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Population dynamics of fish juveniles and invertebrates in Icelandic waters
Get PDFThe marine ecosystem around Iceland is shaped by its position in one of the most hydrographically complicated regions of the North Atlantic. The response of marine populations to those diverse conditions is expected to be different across taxonomically distinct species but by comparing and analysing the differences we can better understand the system as a whole. In the present study, population dynamics of juvenile cod (Gadus morhua), juvenile plaice
(Pleuronectes platessa), brown shrimp (Crangon crangon) and Iceland scallop (Chlamys islandica) were analysed with respect to recruitment patterns and fluctuations. The studies were carried out during a period of increased influx of Atlantic waters around Iceland and consequently higher temperatures. The studied species either have their core distributional areas in Iceland, like the cod, or are at their southern borders, like the Iceland scallop. We also analysed population trends at sheltered sandy beaches, which is an essential habitat for
the juvenile plaice and also the brown shrimp, a newly found invasive species and important predator of juvenile plaice.
Findings revealed the highest abundance of cod larvae within low-salinity waters, characteristic of the Icelandic coastal current (ICC). That is in line with previous studies that have demonstrated a potential link between the freshwater discharge or the strength of the ICC and recruitment of cod. The distribution of the cod juveniles within the boundaries of the ICC highlights the role of the freshwater driven coastal current in successfully transporting larvae
from the spawning areas into the northern nursery grounds. The fluctuation in recruitment is relatively small in the Icelandic cod stock and likely dampened by the smaller northerly grounds.
In an effort to establish the natal origins of juveniles of plaice around Iceland, settlement and growth patterns of juvenile plaice were estimated. There were differences in the size and age distribution around Iceland, which led to the conclusion that juvenile plaice originated from multiple spawning events and locations. Further, the observed spatial variation in size of the juveniles was explained by age difference, not by different temperature-induced growth
rates. The study provides evidence of the existence of a local population structure within the Icelandic plaice stock and supports recent findings on adult plaice, which could have implications for the management of the stock, that currently is managed as a single unit. The study also identified extremely high density peaks of juvenile plaice at the nursery grounds. We further studied two years with variable population density by ageing juveniles and comparing
growth of individuals on particular dates during the settlement period and later in the summer. There was indication of density-dependent growth patterns. Recruitment of the plaice has been stable for the past 25 years. Density dependent processes at the nursery grounds are a likely contribution to that fact, but also the possible complex population structure within the Icelandic plaice stock.
The brown shrimp which was recently found in Icelandic waters (2003), has been described as a potentially invasive species. It has rapidly adapted and became established in its newly colonized area. There was an indication of bi-annual spawning with the number of juveniles increasing in July/August and again in February. The number of recruiting juveniles from previous years significantly affected the adult abundance as well as a positive effect of the
sea surface temperature. Different population trends were observed in the Iceland scallop, where surveys with available environmental- and biological data from 1993 to 2003 were analysed. The period was also marked by an increase in summer sea surface temperature on the studied southern border of the sub-arctic species’ distributional range. The stock was heavily fished but also suffered high natural mortality that was later related to an apicomplexan
parasite or gray meat. Further, low recruitment levels towards the end of the 1990s made the stock vulnerable to increased fishing pressure and consequently, the stock appeared unable to withstand the fishing pressure and declined to historically low levels, leading to a halt to fishing in 2003.
The relative stable cod and plaice stocks in Icelandic waters can most likely be attributed to the their stock subcomponents as well as density dependent processes occurring at the plaice nursery ground. The collapse of the Iceland scallop stock in Breiðafjörður, among the decline or collapse of the northern inshore shrimp stocks, were maybe the first species influenced by the current warm regime which started around 1996. During this period there have also been several records of invasive species, such as the brown shrimp, with the new regime favouring the establishment of the new species. The causes and drivers of recruitment variation are common over a wide range of species and the way forward to understand the key processes influencing recruitment, must be greater emphasis on research on a broader scale.Við Ísland er að finna eitt flóknasta hafstraumakerfi í Norður Atlantshafi. Hér má búast við
mismunandi áhrifum umhverfisbreytinga á ólíka stofna sjávarlífvera, en með því að skoða
nokkrar tegundir má draga víðtækari ályktanir af eðli áhrifanna. Meginviðfangsefni þessa
verkefnis var rannsókn á ungviði og stofnsveiflum með tilliti til nýliðunar hjá þorski (Gadus
morhua), skarkola (Pleuronectes platessa), sandrækju (Crangon crangon) og hörpudiski
(Chlamys islandica). Rannsóknin tók yfir tímabil þegar innstreymi hlýs Atlantssjávar jókst
með tilsvarandi hækkun sjávarhita. Fjallað var bæði um tegundir líkt og þorskinn þar sem
Ísland er við miðju útbreiðslunnar og hörpudisk sem finnst hér á suðurmörkum útbreiðslu
sinnar. Einnig voru skoðaðar skjólsælar sandfjörur, en þær eru mikilvægasta búsvæði kolaseiða
og sandrækju, sem er ný ágeng tegund og mikilvægur afræningi á seiðum skarkolans.
