Continuous THz emission from dipolaritons

We propose a scheme of continuous tunable THz emission based on dipolaritons --- mixtures of strongly interacting cavity photons and direct excitons, where the latter are coupled to indirect excitons via tunnelling. We investigate the property of multistability under continuous wave (CW) pumping, and the stability of the solutions. We establish the conditions of parametric instability, giving rise to oscillations in density between the direct exciton and indirect modes under CW pumping. In this way we achieve continuous and tunable emission in the THz range in a compact single-crystal device. We show that the emission frequency can be tuned in a certain range by varying an applied electric field and pumping conditions. Finally, we demonstrate the dynamic switching between different phases in our system, allowing rapid control of THz radiation.Comment: Main article 6 pages and 5 figures, two appendices 8 pages and 2 figure

Catching the Bound States in the Continuum of a Phantom Atom in Graphene

We explore theoretically the formation of bound states in the continuum (BICs) in graphene hosting two collinear adatoms situated at different sides of the sheet and at the center of the hexagonal cell, where a phantom atom of a fictitious lattice emulates the six carbons of the cell. We verify that in this configuration the local density of states (LDOS) near the Dirac points exhibits two characteristic features: i) the cubic dependence on energy instead of the linear one for graphene as found in New J. Phys. 16, 013045 (2014) and ii) formation of BICs as aftermath of a Fano destructive interference assisted by the Coulomb correlations in the adatoms. For the geometry where adatoms are collinear to carbon atoms, we report absence of BICs

Quantum phase transition triggering magnetic BICs in graphene

Graphene hosting a pair of collinear adatoms in the phantom atom configuration has pseudogap with cubic scaling on energy, $\Delta\propto|\varepsilon|^{3}$ which leads to the appearance of spin-degenerate bound states in the continuum (BICs) [Phys. Rev. B 92, 045409 (2015)]. In the case when adatoms are locally coupled to a single carbon atom the pseudogap scales linearly with energy, which prevents the formation of BICs. In this Letter, we explore the effects of non-local coupling characterized by the Fano factor of interference $q_{0},$ tunable by changing the slope of the Dirac cones in the graphene band-structure. We demonstrate that three distinct regimes can be identified: i) for $q_{0}<q_{c1}$ (critical point) a mixed pseudogap $\Delta\propto|\varepsilon|,|\varepsilon|^{2}$ appears yielding a phase with spin-degenerate BICs; ii) near $q_{0}=q_{c1}$ when $\Delta\propto|\varepsilon|^{2}$ the system undergoes a quantum phase transition in which the new phase is characterized by magnetic BICs and iii) at a second critical value $q_{0}>q_{c2}$ the cubic scaling of the pseudogap with energy $\Delta\propto|\varepsilon|^{3}$ characteristic to the phantom atom configuration is restored and the phase with non-magnetic BICs is recovered. The phase with magnetic BICs can be described in terms of an effective intrinsic exchange field of ferromagnetic nature between the adatoms mediated by graphene monolayer. We thus propose a new type of quantum phase transition resulting from the competition between the states characterized by spin-degenerate and magnetic BICs

The role of parliament under ministerial government

The present paper is concerned with the preconditions for ministerial government in Iceland and the role of parliament in sustaining it. Ministerial government is a form of coalition governance where the division of portfolios between parties functions as the basic mechanism of managing coalitions. Ministers are policy dictators in the sense that they control their ministries without interference from their coalition partners. Ministerial government is considered a weak form of coalition governance in the literature on account of its susceptibility to principal-agent problems, i.e., the temptation of ministers to adopt policies which are beneficial to their own party, or themselves, even if they are harmful to the coalition as a whole. We argue that ministerial government was the guiding principle of coalition governance in Iceland prior to the crash of 2008. We demonstrate that given a number of conditions, ministerial government can in fact function effectively in the sense of providing the necessary minimum of inter-coalition checks. Instead of the cabinet providing oversight, however, the parties and committees in parliament play a key role in controlling policy drift. For a number of reasons, the financial crash in Iceland undermined some of the features on which ministerial government rested and coalition co-ordination after the crash has diverged significantly from the preceding period. It is too early, however, to tell whether these represent a permanent shift in coalition management in Iceland.Peer Reviewe

