Sulphur, zinc and carbon in the Sculptor dwarf spheroidal galaxy

The Sculptor dwarf spheroidal galaxy is a Milky Way satellite with predominantly old stellar population, and therefore the ideal target to study early chemical evolution. The chemical abundances of photospheres of stars reveal the composition of their birth environment; studying stars of different ages, therefore, provides insight into the chemical enrichment history of the galaxy in which they dwell. High-resolution spectra of 100 stars were used to further explore the chemical enrichment history of the Sculptor dwarf spheroidal galaxy. For the first time, the elements S and Zn were measured in large sample of stars, in a stellar system other than the Milky Way. These elements are of special interest, since they are volatile and not depleted onto dust in interstellar gas. Therefore, S and Zn abundances can be used for direct comparison with abundances in absorption systems observed at high redshifts. During the analysis of these data, the first (CEMP-no) star in Sculptor was discovered, but these kinds of stars are believed to show the chemical abundance pattern the very first stellar generation left behind. This exciting discovery, led to the theoretical investigation of the frequency and origin of CEMP stars in the Milky Way dwarf satellites

The 4MOST Survey of Dwarf Galaxies and their Stellar Streams (4DWARFS)

The present-day Milky Way is the result of a long history of mergers and interactions with smaller galaxies. The 4DWARFS survey will target the dwarf galaxies and stellar streams in the 4MOST footprint, and unveil their chrono-chemo-kinematical properties. The survey will provide radial velocities, chemical abundances and stellar ages for 140 000 stars, and thus increase the number of stars with detailed information in such systems by several orders of magnitude. 4DWARFS will provide a new, deeper view of the Milky Way environment, shedding light on the first stars, chemical evolution, dark matter halos, and hierarchical galaxy formation down to the smallest scales

Carbon-enhanced metal-poor stars in dwarf galaxies

We investigate the frequency and origin of carbon-enhanced metal-poor (CEMP) stars in Local Group dwarf galaxies by means of a statistical, data-calibrated cosmological model for the hierarchical build-up of the Milky Way and its dwarf satellites. The model self-consistently explains the variation with dwarf galaxy luminosity of the observed: (i) frequency and [Fe/H] range of CEMP stars; (ii) metallicity distribution functions; (iii) star formation histories. We show that if primordial faint supernovae dominated the early metal-enrichment, then CEMP-no stars enriched by the first stellar generations should be present in all dwarf galaxies, with similar number of stars and CEMP fractions at [Fe/H] 107 L⊙. We present model predictions for the low-Fe tail and CEMP fraction of stars in dwarf galaxies, with particular emphasis on the Sculptor dSph, that can be used to shed light on the properties of the first stars

True Pair-instability Supernova Descendant: Implications for the First Stars’ Mass Distribution

The initial mass function (IMF) of the first Population III (Pop III) stars remains a persistent mystery. Their predicted massive nature implies the existence of stars exploding as pair-instability supernovae (PISNe), but no observational evidence had been found. Now, the LAMOST survey claims to have discovered a pure PISN descendant, J1010+2358, at [Fe/H] = − 2.4. Here we confirm that a massive 250–260 M _⊙ PISN is needed to reproduce the abundance pattern of J1010+2358. However, the PISN contribution can be as low as 10%, since key elements are missing to discriminate between scenarios. We investigate the implications of this discovery for the Pop III IMF, by statistical comparison with the predictions of our cosmological galaxy formation model, NEFERTITI . First, we show that the nondetection of mono-enriched PISN descendants at [Fe/H] 191.16 x − 132.44, where x is the slope, at a 75% confidence level. Second, we show that if J1010+2358 has only inherited 90%) PISN descendant, it will offer strong and complementary constraints on the Pop III IMF, excluding the steepest and bottom-heaviest IMFs: m _ch / M _⊙ < 143.21 x − 225.94. Our work shows that even a single detection of a pure PISN descendant can be crucial to our understanding of the mass distribution of the first stars

Ofþyngd meðal barna á grunnskólaaldri. Fræðileg úttekt á meðferðum fyrir börn yfir kjörþyngd