Niðurstöður rannsóknanna á þorskungviði sýndu fram á háan þéttleika í seltuminni sjó
nærri landi, einkennandi fyrir strandstrauminn (ICC). Það rennur stoðum undir eldri rannsóknir
sem hafa bent á mögulegar tengingar hans við árangursríkari nýliðun í þorski og mikilvægi
ferskvatnsknúna strandstraumsins í flutningi á lirfum frá hrygningarsvæðum yfir á norðlægari
uppeldissvæði. Almennt séð eru sveiflur í nýliðun þorsks litlar við Ísland en líklegt er að
hrygning frá smærri norðlægari hrygningarsvæðum jafni frávikin.
Botntaka og vöxtur skarkolaseiða allt í kringum Ísland var metinn til að varpa ljósi á
uppruna seiðanna. Munur var á stærð og aldursdreifingu seiðanna og benti hann til mismunandi
hrygningartíma og svæða. Mun á stærð milli svæða mátti einkum rekja til aldurs en ekki
hitastigsháðs vaxtar. Niðurstöðurnar benda til að um staðbundnar stofneiningar geti verið að
ræða hjá skarkolastofninum, sem er stutt af rannsóknum á eldri kola, en núverandi ráðgjöf
gerir ráð fyrir einni stofneiningu. Mjög háan þéttleika af kolaseiðum var að finna í nokkrum
fjörum. Skoðuð voru frekar áhrif þéttleika á vöxt og borin saman ár með lágum og háum
þéttleika við botntöku og síðar um sumarið. Merki sáust um þéttleikaháð áhrif á vöxtinn.
Nýliðun skarkola hefur verið stöðug undanfarin 25 ár, en líklegt er að þéttleika háð áhrif spili
þar inní sem og dreifðar og aðskildar hrygningaeiningar.
Sandrækjan hefur aðlagast hratt að nýjum heimkynnum. Skýr merki voru um tvær aðskildar
hrygningar innan ársins, en ungviði sást í júlí/ágúst og aftur í febrúar. Fjöldi nýliða fyrra
árs hafði jákvæð áhrif á magn eldri rækju ári síðar sem og jákvæð áhrif hitastigs. Hið
gagnstæða má segja um stofn hörpudisks í Breiðafirði, en skoðuð voru gögn úr leiðöngrum
auk ýmissa umhverfis og líffræðilegra þátta fyrir árin 1993 til 2003. Það tímabil markaðist
af aukningu í yfirborðshita á þessum suðurmörkum útbreiðslusvæðis tegundarinnar. Hátt
veiðiálag var á rannsókartímabilinu, en einnig hár náttúrulegur dauði, sem síðar var tengdur
við frumdýrasýkingu (Apicomplexa) sem nefnd hefur verið "grár vöðvi". Nokkru fyrr eða í
lok tíunda áratugar síðustu aldar var nýliðun í stofninn metin mjög léleg en með náttúrulegum
afföllum og auknu veiðiálagi lækkaði stofnvísitalan hratt. Það leiddi svo til þess að lagt var til
veiðibann árið 2003.
Stofnstærðarsveiflur hjá þorski og skarkola við Ísland eru almennt litlar og má að einhverju leyti rekja ástæður þess til flókinnar stofngerðar tegundanna og að auki hemjandi
þéttleikaháðum áhrifum á uppeldisslóð skarkolans. Hörpudisksstofninn í Breiðafiði var ásamt
innfjarðarrækjustofnum, fyrsta tegundin við Ísland sem hrundi í kjölfar núverandi hlýindaskeiðs sem hófst í kringum árið 1996. Á þessu tímabili greindust einnig nokkrar ágengar lífverur í sjó, meðal annars sandrækja sem naut góðs af hlýindunum í hafinu. Almennt má
segja að drifkraftur nýliðunarsveiflnanna sé sameiginlegur milli ólíkra tegunda og þarft er að
skoða sveiflurnar á víðum grunni
Uncertainty in Ecological Footprint standard method accounts
Get PDFThe call for a sustainable development of human societies is becoming ever louder. The term sustainability has as a result become thoroughly incorporated into everyday speech, not least among politicians. For the term to hold any meaning some quantitative definitions are needed. We need to know what is sustainable and what isn’t. This is where sustainability gets complicated. Being able to clearly define what is sustainable and what isn’t is notoriously difficult – not least in a world with very complex globalized trade systems. To tackle this problem the UN called for the creation of sustainability indicators in the early nineties. These indicators were supposed to give an indication of what is sustainable and what isn’t and thus aid us in creating the much-coveted sustainable world. In the following years many such indicators were created – among them the Ecological Footprint (EF). EF has been called by some academics “extremely successful” but has at the same time had its fair share of criticism. The aim of this dissertation was to examine EF from the standpoint of uncertainty in input parameters. To do this a single case study method was utilized by focusing on the extreme case of Iceland – an outlier in Ecological Footprint accounts under the defined standard method. The most sensitive areas for the case were identified as the Marine and Carbon footprints, and a deep dive performed on each of the two areas. The work was published in three separate academic papers appearing in peer reviewed academic journals. The results indicate that major uncertainties are involved in EF accounting under the standard method. Their sources are identified as uncertainty in input data, lack of knowledge of natural systems and aggregation and use of averages. Six mitigation measures are suggested to meet these challenges. Regardless, this uncertainty makes the EF vulnerable to abuse and misleading information and it is therefore imperative to always give clear indications of uncertainty levels when publishing such results. Under such conditions science can quickly become tainted and thus great care must be taken not to mix scientific endeavours with political agendas or activism of any kind.Doctoral Grants of the University of Iceland, NordForsk (GreenMAR
