Publikationer från Uppsala Universitet
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Analysing π-π stacking interactions in lignin nanoparticles from molecular simulations – insights and lessons learned
No full textA special molecular association is π–π-stacking, driven by weak interactions within aromatic compounds. The π–π-stacking interactions can occur in either a sandwich-like or T-shaped manner. In this study, a method to recognise π–π-stacking from classical molecular dynamics trajectories is developed. By applying three criteria, the method is tested for simple lignin dimer, tetramer and octamer systems, with all G units and β-O4′ linkages. The criteria are geometric and based on distance between ring centroids, the angle between the planes of the two rings and the lateral displacement of the rings. In addition, a wide-angle X-ray scattering (WAXS) profile was calculated from a tetramer system, in agreement with previous experimental results. However, when the WAXS peak assigned to sandwich-shaped stacking was analysed in-depth, it was found to mainly be caused by other intramolecular structural motifs involving e.g. the α-carbon and ring carbons, rather than π–π-stacking. This finding is important for future analyses of WAXS profiles originating from lignin-based materials and shows the strength of combining X-ray scattering methods with molecular modelling
Secure Tunneling for the IoT Using CoAP and OSCORE
No full textTwo protocols designed for IoT communication are CoAP, a UDP-based communication protocol built on the RESTful paradigm, and OSCORE, which provides end-to-end security on the application-layer for CoAP messages. OSCORE is used to protect CoAP messages end-to-end, but is not able to do so for any intermediary that it may want to. The goal is therefore to implement an additional layer of protection on CoAP messages using OSCORE, so an endpoint can encrypt both to intermediaries and the destination endpoint and evaluating it based on performance effects and security gains. In addition to the necessary changes in how a OSCORE protected CoAP message is processed by an endpoint, a CBOR-type instruction bundle is used to control the encryption order and what options are encrypted or added to the message during processing. The tests measured the time spent by a device on encryption and decryption, the round-trip time and the exchange lifetime. The results indicate an increase in message size of ca 25 bytes (the actual size increase depends on the message and configuration of the device) between every device, increasing the message size by between 42 \% and 87 \%. Secure tunneling between server and proxy rarely provide security benefits and so should only be used when absolutely necessary. There are security benefits to using secure tunneling between client and proxy, such as hiding the Proxy-* options. Additionally, this can be used to protect messages while establishing OSCORE security contexts using EDHOC, including when a combined request is used.
"Många frågar inte efter det som inte syns." : En studie av behov och förväntningar på folkbibliotek från nationella minoriteter och människor med annat modersmål än svenska - och hur väl biblioteken uppfyller dessa.
No full textAbstract Introduction. Under the Libraries Act, libraries must particularly attend to the needs of minority languages and non-native language speakers. This is accomplished in part by acquiring books in a variety of languages. However, librarians are a relatively homogeneous group. Can public libraries really be places where everyone finds subjects of interest and feels seen and affirmed? Method. This thesis investigates the current state of affairs; the minorities expectations and libraries facilitation through qualitative surveys directed to members of minority language communities and librarians. Analysis. The results from the qualitative surveys were analyzed using thematic analysis. Results. By examining library collections and activities and how well they meet the needs and expectations of heterogeneous groups, the thesis highlights the shortcomings of libraries. Libraries should, and can, be different spaces at the same time. For citizens with a different mother tongue, libraries primarily serve as a refuge and a gateway to Swedish society, while for national minorities, the role of libraries as repositories of their own cultural memories and experiences, as well as a bridge between the present and history, is equally important. Conclusion. Libraries are in dire need for increased cultural competence. Not only in order to follow the Libraries Act but also since the law itself simplifies and obscures different needs and expectations of the target groups by lumping them together. This thesis shows that needs and expectations of libraries vary, what newly arrived citizens need is not the same as what national minorities seek and the libraries have to be able to attend to all. This is a two years master’s thesis in Library and Information Science
Fatigue, Sleep Problems, and Self-Efficacy Before and After Heart Transplantation : A 5 Year Follow-Up
No full textIntroduction: Fatigue is a troublesome symptom after heart transplantation and is poorly studied in a long-term perspective. One hypothesis is that there is a strong relationship between fatigue, sleep problems, and self-efficacy, and that fatigue decreases self-efficacy. The aim of this study was to explore self-reported fatigue from the time on the waiting list to 5 years after heart transplantation and its association with self-efficacy and sleep problems. Methods: In this multicenter, longitudinal cohort study 48 heart recipients, 12 women and 36 men with a median age of 57 years, were followed from pre-transplant to 5 years post-transplant. Three instruments were used: (1) the transplant-specific Organ Transplant Symptom and Well-Being Instrument (OTSWI), (2) the Swedish version of the Multi-Dimensional Fatigue Inventory (MFI), and (3) the Self-Efficacy for Managing Chronic Disease 6-Item Scale (SES6G). Results: Sleep problems decreased after transplantation, but after 3-5 years, there were no differences in comparison with pre-transplant. Self-efficacy improved for the whole group from pre-transplant up to 5 years after heart transplantation. General fatigue predicted self-efficacy. Conclusion: Fatigue plays a pivotal role in self-efficacy after heart transplantation. It reduces self-efficacy due to causing uncertainty and should constitute a primary target for future interventions
Lärarperspektiv på värdegrund och demokrati : En analys av lågstadielärares diskussioner
