Self-absorption in the solar transition region

Transient brightenings in the transition region of the Sun have been studied for decades and are usually related to magnetic reconnection. Recently, absorption features due to chromospheric lines have been identified in transition region emission lines raising the question of the thermal stratification during such reconnection events. We analyse data from the Interface Region Imaging Spectrograph (IRIS) in an emerging active region. Here the spectral profiles show clear self-absorption features in the transition region lines of Si\,{\sc{iv}}. While some indications existed that opacity effects might play some role in strong transition region lines, self-absorption has not been observed before. We show why previous instruments could not observe such self-absorption features, and discuss some implications of this observation for the corresponding structure of reconnection events in the atmosphere. Based on this we speculate that a range of phenomena, such as explosive events, blinkers or Ellerman bombs, are just different aspects of the same reconnection event occurring at different heights in the atmosphere.Comment: Accepted for publication in Ap

"Digital kompetanse i individuelle opplæringsplaner?" : hva legges i begrepet digital kompetanse i utdanningspolitiske dokumenter og hvilken relevans har dette for utarbeidelsen av individuelle opplæringsplaner?

1.Problemstilling Temaet i denne masteroppgaven er begrepet digital kompetanse og relevansen av det i individuelle opplæringsplaner. Læreplanverket for kunnskapsløftet (Utdanningsdirektoratet, 2006) opererer med fem grunnleggende ferdigheter som beskriver avgjørende forutsetningene for at elevene skal få utbytte av opplæring. Den femte, grunnleggende ferdighet er å bruke digitale verktøy. Gjennom oppgaven, har jeg forsøkt å belyse, hvilke andre ferdigheter, kriterier og momenter inngår i begrepet digital kompetanse. Hovedproblemstilling er: Hva legges i begrepet digital kompetanse i utdanningspolitiske dokumenter og hvilken relevans har dette for utarbeidelsen av individuelle opplæringsplaner. For å svare på hovedproblemstillingen, har jeg delt oppgaven i tre deler, hvorav i den første del avklares begrepet digital kompetanse med bakgrunn i en teoretisk tilnærming. Definisjoner av kompetanse, literacy, ICT/digital literacy, media literacy og digitale ferdigheter bidrar sammen til å operasjonalisere digital kompetanse. Videre i oppgaven svarer jeg på problemstillingens andre del om hva legges i begrepet digital kompetanse i utdanningspolitiske dokumenter gjennom dokumentanalyse av Læreplanverket for Kunnskapsløfte (Utdanningsdirektoratet, 2006), Storingsmelding 30 Kultur for læring (Kunnskapsdepertementet, 2003-2004) og Program for digital kompetanse 2004-2008 (Utdannings- og forskningsdepartementet, 2004). I oppgavens siste del drøftes relevansen av begrepet digital kompetanse slik den er fremstilt i dokumentene i individuelle opplæringsplaner. 2.Kilder og metode Den metodiske tilnærmingen til oppgaven er teoretisk. Den behandler relevant faglitteratur og dokumenter som blir presentert, analysert og drøftet. Oppgavens konklusjon tar utgangspunkt i en analyse av styringsdokumenter som omhandler digital kompetanse i skolen. Framstillinger og vurderinger i oppgaven er bygd på primær- og sekundærkilder, samt styringsdokumenter. Dokumentanalysen ble foretatt på bakgrunn av Kamil Øzerks (1999) sin pedagogisk- filosofiske tilnærming til grunnskolens opplæringspraksis. Øzerks fremstilling har dannet grunnlaget for identifisering og drøfting av relevante utsagn i dokumentene. Valg av styringsdokumenter og oppgavens problemområde er avgrenset til Goodlads (1979) femte læreplannivået som belyser den formelle og ideenes læreplan. I forhold til drøfting av digital kompetanse i individuelle opplæringsplaner benytter jeg blant annet deler av modellen til Thomas Nordahl og Terje Overland (2001). 3.Konklusjoner Ut ifra en analyse av styringsdokumenter kommer det frem at begrepet digital kompetanse innebærer følgende momenter: For det første vektlegges kritisk holdning eller det å være kritisk. Videre påpekes problemløsning, refleksjon eller det å være vurderende og drøftende. Det neste som trekkes frem er samarbeid eller det å være kommunikativ, tolerant og det å delta i sosiale relasjoner. Videre understrekes utforskning eller det å være utforskende, nysgjerrig, undrende, oppdagende og sannhetssøkende. Samtidig vektlegges det å mestre skiftende omgivelser og oppnåelsen av funksjonell kunnskap. Digital kompetanse synes i tillegg å innebære det å være kreativ, selvstendig og ansvarlig. Evner som ble nevnt utvikles gjennom sosiale relasjoner og erfaringer. Ut fra den foretatte analysen konkluderte jeg med at begrepet digital kompetanse har flere sider og ikke er ensbetydende med bruk av IKT/digitale verktøy. Drøfting av overordede mål for opplæring i individuelle opplæringsplaner (IOP) som omhandler samfunnsnivå, mellommenneskelig nivå og individnivå viser at momentene i begrepet digital kompetanse som jeg har kommet frem gjennom dokumentanalysen er relevante for utarbeidelsen av individuelle opplæringsplaner. Det å klare seg i samfunnet og fremtidig arbeidsliv, utvikle kommunikative evner og samarbeidsevner samt oppnå ferdigheter som er til personlig nytte forutsetter de egenskapene som inngår i begrepet digital kompetanse konstatert i første konklusjon. Skolens oppgave er blant annet å utvikle elevene i retning av å bli likeverdige medlemmer samfunnet. I tråd med læreplanens intensjoner som jeg skisserer omhandler funksjonell og likeverdig fungering i dette samfunnet, også digital kompetanse. Dermed mener jeg at digital kompetanse er relevant i individuelle opplæringsplaner både på samfunnsnivå, mellommenneskelig nivå og individnivå. Og slik jeg påpeker i oppgaven inneholder digital kompetanse mye mer enn bruk av digitale verktøy i teknisk forstand

