Opin visindi
Not a member yet
2982 research outputs found
Sort by
Að bera kennsl á einhverfu snemma
No full textAims.
The objective of this thesis was to test surveillance procedures for early detection of autistic children. The specific aims were: (1) to describe the characteristics of children diagnosed with autism before and after the age of 6 years, and to identify factors that influence the age of diagnosis; (2) to study the implementation of a screening program for autism within the well-child care in primary health care centers (PHCs); (3) to validate the Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F) on a population sample of 30-month-old children; and (4) to evaluate the rate of autism in a group invited to a screening program in comparison with the rates in two groups who received usual care.
Materials and methods.
Study I was a cohort study. We studied all children in Iceland born 1992 to 1995 who had been diagnosed as autistic (N = 99) according to a nationwide database kept at the State Diagnostic and Counseling Center (SDCC). Children diagnosed before and after the age of 6 years were compared, and parents answered a questionnaire about their first developmental concerns.
Studies II, III, and IV dealt with a prospective program on the early detection of autism. The program included a two-stage screening for autism and a course on autism for the well-child care clinicians. The population eligible for screening included all children in Iceland registered for their 30-month well-child visit at a PHC from March 1, 2016, to October 31, 2017. The capital area of Reykjavik was chosen for implementation of the screening, and cluster randomization was used with the PHCs as the units of randomization. Nine PHCs were randomly selected for the screening, while eight PHCs were assigned to control group 1. PHCs outside the capital area were not randomized and were assigned to control group 2.
The well-child care clinicians completed a questionnaire on their pre- and post-course knowledge of autism, and contact persons at the PHCs answered a survey about their experience and attitudes towards the screening. Parents answered the screener during the well-child visit and participated in a follow-up interview if the child showed indications of autism. Children who screened positive were referred to the SDCC for diagnostic assessment and for early intervention provided by their local communities.
The children in the entire population of the corresponding definition were followed up in the database at the SDCC, from March 1, 2016, to October 31, 2019, when they were between 54 and 79 months of age. The performance of the M-CHAT-R/F was evaluated with classical measures. The occurrence of autistic children during the follow-up was measured by cumulative incidence in the respective aforementioned groups. The comparison between the rate of autism in the invited group (asked to participate in screening) and the rates in the control groups (receiving usual care) were done with rate ratios and 95% confidence intervals (CIs).
Results.
Fifty-eight children (58.6%) in Study I received an autism diagnosis before age 6 and 41 children (41.4%) after age 6. Most parents (76.2%) had concerns about the development of their child prior to the third birthday. Further, in hindsight, most parents (83.3%) reported that symptoms of autism were present before age 2 years, and almost all parents (97.6%) that they were present before age 3 years. A delayed diagnosis of autism was associated, among other things, with good cognitive and verbal status, and mild symptoms.
The majority (79%) of the clinicians who participated in the course (N = 56) had not received prior education on autism. Participation in the course contributed to increased self-perceived knowledge and confidence in identifying behaviors indicating autism. A total of 1586 children in the invited group participated in the screening, or 72% of those who attended the 30-month-old well-child visit. Twenty-six children screened positive and 25 of them received diagnostic assessment, eighteen of whom were diagnosed as autistic (true-positive). An additional 11 children received an autism diagnosis in the screened group (false-negative). The sensitivity and specificity of the M-CHAT-R/F were 0.62 and 0.99 respectively. True-positive children were diagnosed 10 months earlier than false-negative children. Autism symptom severity and the proportion of children with verbal and performance IQs/DQs <70 were similar in the true-positive and false-negative groups. The mean time from screening in the PHC to intervention of screen-positive children was 3.56 months (SD = 4.00), and 18.28 months (SD = 2.72) to diagnostic assessment.
A total of 119 children in the study population were diagnosed as autistic during the follow-up period. The overall cumulative incidence was 1.66 (95% CI, 1.37, 1.99), and the male to female ratio was 4.7:1. In the invited group, control group 1, and control group 2, the cumulative incidence rate was 2.13 (95% CI, 1.60, 2.78), 1.83 (95% CI, 1.31, 2.50), and 1.02 (95% CI, 0.66, 1.50), respectively. The rate ratio of invited group versus control group 1 was 1.16 (95% CI, 0.77, 1.75), and the rate ratio of invited group versus control group 2 was 2.10 (95% CI, 1.31, 3.37).
Conclusions.
Despite parental concerns about their child’s development and the early presence of autism symptoms, children still encountered delays in being diagnosed as autistic, which indicated that better efforts to detect autism early were needed. Implementation of the screening with the M-CHAT-R/F in well-child care was feasible. The screening contributed to an earlier detection of autistic children. The specificity of the M-CHAT-R/F was high, but the sensitivity was moderate, such that the M-CHAT-R/F missed more than a third of the autistic children. Limited knowledge of autism among some of the well-child care clinicians indicates a need for continuous education. While the rate of autism was higher in the invited group than in the control groups, interpreting the results is difficult because of the wide confidence intervals. So, one cannot firmly conclude from this study that the screening program detected autism more readily than did the usual care. Moreover, the lower rate of autism in the rural areas than in the urban areas may indicate a shortage of developmental services in rural areas.Markmið
Markmið þessa doktorsverkefnis var að rannsaka hvernig hægt er að finna einhverfu
snemma. Sértæk markmið voru: (1) að lýsa auðkennum barna sem greinast einhverf
fyrir og eftir 6 ára aldur og að finna þá þætti sem gætu haft áhrif á hvenær þau
greinast; (2) að rannsaka innleiðingu skimunar fyrir einhverfu í ung- og smábarnavernd
í heilsugæslunni; (3) að meta gildi skimunartækisins Gátlisti fyrir einhverfu hjá
smábörnum, breyttur og endurskoðaður með eftirfylgdarviðtali (e. Modified Checklist
for Autism in Toddlers, Revised with Follow-Up; M-CHAT-R/F) í lýðgrunduðu úrtaki 30
mánaða barna; (4) að rannsaka tíðni einhverfu í hópi sem boðin var þátttaka í skimun í
samanburði við tíðni einhverfu í tveimur hópum sem ekki var boðin skimun.
Efni og aðferðir
Í grein I er fjallað um ferlirannsókn. Öll börn á Íslandi fædd á árunum 1992-1995, sem
höfðu fengið einhverfugreiningu (N = 99) og voru á skrá hjá Greiningar- og
ráðgjafarstöð ríkisins (GRR), voru þar til rannsóknar. Börn sem greindust fyrir og eftir 6
ára aldur voru borin saman og foreldrar svöruðu spurningum tengdum því hvenær þeir
fóru fyrst að hafa áhyggjur af þroska barna sinna.
Greinar II, III og IV eru um framsýnar rannsóknir á snemmgreiningu einhverfu.
Skimunin fyrir einhverfu var tveggja þrepa og heilbrigðisstarfsfólk í ung- og
smábarnavernd var frætt um einhverfu. Það kom til greina að skima öll börn á Íslandi,
sem voru skráð í 30 mánaða skoðun á heilsugæslustöðvum landsins frá 1. mars 2016 til
31. október 2017, en höfuðborgarsvæðið var valið sérstaklega. Slembun var gerð þar
sem heilsugæslustöðvarnar voru einingar slembunarinnar. Níu heilsugæslustöðvar voru
slembivaldar til þátttöku í skimuninni og átta heilsugæslustöðvum var skipað í
samanburðarhóp 1. Heilsugæslustöðvar utan höfuðborgarsvæðisins voru ekki með í
slembuninni og var skipað í samanburðarhóp 2.
Heilbrigðisstarfsfólk í ung- og smábarnavernd svaraði spurningalista um þekkingu sína á
einhverfu fyrir og eftir námskeiðið sem haldið var fyrir það og tengiliðir á
heilsugæslustöðvunum svöruðu könnun um reynslu sína og viðhorf til skimunar.
Samkvæmt upplýstu samþykki svöruðu foreldrar M-CHAT-R/F skimunarlistanum þegar
þeir komu með barnið í skoðun og tóku þátt í eftirfylgdartviðtali ef vísbendingar komu
fram um einhverfu hjá barninu. Börnum sem skimuðust jákvæð var vísað í greiningu hjá
GRR og til þjálfunar/sérkennslu á vegum skólaþjónustu síns sveitarfélags. Hefðbundnar
aðferðir voru notaðar til þess að meta M-CHAT-R/F.
iv
Öllum börnum, sem skráð voru í 30 mánaða skoðun var fylgt eftir í skrá GRR frá 1.
mars 2016 til 31. október 2019, en þá voru þau á aldrinum 54 til 79 mánaða. Nýgengi
einhverfutilfella var reiknað fyrir hvern fyrrnefndan hóp. Nýgengi einhverfu í hópnum,
sem boðin var skimun, var borin saman við nýgengi í samanburðarhópunum og
reiknað áhættuhlutfall með 95% öryggismörkum.
Niðurstöður
Fimmtíu og átta börn (58,6%) greindust einhverf fyrir 6 ára aldur og 41 barn (41,4%)
eftir 6 ára aldur. Flestir foreldrar (76,2%) voru farnir að hafa áhyggjur af þroska
barnsins fyrir 3 ára aldur þess. Einnig töldu flestir foreldrar (83,3%), eftir á að hyggja,
að einkenni einhverfu hefðu verið komin fram fyrir 2 ára aldur og næstum allir foreldrar
(97,6%) töldu að svo hefði verið fyrir 3 ára aldur. Síðbúin greining einhverfu tengdist
meðal annars góðum vitsmuna- og málþroska og vægum einkennum einhverfu.
