853 results on '"Wikström, Johan"'
Search Results
152. John Hedlund and the modern society
- Author
-
Wikström, Johan
- Subjects
John Hedlund ,Billy Graham ,Den moderna staten ,Evangelisation ,Väckelse ,Kalla kriget ,Evangelikalism ,Religionsvetenskap ,Religious Studies - Abstract
Syftet med denna uppsats är att undersöka hur John Hedlund förhåller sig till det svenska samhället, hans s.k. ”teologi om världen”. Denna kommer att undersökas och analyseras med hjälp av tre frågor• Vilken är enligt Hedlund relationen mellan kristendomen och det moderna svenska samhället?• Hur ser Billy Graham på relationen mellan kristendomen och det amerikanska samhället?• Vilka likheter och skillnader finns i Hedlund och Graham när det gäller synen på kristendomen och samhället? Uppsatsen tar sitt avstamp år 1946. Utgångspunkten motiveras av att detta var ett viktigt brytningsår i Hedlunds verksamhet: han blev ”Nalenpastorn” med det svenska folket, och dessutom reste han detta år till USA för att studera de mötesserier som ”Youth for Christ” organiserade – dvs. den organisation som Graham då verkade för. Grahams Crusade i Los Angeles 1950 ses som det verkliga startskottet för hans karriär och redan senare samma år startade John Hedlund sin motsvarighet som han kallade för ”korståg”. Detta i kombination med både Sveriges och USA:s utveckling från efterkrigstiden och framåt gör tidpunkten till lämplig. Avgränsningen i slutet av denna uppsats sätts till de viktiga brytpunkter som både Sverige och USA kommer till mot slutet av 1980-talet. Jag menar att Sverige når en tydlig brytpunkt med Olof Palmes död 1986 medan det i det amerikanska fallet får bli kommunismens kollaps 1989.
- Published
- 2018
153. Förutspå antalet personer som hamnar i sysselsättning med data från Arbetsförmedlingen
- Author
-
Wikström, Johan
- Subjects
Machine Learning ,SARIMA ,Datavetenskap (datalogi) ,Computer Sciences ,Swedish Public Employment Service ,Arbetsförmedlingen ,LSTM ,Forecasting - Abstract
The objective of this thesis is to forecast the number of people registered at the Swedish Public Employment Service (Arbetsförmedlingen) that will manage to get employment each month and examine how accurate the forecasts are. The Swedish Public Employment Service is a government-funded agency in Sweden working to keep the unemployment rate low. When someone is unemployed or looking for a new job, he or she can register at the Swedish Public Employment Service. Being able to forecast well how many are expected to get employment could be useful when planning and making decisions. It could also be used as an indicator of how well the Swedish Public Employment Service manages to perform and thus how well the tax money is used. The models employed for forecasting were the seasonal autoregressive integrated moving average (SARIMA) and the long short-term memory (LSTM). A persistence model is also used as a baseline. The persistence model is a very simple model and the other models are therefore expected to outperform it. For the LSTM model, the use of both univariate and multivariate approaches will be explored in order to examine if the model can be improved with more data. Results from the experiments performed showed that a multivariate LSTM performed the lowest root mean squared error (RMSE) and is therefore considered the best model. However, the robustness of the model over time needs further research. Syftet med detta arbete är att göra prognoser på hur många av de registrerade på Arbetsförmedlingen som kommer att få arbete en viss månad och undersöka hur noggranna dessa prognoser blir. Arbetsförmedlingen är en skattefinansierad myndighet i Sverige som arbetar med att hålla arbetslösheten låg. När någon är arbetslös eller letar efter ett arbete kan man registrera sig hos Arbetsförmedlingen. Att kunna göra bra prognoser på hur många som kommer att få arbete skulle kunna vara användbart vid planering och beslutfattande. Det skulle också kunna användas som en indikator på hur väl Arbetsförmedlingen använder skattepengarna. De modeller som har använts är seasonal autoregressive integrated moving average (SARIMA) och long short-term memory (LSTM). En persistensmodell används också som baslinje. Persistensmodellen är en enkel modell och därför förväntas de andra modellerna prestera bättre. För LSTM-modellen kommer användningen av både envariabla och flervariabla tillvägagångssätt att undersökas för att testa om mer data kan förbättra modellen. Resultat från experimenten visar att det var en LSTM-modell med flera variabler som presterade lägst root mean squared error (RMSE) och anses därför vara den bästa modellen. Det behövs dock ytterligare studier för att undersöka modellens stabilitet över tid.