Sporadic multiple parathyroid gland disease—a consensus report of the European Society of Endocrine Surgeons (ESES)

Background: Sporadic multiglandular disease (MGD) has been reported in literature in 8–33 % of patients with primary hyperparathyroidism (pHPT). This paper aimed to review controversies in the pathogenesis and management of sporadic MGD. Methods: A literature search and review was made to evaluate the level of evidence concerning diagnosis and management of sporadic MGD according to criteria proposed by Sackett, with recommendation grading by Heinrich et al. and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Results were discussed at the 6th Workshop of the European Society of Endocrine Surgeons entitled ‘Hyperparathyroidism due to multiple gland disease: An evidence-based perspective’. Results: Literature reports no prospective randomised studies; thus, a relatively low level of evidence was achieved. Appropriate surgical therapy of sporadic MGD should consist of a bilateral approach in most patients. Unilateral neck exploration guided by preoperative imaging should be reserved for selected patients, performed by an experienced endocrine surgeon and monitored by intraoperative parathormone assay (levels of evidence III–V, grade C recommendation). There is conflicting or equally weighted levels IV–V evidence supporting that cure rates can be similar or worse for sporadic MGD than for single adenomas (no recommendation). Best outcomes can be expected if surgery is performed by an experienced parathyroid surgeon working in a high-volume centre (grade C recommendation). Levels IV–V evidence supports that recurrent/persistence pHPT occurs more frequently in patients with double adenomas hence in situations where a double adenoma has been identified, the surgeon should have a high index of suspicion during surgery and postoperatively for the possibility of a four-gland disease (grade C recommendation). Conclusions: Identifying preoperatively patients at risk for MGD remains challenging, intraoperative decisions are important for achieving acceptable cure rates and long-term follow-up is mandatory in such patients

Solar prominence diagnostics and their associated estimated errors from 1D NLTE Mg II h&k modelling

Aims. We present further development of the rolling root mean square (rRMS) algorithm. These improvements consist of an increase in computational speed and an estimation of the uncertainty on the recovered diagnostics. This improvement is named the cross root mean square (xRMS) algorithm. Methods. We used the quantile method to recover the statistics of the line profiles in order to study the evolution of the prominence observed by IRIS on 1 October 2019. We then introduced the improvements to rRMS. These improvements greatly increased the computational speed, and this increase in speed allowed us to use a large model grid. Thus, we utilised a grid of 23 940 models to recover the thermodynamic diagnostics. We used the 'good' (but not 'best') fitting models to recover an estimate of the uncertainty on the recovered diagnostics. Results. The maximum line-of-sight (LOS) velocities were found to be 70 km/s. The line widths were mostly 0.4 {\AA} with the asymmetries of most pixels around zero. The central temperature of the prominence was found to range from 10 kK to 20 kK, with uncertainties of approximately +/-5 to +/-15 kK. The central pressure was around 0.2 dyn/cm2, with uncertainties of +/-0.2 to +/-0.3 dyn/cm2. The ionisation degree ranged from 1 to 1000, with uncertainties mostly in the range +/-10 to +/-100. The electron density was mostly 10^10 /cm3, with uncertainties of mostly +/-10^9. Conclusions. The new xRMS algorithm finds an estimation of the errors of the recovered thermodynamic properties. To our knowledge, this is the first attempt at systematically determining the errors from forward modelling. The large range of errors found may hint at the degeneracies present when using a single ion and/or species from forward modelling. In the future, co-aligned observations of more than one ion and/or species should be used to attempt to constrain this problem.Comment: 9 pages, 12 figure