Spectral Memories of Icelandic Culture: Memory, Identity and the Haunted Imagination in Contemporary Art and Literature
Get PDFThe thesis examines what I term spectral memories in Icelandic culture and focuses on the
interplay between memory, identity and the haunted imagination in contemporary literary texts
and visual works of art. I employ the term “spectral” to define memories that have for various
reasons been forgotten, silenced and repressed in the cultural psyche, but have returned to the
public realm by means of contemporary art and literature. Spectrality theory, and the seminal
work of Jacques Derrida, Spectres de Marx, serve as a point of departure for the project, my
initial aim being to relate the spectre to ideas of memory and theories on cultural memory
studies. I argue that the spectral return offers the potential of a transformative dynamic
exchange between memory and recipient, and an opportunity to critically reflect on the past in
order to work towards a better future. The spectre becomes a metaphor for the blind spots of
memory: on the one hand for memories that return from the past to disturb mainstream notions
and homogenous ideas on identity, and on the other for how certain periods have produced
spectral cultural responses. The first part of the thesis explores how the archive becomes a
storage space for spectral memories, whereas the second part examines spectral cultural
memories following the financial crash and crisis in Iceland in 2008. In both parts, I look at
narratives and images that prove to be haunted by repressed memories, which impacts how the
present-day identity is conceived, illustrating the intricate connections between memory,
identity and the haunted imagination.Í ritgerðinni rannsaka ég vofulegar minningar í íslenskri menningu og skoða flókið samspil
minnis, sjálfsmyndar og reimleika í samtímabókmenntatextum og myndlistarverkum. Ég beiti
hugtakinu „vofulegar“ til að skilgreina minningar sem af ólíkum ástæðum hafa gleymst, verið
þaggaðar eða niðurbældar í sameiginlegri menningarvitund þjóðarinnar, en hafa opinberast
aftur fyrir tilstilli samtímabókmennta og myndlistar. Vofufræði (e. spectrality theory), og verk
franska heimspekingsins Jacques Derrida, Vofur Marx, eru upphafspunktur rannsóknarinnar,
með það að leiðarljósi að tengja vofuna við hugmyndir um minni og kenningar í
menningarlegum minnisfræðum (e. cultural memory studies). Ég færi rök fyrir því að
endurkoma vofunnar hvetji til gagnrýnna minnisviðtaka, þar sem viðtakandi, sem staðsettur er
í samtímanum, tekur við minningum fortíðar, greinir þær og skilur með gagnrýnum hætti, og
með það að leiðarljósi að leggja grunninn að sanngjarnari eða réttmætari framtíð. Vofan verður
að myndlíkingu fyrir blinda bletti minnis og minningar sem ekki eru sýnilegir á opinberum
vettvangi en eru samt sem áður til staðar. Rannsóknin tekur annars vegar fyrir gleymdar
minningar fortíðar, sem dregnar eru fram í dagsljósið og trufla ríkjandi, einsleitar og staðnaðar
hugmyndir um sameiginlega sjálfsmynd í samtímanum, og hins vegar sögulegt tímabil og
atburði sem getið hafa af sér vofulegar minningar. Í fyrri hluta ritgerðarinnar rannsaka ég
hvernig arkífið eða skjalasafnið (e. archive) verður að geymslustað vofulegra minninga, en
fjöldamargar opinberar stofnanir geyma minningar sem ekki eru alla jafna til sýnis á opinberum
vettvangi og fjalla til að mynda um nýlendusögu Íslendinga, óeirðir og mótmæli. Þegar þær eru
dregnar fram í dagsljósið, gefa þessar minningar annars konar mynd af sameiginlegri
sjálfsmynd þjóðarinnar en þá sem iðulega birtist opinberlega. Þegar litið er til einkalífs og til
fjölskylduminnis, og minninga sem ólíkar kynslóðir deila, má sjá hvernig ákveðnir staðir
heimilisins, eins og kjallari eða háaloft, verða að geymslustað vofulegra minninga, og geyma
hluti og skjöl sem ekki eru til sýnis eða umræðu í daglegu lífi fjölskyldunnar. Í seinni hluta
ritgerðarinnar beini ég sjónum að efnhagshruninu árið 2008 og hvernig það leiddi af sér
vofulegar minningar; bókmenntatexta og myndlistarverk sem fjalla um reimleika með einum
eða öðrum hætti. Draugahúsið í glæpasögu Yrsu Sigurðardóttur, Ég man þig; melankólía og
sorg fjölskyldunnar í Hvítfeld eftir Kristínu Eiríksdóttur; teikningar Guðjóns Ketilssonar af
hálfbyggðum húsum í efnahagskreppunni, og ljósmyndir Ingvars Högna Ragnarssonar af
vofulegum stöðum í borgarlandslaginu á tímum fjármálahruns, gefa færi á að rannsaka þennan
sögulega tíma út frá hugmyndum um draugagang og bælingu. En hver er ásóttur og af hverjum? Í báðum hlutum ritgerðarinnar greini ég frásagnir og myndir sem reynast ásóttar af
niðurbældum minningum sem hafa áhrif á hvernig sjálfsmynd er mótuð í samtímanum, og sýnir
fram á þau þéttu en flóknu tengsl sem liggja á milli minnis, sjálfsmyndar og reimleika
Fíkniefni í frárennsli frá Reykjavík
Get PDFMælingar á fíkniefnum og lyfseðilsskyldum lyfjum í frárennslisvatni hafa undanfarin ár verið notaðar til þess að meta notkun efnanna. Aðferðafræðin byggir á þeirri kenningu að hægt sé að líta á frárennslisvatn sem samansafn þvagsýna frá heilu samfélagi. Áreiðanlegar niðurstöður eru fengnar á mjög fljótvirkan hátt án þess að inngripum sé beitt.