No full textMultidimensional health patterns and labor market participation among older workers : Evidence from a European six-year follow-up study
No full textHealth is a multidimensional concept and consists of different dimensions such as mental and physical health. In this study, we built on this conception of health by investigating the effects of multidimensional health patterns (MHP) on labor force participation among older workers. We used data from 5`006 older workers (mean age: 55.8 years; 56% female) from the Survey of Health, Ageing and Retirement in Europe. In a first step, we conducted a latent transition analysis with four health indicators (chronic diseases, limitations with activities, self-perceived health, and depressive symptoms) to identify the MHP. In a second step, we assessed the association of the MHP with workers’ labor force participation six years after the first point of observation using Wald tests. Our analysis provided us with four MHP: (1) overall healthy workers, (2) workers with moderate activity limitations and low self-perceived health, (3) physically healthy workers with low self-perceived health and depressive symptoms, and (4) workers with overall poor health. We found differences between the MHP in job situation (p < 0.001) and changes in working hours (p < 0.001) four years later, with MHP 4 showing the highest probability of being permanently sick or disabled and MPH 2 and 3 showing the greatest reductions in working hours. Our results imply that physical health is a better predictor of labor force participation among older workers than other dimensions of health. Using health as a multidimensional construct thus allows to better understand the social implications of poor health
Narrativa konstruktioner av klass : Sociala ordningar och positioneringar i läroverkets studentuppsatser under 1900-talets första tre decennier
No full textNarrative constructions of social class: Social orders and positions in student essays from the Swedish Grammar School during the first three decades of the twentieth century. The article studies class formation in Swedish Grammar School, and how the parallel school system contributed to the forming of social classes. The source material consists of student essays dealing with industrialism, the rise of the working class, the labour movement, and the future lives of students from their own perspective. The research questions focus on the how the social structures were described in these essays and in what way various discourses from school textbooks influenced the student essays. The study is based on Althusser’s concept “interpellation”, which is a point of departure in our understanding of the essays as an act in which students negotiate narratives of the textbooks and position themselves within the society. In this discursive act, the working class was constructed as the Other, mainly carrying pejorative characteristics. Furthermore, the student essays paint a picture of the educated upper class, i.e. the social group of students, having the task of morally educating the lower classes. Thus, the student essays bear witness to how young men of the privileged class, positioned themselves in the social topography of their time
A simplified frailty score predicts outcome in curatively treated older patients with classical Hodgkin lymphoma
No full textOlder patients with classical Hodgkin lymphoma (cHL) have lower tolerance and inferior outcomes after standard chemotherapy regimens. To identify patient-derived indicators of frailty associated with outcome, we retrospectively analyzed patient and disease characteristics, treatment and outcome in a Norwegian population-based cohort of older (≥60 years) patients with cHL diagnosed 2000-2015. We included 279 patients (median age 69 years, range 60-90) treated with curative intent, defined as any typical cHL regimen with ≥50% standard doxorubicin dose in the first cycle. In this Norwegian cohort, treatment-related mortality was 8%, median progression-free survival (PFS) and overall survival (OS) were 7.1 years (95% confidence interval [CI]: 5.0-9.3) and 8.7 years (95% CI: 7.0-10.4), respectively. Multivariable analyses identified patient-derived prognostic factors working independently of stage, histology, and International Prognostic Score. We derived a frailty index ranging from 0-3 with one point each for age ≥70 years, Eastern Cooperative Oncology Group status ≥2, and a Cumulative Illness Rating Scale in Geriatrics score ≥8. Patients were categorized as fit (score 0, 34% of patients), unfit (score 1-2, 60%), and frail (score 3, 7%), with 5-year PFS of 74%, 49%, and 11%, and 5-year OS of 86%, 52%, and 22%, respectively. The proposed frailty score was validated in an external cohort of 792 similarly selected patients from the Swedish Lymphoma Register, where comorbidities were scored based on the Charlson comorbidity index (0-2 vs. 3 or higher). In this comprehensive study, we develop a frailty score for elderly cHL patients to inform clinical decisions and prospective trials evaluating selective therapies for older patients
Searching for peripheral proteomic markers of primary aldosteronism
No full textPurpose Primary aldosteronism (PA) is prevalent among hypertensive patients, and associated with worsened cardiovascular outcomes compared to essential hypertension (HT). Screening and diagnostics for PA are currently complicated and invasive, why new methods are needed. Unilateral PA (uPA) is best treated surgically, and bilateral PA (bPA) - medically. No validated proteomic diagnostic test has been found yet. Our aim was to explore proteomic markers in peripheral serum to discriminate between HT, PA, uPA and bPA. Methods Eighty-eight hypertensive individuals were evaluated for PA, and diagnosed with HT (n = 30); bPA (n = 29); and uPA (n = 29). Serum samples from these study groups were analyzed by Olink® Explore 384 Cardiometabolic Panel. A machine learning model based on ridge logistic regression with a stratified 5-fold cross-validation was used to identify HT, PA, bPA and uPA. Results In the study groups, 56 circulating proteins were significantly different, and some of them specifically: 4 between PA vs. HT; 3 between bPA vs. uPA; 1 between bPA vs. HT; 9 between uPA vs. HT; 1 between HT vs. bPA vs. uPA. Three proteins with strongest differentiation (Coagulation factor IX for PA vs. HT; dipeptidyl peptidase 4 for uPA vs. HT and bPA; heat shock protein B1 for bPA vs. uPA) were validated by enzyme-linked immunosorbent assay. Our machine learning model could successfully identify 95% of HT, bPA, and uPA samples. Conclusion Serum protein biomarkers may serve as a tool for discriminating HT, PA, uPA and bPA. Further studies are needed to support our results