Meirihluti heilbrigðisstarfsfólks (79%) sem tók þátt í námskeiðinu (N = 56) hafði ekki
fengið fræðslu um einhverfu áður. Þátttaka í námskeiðinu stuðlaði að þeirra mati að
aukinni þekkingu og meira öryggi til að bera kennsl á einkenni sem gætu bent til
einhverfu. Samtals tóku 1586 börn í þátt í skimuninni í heilsugæslunni, eða 72% þeirra
barna sem komu í 30 mánaða skoðun. Tuttugu og sex börn skimuðust jákvæð og af
þeim 25 börnum sem fóru í greiningu reyndust 18 vera einhverf. Ellefu börn til viðbótar
greindust einhverf í hópnum sem skimaðist neikvæður. Næmi M-CHAT-R/F var 0,62 og
sértæki var 0,99. Börn sem fundust við skimunina voru að meðaltali 10 mánuðum yngri
við greiningu en börn sem skimunin missti af. Alvarleiki einkenna einhverfu og
greindartala/þroskatala <70 var svipað í hópum einhverfu barnanna. Meðaltími sem
leið frá skimun og þar til þjálfun/sérkennsla hófst var 3,56 mánuðir (SF = 4,00) og
18,28 mánuðir (SF = 2,72) þar til greining fór fram.
Alls greindust 119 börn í þýðinu einhverf á eftirfylgdartímanum. Nýgengi í öllu þýðinu
var 1,66 (95% öryggismörk, 1,37, 1,99) og hlutfall drengja og stúlkna var 4,7:1. Í
hópnum sem boðið var til skimunar, samanburðarhópi 1 og samanburðarhópi 2, voru
nýgengi tölurnar 2,13 (95% öryggismörk, 1,60, 2,78), 1,83 (95% öryggismörk, 1,31,
2,50) og 1,02 (95% öryggismörk, 0,66, 1,50). Miðað við samanburðarhóp 1 var
áhættuhlutfallið 1,16 (95% öryggismörk, 0,77, 1,75) og miðað við samanburðarhóp 2
var áhættuhlutfallið 2,10 (95% öryggismörk, 1,31, 3,37).
Ályktanir
Þrátt fyrir áhyggjur foreldra af þroska barna sinna og að einkenni einhverfu væru komin
fram snemma, var síðbúin einhverfugreining algeng, sem benti til að þörf sé á átaki til
þess að finna einhverfu snemma. Innleiðing skimunar með M-CHAT-R/F í ung- og
smábarnavernd var auðveld í framkvæmd og skimunin stuðlaði að því að einhverfa
fannst fyrr. Sértæki M-CHAT-R/F var hátt, en næmið var miðlungs gott, þannig að MCHAT-R/F missti af ríflega þriðjungi þeirra barna sem voru einhverf. Takmörkuð
þekking heilbrigðisstarfsfólks í ung- og smábarnavernd á einhverfu bendir til þess að
v
þörf sé á meiri fræðslu. Þó að tíðni einhverfu væri hærri í hópnum sem boðinn var til
skimunar en í samanburðarhópunum er erfitt að túlka niðurstöðurnar vegna víðra
öryggismarka. Því er ekki er hægt að álykta með vissu, út frá þessari rannsókn, að
skimunin stuðlaði að því að einhverfa greinist fyrr en ella. Lægri tíðni einhverfu í
dreifbýlinu en á höfuðborgarsvæðinu bendir til þess að efla þurfi þjónustu á þessu sviði í dreifbýliThis research was partly supported by the Freemasons Fund of the Icelandic Order of
Freemasons (Paper I), the Ministry of Social Welfare’s Grant for Quality Projects in
Healthcare, the SDCC’s Memorial Fund, the Barnavinafélagið Sumargjöf Fund, the
Oddur Ólafsson Memorial Fund (Paper II), and the Public Health Fund in Iceland
(Paper III)
Einkenni og svipgerð íþyngjandi dagsyfju: Rannsókn á almennu þýði og kæfisvefnssjúklingum
No full textInngangur: Íþyngjandi dagsyfja er einkenni sem hefur flókið samband við svefn, lífstíl,
andlega- og líkamlega heilsu einstaklinga. Kæfisvefn er algengasti sjúkdómurinn sem
veldur dagsyfju. Epworth Syfjuskali (ESS) og er stuttur spurningalisti sem metur líkur á
að sofna/dotta og er ESS sú aðferð sem oftast er notuð til að mæla dagsyfju. Veik
fylgni er á milli mælinga með ESS og þess hversu oft eða ákaft einstaklingur upplifir
syfju. Syfja virðist því ekki vera einsleitt ástand sem unnt er að mæla einungis með
“líkum á að dotta”, heldur flókið og margþætt einkenni, sem samanstendur af mörgum
syfju-tengdum þáttum. Það skortir betri skilning á bæði orsökum og afleiðingum
mismunandi þátta huglægrar syfju. Slíkur skilningur gæti stuðlað að þróun á
heildstæðari og nákvæmari aðferða við mat á íþyngjandi dagsyfju.
Markmið: Að kanna algengi, sérkenni og fylgni tveggja skilgreininga íþyngjandi
dagsyfju bæði meðal almennings og hjá kæfisvefnssjúklingum fyrir og eftir meðferð.
Að auki voru skoðuð tengsl margháttaðra mælibreyta í svefni við dagsyfju einkennin.
Efniviður og aðferðir: Tveir þættir íþyngjandi dagsyfju voru metnir; ESS stig (>10 stig
skilgreint sem “líklegir til að dotta”) og upplifun dagsyfju (≥3 sinnum í viku skilgreint
sem að “upplifa dagsyfju”). Þátttakendum var síðan skipt í fjóra syfjuhópa m.t.t.
svipgerðar: “ekki syfjaðir”, “bara líklegir að dotta”, “upplifa bara dagsyfju” og “bæði
líklegir að dotta og upplifa dagsyfju”. Í grein I voru syfjuhóparnir skoðaðir meðal
slembiúrtaks úr almennu þýði einstaklinga 40 ára og eldri sem tóku þátt í
faraldsfræðilegri rannsókn á algengi og eðli langvinnrar lungnateppu (e. Burden of
Obstructive Lung Disease (BOLD)). Syfjuhóparnir voru bornir saman m.t.t.
lýðfræðilegra- og lífsstílsþátta, almennrar heilsu, svefntengdra einkenna, líkum á
kæfisvefni og lífsgæða. Í grein II voru syfjuhóparnir kannaðar á meðal sjúklinga með
miðlungs-til-alvarlegan kæfisvefn í Íslenska svefnrannsóknarhópnum (e. Icelandic Sleep
Apnea Cohort (ISAC)). Algengi og sérkenni syfjuhópanna voru metin við greiningu og
aftur 2 árum eftir að meðferð með svefnöndunarvél hófst. Við eftirfylgdina var
meðferðarheldni þeirra metin ásamt breytingu á syfju-tengdum einkennum, svefnleysi
og lífsgæðum. Þeir sem upplifðu viðvarandi íþyngjandi dagsyfju (voru “líklegir til að
dotta” og/eða „upplifa dagsyfju“ við greiningu og eftirfylgd) voru bornir saman við þá
sem fengu bata. Í grein III voru niðurstöður úr grein II sannreyndar með svipuðum
aðferðum og í grein I og II í alþjóðlegum hópi kæfisvefnssjúklinga (e. Sleep Apnea
Global Interdisciplinary Consortium (SAGIC)) með miðlungs-til-alvarlegan kæfisvefn. Að
lokum, í grein IV, voru svefnbreytur mældar með svefnmælingu (e. polysomnography
(PSG)) og bornar saman á milli milli syfjuhópanna meðal sjúklinga með vægan-tilalvarlegan kæfisvefn í SAGIC.
iv
Niðurstöður: Í almenna þýðinu (n=1338, 53% karlar) voru 70.2% „ekki syfjaðir“, 6.7%
„bara líklegir til að dotta“, 16.7% „upplifðu bara dagsyfju” og 6.4% voru “bæði líklegir
til að dotta og upplifðu dagsyfju”. Þeir sem voru „bæði líklegir til að dotta og upplifðu
dagsyfju” lýstu oftar hrotum, nætursvita og öndunarstoppum í svefni. Þeir sem „upplifði
bara dagsyfju“ var oftar með háþrýsting, hjarta- og æðasjúkdóma, sykursýki og einkenni
svefnleysis. Einstaklingar í syfjuhópunum tveimur sem “upplifðu dagsyfju” mátu
lífsgæði sín marktækt verri en aðrir. Þeir sem voru „bara líklegir til að dotta“ voru
líklegri til að lýsa einkennum kæfisvefns (hrotur og öndunarstopp í svefni) en voru að
öðru leyti eins og þeir sem voru „ekki syfjaðir“. Á meðal kæfisvefnssjúklinga í ISAC
(n=810, 81% karlar) voru 17.7% „ekki syfjaðir“, 7.7% „bara líklegir til að dotta“, 24.7%
“upplifðu bara dagsyfju” og 49.9% voru “bæði líklegir til að dotta og upplifðu
dagsyfju”. Svipað og hjá einstaklingum í almennu þýði syfjuhóparnir tveir sem
“upplifðu dagsyfju” oftar með einkenni svefnleysis og mátu lífsgæði sín verri en
einstaklingar öðrum syfjuhópum. Þeir sem “upplifðu bara dagsyfju“ voru líklegri til að
vera kvöldtýpur. Meðferðarheldni á notkun svefnöndunarvélar var svipuð milli
syfjuhópanna. Þeir sjúklingar sem voru “líklegir til að dotta” (með/án að „upplifa
dagsyfju) sýndu meiri ávinning af meðferð en aðrir. Við 2ja ára eftirfylgni höfðu 42.3%
viðvarandi syfju þrátt fyrir meðferð. Þeir voru með vægari kæfisvefn við greiningu og
við eftirfylgd höfðu þeir oftar viðvarandi einkenni kæfisvefns og kvartanir um svefnleysi
borið saman við þá sem hafði batnað. Meðal kæfisvefnssjúklinga í SAGIC hópnum
(n=2352, 77% karlar) var algengi þess að hafa ESS stig >10 svipað og í ISAC hópnum
(57% í SAGIC og 52% í ISAC) en tíðni þess að upplifa dagsyfju ≥3 sinnum á viku var
mun lægra (31,3% í SAGIC og 74,7% í ISAC). Á heildina litið studdu niðurstöðurnar í
SAGIC hópnum niðurstöður okkar í ISAC. Meðal sjúklinga með vægan-til-alvarlegan
kæfisvefn í SAGIC (n= 2097, 68% karlar) höfðu syfjuhóparnir tveir sem voru “líklegir til
að dotta” fleiri skipti á klukkustund með öndunarhléum eða minnkaðri öndun (e. apneahypopnea index), alvarlegri súrefnisskort mælt með stuðli súrefnismettunarfalls (e.