"I feel I have been taken seriously" Women's experience of greater trochanteric pain syndrome treatment-A nested qualitative study

BACKGROUND: Women experiencing greater trochanteric pain syndrome (GTPS) report high levels of pain and reduced quality of life. Exploring how they manage GTPS in a daily life context can provide important knowledge about individual coping strategies. Education, extracorporeal shockwave therapy (ESWT) and exercise have good group level evidence for efficacy in clinical trials and are increasingly used in routine care for patients with GTPS. Exploring women’s experiences of such treatment may help understand the mechanisms underpinning these positive results and inform treatment strategies. We therefore aimed to explore how women with GTPS experience and manage their daily life, and their experience of the combined treatment of education, ESWT and exercises. METHODS: This qualitative study was nested within a cohort study based in a hospital outpatient clinic and a physiotherapy clinic in Denmark assessing the combined treatment of education, ESWT and exercises. Data was collected from eleven women using in-person, individual, semi-structured interviews which were audio recorded. Transcripts were coded and analysed using an inductive thematic analysis approach. FINDINGS: Five themes were identified: (1) Daily life was controlled and structured by pain; (2) The condition was acknowledged and taken seriously by treating professionals; (3) The participants´ experiences of the intervention–information is key; (4) Improved capability and autonomy in pain management and (5) The women´s perspectives on improving and expanding the intervention. Learning how to manage pain was experienced as the most important element of the program to the women to be able to minimize pain and manage daily life. CONCLUSION: Exploration of how women with greater trochanteric pain syndrome experienced and managed daily hip pain, and how they experienced and adapted to treatment are important novel findings that will inform clinical practice. This new knowledge may be used to inform an individualized patient education, treatment and evaluation strategy for women with the painful and debilitating condition of GTPS

Invasive infections due to Streptococcus pyogenes: seasonal variation of severity and clinical characteristics, Iceland, 1975 to 2012.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageEpidemiology and clinical characteristics of invasive Group A streptococcal infections (IGASI) are highly variable. Long-term studies are needed to understand the interplay between epidemiology and virulence. In a population-based study of IGASI in Iceland from 1975 to 2012, 288 cases were identified by positive cultures from normally sterile body sites. Charts were reviewed retrospectively and emm-types of viable Streptococcus pyogenes isolates (n=226) determined. Comparing the first and last decade of the study period, IGASI incidence increased from 1.09 to 3.96 cases per 100,000 inhabitants per year. The most common were emm types 1 (25%), 28 (11%) and 89 (11%); emm1 strains were most likely to cause severe infections. Infections in adults were significantly more likely to be severe during the seasonal peak from January to April (risk ratio: 2.36, 95% confidence interval: 1.34–4.15). Significant seasonal variability in severity was noted among patients with diagnosis of sepsis, respiratory infection and cellulitis, with 38% of severe infections in January to April compared with 16% in other months (p<0.01). A seasonal increase in severity of IGASI suggested that generalised seasonal increase in host susceptibility, rather than introduction of more virulent strains may play a role in the pathogenesis of these potentially fatal infections.Icelandic Center for Research, Rannis/100436021 Landspitali University Hospital Science Fun

