Nodule detection in digital chest radiography: part of image background acting as pure noise

There are several factors that influence the radiologist's ability to detect a specific structure/lesion in a radiograph. Three factors that are commonly known to be of major importance are the signal itself, the system noise and the projected anatomy. The aim of this study was to determine to what extent the image background acts as pure noise for the detection of subtle lung nodules in five different regions of the chest. A receiver operating characteristic (ROC) study with five observers was conducted on two different sets of images, clinical chest X-ray images and images with a similar power spectrum as the clinical images but with a random phase spectrum, resulting in an image background containing pure noise. Simulated designer nodules with a full-width-at-fifth-maximum of 10 mm but with varying contrasts were added to the images. As a measure of the part of the image background that acts as pure noise, the ratio between the contrast needed to obtain an area under the ROC curve of 0.80 in the clinical images to that in the random-phase images was used. The ratio ranged from 0.40 (in the lateral pulmonary regions) to 0.83 (in the hilar regions) indicating that there was a large difference between different regions regarding to what extent the image background acted as pure noise; and that in the hilar regions the image background almost completely acted as pure noise for the detection of 10 mm nodule

Predictors of the first cardiovascular event in patients with systemic lupus erythematosus - a prospective cohort study

Systemic Lupus Erythematosus (SLE) is an autoimmune, inflammatory disease that mainly affects women. The prognosis of SLE has improved dramatically, but mortality rates are still higher than in the general population. With the improved general prognosis, cardiovascular disease (CVD) has emerged as a major cause of morbidity and mortality among SLE patients. Previous studies have demonstrated that the development of atherosclerosis is accelerated in SLE, and have identified a set of traditional and nontraditional risk factors that characterize SLE patients with CVD. Nevertheless, many unsolved issues with respect to SLE related CVD remain. The general aim of this thesis was to investigate risk factors for manifest CVD and for cardiovascular mortality (CVM) in SLE, with special focus on traditional risk factors, lupus phenotype, inflammatory and endothelial biomarkers, autoantibodies and genetic predisposition. In the first paper, we prospectively studied traditional and non-traditional risk factors for the development of the first cardiovascular event (CVE) in 182 SLE patients with a follow-up time of 8 years. 24(13%) patients had a first event. We demonstrated that of the traditional risk factors, only age and smoking predicted the first CVE. Additionally, antiphospholipid antibodies (aPL), endothelial biomarkers, represented by soluble vascular cell adhesion molecule 1(sVCAM-1), and absence of thrombocytopenia were independent predictors of CVE. Thus, activation of the endothelium and the coagulation system are important features in SLE-related CVD and the importance to advocate smoking cessation among SLE patients is underscored In the second paper, we prospectively investigated causes of mortality and risk factors for overall mortality and CVM in a cohort of 208 SLE patients, with a follow-up time of 12 years. We also evaluated Systematic coronary risk evaluation (SCORE, tool for evaluating the 10 year risk for cardiovascular death in the age span 40-65 years, based on traditional risk factors) in this population. Cystatin C, a sensitive measure of renal function, in addition to traditional and non-traditional risk factors, were evaluated as risk factors. 42 patients died, 48 % of which were due to CVM. Age, previous arterial events and high cystatin C levels were the strongest predictors for overall mortality and for CVM. After adjusting for these three variables, smoking, sVCAM-1 and high sensitiviy C-reactive protein (hsCRP) predicted CVM. SCORE estimated 4 but we observed 9 cases of CVM, a non-significant difference. We conclude that except for smoking, traditional risk factors are less important than cystatin C, endothelial and inflammatory biomarkers as predictors of CVM in SLE patients. In the third paper, we investigated whether a risk allele for SLE in the signal transducer and activator of transcription factor 4 gene (STAT4) was associated with vascular events or presence of antiphospholipid antibodies (aPL). A total of 578 unrelated SLE patients (424 from mid-Sweden and 154 from southern-Sweden) were included in a cross-sectional design. Occurrence of previous cardiovascular events and aPL were tabulated. Matched controls (N=651) were genotyped as a comparison. The results demonstrate that the STAT4 risk allele was associated with ischemic cerebrovascular disease (ICVD), with a dose-dependent relationship between ICVD and number of risk alleles. The risk allele was furthermore associated with the presence of two or more aPLs, also in a dose-dependent manner. The association remained after adjustment for known traditional risk factors. We conclude that patients with the STAT4 risk allele have an increased risk of ICVD. Our results imply that genetic predisposition is an important risk factor for ICVD in SLE patients, and that aPL may be one underlying mechanism. In the fourth paper, we evaluated the potential association between smoking and aPL. 367 SLE patients were investigated in a cross-sectional study. Occurrence of aPL (anticardiolipin (aCL) IgG and IgM, anti-β2 glycoprotein-1 IgG (aβ2GP1 IgG), lupus anticoagulant (LAC)) and smoking habits (never, ever, former, current) were tabulated. Never smoking was used as reference in all calculations. In multivariable models, adjusted for age, sex and age at disease onset, aCL and aβ2GP1 of the IgG isotype and LAC were associated with ever smoking, this association seemed to be driven mainly by the former smoking group. Our results demonstrate that smoking is associated with pro-thrombotic aPL in SLE patients, though we can not from this study draw firm conclusions about the temporal relationship between exposure to smoking and occurrence of aPL. Further studies are warranted to investigate the mechanisms behind these observations. In prospective studies we have demonstrated that in particular smoking, systemic inflammation, endothelial activation and aPL are major risk factors for SLE related CVD and CVM. Furthermore, genetic predisposition, in our studies represented by a STAT4 SLE risk allele, contributes to the high risk of ICVD and to the occurrence of aPL, a possible underlying pathogenic mechanism. Finally we demonstrate that smoking, known to have unfavorable effects on the immune system and to significantly increase cardiovascular risk in SLE patients, is also associated with pro-thrombotic aPL in patients with SLE. Thus in SLE smoking stands out as the most important of the traditional risk factors with potential influence also on lupus related risk factors such as aPL