oxygen-desaturation index), lágmarks- og meðalsúrefnismettun og tíma varið <90% í
súrefnismettun og vörðu styttri tíma vakandi en þeir sem voru „ekki syfjaðir“ og
„upplifðu bara dagsyfju“. Á heildina litið var sambandið milli svefnbreytanna á PSG og
syfjuhópanna veikt. Ekki reyndist marktækur munur milli syfjuhópanna á svefnstigum,
svefndýpt, tíðni og styrkleika uppvaknana, tíma að sofnun, vökutíma eftir sofnun og
hreyfingu útlima í svefni.
Ályktanir: Íþyngjandi dagsyfja er margþætt einkenni. Íþyngjandi dagsyfja metin út frá
líkum að dotta annars vegar og hins vegar að upplifa dagsyfju tengjast heilsu, svefni,
kæfisvefni og lífsgæðum á mismunandi hátt meðal einstaklinga í almennu þýði og
einnig meðal íslenskra kæfisvefnssjúklinga og stórs hóps sjúklinga frá fjölda landa.
Eingöngu voru væg tengsl milli margháttaðra mælibreyta í svefni við dagsyfju einkenna.Introduction: Excessive daytime sleepiness (EDS) is a symptom that has a complex
relationship with a person’s sleep and lifestyle as well as their mental and physical
health. The most frequently identified medical disorder causing EDS is obstructive sleep
apnea (OSA). The Epworth Sleepiness Scale (ESS) is a brief questionnaire that assesses
risk of dozing and ESS is the most widely used method to measure sleepiness. There is
a weak correlation between the ESS score and measures of how often or how intensely
a person experiences a general feeling of sleepiness. This suggests that sleepiness is
not a uniform condition that is accurately assessed by the tendency to doze off but a
complex symptom comprising multiple components. A better understanding of both the
causes and consequences of the different components of subjective sleepiness are
needed for the development of a more comprehensive approach when evaluating
sleepiness.
Objectives: To examine the prevalence, characteristics and correlation of two subjective
EDS measures both among the general population and OSA patients before and after
treatment. Also to investigate the association between physiological characteristics
during sleep and EDS.
Methods: Two components of EDS were assessed; the ESS score (>10 points defined
as having “risk of dozing”) and a measure of general sleepiness (feeling sleepy ≥3
times per week defined as “feeling sleepy“). Participants were subsequently
categorized into four sleepiness phenotypes: “non-sleepy”, “risk of dozing only”,
“feeling sleepy only” and “both at risk of dozing and feeling sleepy”. Paper I assessed
the sleepiness phenotypes in a random sample of the general population aged 40
years and above who participated in the Burden of Obstructive Lung Disease (BOLD)
study. Sleepiness phenotypes were compared regarding sociodemographic and
lifestyle factors, general health, sleep-related symptoms, OSA risk and quality of life. In
paper II, the sleepiness phenotypes were explored among OSA patients with moderateto-severe disease in the Icelandic Sleep Apnea cohort (ISAC). Similarly, as in paper I,
the sleepiness phenotypes were assessed and their characteristics compared at time of
diagnosis and again after 2 years of positive airway pressure (PAP) treatment. At the 2-
year follow-up, their PAP adherence was assessed and changes in symptoms of daytime
impairment, insomnia symptoms and quality of life were evaluated. OSA patients
experiencing persistent EDS (having “risk of dozing and/or “feeling sleepy” at baseline
and follow-up) were compared to those whose sleepiness improved. In paper III, the
results from paper II were validated among OSA patients with moderate-to-severe
disease in the large international Sleep Apnea Global Interdisciplinary Consortium
(SAGIC) cohort using similar methods as in paper I and II. Finally, in paper IV,
vi
polysomnography (PSG) characteristics of the sleepiness phenotypes among OSA
patients with mild-to-severe OSA in the SAGIC cohort were assessed and compared.
Results: In the general population (n=1338, 53% males), 70.2% were “non-sleepy”,
6.7% reported “risk of dozing only”, 16.7% were “feeling sleepy only” and 6.4% had
both symptoms. Those “both at risk of dozing and feeling sleepy” had the highest
prevalence of snoring, nocturnal sweating, and reporting apneas. Those “feeling sleepy
only” more often reported hypertension, cardiovascular disease, diabetes, and
insomnia symptoms. Quality of life was poorest among the two phenotypes “feeling
sleepy”. Those at “risk of dozing only” however had a higher prevalence of OSA
symptoms (self-reported apneas and snoring) but were otherwise like the “non-sleepy”
subjects. Among OSA patients in ISAC (n=810, 81% males) 17.7% were “non-sleepy”,
7.7% were at “risk of dozing only”, 24.7% were “feeling sleepy only” and 49.9%
reported both symptoms. As in the general population, the two phenotypes “feeling
sleepy” had a higher prevalence of insomnia symptoms and reported poorer quality of
life. Those “feeling sleepy only” reported the evening chronotype more often. PAP
adherence did not differ by baseline sleepiness phenotype, but the two phenotypes
with “risk of dozing” showed greater benefits of PAP treatment than “non-sleepy” and
“feeling sleepy only” phenotypes. At the 2-year follow-up, 42.3% of PAP users had
persistent sleepiness. They had less severe OSA at baseline, more persistent OSA
symptoms and more often had symptoms of insomnia than OSA patients in whom
sleepiness resolved. Among the OSA patients in the SAGIC cohort (n=2.352, 77%
males), the prevalence of having an ESS score >10 was similar to the ISAC cohort (57%
vs. 52% respectively) but reporting feeling sleepy ≥3 times per week was not as
common as in ISAC (31.3% vs. 74.7% respectively). Overall, the results in the SAGIC
cohort supported our findings in the ISAC. Among OSA patients with mild-to-severe
disease in SAGIC (n= 2.097, 68% males), the two phenotypes at “risk of dozing” had a
higher apnea hypopnea index (AHI) and more severe hypoxemia as measured by the
oxygen desaturation index, minimum and average oxygen saturation (SpO2) and time
spent <90% SpO2 and spent less time awake than “non-sleepy” and “feeling sleepy
only” phenotypes. Overall, effect sizes were small. Sleep stages, odds ratio product,
frequency and intensity of arousals, sleep latency, wake after sleep onset and limb
movement did not differ between sleepiness phenotypes after adjusting for
confounders.
Conclusions: EDS is a multifaceted symptom. Defining EDS based on the propensity to
doze off and the more general feeling of sleepiness correlates differently with health
aspects, sleep, OSA and quality of life among individuals in the general population, in
Icelandic OSA patients and in a large group of international OSA patients. Only a weak
association was found between EDS and physiological characteristics during sleep
Decision usefulness of accounting information and compliance with accounting standards
Get PDFThe overall aim of this thesis is to investigate decision usefulness of financial accounting information and compliance with financial accounting standards. This thesis builds on three complementary studies, which explore the decision usefulness of fair value accounting information and compliance of private companies with financial accounting standards. The information perspective of accounting information provides the theoretical framework for the thesis. From this perspective, information content of financial information is useful if it has impact on the users of the accounting information.
The decision usefulness of fair value accounting (FVA) is analysed for two important user groups of financial statements, equity analysts and investors. The first study uses a case study approach and interviews with equity analysts to examine the usefulness of judgemental fair value adjustments (Level 3) and the impact that the implementation of IFRS 13 Fair Value Measurement had on the relevance of disclosures and disclosure practice. The second study focuses on investors and uses an event study methodology and regression analysis to examine the association between judgemental fair value adjustments recognised in the income statements and stock price reaction for listed European real estate companies. It also probes if increased disclosures about fair value following the implementation of IFRS 13 increased the relevance of the FVA. The third study examines the level of compliance with national accounting standards and factors which may influence the compliance level for a sample of Icelandic private companies.
The first study finds that equity analysts focus on cash-flow and do not incorporate Level 3 fair values as an input in their valuation. These results indicate that Level 3 fair value measurements or fair value disclosures have little relevance or information value for equity analysts. However, the fair value disclosures appear to have to some extent confirmative value as they provide analysts with comfort over their own fair valuation measurements and verify the credibility of management. The additional fair value disclosure requirements implemented with IFRS 13 have scant relevance for equity analysts. The results provide evidence that standard-setters, auditors and preparers of financial statements with significant Level 3 fair value adjustments should focus on predictive and forward-looking disclosures to evaluate future cash flows. Detailed disclosures about the management valuation process and sensitivity
analysis have limited relevance for the equity analysts. On the other hand, from the investors´ perspective, the findings of the second study indicate that FVA are value relevant after implementation of IFRS 13 but not in the period before the implementation. In addition, the findings indicate that FVA recognised in semi-annual financial statements are more value relevant compared to annual accounts and positive FVA have more value relevance than negative FVA.