Aðal markmið þessarar rannsóknar var að setja upp og gilda greiningaraðferð fyrir fíkniefni og lyfseðilsskyld lyf í frárennsli frá Reykjavík. Fastfasa súluskiljun (SPE) var notuð við úrhlutun fíkniefna og lyfja í frárennslisvatni frá Reykjavík með ásættanlegum heimtum. Háþrýstivökvagreinir tengdur tvöföldum massaskynjara (UPLC-MS/MS) var notaður við greiningu efnanna. Frárennslissýnum var safnað í Reykjavík á ellefu tímapunktum frá febrúar 2017 til júní 2020. Algeng fíkniefni sem notuð eru á Íslandi voru valin til greiningar ásamt lyfseðilsskyldum lyfjum með þekkta misnotkun. Notkun efnanna var metin í mg/dag/1000 íbúa.
Langtímaþróun í fíkniefnanotkun í Reykjavik var metin með mælingum á frárennslisvatni. Notkun kókaíns hækkaði verulega frá 2017 til 2019 en hafði minnkað umtalsvert í júní 2020 á tímum kórónuveirunnar. Notkun bæði amfetamíns og metamfetamíns sýndu merki aukningar frá 2017 til 2020, en notkun amfetamíns var mun meiri en metamfetamíns. Notkun 3,4 methylene-dioxymethamphetamine (MDMA) var stöðug frá 2017 til 2020. Notkun kannabis var stöðug frá 2017 til 2019 en sýndi merki aukningar á tímum kórónuveirunnar árið 2020. Aukning í notkun kókaíns og MDMA sást einnig um helgar þegar borið var saman við aðra vikudaga og einnig á tónlistarhátíð sem haldin var í Reykjavík. Niðurstöður byggðar á mælingum á frárennslisvatni voru bornar saman við aðra vísa að fíkniefnanotkun, fjölda mála vegna fíkniefnaaksturs og gögn um haldlagt magn fíkniefna.
Afkastamikil sýnameðhöndlunaraðferð var þróuð þar sem minna rúmmál frárennslissýna var úrhlutað samanborið við aðrar hefðbundnari aðferðir. Þessi aðferð var þróuð bæði fyrir fíkniefni og lyfseðilsskyld lyf. Mikill tímasparnaður felst í því að úrhluta minna rúmmál af sýni, samanborið við aðrar eldri aðferðir og fást þá niðurstöður á mun skemmri tíma. Frárennslisýni frá fjórum höfuðborgum á Norðurlöndum (Osló, Stokkhólmur, Reykjavík og Þórshöfn) voru úrhlutuð með þessari aðferð. Gögn frá Helsinki voru einnig fengin og þróun í notkun örvandi fíkniefna var metin milli borganna. Niðurstöður sýndu að amfetamínmagn í frárennsli var mest í Reykjavík og Stokkhólmi. Magn metamfetamíns í frárennsli var hæst í Helsinki og magn MDMA var mest í Osló. Magn kókaíns í frárennsli var sambærilegt í Osló, Stokkhólmi og Reykjavík en mun lægra í Helsinki. Augljós aukning í magni MDMA og kókaíns sást um helgar sem bendir til að notkun efnanna til afþreyingar sé vinsæl á Norðurlöndum.
Þróun í notkun fíkniefna og lyfja var metin með mælingum á frárennsli með góðum árangri ásamt samanburði við önnur lönd. Niðurstöður byggðar á mælingum á frárennslisvatni voru almennt sambærilegar gögnum yfir fíkniefnaakstur og haldlagningar. Hægt er að ná fram heildstæðari mynd af notkun fíkniefna í Reykjavík með því að sameina niðurstöður sem byggðar eru á mælingum á frárennsli og önnur gögn. Þetta getur veitt hagsmunaaðilum eins og lögregluyfirvöldum og heilbrigðisstarfsmönnum mikilvægar upplýsingar sem nota má í baráttunni gegn fíkniefnavandanum.Wastewater-based epidemiology (WBE) has in recent years emerged as a reliable way to estimate the use of illicit drugs and pharmaceuticals at a community level. This methodology is based on the hypothesis that wastewater can be considered a pooled urine sample of a total population. This is a non-intrusive tool which provides objective results in near real-time.
The primary aim of this project was to adapt and validate a reliable analytical method for illicit drugs and pharmaceuticals in wastewater from Reykjavik. A solid phase extraction (SPE) method was adapted for the analysis of illicit drugs and pharmaceuticals in wastewater samples from Reykjavik with satisfactory recoveries. Ultra-performance liquid chromatography coupled to a tandem mass spectrometry (UPLC-MS/MS) was used for the analysis of samples. Wastewater samples were collected in Reykjavik at eleven timepoints from February 2017 to June 2020. The estimated use of the analytes of interest was expressed as mg/day/1000 inhabitants.
