée comme l'une des expériences les plus difficiles à laquelle une personne puisse faire face. Les cliniciens, les hôpitaux et plusieurs organismes ont pour objectif d’aider les parents endeuillés, mais leurs efforts sont compliqués par un manque de recherche dans le domaine du deuil parental. Cette thèse est composée de trois articles, soit deux revues de littérature et une étude empirique, qui tentent de combler cette lacune et d’informer les services en soins palliatifs pédiatriques et les services de soutien au deuil en particulier. Le premier article porte sur les besoins des patients recevant des soins palliatifs pédiatriques et de leurs familles. Par le biais d’un méta-résumé de la recherche descriptive et qualitative récente, 10 domaines de besoins ont été identifiés qui correspondent aux lignes directrices actuelles en soins palliatifs pédiatriques et de fin de vie. Ces besoins sont présentés de manière à être facilement applicables à la pratique. Cependant, les résultats mettent aussi en évidence plusieurs aspects des soins identifiés comme déficitaires ou problématiques qui mériteraient une attention particulière dans le cadre de politiques futures. Dans le deuxième article, l'objectif était de résumer une vaste littérature d'une manière utile aux cliniciens. À cette fin, une synthèse narrative a permis d’intégrer la recherche quantitative et qualitative dans le domaine du deuil parental. Les résultats mettent en évidence les éléments susceptibles de favoriser l’adaptation des parents au deuil, éléments qui suggèrent par le fait même des avenues possibles de soutien et d'intervention. Cette synthèse a cependant cerné dans la littérature certaines failles méthodologiques qui rendent l'applicabilité clinique des résultats difficile. L'objectif du troisième article était d'informer les services de suivi et de soutien au deuil auprès des parents en se renseignant directement auprès de parents endeuillés. À cette fin, 21 parents (dont 8 couples) et 7 membres du personnel impliqués dans des activités de suivi de deuil de 2 hôpitaux pédiatriques ont été interrogés dans le cadre d’une description interprétative, et l'application clinique des résultats a été vérifiée par le biais de réunions avec des collaborateurs de recherche et les décideurs des centres hospitaliers. Les résultats décrivent comment les parents ont fait face à leur détresse dans la phase précoce de leur deuil, ainsi que leurs points de vue sur la façon dont les divers services de suivi de deuil ont été aidants. Les résultats suggèrent que les parents gèrent leurs sentiments intenses de douleur par une alternance de stratégies axées soit sur leur deuil ou sur leur quotidien et que dans plusieurs cas leurs relations avec autrui les ont aidé. Cette étude a également permis d'élucider la façon dont divers services de soutien aide les parents à aborder leur deuil. Les implications cliniques de ces résultats sont discutées ainsi que des recommandations à l’intention de ceux qui sont impliqués dans la provision des services en deuil.The death of a child is considered one of the most stressful and difficult experiences a person can face. Clinicians, hospitals, and other organizations want to help and support bereaved parents through their grief, but their efforts are hampered by a lack of research in the area of parental bereavement. This dissertation is comprised of two literature reviews and one empirical study that attempt to address this gap and inform services in paediatric palliative care in general, and in bereavement support in particular. The first article consists of an examination of the needs of patients receiving paediatric palliative care and their families. By metasummarizing the descriptive and qualitative research in the area, 10 need domains were found. The results were generally in agreement with current guidelines in paediatric palliative and end-of-life care; however, there were several aspects of care that were reported as lacking or problematic that are not addressed in these guidelines and that should be considered in future guideline and policy creation. In the second article, parents’ adaptation to their grief and elements found to influence their adaptation were examined. The aim was to synthesize the relevant literature in a way that could be useful to clinicians; to this end, a narrative synthesis method was employed in order to synthesize both quantitative and qualitative research in the area of parental bereavement. The results suggest important elements to keep in mind when assessing how parents adapt to their grief. The results also suggest aspects related to better adaptation, which could serve as potential avenues for support and intervention. However, this review also demonstrated certain methodological issues in the literature that hinder the synthesis and clinical applicability of the findings. The objective of the third article was to inform bereavement follow-up and support services through the use of an interpretive description methodology. To this end, 21 bereaved parents (including 5 parental couples) and 7 hospital staff involved in bereavement follow-up activities at two paediatric hospitals were interviewed, and the clinical applicability of the results verified through various meetings with project collaborators and service/program providers. The results of the study describe how parents coped with their grief in the early phase of their bereavement, as well as their perspectives on how various bereavement follow-up services helped them cope. We found that parents regulate their intense feelings of grief through either loss-oriented or restoration-oriented strategies, including attempts to reorganize their self-identity and connection to their deceased child; often parents’ relationships with others help them cope in these ways. The insights we gained from the respondents also allowed us to elucidate how various bereavement support and follow-up services were helpful. These results are discussed along with the clinical implications and how these findings can inform bereavement service providers