While the first two studies focus on the usefulness of accounting information, the third study goes a step further and explores management intentions to provide useful accounting information by analysing compliance with accounting standards. This study expands the literature by using management incentive theories to investigate compliance with national accounting standards by private companies, whereas prior research has mainly focused on publicly listed companies. The research reveals an overall compliance level of 75%, which demonstrates poor compliance, as the study is based on compliance with mandatory disclosures, where 100% compliance is required by law. Compliance is particularly low with mandatory disclosure requirements regarding investment in other companies, related party transactions and off-balance sheet liabilities. The overall results support concerns about lack of compliance, which have been raised by authorities, analysts, credit institutions and other consumers of Icelandic financial statements. Even though the information asymmetry in private companies appears to be resolved to some extent through private communications with different stakeholders, public financial statements play an important role. These findings have therefore direct implications for policy makers and regulators, as they highlight the importance of improving the enforcement and monitoring of compliance with the accounting regulation. Additionally, the study finds association between compliance levels and the size of a company, size of audit firm and sign-off date of financial statements. However, the age of a company, leverage or family ownership do not appear to influence compliance levels
Að byggja sér breytilegt fallakerfi: Tileinkun þágufalls í máltöku barna
No full textThe Icelandic case marking system has for decades proved an important testing ground
for theories on case and productivity. This is in part because Icelandic has the rare
property of marking argument function redundantly, with both rich morphological case
marking and a relatively rigid word order (Kiparsky 1997, Fedzechkina et al. 2016).
Additionally, the Icelandic (non-default) dative is surprisingly robust and productive, both
in object and subject case (e.g. Andrews 1976, Thráinsson 1979, Svavarsdóttir 1982,
Maling 2002, Jónsson & Eythórsson 2005 and Barðdal 2008). The productivity of the
Icelandic dative does appear in typologically expected semantic contexts, namely with
experiencer and recipient arguments, but also with e.g. themes of motion verbs (Maling
2002, Jónsson 2003, Barðdal 2008). Despite these well-known associations between
morphological dative case and specific semantics, the relationship between case and
meaning in Icelandic is still a matter of debate. Although various patterns have been
identified (agents are always nominative, patients are typically accusative and indirect
objects (recipients) most frequently dative), linguists have pointed out that the correlations
are not exact and exceptions can be found (e.g. Maling 2002, Thráinsson 2007, H.Á.
Sigurðsson 2012 and Wood 2015). Conflicting views can therefore be discerned in
previous work: Case productivity is assumed to be semantically conditioned while the
relationship between case and meaning is rejected on the basis of being too
approximative. But do patterns (rules of language) always have to be absolute and
without exceptions?
In this thesis I argue that from the standpoint of language acquisition, which has
been lacking in research on Icelandic case marking, rules do not need to be exceptionless
to be discovered by children and thus become part of the grammar. If the distributional
evidence for case-semantics associations is present in children’s language environment,
they will learn these patterns as long as the number of exceptions is tolerable (Yang
2016). This hypothesis is supported by the results of this thesis, which builds on
experimental data from 148 children aged 2–13 as well as incremental child language
corpus analyses. Broadly, the results show that children associate the dative more with
experiencers, recipients and motion themes in comparison to other thematic roles,
despite known exceptions. The association between the dative and applied arguments
(experiencers and recipients) is formed earlier than the association with themes of motion
verbs. The corpus analysis furthermore shows that these mappings of form and meaning
can be derived from the distributional properties of the input, which can also predict the
well-studied patterns of dative productivity and case marking variation in Icelandic. I argue
that the learnability perspective is crucial to the understanding of language variation and
change, as well as providing valuable insights into theoretical approaches to case.
However, the main contributions of the thesis lie in the field of language acquisition,
where the properties of the Icelandic case marking system also have the potential to
become important testing grounds for various fundamental questions. The results of the
dissertation have implications within three distinct but related topics in language
acquisition research: (1) (Morpho)syntactic bootstrapping, (2) Rule formation and
productivity and (3) Variation and change in acquisition.
First, I argue that the Icelandic data provides additional support for the claim that
children can rely on language-specific, morphological cues to derive verb meaning
(Göksun et al. 2008, Matsuo et al. 2012, Trueswell et al. 2012 and Leischner et al. 2016).
The results show that children acquiring Icelandic can, early on, use case to determine
verb meaning when word order is uninformative. I furthermore show, by testing transitivity
and case morphology within the same experiment, that case morphology can be as
salient as the number of arguments in specific contexts. Second, the data call for a model
of rule formation which accounts for nested non-default productivity and does not hinge
on frequency to determine gradient overgeneralization, since patterns which are not
statistically dominant (the dative) can become productive and multiple rules can apply to
a context simultaneously. I argue this is most compatible with rule-based accounts which
assume that rules are derived from distributional information in the input (Yang 2002,
Albright & Hayes 2003, O’Donnell 2015 and Yang 2016). Third, I show how such an
account, a combination of Yang’s Tolerance Principle (2016) and his Variational Model of
language acquisition (2002), can also account for the acquisition of the Icelandic case
marking system in well-known scenarios of language variation and change, and that a
case should be made for stochastic exceptions in addition to stochastic rules. I argue that
the underlying mechanisms in language acquisition, namely a constant search for
productive rules while tracking exceptions, and both convergence with and divergence
from the language environment, shape the directionality and dynamics of language variation and change.Íslenska fallmörkunarkerfið hefur um áratugaskeið reynst mikilvægur prófsteinn á
formlegar kenningar um fall, virkni málfræðireglna og breytileika í máli, m.a. vegna þess
að íslenska hefur þann sjaldgæfa eiginleika að merkja hlutverk rökliða bæði með nokkuð
fastri orðaröð og ríkulegri fallbeygingu (Kiparsky 1997 og Fedzechkina o.fl. 2016). Þar að
auki telst íslenska þágufallið bæði óvenju algengt og virkt miðað við það sem þekkist í
skyldum málum og birtist þessi virkni bæði í falli frumlaga og andlaga (sjá t.d. Andrews
1976, Höskuld Þráinsson 1979, Ástu Svavarsdóttur 1982, Maling 2002, Jóhannes Gísla
Jónsson og Þórhall Eyþórsson 2003 og Jóhönnu Barðdal 2008). Virkni íslenska
þágufallsins kemur bæði fram í samhengi sem er vel þekkt í tungumálum heimsins, þ.e.
með rökliðum sem teljast til skynjenda og þiggjenda, og einnig í óvenjulegra samhengi
eins og á þemum hreyfisagna. Þannig er viðurkennt að virkni þágufalls í íslensku fer að
einhverju leyti eftir merkingarlegum þáttum, þar sem þágufall birtist oftar með
skynjendum, þiggjendum og þemum hreyfisagna (sjá t.d. Jóhannes Gísla Jónsson 2003
og Jóhönnu Barðdal 2008), en á sama tíma er umdeilt að hversu miklu leyti fall felur í sér
merkingu. Bent er á að þrátt fyrir ýmis mynstur í dreifingu falls og merkingarhlutverka
(t.a.m. eru gerendur alltaf í nefnifalli, þolendur iðulega í þolfalli og óbein andlög
(viðtakendur) í þágufalli) sé samband falls og merkingar ekki áreiðanlegt og ýmsar
undantekningar á mynstrunum séu til staðar (sjá t.d. Maling 2002, Höskuld Þráinsson
2007, Halldór Ármann Sigurðsson 2012 og Wood 2015). Þannig togast í raun á andstæð
sjónarmið í fræðunum: Gert er ráð fyrir því að virkni falls fari eftir merkingarlegum þáttum
en um leið er tengslum falls og merkingar hafnað á grundvelli óáreiðanleika og
undantekninga. En þurfa mynstur (málfræðireglur) að vera algild til að teljast raunveruleg?
Í ritgerðinni eru færð rök fyrir því að út frá sjónarhóli máltökunnar, sem hefur skort
í umræðu um íslenskt fall hingað til, þurfi reglur ekki að vera algildar til þess að verða til í
málkerfi barna og þ.a.l. fullorðinna. Ef börn uppgötva mynstur í dreifingu falls og
merkingar í málumhverfi sínu tileinka þau sér þau mynstur svo lengi sem undantekningar
fara ekki yfir ákveðin þolmörk eða virkniþröskuld (Yang 2016). Rannsóknargögnin sem
niðurstöður þessarar ritgerðar byggja á eru annars vegar tilraunagögn frá 148 börnum á
aldrinum tveggja til þrettán ára, sem safnað var að mestu innan öndvegisverkefnisins
„Greining á málfræðilegum afleiðingum stafræns málsambýlis“ (verkefnisstjórar: Sigríður
Sigurjónsdóttir og Eiríkur Rögnvaldsson), og hins vegar greiningar á algengustu
sögnunum í barnamálsgögnum sem að mestu var safnað af Jóhönnu T. Einarsdóttur og
Sigríði Sigurjónsdóttur. Niðurstöður sýna á heildina litið að börn tengja þágufall frekar við
skynjendur, þiggjendur og hreyfiþemu en við önnur merkingarhlutverk þrátt fyrir
undantekningar. Tenging þágufalls við skynjendur og þiggjendur kemur auk þess fram
fyrr en tengingin við hreyfiþemu. Niðurstöður greininga á barnamálsgögnunum sýna síðan
að börn geta áttað sig á þessum tengslum forms og merkingar út frá vísbendingum í
málumhverfinu. Í ritgerðinni eru þessar niðurstöður ræddar og tengdar áðurnefndri
fræðilegri umræðu um merkingu falls og færð rök fyrir því að í formlegum kenningum um
fall þurfi frekar að taka mið af því hvernig fallmörkunarkerfið byggist upp í máltöku en að
einblína á stöku undantekningar frá þekktum mynstrum.
