| 1. |
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| 2. |
- Eklund, Monica, et al.
(författare)
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Medreflektioner inom lärarutbildningens examensarbete
- 2008
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Ingår i: Kongresrapport til den 10. nordiske læreruddannelseskongres. - Reykjavik : School of Education, University of Iceland. - 9789979985167
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Konferensbidrag (refereegranskat)abstract
- Studenterna inom lärarutbildningen vid Högskolan i Halmstad skriver under sin sista termin ett examensarbete. Enligt de bedömningskriterier som tillämpas ska examensarbetet vara såväl vetenskapligt som skol- och yrkesrelevant. Examensarbetet bedöms av akademiska lärare och bedömningarna ligger till grund för betygsättningen av examensarbetena. Efter att examensarbetena betygsatts, kommenteras de godkända examensarbetena av personal inom för-, grund och gymnasieskolor, s.k. medreflektörer. I föreliggande paper undersöks ett 50-tal medreflektioner med utgångspunkt från tre frågeställningar: 1. Vad slags reflektioner förmedlas i medreflektörernas texter?; 2. Vilka likheter och skillnader finns mellan medreflektörernas kommentarer och de akademiska bedömningarna?; 3. Ger medreflektörernas verksamhet bidrag till kompetensutveckling och skolutveckling?
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| 3. |
- Jónsdóttir, Kristín, et al.
(författare)
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Glacial long period seismic events at Katla volcano, Iceland
- 2009
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Ingår i: Geophysical Research Letters. - : American Geophysical Union (AGU). - 0094-8276 .- 1944-8007. ; 36:11
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Tidskriftsartikel (refereegranskat)abstract
- Repeating long-period (lp) earthquakes are commonly observed in volcanic regions worldwide. They are usually explained in terms of a volcanic source effect or anomalous propagation through the volcano. Recently, large lp events have also been associated with the motion of massive ice streams. Our joint analysis of climatic and new seismic data shows that small lp events observed at Katla volcano, Iceland, are in fact related to ice movement in a steep outlet glacier and not, as previously thought, to volcanic intrusive activity. The over 13000 lp events recorded since 2000 are consistent in character and magnitude with seasonal changes of the glacier. As the current global warming trend could cause similar earthquake sequences at other glacier covered volcanoes, identifying them as glacial rather than eruption precursors is vital.
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| 4. |
- Jónsdóttir, Kristín, et al.
(författare)
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Habits of a glacier-covered volcano : Seismicity patterns and velocity structure of Katla volcano, Iceland
- 2007
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Ingår i: Annals of Glaciology. - : International Glaciological Society. - 0260-3055 .- 1727-5644. ; 45, s. 169-177
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Tidskriftsartikel (refereegranskat)abstract
- The Katla volcano, overlain by the Mýrdalsjökull glacier, is one of the most active and hazardous volcanoes in Iceland. Earthquakes show anomalous magnitude-frequency behaviour and mainly occur in two distinct areas: within the oval caldera and around Goðabunga, a bulge on its western flank. The seismicity differs between the areas; earthquakes in Goðabunga are low frequency and shallow whereas those beneath the caldera occur at greater depths and are volcano-tectonic. The seismicity shows seasonal variations but the rates peak at different times in the two areas. A snow budget model, which gives an estimate of the glacial loading, shows good correlation with seismic activity on an annual scale. Data recorded by the permanent network South Iceland Lowland (SIL), as well as by a temporary network, are used to invert for a 3D seismic velocity model underneath Eyjafjallajökull, Goðabunga and the Katla caldera. The tomography resolves a 15 km wide, aseismic, high-velocity structure at a depth of more than 4 km between the Eyjafjallajökull volcano in the west and the Katla volcano in the east. Anomalously low velocities are observed beneath the Katla caldera, which is interpreted as being a significantly fractured area of anomalously high temperature.
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| 5. |
- Jónsdóttir, Kristin, et al.