Intensive care patients with influenza A (H1N1) infection in Iceland 2009

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn Skoða/Opna(view/open)BACKGROUND: We describe the main characteristics of patients that required intensive care due to the influenza (H1N1) outbrake in 2009. METHODS: Retrospective and prospective analysis of medical records from patients admitted to ICU with positive RT-PCR for (H1N1). RESULTS: During a six week period in the fall of 2009, 16 patients were admitted to intensive care in Iceland with confirmed H1N1 infection. Mean age was 48 years (range 1-81). Most patients were considered quite healthy but the majority had risk factors such as smoking, obesity or hypertension. All but one had fever, cough, dyspnea and bilateral infiltrates on chest x-ray and developed any organ failures (mean SOFA score 7). 12 needed mechanical ventilation and two extra corporeal membrane oxygenation (ECMO). Mean APACHE II score was 20. No patient died in the ICU but one elderly patient with multiple underlying diseases died a few days after being discharged from the ICU. CONCLUSIONS: (1) The incidence of severe influenza A (H1N1) that leads to ICU admission appears to be high in Iceland. (2) Many patients developed acute respiratory distress syndrome in addition to other organ failures, and required additional measures for oxygenation such as prone position, nitric oxide inhalation and ECMO. (3) 28 day mortality was low. (4) This study will aid in future outbreak planning in Iceland. Key words: influenza A, pneumonia, multiple organ failure, death rate, intensive care, ventilator therapy, ECMO.Tilgangur: Að lýsa helstu einkennum og afdrifum þeirra sem lögðust inn á gjörgæsludeildir á Íslandi vegna inflúensusýkingar af A stofni (H1N1) haustið 2009. Aðferðir: Aflað var upplýsinga um sjúklinga sem lögðust inn á gjörgæsludeildir á Íslandi með staðfesta H1N1 2009 sýkingu. Niðurstöður: 16 sjúklingar lögðust inn á gjörgæsludeildir vegna inflúensu A (H1N1) sýkingar, meðalaldur 48 ár (1-81). Flestir töldust vera tiltölulega frískir fyrir, en 13 höfðu þó sögu um reykingar, offitu eða háþrýsting. 15 höfðu hita, hósta, öndunarþyngsli og dreifðar íferðir í báðum lungum á lungnamynd og margir fengu fjöllíffærabilun. Allir fengu veirulyf og 12 voru meðhöndlaðir í öndunarvél, þar af tveir einnig í hjarta- og lungnavél. Enginn sjúklingur lést á gjörgæsludeild, en einn fjölveikur aldraður sjúklingur lést síðar á legudeild. Ályktanir: (1) Tíðni alvarlegra sjúkdómseinkenna af völdum inflúensu A (H1N1) sem leiða til gjörgæslumeðferðar er há á Íslandi. (2) Þessir sjúklingar fá flestir, auk annarra líffæratruflana, mjög alvarlega öndunarbilun sem oft lætur ekki undan hefðbundinni öndunarvélameðferð. (3) Árangur meðferðar á íslenskum gjörgæsludeildum hefur verið góður. (4) Niðurstöður þessarar rannsóknar geta nýst yfirvöldum við mat á meðferðarmöguleikum og fyrirbyggjandi aðgerðum gegn þessum lífshættulega sjúkdómi

History of autoimmune disease is associated with impaired survival in multiple myeloma and monoclonal gammopathy of undetermined significance: a population-based study

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesMultiple myeloma (MM) is a plasma cell disorder preceded by monoclonal gammopathy of undetermined significance (MGUS). Incidence of MM and MGUS is higher among patients with autoimmune disease. The aim of this study was to determine whether a history of autoimmunity has an impact on survival in MM and MGUS. Using high-quality national Swedish registries, we identified 8367 patients with MM, 18,768 patients with MGUS, and 110,251 matched control subjects, and obtained information on previous autoimmune disease in patients and controls. Cox regression was used to calculate hazard ratios (HRs) for overall survival with 95 % confidence intervals (CIs). In patients with MM and a prior autoimmune disease, the risk of death was significantly increased, HR = 1.2 (95 % CI 1.2-1.3) compared to MM patients with no history of autoimmunity. In MGUS patients, a prior autoimmune disease was associated with a significantly 1.4-fold elevated risk of death (95 % CI 1.3-1.4). When analyzing different types of autoimmune diseases, a history of ulcerative colitis had a stronger impact on survival in MM than in controls. Our findings that a history of autoimmune disease has a negative impact on survival in MM and MGUS could be due to shared underlying common genetic factors, or that patients with a history of autoimmunity develop more severe cases of MM and MGUS, or cumulative comorbidity in the individual. Our results suggest that more attention should be paid to comorbidity as a prognostic factor in MGUS and MM, and underlines the need for studies aimed at tailoring therapy according to comorbidity.Swedish Blodcancerfonden Swedish Cancer Society Stockholm County Council Karolinska Institutet Karolinska Institutet Foundations University of Iceland Icelandic Centre for Research (RANNIS) Landspitali University Hospita