Helsta framlag þessarar doktorsritgerðar er þó innan máltökufræða. Sýnt er fram
á að þágufall í íslensku, og íslenska fallmörkunarkerfið almennt, getur einnig svarað
ýmsum grundvallarspurningum um máltöku barna. Niðurstöður ritgerðarinnar fela þannig
í sér nýja þekkingu innan þriggja ólíkra en skyldra sviða máltökufræða: (1) notkunar forms
til að leiða út merkingu í máltöku (e. (syntactic) bootstrapping), (2) reglumyndunar barna
og virkni málfræðireglna þeirra og (3) tileinkunar barna á tilbrigðum í máli og tengslunum
á milli máltöku barna og málbreytinga. Uppbygging ritgerðarinnar fylgir þessum þremur
sviðum og hver kafli, fyrir utan þann fyrsta sem er almenn kynning á falli í íslensku,
inniheldur sérstakar tilraunir og niðurstöður þar sem afmörkuðum spurningum er svarað.
Í öðrum kafla er meginspurningin sú hvort börn nýti fallmörkun til þess að leiða út
merkingu sagna, en þekkt hefur verið um árabil (Landau og Gleitman 1985) að börn geta
nýtt setningagerð til þess að draga ályktanir um merkingu orða. Hins vegar er álitamál í
hversu miklum mæli breytur eins og fallmörkun gagnast að þessu leyti. Niðurstöður
kaflans benda þó til þess, í samræmi við rannsóknir á tyrknesku, japönsku, tagalog og
þýsku (Göksun o.fl. 2008, Matsuo o.fl. 2012, Trueswell o.fl. 2012 og Leischner o.fl. 2016),
að börn geti notað fall sem vísbendingu um merkingu sagna. Þannig geta
íslenskumælandi börn t.a.m. snemma notað fall til þess að leiða út merkingu sagna þegar
setningagerðin felur ekki í sér neinar viðbótarupplýsingar um merkingu. Í þriðja og fjórða
kafla er áhersla lögð á reglumyndun og virkni í máltöku barna og athugað hvort og þá
hvernig fall tengist merkingu í svokölluðum framköllunarprófum (e. elicited production) á
falli. Niðurstöður þessara kafla, þar sem skýr merkingarlega skilyrt virkni þágufallsins
kemur fram, kalla á líkön um reglumyndun í máli barna sem geta gert grein fyrir virkni
markaðra mynstra og reiða sig ekki eingöngu á tíðni til þess. Færð eru rök fyrir því að
reglumiðuð (e. rule-based) líkön sem byggja á tölfræðilegri dreifingu ílagsins séu best til
þess fallin (t.d. Yang 2002, Albright og Hayes 2003, O’Donnell 2015 og Yang 2016), bæði
þegar gert er ráð fyrir máltöku með og án tilbrigða í málumhverfinu. Í fimmta kafla er
sjónum nefnilega beint að tileinkun fallmörkunar þegar umfangsmikill innri breytileiki er
staðar eins og í tilviki þágufallshneigðar. Sýnt er fram á að breytileiki í því hvort
þágufallshneigð kemur fram í máli einstaklings eða ekki er skilyrtur af m.a. persónu og
tölu frumlagsins og því hvort samfall beygingarmynda kemur fram í beygingarmynstri
þess eða ekki. Samfall nefnifalls og þolfalls, þar sem ekki kemur eins skýrt fram að um
aukafallsfrumlag er að ræða og í samfalli aukafalla, hefur í för með sér aukna notkun
þágufalls. Athugað er hvort umfang þágufallshneigðar foreldra spái fyrir um tíðni
þágufallshneigðar hjá börnum þeirra en svo reynist ekki vera. Börn sýna almennt meiri
þágufallshneigð en fullorðnir en tileinka sér þó sömu málfræðilegu skilyrðingu á
breytileikanum og birtist í máli foreldra þeirra, sem er í samræmi við nýlegar rannsóknir á
því hvernig börn tileinka sér breytileika í máli (t.d. Hall og Maddeaux 2020 og RepettiLudlow og MacKenzie 2022). Færð eru rök fyrir því að þau ferli sem eru undirliggjandi í máltöku barna, annars vegar stöðug leit þeirra að virkum reglum og skráning á undantekningum frá þeim og hins vegar bæði sam- og sundurleitni með málumhverfinu, séu ráðandi öfl í þróun tilbrigða og málbreytinga. Í sjötta kafla eru niðurstöður ritgerðarinnar loks fléttaðar saman í eina heild þar sem sýnt er fram á að íslenskumælandi börn byggja sér breytilegt fallmörkunarkerfi með umfangsmikilli þágufallsvirkni þar sem merkingarlegir þættir skipta höfuðmáli. Þetta ferli mótar tilbrigði í máli og hefur áhrif á þróun málbreytinga, og ætti auk þess að mynda grunninn að formlegum kenningum um fallmörkun – í takt við þá staðreynd að málkerfi fullorðinna byggir á máltöku barna.Doktorssjóður Háskóla Íslands, Rannsóknarsjóður Ísland
Sjúkdómar sem fyrirbyggja má með bólusetningum hjá börnum, unglingum og ungu fólki á Íslandi – rótaveira, meningókokkar og inflúensa: Er þörf á umbótum?
No full textVaccines are among the most important medical discoveries ever made and
are the cornerstone of public health interventions. Public health authorities
must be attentive to the local epidemiology of infectious diseases and the
benefits of changing the immunisation schedule and introducing new
vaccines into the national immunisation programmes. The aims of the thesis
were to assess whether changes and improvements are needed to the
Icelandic national immunisation programme regarding immunisations against
rotavirus, Neisseria meningitidis and influenza. The thesis is comprised of
four studies.
In study I, the disease burden of rotavirus in young children in Iceland was
assessed, as well as the cost-effectiveness of including rotavirus
vaccinations in the national immunisation programme in Iceland. A two-year
prospective study was conducted. Children under the age of six attending a
paediatric emergency department with acute gastroenteritis were recruited.
Stool samples were collected from participants, as well as information about
the total duration of symptoms, the need for treatment in the emergency
department and for hospital admissions, the number of days parents missed
from work etc. Parents were also asked about their opinion on rotavirus
vaccinations. Study I showed that rotavirus is the most common virus causing
acute gastroenteritis leading to emergency department visits in young
children in Iceland. Rotavirus causes a significant disease burden on young
children, their parents, and the health care system. A substantial loss of
productivity is attributable to rotavirus acute gastroenteritis, leading to
considerable societal costs. The addition of a rotavirus vaccine to the national
immunisation programme would be cost-effective and most parents are in
favour of it. We conclude that rotavirus vaccines should be added to the
national immunisation programme.
Study II assessed the prevalence of asymptomatic meningococcal
carriage in children, adolescents and young adults in Iceland, the prevalence
of meningococcal capsular groups in colonisation and the duration of
colonisation. Nasopharyngeal swabs were collected from 1–6-year-old
children in daycare centres and oropharyngeal swabs from 15–16-year-old
adolescents and 18–20-year-old young adults in the spring of 2019. Of 460
children, none carried meningococci. The colonisation prevalence was 0.5% among adolescents (1/197) and 6.5% among young adults (34/525). Non-groupable meningococci were most common in colonisation (26/35 carriers),
followed by MenB (6/35 carriers). Two participants carried MenY and one
carried MenW. No carriage of MenC, the group that is currently vaccinated
against in Iceland, was detected. The longest duration of carriage was 21
months (from the first positive swab to the last positive swab). Meningococcal
isolates from successive swabs from the same carrier were closely related,
indicating a prolonged carriage with the same strain. Study II shows that
meningococcal colonisation prevalence, especially of capsulated
meningococci, is low in Iceland. Considering both the low colonisation
prevalence and low incidence of invasive meningococcal disease, we
conclude that changes in meningococcal vaccination strategies in the
national immunisation programme are not currently needed.
In study III, the humoral and cellular immune responses to influenza
vaccinations were assessed in adolescents with obesity compared to
adolescents with normal weight. Thirty adolescents with obesity and thirty
adolescents with normal weight were recruited. The participants were
vaccinated with a tetravalent influenza vaccine. Venous blood samples were
collected before vaccination and again four weeks after vaccination. The
results of study III show that both humoral and cellular immune responses to
influenza vaccination are similar in adolescents with obesity and adolescents
with normal weight. Therefore, changes are not needed to influenza
vaccination methods for adolescents with obesity.
Study IV assessed the influenza vaccine uptake in pregnant women in the
ten influenza seasons 2010-2020, and the burden of influenza on pregnant
women and their infants. The influenza vaccine uptake ranged from 6.2% in
2011-2012 to 37.5% in 2019-2020. Vaccinations against influenza in
pregnancy protect pregnant women and their infants in the season of
vaccination and provide probable protection for infants <6 months of age.
The uptake of influenza vaccinations among pregnant women was
suboptimal. Initiatives are needed to increase awareness about the safety
and the benefits of influenza vaccinations, to increase influenza vaccine
uptake and protect these vulnerable groups against influenza.Bólusetningar eru meðal merkustu uppgötvana í sögu læknavísindanna. Með
þeim hefur fjölmörgum lífum verið bjargað og hafa áður skæðir
smitsjúkdómar nánast horfið eftir tilkomu bólusetninga. Mikilvægt er að
heilbrigðisyfirvöld séu vel vakandi fyrir tilkomu nýrra bóluefna, sem og
breytingum á faraldsfræði smitsjúkdóma sem kallað gætu á breytingar á
bólusetningarskema. Þar að auki er afar mikilvægt að almenn þátttaka í
bólusetningum sé góð og að þeir hópar sem eru í mestri hættu á að veikjast
alvarlega séu verndaðir eins og hægt er.