(författare)
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Investigation of local very long period seismic signals registered at Mýrdalsjökull glacier, south Iceland
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Strong and repeating very long period (vlp) signals (10-30 sec) on and around the western Mýrdalsjökull ice cap, which covers the Katla volcano in South Iceland, are recorded simultaneously with long period (lp) events of magnitude >2. The signals are recorded on 6 broadband and 2 higher frequency three-component seismic stations. The vlp signals are linearly polarized and the horizontal polarization direction points to the same source as the lp events, which have recently been interpreted as being generated by ice falls over an escarpment in a steep outlet glacier. The vlp events are registered on several different instrument types, which implies that they must be due either to a generic problem with the instruments or that they are real signals. They do not appear to be consistent with P-, S- or surface wave behaviour.Similar signals elsewhere have been interpreted as the combined effect of static displacement and tilt caused by ground deformation due to magma movements within a volcano. The three-component data are therefore modelled as the combined effects of tilt and vertical translation caused by the ice movements. Simple deformation modelling shows that the observed vlp signals are inconsistent with the ice fall source in the relative magnitudes of the vertical and radial displacements and, in line with results from elsewhere, the magnitudes of the observed effects are large relative to the model response. Thus the origin of the vlp signals remains enigmatic.Our analysis suggests that it is unlikely that the signal is an instrumental artefact. Possible physical origins are discussed.
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| 6. |
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| 7. |
- Jónsdóttir, Kristin, et al.
(författare)
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Modelling fundamental waiting time distributions for earthquake sequences
- 2006
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Ingår i: Tectonophysics. - : Elsevier BV. - 0040-1951 .- 1879-3266. ; 424:3-4, s. 195-208
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Tidskriftsartikel (refereegranskat)abstract
- The distribution of waiting times between time-neighbouring events for a time series obeying the Omori law is examined theoretically and numerically with the aim of understanding the characteristics of these distributions, how these characteristics change (e.g. scale) with the parameters of the Omori series, and thus how empirical waiting time data may be correctly interpreted. It is found that the waiting time distribution, for a single Omori aftershock sequence, consists in general of two power law segments followed by a rapid decay at larger waiting times. The analyses are illustrated using real data from the SIL network on Iceland. This data often shows characteristics predominantly consistent with the Omori law, but there are significant exceptions. We conclude that waiting time distributions and related statistical analysis has meaningful potential for the analysis of earthquake data sets, as a step towards developing physical models of the earthquake process.
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| 8. |
- Jónsdóttir, Kristín
(författare)
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Studies of Unusual Seismicity and Long Period Events at the Glacier Overlain Katla Volcano, Iceland
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Earthquake catalogues are usually dominated by diffusive behaviour consistent with the Omori law of aftershocks. This is investigated in terms of waiting times, i.e. the time between successive events in a time-sorted earthquake catalogue. The theoretical waiting time probability distribution for the Omori law is derived and shown to predict the numerically produced Omori aftershock sequence well. These results enhance our understanding of aftershock processes and demonstrate that previous waiting time interpretations were severely flawed.Iceland earthquake catalogues are studied in terms of waiting times. Omori aftershock sequences are shown to predict most datasets well but there are some significant exceptions. One of these is data from the glacier covered Katla volcano in South Iceland, with few aftershocks. This dataset can be further split into two geographical groups: Several hundred volcano-tectonic earthquakes occurring within the caldera, reaching depths down to 15 km, and thousands of emergent low frequency earthquakes with a poorly defined shallow source in Goðabunga, in the western part of Katla. These events are investigated further.The lp events at Goðabunga have been recorded for decades and show a clear seasonal and climate-related correlation where their number increases in the autumn as well as during warmer years. Many of them form groups with very with similar waveforms. New broad-band seismic data suggests that the lp events originate in a steep outlet glacier covering Katla. Here, ice movement leads to ice falls over the steep escarpment, and we now believe that the lp events are generated by large ice falls rather than being related to gas or magma movements within the volcano, and are not precursors to an eruption as previously suspected. This observation probably has major significance for hazard estimation at the many ice-covered volcanoes around the world.We report near-field (vlp) signals simultaneous with the largest lp events. Our data is partly consistent in character with surface deformation (displacement and tilt) due to the ice movements. However, in line with results from elsewhere, the magnitudes of the observed effects are large relative to those from mathematical modelling. Our analysis suggests that the signal is not an instrumental artefact. Possible explanations are discussed.