Temporal trends in illicit drug use in Reykjavik were successfully assessed using WBE. The results showed that cocaine use had increased extensively from 2017 to 2019 but had decreased considerably in June 2020 during the COVID-19 pandemic. Amphetamine and methamphetamine both showed signs of increased use between 2017 and 2020, but amphetamine use remained significantly higher. MDMA use was estimated to be stable from 2017 to 2020. Estimated cannabis use by WBE was stable from 2017 to 2019 but showed signs of an increase in 2020 during the pandemic. Trends between weekdays and during special events were also observed showing a significant increase in cocaine and MDMA use during weekends and a music festival held in Reykjavik. Further, a comparison was made with other indicators of drug use based on seizure data and driving under the influence cases.
A high-throughput SPE micro-extraction method combined with large volume injection and post-loop mixing was developed for both illicit drugs and pharmaceuticals. By extracting smaller volumes of samples compared to other conventional methods, the time per sample was lowered considerably allowing for faster reporting of results. Samples from four Nordic capitals (Oslo, Stockholm, Reykjavik, and Torshavn) were analysed using SPE micro-extraction where spatial trends were successfully estimated alongside data obtained from Helsinki. The results showed high amphetamine loads in Reykjavik and Stockholm. Methamphetamine loads were highest in Helsinki and MDMA loads were highest from Oslo. Cocaine loads were similar from Oslo, Stockholm, and Reykjavik, but notably lower from Helsinki. A clear increase was observed in MDMA and cocaine loads during weekends indicating recreational use of the drugs.
Both temporal and spatial trends in illicit drug use were successfully estimated by using WBE. Overall, results by WBE were comparable with the other indicators of drug use. By complimenting data by WBE and other methods used to assess the use of drugs, a more comprehensive picture of the community drug abuse can be achieved. This could provide stakeholders such as the law enforcement or health care authorities valuable and useful information in their fight against drug abuse.Icelandic Research Fund and the University of
Iceland Research Fun
Icelandic stroke survivors: Functioning and contextual factors and ActivABLES for home-based exercise and physical activity
Get PDFAims: The aims of this thesis were: (1) to describe functioning and contextual
factors of community-dwelling stroke survivors 1-2 years after their first
stroke, based on the International Classification of Functioning, Disability and
Health (ICF) with focus on potential differences between age-groups, (2) to
describe the process of developing ActivABLES, which aims to increase
home-based therapeutic exercise and daily physical activity among stroke
survivors, and (3) to investigate the feasibility of ActivABLES in terms of
acceptability, demand, implementation and practicality.
Methods: A cross-sectional national survey was used to collect data.
Potential participants were identified through registries from the two main
hospitals in Iceland and included community-dwelling stroke survivors who
had been admitted with their first stroke 1-2 years earlier. Exclusion criteria
included living in nursing homes, diagnosis of dementia, not having an
Icelandic national insurance number and living abroad. Participants were 114
(56.2% response rate), 50% men, 27 to 94 years old (71.6±12.9 years), and
categorized into the age-groups: ≥75 years(n=51), 65-74 years (n=34) and
<65 years (n=29). They answered questions on health, functioning (body
function, activities, participation) and contextual factors (environmental,
personal) along with two standardized questionnaires, the Stroke Impact
Scale (SIS) and the Behavioural Regulation Exercise Questionnaire-2
(BREQ-2). The process of developing ActivABLES was guided by principles
of human-centred design and the Medical Research Council framework for
development and evaluation of complex interventions. A mixed methods
design was utilized to test the feasibility of ActivABLES among ten stroke
survivors (55–79 years) who used six prototypes for four weeks with support
from their informal caregivers. Data collection included measures on balance,
mobility and hand function before and after the four-week period, along with
adherence diaries and motion detectors. Semi-structured interviews were
conducted with the stroke survivors and their caregivers after the four-week
period. Themes were identified related to four domains of feasibility:
acceptability, demand, implementation and practicality. Data was integrated
by examining any (dis)congruence in the quantitative and qualitative findings.
Results: The results from the cross-sectional survey revealed a complex and
informative pattern of functioning and contextual factors in the lives of
community-dwelling stroke survivors, where the most common symptom
immediately after the stroke was balance impairments. Some differences and
similarities in functioning and contextual factors were found between the age-
groups. The oldest participants reported more comorbidities, used more
walking devices and fewer smart devices than both younger groups. In the
SIS, the oldest participants had lower scores than both younger groups in the
domains of activities of daily living and mobility. The development of
ActivABLES resulted in six prototypes which were tested in the feasibility
study: (1) ActivFOAM for balance exercises, (2) WalkingSTARR to facilitate
walking, (3) ActivBALL for hand exercises, (4) ActivSTICKS for upper arm
exercises, and (5) ActivLAMP and (6) ActivTREE which both give visual
feedback on progress of exercise and physical activity. ActivFOAM,
ActivBALL and ActivSTICKS were all connected to a tablet which gave
exercise instructions. All the exercise prototypes could be connected to
ActivLAMP and ActivTREE to give feedback on the magnitude of exercise.