Markmið doktorsverkefnisins var að meta hvort þörf sé á umbótum á
bólusetningum á Íslandi, með tilliti til bólusetninga gegn rótaveiru,
meningókokkum og inflúensu. Doktorsverkefnið samanstendur af fjórum
rannsóknum.
Rannsókn I fjallaði um sjúkdómsbyrði rótaveiru hjá ungum börnum á
Íslandi og kostnaðarhagkvæmni þess að bæta rótaveirubólusetningum við
íslenskt bólusetningarskema. Framskyggn, tveggja ára rannsókn var gerð á
Bráðamóttöku Barnaspítala Hringsins. Börnum undir sex ára aldri sem leituðu
þangað vegna bráðra garnasýkinga var boðin þátttaka í rannsókninni.
Saursýnum var safnað frá þátttakendum og upplýsingum safnað um
heildarlengd veikinda, þörf á meðferð á bráðamóttöku barna og innlögn á
sjúkrahús, dagafjölda sem foreldrar misstu frá vinnu og fleira. Foreldrar voru
einnig spurðir um afstöðu sína til rótaveirubólusetninga. Niðurstöður
rannsóknarinnar leiddu í ljós að rótaveira er algengasta veiran í bráðum
garnasýkingum hjá ungum börnum sem leiðir til komu á bráðamóttöku barna.
Rótaveira veldur umtalsverðri sjúkdómsbyrði á ung börn, foreldra þeirra og
heilbrigðiskerfið, sem leiðir til töluverðs vinnutaps foreldra. Vinnutapið er
stærsti samfélagslegi kostnaðurinn sem hlýst af bráðum garnasýkingum af
völdum rótaveiru. Meirihluti foreldra er hlynntur notkun rótaveirubóluefna, auk
þess sem rótaveirubólusetningar á Íslandi væru kostnaðarhagkvæmar. Við
ályktum sem svo að bæta ætti rótaveirubólusetningum í bólusetningarskema
barna á Íslandi.
Markmið rannsóknar II var að meta algengi einkennalausrar
meningókokka-sýklunar í þremur aldurshópum (hjá leikskólabörnum, 10.
bekkingum og menntaskólanemum á aldrinum 18-20 ára), kortleggja algengi
mismunandi hjúpgerða meningókokka í einkennalausri sýklun og hve lengi
iv
sýklun meningókokka varir. Nefkoksstrokum var safnað frá leikskólabörnum
og hálsstrokum frá 10. bekkingum og menntaskólanemum á vormánuðum
2019. Engir meningókokkar greindust í 460 sýnum frá leikskólabörnum. Af
sýnum frá 10. bekkingum var eitt jákvætt fyrir meningókokkum (1/197, 0,5%)
og 34 frá menntaskólanemum (34/525, 6,5%). Flestir meningókokkar sem
greindust voru óhjúpaðir (hjá 26/35 berum). Af hjúpuðum meningókokkum
voru meningókokkar B algengastir (hjá 6/35 berum). Tveir einstaklingar báru
meningókokka Y og einn meningókokka W. Enginn greindist með
meningókokka C, þá týpu sem bólusett er gegn á Íslandi. Lengsta tímalengd
sýklunar í rannsókninni var 21 mánuður (frá fyrsta jákvæða sýni til síðasta
jákvæða sýnis). Meningókokkar sem greindust við endurteknar sýnatökur í
langvarandi sýklun voru náskyldir, sem bendir til viðvarandi sýklunar með
sama stofni. Niðurstöður rannsóknarinnar sýna að beratíðni meningókokka,
sérstaklega hjúpaðra meningókokka, er lág á Íslandi. Í ljósi þess að nýgengi
ífarandi meningókokkasýkinga er einnig lágt er ekki þörf á breytingum á
bólusetningum gegn meningókokkum á Íslandi að svo stöddu.
Í rannsókn III var vessabundið og frumubundið ónæmissvar við
inflúensubólusetningu borið saman á milli unglinga með offitu og unglinga í
kjörþyngd. Þrjátíu unglingar með offitu og þrjátíu unglingar í kjörþyngd tóku
þátt í rannsókninni. Þátttakendur voru bólusettir með fjórgildu inflúensubóluefni. Blóðprufur voru teknar fyrir bólusetningu og aftur fjórum vikum eftir
bólusetningu. Niðurstöður rannsóknarinnar benda til þess að bæði
vessabundin og frumubundin svörun við inflúensubólusetningu sé
sambærileg á milli hópanna tveggja og því ekki þörf á breytingum á
inflúensubólusetningum unglinga með offitu.
Rannsókn IV fjallaði um inflúensubólusetningar barnshafandi kvenna yfir
tíu inflúensu-tímabil og sjúkdómsbyrði inflúensu hjá barnshafandi konum og
ungbörnum þeirra. Rannsóknin náði til inflúensu-tímabilanna 2010-2020.
Bólusetningarhlutfallið var lægst 6,2% á inflúensu-tímabilinu 2011-2012 en
hækkaði yfir tímabilið og var hæst 37,5% á tímabilinu 2019-2020.
Inflúensubólusetning á meðgöngu er verndandi gegn inflúensu á viðkomandi
inflúensu-tímabili en virkni bóluefnisins var 34-100% eftir tímabilum.
Inflúensubólusetning á meðgöngu ver einnig ungbörn gegn inflúensu á því
tímabili sem móðir er bólusett og veitir líklega vernd gegn inflúensu á fyrstu
sex mánuðum lífs.RANNÍS, Vísindasjóður Landspítal
Stuðningur við fötluð börn og fjölskyldur á Íslandi: Kenningar og framkvæmd
No full textDespite the avowed aims of Icelandic welfare policies to provide services in a family-centred manner, parents commonly express their experiences of fragmented services
that are offered more on the terms of the service providers than the families. Theories
on family-centred approaches call for services to be planned around the whole family,
not just an individual child or person, and the family unit is recognised as the service
user. Accordingly, the service providers and the family are urged to collaborate when
making informed decisions about the support and services needed. The overall aim of
this study has been to gain a better understanding of the discrepancies reported in the
literature between the welfare policy on providing comprehensive and flexible services
and the lived experiences of families raising disabled children. In particular, the
dissertation endeavours to capture the views and wishes of families with disabled
children while examining the roles, attitudes, and working environments of the
professionals who provide services to disabled children and their families.
The study was conducted within the field of disability studies and combines a number
of intersecting theoretical approaches. The first is a socio-relational and human rights
understanding of disability developed by disability and legal scholars over the past
decades, which is at the core of the UN Convention on the Rights of Persons with
Disabilities (CRPD). The study is also grounded in social childhood studies emphasising
children’s rights and the UN Convention on the Rights of the Child (CRC), the first
binding international law to comprehensively address the human rights of children,
including disabled children. Other central theoretical foundations of the study are
family-centred theories, which emphasise collaboration and partnership between the
service providers and the family on goals and implementation of services. Finally, the
study is informed by the third generation of cultural-historical activity theory (CHAT) and
relational practices, which focus on interprofessional and interorganisational
collaboration and learning.
A qualitative case study was chosen for this research because it provides an opportunity
to contribute to the knowledge and understanding of individual, group, organisational,
social, and related matters. The research consisted of three case studies located in
three different municipalities in Iceland. Each case included disabled preschool
children, their families, and the entire service team for each child. In accordance with
the case study approach, a variety of methods were employed to gain a comprehensive
view of each case. The data gathering involved in-depth interviews with the families of
nine children and with 11 professionals from diverse disciplines who worked within or
in relation to the preschools. Focus group interviews with professionals working outside
the preschool were conducted in each municipality along with document review and
participant observations. The data were analysed and interpreted using theoretical
guidance from family-centred, socio-relational, and rights-based views on disability and
cultural-historical activity theory.
The findings reveal a high level of convergence between the cases with variations
based on experiences of individual families rather than geographical location or type of
municipality. Overall, the parents praised the preschools for welcoming their children
and for good interpersonal relationships but reported that other services are
fragmented, inflexible, and burdensome. Therapy services were consistently regarded
as hardly reachable and disconnected from the daily routine of both children and
parents. The findings furthermore indicate services governed by prevailing medical
notions of disability, financial restraints, and practical considerations rather than the
ideals in welfare policies or family-centred practice. Drawing on the study findings and
theoretical foundations, the thesis concludes by proposing some ideas for much
needed reforms.Þrátt fyrir yfirlýst markmið íslenska velferðarkerfisins um að veita fjölskyldum fatlaðra
barna fjölskyldumiðaða þjónustu í samræmi við þarfir þeirra og óskir greina foreldrar
oft frá því að þjónustan sé sundurleit, dreifð og fremur veitt á forsendum
þjónustuveitenda en þjónustunotenda. Kenningar um fjölskyldumiðaða þjónustu kalla á
heildræna nálgun þar sem athyglinni er beint að fjölskyldunni í heild en ekki einungis
því barni eða einstaklingi sem í hlut á. Í samræmi við það eru þjónustuveitendur og
þjónustunotendur hvattir til samstarfs og sameiginlegrar ákvarðanatöku um framkvæmd
þjónustunnar. Heildarmarkmið þessarar doktorsrannsóknar var að öðlast betri skilning á
misræminu milli opinberrar stefnu velferðarkerfisins og reynslu fjölskyldna fatlaðra
barna af þjónustunni. Megináhersla var lögð á að fanga skoðanir og óskir foreldra
fatlaðra barna en einnig var rýnt í hlutverk, viðhorf og starfsumhverfi fagaðila sem veita
fötluðum börnum og fjölskyldum þeirra stuðning og þjónustu.