Offita er vaxandi vandamál jafnt hjá fullorðnum og börnum í nútíma samfélagi og er Ísland þar ekki undanskilið. Tilgangur þessa fræðilega yfirlits var að varpa ljósi á þekkingu um orsakir offitu barna og um meðferðarúrræði sem standa til boða fyrir börn yfir kjörþyngd, einkum með hliðsjón af hlutverki hjúkrunarfræðinga gegn þróun ofþyngdar. Leitað var eftir rannsóknum og fræðilegum heimildum á gagnagrunnum Scopus, Pubmed, Web of Science og víðar. Rannsóknir sýna að offita getur haft afdrifaríkar afleiðingar fyrir andlega og líkamlega heilsu eins og geðræna kvilla, hjarta- og æðasjúkdóma og efnaskiptasjúkdóma. Samfara aukinni tíðni ofþyngdar hérlendis hefur þörfin fyrir heilsueflingu aukist en forvarnarstarf hefur stóreflst á síðastliðnum áratug. Mikilvægt er að sporna gegn þróun offitu barna. Helstu meðferðir fyrir börn í ofþyngd miða að því að ná jafnvægi milli orkuneyslu og hreyfingu barna án þess að hindra eðlilegan vöxt barnsins og þroska þess. Jafnframt hefur góður meðferðarárangur hlotist með þátttöku foreldra í meðferð barna gegn ofþyngd. Skólahjúkrunarfræðingar gegna mikilvægu hlutverki í heilsueflingu nemenda og eru í lykilhlutverki til að hafa jákvæð áhrif á forvarnarstarf innan skólans. Niðurstöður sýna að auka þarf áherslu á meðferðaúrræði fyrir börn yfir kjörþyngd en skortur er á meðferðarúrræðum hérlendis. Lykilorð: Hjúkrunarfræði, offita barna, forvarnir, meðferðir, hlutverk skólahjúkrunarfræðinga, hlutverk foreldra.Obesity is a growing problem among both adults and children in modern society and Iceland is no exception. The purpose of this literature review is to cast a light on the knowledge of the cause of childhood obesity and the therapeutic treatments available for overweight children, especially in relation to the role of nurses in the countering obesity. Various academic articles and research has been accessed through Scopus, Pubmed, Web of Science and beyond. Research shows that obesity can have drastic consequences for mental and physical health as well as psychological, cardiovascular and metabolism diseases. Alongside an increased frequency of national obesity the need for health promotion has increased and prevention work has been strengthened considerably in the last decade. Countering the development of childhood obesity is of great importance. Primary treatments for childhood obesity aim towards achieving a balance between physical activity and the energy consumption of children without obstructing the natural growth of the child or its maturity. A positive treatment result has furthermore resulted from the participation of parents in the treatment of children with obesity. School nurses play an important role in health promotion of students and they are in a key position to influence prevention work at schools in a positive manner. Results of the literature review show that an increased emphasis on therapeutic treatment for overweight children is needed but the availability of such treatments in Iceland is limited. Key words: Nursing, childhood obesity, treatments, role of parents, role of school nurse

Próffræðilegir eiginleikar réttritunarprófs: Fyrir grunnskólanema í 3. til 10.bekk

Lestur og ritun eru grundvallaratriði í menntun og áherslum í grunnskóla. Því er mikilvægt fyrir menntastofnanir landsins að hafa aðgang að áreiðanlegum og réttmætum námsmatskvörðum. Markmið þessarar rannsóknar var að athuga próffræðilega eiginleika réttritunarprófs sem Menntamálastofnun er með í prófun. Þátttakendur voru 2.622 nemendur úr átta árgöngum (3. til 10. bekk) frá 12 skólum. Þátttakendur voru á aldrinum 8 til 16 ára. Frumbreytur rannsóknarinnar voru orðin sem lögð voru fyrir og fylgibreytan hlutfall réttra svara. Próffræðilegir eiginleikar voru eiginleikar metnir fyrir hvern árgang út frá innri áreiðanleika atriða (ásamt áhrifum þeirra á heildar áreiðanleika árgangsins), aðgreiningarstuðlum, og þyngd þeirra. Ásamt skörun þeirra atriða sem voru sameiginleg milli árganga. Prófið var lagt fyrir á rafrænu formi í október og nóvember árið 2018. Niðurstöður rannsóknar sýndu viðunandi próffræðilega eiginleika réttritunarprófsins í hverjum árgangi en með fyrirvara um að það væru nokkur atriði sem þyrfti að skoða.Reading and writing are fundamental features in education. Therefore, it is important for educational institutes to have access to a reliable and valid assessment tools. The objective in this research is to assess the psychometric properties of the orthographic test that Menntamálastofnun is making. Participants were 2.622 students from eight cohorts (3rd to 10th grade) from 12 schools. The participants were between the ages of 8 and 16. The independent variable was the words used for testing and the dependent variable was the rate of correct spelling. Psychometric properties were assessed per group based on inter-reliability of each item (along with their influence on the groups reliability score), discrimination index and their difficulty. Along with overlap of items that were mutual between groups. The orthographic test was administered in October and November of 2018. The results indicate acceptable psychometric properties for each group, but a few items need to be examined further

dSph RGB abundance and velocities

VizieR online Data Catalogue associated with article published in journal Astronomy &amp; Astrophysics with title 'Zinc abundances in the Sculptor dwarf spheroidal galaxy.' (bibcode: 2017A&amp;A...606A..71S

Sulphur in the Sculptor dSph

VizieR online Data Catalogue associated with article published in journal Astronomy &amp; Astrophysics with title 'Sulphur in the Sculptor dwarf spheroidal galaxy. Including NLTE corrections.' (bibcode: 2015A&amp;A...580A.129S