Settings could be individualised and recommended in daily time and/or
repetition could easily be progressed to match higher activity levels. In the
feasibility study, improvements in functional measures were shown after the
four-week use and more physical activity was detected with motion detectors.
The themes identified from the interviews for each feasibility domain were: (1)
acceptability: appreciation, functional improvements, self-initiated activities
and expressed potential use for future stroke survivors; (2) demand: reported
use, interest in further use and need for follow-up; (3) implementation:
importance of feedback, variety of exercises and progression of exercises;
and (4) practicality: need for support and technical problems. The quantitative
and qualitative findings converged well with each other and supported the
feasibility of ActivABLES.
Conclusion: This thesis is a good example of how the international language
of ICF can be used to holistically describe functioning and contextual factors
of a population and how a technical application can be developed and used
by stroke survivors to increase exercise and physical activity. Our results
show that stroke survivors are highly capable of using ActivABLES in
community rehabilitation. Future research should focus on further studies in
larger samples to prepare full development and marketing of ActivABLES.
Thereby, it is important to focus on heterogeneity among older stroke
survivors and the fact that they need person-centred rehabilitation but not
“one fit for all”.Markmið: Markmið doktorsverkefnisins voru að: (1) lýsa færni og aðstæðum
einstaklinga sem búa í heimahúsum 1-2 árum eftir að hafa fengið fyrsta
heilaslag, á grundvelli alþjóða flokkunarkerfisins ICF um færni, fötlun og
heilsu og með áherslu á mögulegan mun á milli einstaklinga í þremur
aldurshópum, (2) lýsa þróun á tæknibúnaðinum ActivABLES sem miðar að
því að auka þátttöku einstaklinga sem hafa fengið heilaslag í markvissum
heimaæfingum og daglegri hreyfingu og (3) meta fýsileika ActivABLES með
því að rýna í ásættanleika, eftirspurn, útbúnað og hentugleika
tæknibúnaðarins.
Aðferðir: Þversniðskönnun á landsvísu þar sem upplýsingar um mögulega
þátttakendur komu úr sjúkraskrám um þá sem höfðu verið lagðir inn með
sjúkdómsgreininguna heilaslag í fyrsta sinn á tímabilinu 1.apríl 2016 –
31.mars 2017. Útilokunarskilyrði voru búseta á hjúkrunarheimili, vitræn
skerðing samkvæmt sjúkdómsgreiningu, íslenska kennitölu vantar og búseta
erlendis. Þátttakendur voru 114 (56,2% þátttökuhlutfall), 50% karlar, á
aldrinum 27-94 ára (71,6±12,9 ára) og úr þremur aldurshópum: 75 ára og
eldri (n=51), 65-74 ára (n=34) og yngri en 65 ára (n=29). Könnunin
samanstóð af spurningum um heilsufar, færni (líkamsstarfsemi, athafnir og
þátttöku) og aðstæður (persónubundnar og umhverfistengdar) ásamt tveimur
stöðluðum spurningalistum; Mælistiku um áhrif heilaslags (SIS) og
Spurningalista um viðhorf til æfinga (BREQ-2). Þróun ActivABLES var byggð
á persónumiðaðri nálgun og líkani um þróun og mat á margþátta íhlutunum
frá Medical Research Council í Bretlandi. Blandað snið var notað til að
rannsaka fýsileika ActivABLES með tíu einstaklingum (55-79 ára) sem höfðu
fengið heilaslag og notuðu sex frumgerðir af tæknibúnaðinum til æfinga og
hreyfingar yfir fjögurra vikna tímabil með aðstoð aðstandenda. Jafnvægi,
hreyfifærni og færni handa var metin með stöðluðum mælitækjum fyrir og eftir
tímabilið, dagleg hreyfing var metin með hreyfimælum og þátttakendur skráðu
notkun og athugasemdir í dagbók. Í lokin voru tekin hálf-stöðluð viðtöl við
þátttakendur og aðstandendur. Við þemagreiningu viðtalsgagna var tekið tillit
til fjögurra þátta fýsileika; ásættanleika, krafna, útbúnaðar og hentugleika.
Megindleg og eigindleg gögn voru síðan sameinuð og greint hvort niðurstöður
voru samhljóma.