Rannsóknin er á sviði fötlunarfræða og fræðileg nálgun einkennist af samþættingu
nokkurra tengdra fræðikenninga. Fyrst ber að nefna félagslegan og
mannréttindamiðaðan skilning á fötlun sem hefur þróast innan fötlunarfræða á
undanförnum áratugum og er sá skilningur sem samningur Sameinuðu þjóðanna um
réttindi fatlaðs fólks byggir á. Félagsfræði barnæskunnar gegnir einnig mikilvægu
hlutverki en hún leggur grunninn að barnasáttmála Sameinuðu þjóðanna, fyrstu
bindandi alþjóðalögunum sem fjalla ítarlega um mannréttindi barna, þar með talið
fatlaðra barna. Aðrar fræðilegar undirstöður rannsóknarinnar eru fjölskyldumiðaðar
kenningar sem leggja áherslu á heildræna sýn og samstarf á milli þjónustuaðila og
fjölskyldna um sameiginleg markmið og framkvæmd þjónustunnar. Að lokum er stuðst
við þriðju kynslóð menningarsögulegrar starfsemiskenningar (CHAT) og
starfsþróunaraðferðir sem byggja á samvinnu, sameiginlegum skilningi og námi þvert á
faggreinar og skipulagsheildir.
Aðferðafræðin sem valin var fyrir rannsóknina er eigindleg tilviksrannsókn en markmið
tilviksrannsókna er að lýsa og veita skilning á afmörkuðum fyrirbærum í lífi fólks. Eitt
eða fleiri tilvik eru skoðuð og leitast við að nálgast verkefnið frá mismunandi
sjónarhornum til að fá sem gleggsta mynd af tilvikinu. Rannsóknin sem hér um ræðir
samanstendur af þremur tilviksrannsóknum sem gerðar voru í þremur ólíkum
sveitarfélögum á Íslandi og myndaði hvert sveitarfélag eitt tilvik. Í hverju tilviki voru
fötluð börn á leikskólaaldri, fjölskyldur þeirra og þjónustuteymi. Tekin voru ítarleg viðtöl
við foreldra níu barna og 11 fagmenn úr mismunandi faggreinum sem störfuðu innan
eða í tengslum við leikskóla barnanna. Einnig voru tekin rýnihópaviðtöl í hverju
sveitarfélagi við fagfólk sem starfaði utan leikskólanna ásamt því sem opinber
þjónustugögn voru rýnd og þátttökuathuganir gerðar innan leikskóla barnanna. Þessi
fjölbreyttu gögn voru greind og túlkuð með hliðsjón af grunngildum fjölskyldumiðaðrar
þjónustu, félagslegri og réttindamiðaðri tengslasýn á fötlun og menningarsögulegri
starfsemiskenningu.
Niðurstöður rannsóknarinnar leiddu í ljós mikið samræmi á milli tilvikanna þriggja þar
sem breytileiki byggðist fremur á reynslu einstakra fjölskyldna en landfræðilegri
staðsetningu eða tegund sveitarfélags. Á heildina litið hrósuðu foreldrarnir leikskóla
barna sinna fyrir að taka vel á móti börnunum og fyrir hlýleg og góð samskipti en töldu
jafnframt að önnur þjónusta væri sundurleit, ósveigjanleg og íþyngjandi. Þjálfun og
meðferð utan leikskólans var álitin óaðgengileg og ótengd daglegu lífi bæði barna og
foreldra. Niðurstöðurnar benda jafnframt til að þjónustan stjórnist af ríkjandi
læknisfræðilegri sýn á fötlun, þröngum fjárhagslegum ramma og að ýmis hagnýt
sjónarmið þjónustuveitenda ráði för fremur en yfirlýst velferðarstefna eða grunngildi
fjölskyldumiðaðrar þjónustu. Með hliðsjón af niðurstöðum rannsóknarinnar sem og
fræðilegum grunni hennar, lýkur ritgerðinni á því að settar eru fram nokkrar
leiðbeinandi hugmyndir um nauðsynlegar umbætur
Samfella í sjónskynjun: Raðáhrif, eftiráhrif og athygli.
No full textWhen we are viewing the environment around us, we are exposed to an overwhelming continuous stream of information: not everything can be processed at once, and the perceptual system must pick and choose. We must direct our attention and select stimuli of interest while ignoring or discarding irrelevant information in order to solve daily tasks and problems. An effective tool to simplify such a daunting task is for the perceptual system to chunk information together. Various pieces of spatial and temporal information can be used to bind several features which correlate in space and time into singular objects. However, because the visual world is ambiguous and prone to noise, correctly combining and selecting similar yet distinct features and objects is still an ambitious undertaking. Prior assumptions and expectations of our visual environment provide additional aid. They do this, for example, by assuming that objects and their defining features are stable entities which are maintained over time and taking advantage of such stability and regularities over time. Additionally, maintaining representational maps containing predictions of relevant or irrelevant locations or features associated with objects further eases the task of sorting the vast amounts of continuous visual information. A vast number of history-driven biases in attention and behavior have been demonstrated experimentally to improve performance when locating and discriminating between visual stimuli. Encoding of sequentially presented stimuli is attentionally facilitated when stimuli share a feature or location. Similarly, if such characteristics occur within the same object, attentional effects are spread within the entire object. The continuous flow of information can be subject to transient changes, such as blinking and changes in lighting, requiring a mechanism which employs this general predictability in order to maintain perceptual stability despite such transient changes. Serial dependence, a general attraction to previously viewed stimuli information, has been proposed as such a perceptual smoothing mechanism (J. Fischer & Whitney, 2014). It is proposed that perception is smoothed, and perceptual decisions of present stimuli are influenced by past stimuli within a spatial and temporal continuity field. Further, attention has been deemed a crucial factor: perceptual decisions about attended stimuli are attracted towards previously attended stimuli. In the papers of this thesis, we further explore the role of attentional selection in serial dependence by employing and adapting spatial, feature-based, and object-based attentional and serial dependence paradigms. In the first paper, we investigated representation traces left over after attentional filtering of irrelevant stimuli when spatially suppressed. Observers performed two tasks sequentially: first, they performed a discrimination task while ignoring a distractor Gabor, reproducing the orientation of a Gabor afterwards. Notably, we did not observe a difference between suppressed or non-suppressed distractors, which equally interfered with perceptual decisions of the reported Gabor. This showed that perceptual decisions are biased away from the features of recent distractors. Such effects could be caused by either attentional filtering or active removal of irrelevant traces of information. We speculate that distractors were processed to the extent that they left a trace or interfered with other ongoing traces of prior stimuli. In the second paper, we studied the role of feature-based attention and task demands related to secondary contextual features. Participants performed either a detection task, responding to a cued color, or a discrimination task, actively responding differently to two colors, while a sequence of red or green Gabors were presented; the orientation of the last Gabor was reproduced. We observed that during the detection task, attraction only occurred towards the target color, whereas during the discrimination task perceptual decisions were attracted to previous stimuli regardless of color. The results provide further evidence that serial dependence is modulated by task demands and task contextual information. They further suggest that serial dependence can operate on features and does not need object representations, i.e., attraction can occur between features of different objects. We propose an account of parsimony, wherein the representation required by the task determines what information is propagated from one instance to another. Finally, in the third paper, we investigated the tuning of serial dependence to object representations, employing object-based attention by presenting a Gabor at one of the ends of two triangles. When the previous Gabor was presented within the same object, we observed a widening of the range of relative orientation differences in which attraction took place. We suggest an increase in stimulus sensitivity caused by attentional employment based on objects. Overall, our results show that task demands, attentional facilitation and filtering processes have an important and nuanced role in serial dependence
Collective identity, solidarity, and sisterhood in the ASAB cleaning women’s strike in Sweden and the Women’s Day Off in Iceland
Get PDFIn recent years feminist movements have increasingly employed the form and rhetoric of strikes in framing their protests. The rise of the women’s strike movement has been seen as an indicator of an invigorated wave of feminist activism that focuses, to a greater extent, on structural economic injustices. The aim of this article is to provide a historical aspect to the growing research on strikes as a multifaceted form of protest. The article analyses articulations of collective identity, solidarity, and sisterhood in two different kinds of ‘women’s strikes’ that took place in the Nordic region during the mid-1970s; the ASAB cleaners’ strikes in Sweden during 1974–1975 and the Icelandic Women’s Day Off that took place on October 24, 1975. The article explores how the relationship between gender and class was conceptualized by participants, organizers, and bystanders. We employ these cases to study how solidarity and sisterhood across differences among women might have appeared in practice while at the same time reflecting internal tensions and varying interests. Moreover, the article reflects on the specific form of the strikes and the potential impact their respective form might have had on the political articulations that came out of them.Rannsóknarsjóður / The Icelandic Research Fund grant no. 218064-051Post-print (lokagerð höfundar
MicroRNA-190b in breast and ovarian cancer
No full textBreast cancer is the most frequently diagnosed cancer today, with approximately 2.3 million new cases for the year 2020. Regardless of gender, these diagnoses represent 11.7% of all cases. For women, breast cancer falls under roughly one-third of cancer cases. Prognosis and treatment of breast cancer are assessed by various factors such as stage, grade, biomarker expression and genetic markers in the tumor. The subdivision of breast cancer is categorized by the expression of proto-oncogenes, steroids, and growth factors such as the estrogen receptor (ER), progesterone receptor (PR), human epithelial growth factor 2 receptor (HER2), epidermal growth factor receptor (EGFR), cytokeratins 5/6 and the proliferation marker KI67. The clinically determined subtypes of breast cancer are Luminal A, Luminal B, HER2 and Triple negative. The most common subtypes which represent approximately 70% of all breast cancer cases, Luminal A and Luminal B, overexpress the estrogen receptor (ER+) which is a key factor in their development and treatment. Prognosis for these patients is good though some respond better to treatment than others.