The impact of prior malignancies on second malignancies and survival in MM patients: a population-based study

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesIn the present study, we aimed to evaluate 2 hypotheses. First, we hypothesize that prior malignancy is a proxy for genetic susceptibility that could be a risk factor for subsequent malignancy development in multiple myeloma (MM) patients. Second, we hypothesize that survival after MM is influenced by a prior malignancy. All patients diagnosed with MM from 1 January 1973 to 31 December 2010 were identified from the Swedish Cancer Register. Cox regression model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) where prior malignancy was compared in MM patients who developed a subsequent malignancy and MM patients who did not. In another Cox regression model, survival was compared in MM patients with and without a prior malignancy diagnosis. A total of 19 791 patients were diagnosed with MM. Patients with a prior malignancy diagnosis had a significantly increased risk of developing a subsequent malignancy compared with MM patients without (HR 1.42, 95% CI 1.23-1.65, P 1 prior malignancy reduces survival even further.Asrun Einarsdottir Foundation in Iceland Blodcancerfonden Swedish Cancer Society Stockholm County Council Karolinska Institutet Foundation University of Iceland Research Fund Icelandic Centre for Research Landspitali University Hospital Research Fund Marie Curie Career Integration Grant Memorial Sloan Kettering Cancer Center Core Grant by the National Cancer Institute, National Institutes of Healt

A comparison of behavioral and psychological characteristics of patients opting for surgical and conservative treatment for morbid obesity

Background Little is known about the psychological prerequisites for weight loss maintenance after bariatric surgery. A first step in investigating whether existing knowledge of conservative weight loss treatment is applicable for lifestyle interventions postoperatively is to compare specific psychological characteristics at baseline. The aim of this study was to compare patients scheduled for bariatric surgery with patients receiving conservative treatment for morbid obesity on measures of behavioral and psychosocial characteristics considered predictors of their adoption of and adherence to long-term lifestyle recommendations. Methods Baseline clinical and questionnaire data from the prospective “Oslo Bariatric Surgery Study” were used to examine potential differences between bariatric surgery patients (n = 301) and patients receiving conservative weight loss treatment (n = 261). Results The surgical group was characterized by their younger age (43.8 vs. 46.2 years, p <0.01), higher percentage of women (79.1 vs. 70.1 %, p <0.05), and higher Body Mass Index (BMI; 45.0 vs. 41.9 kg/m2, p <0.001). A multiple logistic regression analysis, adjusting for group differences in BMI, gender, and age, showed that the surgical group had higher self-efficacy (Odds ratio; OR = 3.44, 95 % Confidence interval; CI 1.65, 7.14), more positive outcome expectations (OR = 1.53, 95 % CI 1.23, 1.89), and plans that were more explicit for changing their eating behaviors (OR = 1.80, 95 % CI 1.06, 1.93). The surgical patients were also less ready to change physical activity levels (OR = 0.59, 95 % CI 0.48, 0.73), had tried more types of unhealthy weight loss methods in the past (OR = 1.16, 95 % CI 1.01, 1.33), drank soda more frequently (OR = 1.24, 95 % CI 1.02, 1.50), had fewer binge eating episodes (OR = 0.38, 95 % CI 0.20, 0.71), and had more depressive symptoms (OR = 1.19, 95 % CI 1.09, 1.29). Conclusions Patients opting for bariatric surgery had more positive expectations of the treatment outcomes and stronger beliefs in their ability to achieve these outcomes. Those starting conservative treatment had stronger beliefs in readiness to change physical activity levels. Future studies should explore the effect of interventions for bariatric surgery patients, promoting postoperative physical activity and stress realistic outcome expectations. The potential effects of incorporating this knowledge in intervention strategies remain to be explored