Niðurstöður: Niðurstöður könnunarinnar sýndu margbreytilegt og flókið
samspil færni og aðstæðna hjá þátttakendum. Algengasta einkennið strax í
kjölfar heilaslags var skerðing á jafnvægi. Við samanburð á færni og
aðstæðum milli aldurshópa kom fram munur en einnig líkindi á milli hópa. Elsti hópurinn hafði meiri fjölkvilla, notaði frekar gönguhjálpartæki og síður
snjalltæki en yngri hóparnir. Jafnframt fékk elsti hópurinn færri stig en yngri
hóparnir í þáttum í SIS-spurningalistanum sem lúta að athöfnum dagslegs lífs
og hreyfanleika. Þróunarferli ActivABLES skilaði sex frumgerðum sem voru
prófaðar í fýsileikarannsókninni: (1) ActivFOAM fyrir jafnvægisæfingar, (2)
WalkingSTARR til að ýta undir göngu, (3) ActivBALL til að æfa færni handa
og efri útlima, (4) ActivSTICKS til að æfa færni efri útlima, og (5) ActivLAMP
og (6) ActivTREE sem veittu endurgjöf í formi ljóss eftir því sem
þátttakandanum miðaði áfram í heimaæfingum og hreyfingu. ActivFOAM,
ActivBALL og ActivSTICKS voru öll tengd við spjaldtölvu sem sýndi
æfingarnar. Þær fjórar frumgerðir sem voru til æfinga og þjálfunar voru
tengdar við ActivLAMP eða ActivTREE sem veittu sjónræna endurgjöf um
magn æfinga og hreyfingar. Stillingar voru einstaklingsmiðaðar og einfalt var
að breyta ráðleggingum um tímalengd og/eða fjölda endurtekninga fyrir
viðeigandi stignun. Í fýsileikarannsókninni komu fram bætingar í stöðluðum
mælingum að lokinni fjögurra vikna notkun og hreyfimælar sýndu meiri
líkamlega virkni. Greining á niðurstöðum fyrir hvern þátt fýsileika leiddi í ljós
eftirfarandi þemu: (1) ásættanleiki: þakklæti, meiri færni, frumkvæði í virkni
og möguleg notkun fyrir einstaklinga sem munu fá heilaslag í framtíðinni; (2)
eftirspurn: raunveruleg notkun, áhugi á frekari notkun og þörf fyrir eftirfylgd;
(3) útbúnaður: mikilvægi endurgjafar, fjölbreytni í æfingu og framgangur í
æfingum; og (4) hentugleiki: þörf á aðstoð og tæknileg vandkvæði.
Megindlegar og eigindlegar niðurstöður voru mjög samhljóma og studdu vel
við fýsileika ActivABLES.
Ályktun: Þetta verkefni er gott dæmi um hvernig nýta má alþjóðlega
flokkunarkerfi ICF fyrir heildræna lýsingu á færni og aðstæðum ákveðins
hóps af einstaklingum og hvernig þróa má tæknibúnað tengdan snjalltækjum
fyrir einstaklinga sem hafa fengið heilaslag fyrir markvissar heimaæfingar og
daglegra hreyfingu. Fýsileiki ActivABLES fyrir einstaklinga sem hafa fengið
heilaslag rennir stoðum undir mikilvægi tæknibúnaðar í endurhæfingu þessa
hóps og kallar á frekari rannsóknir í stærri hópum til að fullvinna
tæknibúnaðinn og koma honum á markað. Frekari rannsóknir á færni og
aðstæðum eldri einstaklinga eru einnig nauðsynlegar til að sýna fram á þá
staðreynd að endurhæfing einstaklinga eftir heilaslag þarf að vera fjölbreytt
og einstaklingsmiðuð.NordForsk, Ranní
Compact 4 × 4 butler matrix with non‐standard phase differences for IoT applications
Get PDFPublisher's version (útgefin grein)Butler matrices represent a popular class of feeding networks for antenna arrays. Large dimensions and the lack of flexibility in terms of achievable output phase difference make conventional Butler structures of limited use for modern communication devices. In this work, a com-pact planar 4×4 matrix with non-standard relative phase shifts of –30,150, –120, and 60° has been proposed. The structure is designed to operate at the centre frequency of 2.45 GHz. Small dimensions of 31.3×22.9 mm make it useful for Internet of Things applications. The structure operates from 2.35 to 2.55 GHz, which covers the industrial, scientific and medical bandwidth. At the centre frequency, the measured amplitude and phase imbalance are 1.65 dB and±4.3°, respectively. The proposed circuit has been compared to the state-of-the-art structures from the literature.This work was supported in part by National Centre for Research and Development Grant NOR/POLNOR/HAPADS/ 0049/2019-00, by National Science Centre of Poland Grant 2017/27/B/ST7/00563, and by Icelandic Centre for Research (RANNIS) Grant 206606051.Peer reviewe
EM-Driven Multi-Objective Optimization of a Generic Monopole Antenna by Means of a Nested Trust-Region Algorithm
Get PDFPublisher's version (útgefin grein)Antenna structures for modern applications are characterized by complex and unintuitive topologies that are difficult to develop when conventional, experience-driven techniques are of use.In this work, a method for the automatic generation of antenna geometries in a multi-objective set up has been proposed. The approach involves optimization of a generic spline-based radiator with an adjustable number of parameters using a nested, trust region-based algorithm. The latter iteratively increases the dimensionality of the radiator in order to gradually improve its performance. The method has been used to generate a set of nine antenna designs, representing a trade-off between minimization of reflection within 3.1 GHz to 10.6 GHz and a reduction of size. The properties of the optimized designs vary along the Pareto set from−10 dB to−20 dB and from 230 mm2to 757 mm2for the first and second objectives, respectively. The presented design approach has been validated against a genuine, population-based optimization routine. Furthermore, the smallest Pareto-optimal design has been compared to the antennas from the literature.This work was supported in part by the National Science Centre of Poland Grant 2017/27/B/ST7/00563 and by the National Centre for Research and Development Grant NOR/ POLNOR/HAPADS/0049/2019-00.Peer reviewe
Failure of Healthcare Provision for Attention-Deficit/Hyperactivity Disorder in the United Kingdom: A Consensus Statement
Get PDFPublisher's version (útgefin grein)Background: Despite evidence-based national guidelines for ADHD in the
United Kingdom (UK), ADHD is under-identified, under-diagnosed, and under-treated.