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| 9. |
- Jonsdottir, Kristin, et al.
(författare)
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The prognostic value of MARCKS-like 1 in lymph node-negative breast cancer
- 2012
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Ingår i: Breast Cancer Research and Treatment. - : Springer. - 0167-6806 .- 1573-7217. ; 135:2, s. 381-390
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Tidskriftsartikel (refereegranskat)abstract
- There is a need for new biomarkers to more correctly identify node-negative breast cancer patients with a good or bad prognosis. Myristoylated alanine-rich C kinase substrate like-1 (MARCKSL1) is a membrane-bound protein that is associated with cell spreading, integrin activation and exocytosis. Three hundred and five operable T1,2N0M0 lymph node-negative breast cancer patients (median follow-up time 121 months, range 10–178 months) were evaluated for MARCKSL1 expression by immunohistochemistry and quantitative real-time PCR. The results were compared with classical prognosticators (age, tumor diameter, grade, estrogen receptor, and proliferation), using single (Kaplan–Meier) and multivariate survival analysis (Cox model). Forty-seven patients (15 %) developed distant metastases. With single and multivariate analysis of all features, MARCKSL1 protein expression was the strongest prognosticator (P < 0.001, HR = 5.1, 95 % CI = 2.7–9.8). Patients with high MARCKSL1 expression (n = 23) showed a 44 % survival versus 88 % in patients with low expression at 15-year follow-up. mRNA expression of MARCKSL1 in formalin fixed paraffin-embedded tissue was also prognostic (P = 0.002, HR = 3.6, 95 % CI = 1.5–8.3). However, the prognostic effect of high and low was opposite from the protein expression, i.e., low expression (relative expression ≤ 0.0264, n = 76) showed a 79 % survival versus 92 % in those with high expression of MARCKSL1 mRNA. Multivariate analysis of all features with distant metastases free survival as the end-point showed that the combination of MARCKSL1 protein and phosphohistone H3 (PPH3) has the strongest independent prognostic value. Patients with high expression (≥13) of PPH3 and high MARCKSL1 protein had 45 % survival versus 78 % survival for patients with low MARCKSL1 protein expression and high expression (≥13) of PPH3. In conclusion, MARCKSL1 has strong prognostic value in lymph node-negative breast cancer patients, especially in those with high proliferation.
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| 10. |
- Jonsdottir, Lilja Kristin, et al.
(författare)
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Autistic children quickly orient away from both eyes and mouths during face observation
- 2023
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Ingår i: Journal of autism and developmental disorders. - : Springer Nature. - 0162-3257 .- 1573-3432. ; 53:1, s. 495-502
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Tidskriftsartikel (refereegranskat)abstract
- Studies have supported two different hypotheses of reduced eye gaze in people with ASD; gaze avoidance and gaze indifference, while less is known about the role of anxiety. We tested these hypotheses using an eye-tracking paradigm that cued the eyes or mouth of emotional faces. Autistic children (n = 12, mean age 7 years) looked faster away from both eyes and mouths than controls (n = 22). This effect was not explained by anxiety symptoms. No difference was found in latency towards either area. These results indicate that attentional avoidance of autistic children is not specific to eyes, and that they do not show attentional indifference to eyes compared to controls. Atypicalities in visual scanning in ASD are possibly unrelated to specific facial areas.
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