MicroRNAs (MiRNAs) are RNA molecules which do not code for protein but have a role in gene silencing post DNA-transcription. MiRNAs bind to mRNA resulting in their breakdown or block of protein translation. MiRNAs are flexible in their role since they can bind different mRNA molecules depending on the tissue and transcriptional profile.
A previous study had shown that microRNA-190b (miR-190b) was upregulated in ER+ breast cancer but few target genes had been associated with the molecule. Little was thus known of the role of miR-190b in breast cancer.
The first aim of this study was to investigate whether CpG methylation on miR-190b’s promoter had a role in its upregulation in ER+ breast cancers and whether it had an influence on disease progression. It was confirmed by qPCR in breast cancer samples that miR-190b was indeed upregulated in ER+ subtype. It was furthermore confirmed by pyrosequencing that miR-190b is promoter hypo-methylated in ER+ breast cancers in correlation with its expression. In other words, it was showed that when the tumors had lost CpG methylation on the miR-190b promoter (DNA), the molecule was upregulated. Finally, it was showed that breast cancer specific survival was significantly different in patients by whether their tumors were miR-190b promoter hypo-methylated or not.
The second aim of the study was to investigate miR-190b’s target genes in breast cancer and study whether their expression regulation had a similar influence on patient prognosis as miR-190b. With biotin-miR-190b-mimic pulldown followed by RNA sequencing analysis and western blot it was confirmed that RFWD3 is a miR-190b target. With survival analysis it was shown that patient prognosis was less favorable when RFWD3 was expressed, which was consistent with previous results for miR-190b in this project.
The last aim of the study was to investigate miR-190b in ovarian cancer and research whether its expression had a predictive value on patient survival. With data from The Cancer Genome Atlas (TCGA), it was shown that there was neither a connection between miR-190b expression and ER nor RFWD3 expression. It was additionally shown that there was no difference in miR-190b expression between stages or grades. With survival analysis it was shown however, that prognosis was worse in ovarian cancer patients with high levels of miR-190b indicating that it is clinically relevant in ovarian cancer and needs to be studied further.Brjóstakrabbamein er algengasta gerð krabbameins sem greinist í dag, með um 2.3 milljón ný tilfelli á heimsvísu árið 2020. Óháð kyni eru þetta um 11.7% allra nýrra tilfella. Í konum er brjóstakrabbamein tæplega þriðjungur krabbameinstilfella. Horfur og meðferð á brjóstakrabbameini eru metin af mismunandi þáttum, svo sem stigun, gráðun, og tjáningu ákveðinna próteina og erfðamarka sem finnast í æxlinu. Brjóstakrabbamein eru flokkuð í undirhópa og ræðst sú flokkun af tjáningu foræxligena, hormóna og vaxtaþáttaviðtaka eins og estrogen viðtakans (ER), prógesterón viðtakans (PR), human epithelial growth factor 2 viðtakans (HER2), epidermal growth factor receptor (EGFR), cytokeratinin 5/6 og frumufjölgunar-merkisameindina KI67. Undirgerðir brjóstakrabbameins í klínísku samhengi eru Luminal A, Luminal B, HER2 og Þríneikvæð æxli. Algengustu undirgerðirnar eru Luminal A og Luminal B sem eru um 70% af öllum tilfellum. Þessi krabbamein yfirtjá estrogen viðtakann (ER+) sem er lykilþáttur í myndun þeirra og tekur meðferð mið af því. Lifun og batahorfur eru því tiltölulega góðar hjá þessum sjúklingum þótt ekki allir svari meðferð jafn vel.
MicroRNA (MiRNA) eru RNA-sameindir sem tjá ekki fyrir próteini en gegna hlutverki í genaþöggun eftir DNA umritun. MiRNA parast við mRNA-sameindir með þeim afleiðingum að ekki myndast prótein. MiRNA eru sveigjanleg í miðlun svipgerðar þar sem að þau hafa eiginleikann til að bindast mismunandi mRNA sameindum og fer það eftir vef og tjáningarmynstri hverju það binst.
Sýnt hafði verið fram á að microRNA-190b (miR-190b) er yfirtjáð í ER+ brjóstakrabbameinum og örfá markgen hafa verið bendluð við sameindina. Lítið er því vitað um áhrif miR-190b í brjóstakrabbameinum.
Fyrstu markmið verkefnisins voru að skoða hvort CpG metýlun á stýrilröð miR-190b væri ráðandi þáttur í tjáningu þess í ER+ brjóstakrabbameinum og hvort það hefði forspágildi fyrir framvindu sjúkdómsins. Í þessu verkefni var staðfest með qPCR úr brjóstakrabbameinssýnum að miR-190b væri yfirtjáð í ER+ brjóstakrabbameinum. Ennfremur var staðfest með pyroraðgreiningu að miR-190b væri undir-metýlað á stýrisvæði þess í ER+ brjóstakrabbameinum og að það væri í fylgni við tjáningu. Með öðrum orðum var sýnt að tap á DNA metýlun á stýrlisvæði miR-190b orsakaði yfirtjáningu á miR-190b sameindinni. Loks var sýnt að munur væri á brjóstakrabbameinsháðri lifun sjúklinga eftir því hvort tap hafði verið á DNA metýlun á stýrisvæði miR-190b eða ekki.
Önnur markmið verkefnisins voru að rannsaka markgen miR-190b í brjóstakrabbameini og skoða hvort stýring á þeim hefðu svipað forspágildi á horfur sjúklinga og sú sem miR-190b tjáning hafði. Með RNA raðgreiningu á biotin-miR-190b-mimic útfellingu og western blotti var staðfest að RFWD3 er markgen miR-190b. Með lifunargreiningu sást að horfur sjúklinga voru verri þegar RFWD3 er yfirtjáð sem var í samræmi við fyrri niðurstöður verkefnisins.
Síðasta markmið rannsóknarinnar var að skoða tjáningu miR190b í eggjastokkakrabbameini, og athuga áhrif þess á lifun sjúklinga. Með gögnum úr The Cancer Genome Atlas (TCGA) sást að hvorki voru tengsl milli miR-190b tjáningar og ER eða RFWD3 tjáningar. Einnig sást að tjáning miR-190b var ekki mismunandi milli stigunar eða gráðunar. Með lifunargreiningu var þó uppgötvað að lifun var verri hjá eggjastokkakrabbameinssjúklingum með háa tjáningu af miR-190b sem bendir til þess að það sé mikilvægt í klínísku samhengi og þarfnast frekari rannsóknar.This work was funded by Göngum saman, the Eimskip University fund
(Háskólasjóður Eimskipafélags Íslands) and The Icelandic Research Fund
(Rannís)
Evolution of Stresses Over Conjugate Faults in Hjalli‐Ölfus, South Iceland
Get PDFPlain Language Summary Iceland hosts a predominantly rifting plate boundary that is offset by two ∼east-west trending, horizontally sliding (transform-faulting) segments, one in the north and the other in the south. The southern segment, known as the South Iceland Seismic Zone (SISZ), is seismically productive and is flanked by diverging volcanic arms. The SISZ has hosted several moderate to large earthquakes on
north-south faults that cut across it. However, the westernmost end of the SISZ, also known as Hjalli-Ölfus, differs from the rest of the SISZ as it seems to host earthquakes in an ∼east-northeast direction, similar to its western, rifting neighbor, namely, the Reykjanes Peninsula. The activity in Hjalli-Ölfus also seems to be responsive to volcanic/magmatic activity in the Hengill volcano to its north. This suggests the existence
of multiple stress fields—volcanic, tectonic, or both—acting on the Hjalli-Ölfus segment. Here, we study earthquakes in Hjalli-Ölfus from January 1991 to December 1999, including a magnitude 5.1 earthquake in November 1998, to identify possible stress changes along the segment over time. Results indicate that magmatic
deformation and seismic activity near the Hengill volcano directly influence the seismic productivity of Hjalli-Ölfus, and that this seismicity is similar to that of the Reykjanes Peninsula.Hjalli-Ölfus is the westernmost segment of the east-west transform South Iceland Seismic Zone
(SISZ), which is the eastward extension of the ∼ENE-trending transtensional Reykjanes Peninsula (RP).
Historically, the area has shown an interactive behavior with the Hengill volcanic system to the north and the
central SISZ to the east. We analyzed the state of stress and faulting mechanisms in Hjalli-Ölfus between July
1991 and December 1999, in connection with the Hengill inflation episode (Feigl et al., 2000, https://doi.
org/10.1029/2000JB900209) and the 13th November 1998 Mw 5.1 Hjalli-Ölfus earthquake. We find that this
region predominantly hosted oblique-normal and left-lateral strike-slip events (4–10 km-depth), with most
nodal planes oriented along ∼ENE or ∼WSW directions (75° ± 15° or 255° ± 15°). We identify 5 stages of
stress evolution from January 1991 to December 1999 over which Hjalli-Ölfus experiences both spatial and
temporal shifts in stress-states. The Hengill inflation likely loaded both the fissure zone and western Ölfus,
culminating in the Mw 5.4 (Hengill) and Mw 5.1 (Hjalli-Ölfus) earthquakes. Following these events, the
maximum compressive stress (SHmax) orientation near the location of the Mw 5.1 earthquake showed a
∼5°–7° counterclockwise swing, compared to SHmax before June 1998. The average SHmax (∼40° ± 1°) and
minimum principal stress
(sigma3 ∼ 130° ± 1°) are comparable to geological trends in the RP. We conclude that
Hjalli-Ölfus shows clockwise SHmax rotation upon loading, while a stress-drop reverses the rotation. We also
posit that the region, especially the western end, behaves like the RP during interseismic periods.Icelandic Research Fund (IRF) (Rannís). Grant Number:152432-053Peer Reviewe