Mapping the Polarization of the Radio-Loud Lyα\alpha Nebula B3 J2330+3927

Lya nebulae, or "Lya blobs", are extended (up to ~100 kpc), bright (L[Lya] > 10^43 erg/s) clouds of Lya emitting gas that tend to lie in overdense regions at z ~ 2--5. The origin of the Lya emission remains unknown, but recent theoretical work suggests that measuring the polarization might discriminate among powering mechanisms. Here we present the first narrowband, imaging polarimetry of a radio-loud Lya nebula, B3 J2330+3927 at z=3.09, with an embedded active galactic nucleus (AGN). The AGN lies near the blob's Lya emission peak and its radio lobes align roughly with the blob's major axis. With the SPOL polarimeter on the 6.5m MMT telescope, we map the total (Lya + continuum) polarization in a grid of circular apertures of radius 0.6" (4.4kpc), detecting a significant (>2sigma) polarization fraction P in nine apertures and achieving strong upper-limits (as low as 2%) elsewhere. P increases from <2% at ~5kpc from the blob center to ~17% at ~15-25kpc. The detections are distributed asymmetrically, roughly along the nebula's major axis. The polarization angles theta are mostly perpendicular to this axis. Comparing the Lya flux to that of the continuum, and conservatively assuming that the continuum is highly polarized (20-100%) and aligned with the total polarization, we place lower limits on the polarization of the Lya emission P(Lya) ranging from no significant polarization at ~5 kpc from the blob center to ~ 3--17% at 10--25kpc. Like the total polarization, the Lya polarization detections occur more often along the blob's major axis.Comment: 9 pages, 7 figures, accepted for publication in Ap

The Diversity of Diffuse Lyα\alpha Nebulae around Star-Forming Galaxies at High Redshift

We report the detection of diffuse Ly$\alpha$ emission, or Ly$\alpha$ halos (LAHs), around star-forming galaxies at $z\approx3.78$ and $2.66$ in the NOAO Deep Wide-Field Survey Bo\"otes field. Our samples consist of a total of $\sim$1400 galaxies, within two separate regions containing spectroscopically confirmed galaxy overdensities. They provide a unique opportunity to investigate how the LAH characteristics vary with host galaxy large-scale environment and physical properties. We stack Ly$\alpha$ images of different samples defined by these properties and measure their median LAH sizes by decomposing the stacked Ly$\alpha$ radial profile into a compact galaxy-like and an extended halo-like component. We find that the exponential scale-length of LAHs depends on UV continuum and Ly$\alpha$ luminosities, but not on Ly$\alpha$ equivalent widths or galaxy overdensity parameters. The full samples, which are dominated by low UV-continuum luminosity Ly$\alpha$ emitters ($M_{\rm UV} \gtrsim -21$), exhibit LAH sizes of 5$\,-\,6\,$kpc. However, the most UV- or Ly$\alpha$-luminous galaxies have more extended halos with scale-lengths of 7$\,-\,9\,$kpc. The stacked Ly$\alpha$ radial profiles decline more steeply than recent theoretical predictions that include the contributions from gravitational cooling of infalling gas and from low-level star formation in satellites. On the other hand, the LAH extent matches what one would expect for photons produced in the galaxy and then resonantly scattered by gas in an outflowing envelope. The observed trends of LAH sizes with host galaxy properties suggest that the physical conditions of the circumgalactic medium (covering fraction, HI column density, and outflow velocity) change with halo mass and/or star-formation rates.Comment: published in ApJ, minor proof corrections applie