Many seeking help for ADHD face prejudice, long waiting lists, and patchy or unavailable
services, and are turning to service-user support groups and/or private healthcare
for help.
Methods: A group of UK experts representing clinical and healthcare providers
from public and private healthcare, academia, ADHD patient groups, educational,
and occupational specialists, met to discuss shortfalls in ADHD service provision in
the UK. Discussions explored causes of under-diagnosis, examined biases operating
across referral, diagnosis and treatment, together with recommendations for resolving
these matters.
Young et al. Failure of ADHD Healthcare Provision
Results: Cultural and structural barriers operate at all levels of the healthcare system,
resulting in a de-prioritization of ADHD. Services for ADHD are insufficient in many
regions, and problems with service provision have intensified as a result of the response
to the COVID-19 pandemic. Research has established a range of adverse outcomes of
untreated ADHD, and associated long-term personal, social, health and economic costs
are high. The consensus group called for training of professionals who come into contact
with people with ADHD, increased funding, commissioning and monitoring to improve
service provision, and streamlined communication between health services to support
better outcomes for people with ADHD.
Conclusions: Evidence-based national clinical guidelines for ADHD are not being met.
People with ADHD should have access to healthcare free from discrimination, and in
line with their legal rights. UK Governments and clinical and regulatory bodies must act
urgently on this important public health issue.The meeting was jointly funded by the ADHD Foundation,
the UK Adult ADHD Network (UKAAN), and the UK ADHD
Partnership (UKAP). Other than reimbursement of travel
expenses to attend the meeting, none of the authors received
any financial compensation for attending the meeting or writing
the manuscript, aside from CS who was remunerated for her
time. PA was supported by NIHR Biomedical Research Center
for Mental Health, NIHR/MRC (14/23/17) and NIHR senior
investigator award (NF-SI-0616-10040). TN-D was funded by an
NIHR Advanced Fellowship (NIHR300056). The views expressed
in this publication are those of the authors and not necessarily
those of the NHS, the National Institute for Health Research or
the Department of Health and Social Care.Peer Reviewed (ritrýnd grein
The effect of trehalose, antioxidants, and acetate buffer concentration on oxytocin stability
Get PDFPost-printOxytocin is a cyclic nonapeptide used to induce labor and prevent bleeding after childbirth. Due to its instability, storage and transport of oxytocin formulations can be problematic in hot/tropical climates. The aim of this study was to investigate the effect of trehalose and select antioxidants (uric acid, butylated hydroxytoluene, and L-ascorbic acid) on oxytocin stability in solution. The effect of buffer composition and acetate buffer concentration was also studied. Acetate buffer was found to work better than citrate/phosphate buffer for the oxytocin stability. Lower acetate buffer concentrations (0.025 M or less) were also found to yield improved oxytocin stability than higher concentrations. Although known degradation pathways of oxytocin include oxidation, the antioxidants uric acid and butylated hydroxytoluene had negligible effect on the oxytocin stability while L-ascorbic acid led to significantly faster degradation. Despite trehalose’s reputation as a great stabilizer for biomolecules, it also had small to negligible effect on oxytocin stability at concentrations up to 1 M in acetate buffer. These results were surprising given the present literature on trehalose as a stabilizer for various biomolecules, including proteins and lipids.Tækniþróunarsjóður (164072-0613)Peer Reviewe
Standardized analysis of juvenile pyroclasts in comparative studies of primary magma fragmentation: 2. Choice of size fraction and method optimization for particle cross-sections
Get PDFPre-print (óritrýnt handrit)The morphological and textural features of juvenile pyroclasts record crucial details on magma conditions at the time of fragmentation. Their study is therefore essential to better understand the dynamics of explosive eruptions. Unfortunately, the absence of a standardized protocol of investigation hinders data reproducibility and comparison among different laboratories. Here we focus on morphometric parameters, 2D crystallinity and 2D vesicularity resulting from cross-section analysis of juvenile particles using backscattered electron imaging, and address the following questions: (i) how to prepare polished epoxy grain mounts, (ii) which pixel density to be used, (iii) how to facilitate image preparation and image analysis, (iv) which sample size is necessary to obtain statistically robust results, and (v) what is the optimum size fraction for analysis. We test juvenile particles in grain size bins ranging from 2–1 mm (− 1 to 0ɸ) to 88–63 µm (+ 3.5 to + 4ɸ), using samples from the 1977 Ukinrek eruption. We find that the required resolution ranges from 75 000 to 10 000 pixels per particle, depending on the size fraction, higher than previously postulated. In the same size ranges, less than 50 grains per size fraction and sample are needed to get robust averages. Based on theoretical, empirical, and practical considerations, we propose 0.71–0.5 mm (+ 0.5 to + 1ɸ) as the optimum size fraction to be analyzed as particle cross-sections in standardized comparative studies of magma fragmentation. We provide a detailed guide for preparing polished epoxy grain mounts and introduce a software package (PASTA) for semi-automated image preparation, image processing, and measurement of morphological and textural parameters.This study was funded by a Discovery Grant to PSR from the Natural Sciences and Engineering Research Council of Canada (NSERC) (RGPIN-2015–06782). TD is supported by the Icelandic Research Fund (Rannís), grant Nr. 206527–051