Systematic review of cure and recurrence rates following minimally invasive parathyroidectomy

Background The majority of patients with primary hyperparathyroidism (PHPT) have a single overactive adenoma. Advances in preoperative imaging and surgical adjuncts have given rise to minimally invasive parathyroidectomy (MIP), with lower complication rates in comparison with bilateral neck exploration. Misdiagnosis and undertreatment of multiglandular disease, leading to potentially higher recurrence rates, remains a concern. This study evaluated risks of long‐term (1 year or more) recurrence following ‘targeted’ MIP in PHPT. Methods Multiple databases were searched for studies published between January 2004 and March 2017, looking at long‐term outcomes (1 year or more) following targeted MIP for PHPT. English‐language studies, with at least 50 patients and a mean follow‐up of 1 year, were included. Results A total of 5282 patients from 14 studies were included. Overall mean recurrence and cure rates were 1·6 (range 0–3·5) and 96·9 (95·5–100) per cent respectively. Mean follow‐up was 33·5 (1–145) months. When intraoperative parathyroid hormone (PTH) measurements were not done, cure rates were higher (99·3 per cent versus 98·1 per cent with use of intraoperative PTH measurement; P < 0·001) and recurrence rates lower (0·2 versus 1·5 per cent respectively; P < 0·001). Conclusion Targeted MIP for a presumed single overactive adenoma was associated with very low recurrence rates, without the need for intraoperative PTH measurement when preoperative imaging studies were concordant. Targeted MIP should be encouraged

Two-horn quiescent prominence observed in H-alpha and MgII h&k lines with THEMIS and IRIS

Prominences are large magnetic structures in the corona filled by cool plasma with fast evolving fine structure. We aim to better understand the plasma conditions in the fine structure of a quiescent prominence including two transient horns observed at the bottom of the cavity using the high-resolution spectrograph IRIS and the MulTi-Raies (MTR) spectrograph of the THEMIS in the Canary Islands. We analysed the spectra obtained in H-alpha by THEMIS and MgII by IRIS and compare them with a grid of 23940 1D radiative transfer models which include a prominence-to-corona transition region (PCTR). The full observed profiles of MgII in each pixel are fitted completely by synthesised profiles with xRMS (Cross RMS; an improved version of the rolling root mean square (rRMS) method). When the RMS is below a certain threshold value, we recover the plasma conditions from the parameters of the model best fitting the observed line profile. This criterion is met in two regions (the horns and edge of the prominence) where the line profiles can generally be described as single peaked. The 1D models suggest that two different kinds of model atmospheres correspond to these two regions. The region at the edge is found to be fitted mainly with isothermal and isobaric models, while the other area (the horns) is seen to be fitted with models with a PCTR that have optical thicknesses <5. In the prominence edge, the theoretical relationship between the integrated intensities in H-alpha and MgII is verified and corresponds to low emission measure values. In these regions the electron density is ~10^10 cm^{-3}, while it is one order of magnitude less in the horn regions. In the horns, we find some profiles are best fitted with models with high mean temperatures. This suggests that the hot PCTR found in the horns could be interpreted as prominence plasma in condensation phase at the bottom of the coronal cavity.Comment: 24 pages, 19 figures, manuscript accepted to publication in A&

1,3-Bis(carboxy­meth­yl)imidazolium triiodide 1-carboxyl­atomethyl-3-carboxy­methyl­imidazolium

In the title compound, C7H9N2O4 +·I3 −·C7H8N2O4, the two imidazolium units are hydrogen bonded through the carboxyl groups. The units are further linked via inter­molecular O—H⋯O hydrogen bonding, resulting in a one-dimensional ladder-type structure. As a result, the two carb­oxy groups of each imidazolium unit adopt a cis configuration with respect to the imidazolium ring