Cytostatikautlöst smärta hos kvinnor med bröstcancer

Syftet med denna systematiska litteraturstudie var att beskriva cytostatikautlöst smärta och dess konsekvenser hos kvinnor med bröstcancer. Vid sökning gjordes begränsning till engelskspråkig litteratur och 17 vetenskapliga artiklar, hittades på Högskolan Dalarnas databas, Electronic Library Information Navigator (ELIN) med hjälp av olika kombinerade sökord. Även manuellt funna artiklar har använts. Resultatet visar att kvinnor som behandlats med cytostatika mot bröstcancer får ökade smärtor av behandlingen. Smärtförekomsten varierar beroende på vilken behandling kvinnan fått. Högre doser av ingående cytostatikaläkemedel, tätare intervall mellan kurerna och läkemedelsval kan inverka negativt på uppkomsten av smärta. De smärtor kvinnorna riskerar att få av behandlingen är neuropatier, smärtor från munhålan, händer och fötter, smärtor i magen, muskler, skelett samt huvudvärk. Framför allt cytostatika ur gruppen taxaner ger en smärtprofil med mer neuropatiska smärtor. Smärta i samband med cytostatikabehandling interagera med ökad oro, rädsla, försämrad funktionsförmåga och kan också ge sömnstörningar, trötthet, depression och ökad stress. Smärta inverkar menligt i det dagliga livet. Smärta kan också vara en prediktor för minskat välbefinnande vid behandlingens slut. Hur kvinnorna uppfattar smärtans inverkan på det egna jaget och hur de tolkar den upplevda smärtans i ett meningssammanhang beskrivs inte alls. Slutsatsen blir att cytostatikarelaterad smärta hos kvinnor med bröstcancer kräver vidare forskning

Cytostatikautlöst smärta hos kvinnor med bröstcancer

Syftet med denna systematiska litteraturstudie var att beskriva cytostatikautlöst smärta och dess konsekvenser hos kvinnor med bröstcancer. Vid sökning gjordes begränsning till engelskspråkig litteratur och 17 vetenskapliga artiklar, hittades på Högskolan Dalarnas databas, Electronic Library Information Navigator (ELIN) med hjälp av olika kombinerade sökord. Även manuellt funna artiklar har använts. Resultatet visar att kvinnor som behandlats med cytostatika mot bröstcancer får ökade smärtor av behandlingen. Smärtförekomsten varierar beroende på vilken behandling kvinnan fått. Högre doser av ingående cytostatikaläkemedel, tätare intervall mellan kurerna och läkemedelsval kan inverka negativt på uppkomsten av smärta. De smärtor kvinnorna riskerar att få av behandlingen är neuropatier, smärtor från munhålan, händer och fötter, smärtor i magen, muskler, skelett samt huvudvärk. Framför allt cytostatika ur gruppen taxaner ger en smärtprofil med mer neuropatiska smärtor. Smärta i samband med cytostatikabehandling interagera med ökad oro, rädsla, försämrad funktionsförmåga och kan också ge sömnstörningar, trötthet, depression och ökad stress. Smärta inverkar menligt i det dagliga livet. Smärta kan också vara en prediktor för minskat välbefinnande vid behandlingens slut. Hur kvinnorna uppfattar smärtans inverkan på det egna jaget och hur de tolkar den upplevda smärtans i ett meningssammanhang beskrivs inte alls. Slutsatsen blir att cytostatikarelaterad smärta hos kvinnor med bröstcancer kräver vidare forskning

Under the Surface in Teacher's Writing Tasks : Writing Discources within the Subject of Swedish in Upper Secondary School

Writing tasks are central in the subject of Swedish, and they can be designed in various ways. The variation in design when teachers construct their own writing tasks can be due to differing views of the teaching of writing and exercises in writing. The aim of this work is to investigate how different discourses about writing and learning to write become visible in teachers’ constructions of writing tasks, and whether there are different degrees of steering in the tasks in relation to the discourse(s) to which they can be said to belong. Twelve writing tasks were examined in the study with the aid of Ivanič’s (2004) framework for analysis of discourses about writing and learning to write, and the result shows that the creativity discourse dominates among the tasks and that the sociopolitical discourse is sparsely represented among them. Several tasks have features of more than one discourse and can therefore be called hybrids. The degree of steering by the designer of the task differs between the tasks. In tasks that can be linked to the skills discourse there is usually a high degree of steering of the content, and in tasks that can be linked to the creativity discourse the designer of the task uses a different form of steering with questions which mean that the teacher gains access to personal information about the pupils

Computer Modelling of the Interaction between Water and Complex Solid Phases

In this work the program package PASSIPHIC is described. The program has been developed to calculate the equilibrium for an aqueous phase in contact with a complex solid. The complex solid is considered as consisting of pure minerals and /or solid solutions. Cement has been used as an example.<p /> Cementitious materials are likely to be present in large quantities in repositories for radioactive waste. The chemistry in the vicinity of such a repository will hence be influenced by the cement. Cement has been shown to serve as an immobiliser of many elements due to its high internal pH (> 12.5), large surface area and the ability of the hydrated phases in the cement matrix to incorporate radionuclides. Thus, the modelling of the evolution of cement-water interaction is an important factor in determining the release rates of radionuclides from a repository for radioactive waste.<p /> The PASSIPHIC program has been used to simulate leaching of cement with non-saline groundwater and the result is compared to experimental data. The agreement between experimental and calculated data has been found to be good

Bedömning - en konst

Syftet med undersökningen är att ta reda på hur fem lärare i svenska och engelska verksamma i gymnasieskolan uttrycker sig om bedömning av estetiska lärprocesser. Metoden tar sin utgångspunkt inom ramen för diskursanalys. Materialet består av fem halvstrukturerade intervjuer vilka har analyserats utifrån ett diskursanalytiskt angreppssätt. Resultatet visar på att det finns en skiljelinje mellan de lärare som bedömer den estetiska dimensionen och de som inte gör det

Bedömning - en konst

Syftet med undersökningen är att ta reda på hur fem lärare i svenska och engelska verksamma i gymnasieskolan uttrycker sig om bedömning av estetiska lärprocesser. Metoden tar sin utgångspunkt inom ramen för diskursanalys. Materialet består av fem halvstrukturerade intervjuer vilka har analyserats utifrån ett diskursanalytiskt angreppssätt. Resultatet visar på att det finns en skiljelinje mellan de lärare som bedömer den estetiska dimensionen och de som inte gör det

Taxane-induced pain : Experiences of women with breast cancer and nurses providing their care

Breast cancer patients receiving taxane chemotherapy run a substantial risk of develop taxane-induced pain, but little is known about women’s experiences of such pain. The aim of this thesis was to explore women’s acute and longstanding experiences of taxane-induced pain, to evaluate the pain intensity and distribution using different assessment methods, and to study nurses´ perceptions of taxane-induced pain in people with breast cancer. The women experienced pain during chemotherapy with 37– 48% incidence of acute taxane-induced pain. The subjective burden of taxane-induced pain described by the women covered narratives from manageable pain to very difficult and disabling pain with a major impact on their lifeworld (Study I). Longstanding pain in the lifeworld of women with previous breast cancer, was explored through a retrospective reflection after 12 months. The descriptions of pain revealed a time perspective; as pain perceived at that specific time, currently ongoing pain, and pain expectations for the future. This resulted in the women sensing themselves of being somewhere between health and illness gazing into an uncertain future (Study II). A quantitative longitudinal assessment of taxane-induced pain using; the body image, the VAS, and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ-C30) showed the women’s estimated pain; its intensity, distribution and occurrence - as it appeared during the actual taxane treatment and up to a year afterward. The baseline measurement on the VAS revealed low initial pain, VAS &lt;10, which changed at treatment Cycle 1. The body image revealed intense and widespread pain, and pain after 12 months, as did the EORTC QLQ -C30 (Study III). The nurses’ estimations of taxane-induced pain varied to large extent in both prevalence and intensity. Large parts of the body were expected to be involved in the pain. Nurses lacked local and/or national guidelines reflecting a low level of generalized use of prophylaxis against taxane pain (Study IV). In conclusion, taxane-induced pain is a common debilitating symptom during taxane chemotherapy for women with breast cancer. Pain impacts women´s life during as well as long time after the completion of taxane treatment. Taxane pain can be accurately or successfully estimated using various pain assessment tools. Furthermore, guidelines for dealing with taxane-induced pain are needed

Taxane-induced pain : Experiences of women with breast cancer and nurses providing their care

Breast cancer patients receiving taxane chemotherapy run a substantial risk of develop taxane-induced pain, but little is known about women’s experiences of such pain. The aim of this thesis was to explore women’s acute and longstanding experiences of taxane-induced pain, to evaluate the pain intensity and distribution using different assessment methods, and to study nurses´ perceptions of taxane-induced pain in people with breast cancer. The women experienced pain during chemotherapy with 37– 48% incidence of acute taxane-induced pain. The subjective burden of taxane-induced pain described by the women covered narratives from manageable pain to very difficult and disabling pain with a major impact on their lifeworld (Study I). Longstanding pain in the lifeworld of women with previous breast cancer, was explored through a retrospective reflection after 12 months. The descriptions of pain revealed a time perspective; as pain perceived at that specific time, currently ongoing pain, and pain expectations for the future. This resulted in the women sensing themselves of being somewhere between health and illness gazing into an uncertain future (Study II). A quantitative longitudinal assessment of taxane-induced pain using; the body image, the VAS, and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ-C30) showed the women’s estimated pain; its intensity, distribution and occurrence - as it appeared during the actual taxane treatment and up to a year afterward. The baseline measurement on the VAS revealed low initial pain, VAS &lt;10, which changed at treatment Cycle 1. The body image revealed intense and widespread pain, and pain after 12 months, as did the EORTC QLQ -C30 (Study III). The nurses’ estimations of taxane-induced pain varied to large extent in both prevalence and intensity. Large parts of the body were expected to be involved in the pain. Nurses lacked local and/or national guidelines reflecting a low level of generalized use of prophylaxis against taxane pain (Study IV). In conclusion, taxane-induced pain is a common debilitating symptom during taxane chemotherapy for women with breast cancer. Pain impacts women´s life during as well as long time after the completion of taxane treatment. Taxane pain can be accurately or successfully estimated using various pain assessment tools. Furthermore, guidelines for dealing with taxane-induced pain are needed