- Published
- 2018
154. Plasma from women with preeclampsia impairs the blood brain barrier in an in vitro model
- Author
-
Bergman, Lina, primary, Acurio, Jesenia, additional, Leon, Jose, additional, Gatu, Emily, additional, Friis, Therese, additional, Nelander, Maria, additional, Wikström, Johan, additional, Torres, Pablo, additional, Wikström, Anna-Karin, additional, and Escudero, Carlos, additional
- Published
- 2019
- Full Text
- View/download PDF
155. Increased cerebral biomarkers in plasma and decreased intracerebral magnesium levels are correlated to an impaired blood brain barrier in vitro in preeclampsia
- Author
-
Friis, Therese, primary, Wikström, Anna-Karin, additional, Acurio, Jesenia, additional, Leon, Jose, additional, Zetterberg, Henrik, additional, Blennow, Kaj, additional, Nelander, Maria, additional, Åkerud, Helena, additional, Kaihola, Helena, additional, Cluver, Catherine, additional, Wikström, Johan, additional, Torres-Vergara, Pablo, additional, Bergman, Lina, additional, and Escudero, Carlos, additional
- Published
- 2019
- Full Text
- View/download PDF
156. Primary microcephaly, primordial dwarfism, and brachydactyly in adult cases with biallelic skipping of RTTN exon 42
- Author
-
Zakaria, Muhammad, primary, Fatima, Ambrin, additional, Klar, Joakim, additional, Wikström, Johan, additional, Abdullah, Uzma, additional, Ali, Zafar, additional, Akram, Talia, additional, Tariq, Muhammad, additional, Ahmad, Habib, additional, Schuster, Jens, additional, Baig, Shahid M, additional, and Dahl, Niklas, additional
- Published
- 2019
- Full Text
- View/download PDF
157. Postmortem magnetic resonance imaging vs autopsy of second trimester fetuses terminated due to anomalies
- Author
-
Hellkvist, Anna, primary, Wikström, Johan, additional, Mulic‐Lutvica, Ajlana, additional, Ericson, Katharina, additional, Eriksson‐Falkerby, Christopher, additional, Lindgren, Peter, additional, Penno, Eva, additional, and Axelsson, Ove, additional
- Published
- 2019
- Full Text
- View/download PDF
158. Assessment of cerebral perfusion and edema in preeclampsia with intravoxel incoherent motion MRI
- Author
-
Nelander, Maria, Hannsberger, Daniel, Sundström Poromaa, Inger, Bergman, Lina, Weis, Jan, Åkerud, Helena, Wikström, Johan, Wikström, Anna-Karin, Nelander, Maria, Hannsberger, Daniel, Sundström Poromaa, Inger, Bergman, Lina, Weis, Jan, Åkerud, Helena, Wikström, Johan, and Wikström, Anna-Karin
- Abstract
Background Cerebral complications are the main reasons for morbidity and mortality in preeclampsia and eclampsia. Still we do not know if the pathophysiology entails hypo- or hyperperfusion of the brain, or how and when edema emerges, due to the difficulty to examine the cerebral circulation. Material and methods We have used a non-invasive diffusion weighted magnetic resonance imaging (MRI) technique, intravoxel incoherent motion, to study cerebral perfusion on the capillary level and cerebral edema in women with preeclampsia (n=30), normal pregnancy (n=32) and non-pregnant women (n=16). Estimates of cerebral blood volume, blood flow and edema were measured in five different regions. These points were chosen to represent blood supply areas of both the carotid and vertebrobasilar arteries, and to include both white and grey matter. Results Except for the caudate nucleus, we did not detect any differences in cerebral perfusion measures on a group level. In the caudate nucleus we found lower cerebral blood volume and lower blood flow in preeclampsia compared to both normal pregnancy (p=0.01 and p=0.03, respectively) and non-pregnant women (both p=0.02). No differences in edema were detected between study groups. Conclusion The cerebral perfusion measures were comparable between the study groups, except for a portion of the basal ganglia where hypoperfusion was detected in preeclampsia compared to normal pregnancy and non-pregnant women.
- Published
- 2018
- Full Text
- View/download PDF
159. Hormonal Cycle and Contraceptive Effects on Amygdala and Salience Resting-State Networks in Women with Previous Affective Side Effects on the Pill.
- Author
-
Engman, Jonas, Sundström Poromaa, Inger, Moby, Lena, Wikström, Johan, Fredriksson, Mats, Gingnell, Malin, Engman, Jonas, Sundström Poromaa, Inger, Moby, Lena, Wikström, Johan, Fredriksson, Mats, and Gingnell, Malin
- Abstract
The mechanisms linking ovarian hormones to negative affect are poorly characterized, but important clues may come from the examination of the brain's intrinsic organization. Here, we studied the effects of both the menstrual cycle and oral contraceptives (OCs) on amygdala and salience network resting-state functional connectivity using a double-blind, randomized, and placebo-controlled design. Hormone levels, depressive symptoms, and resting-state functional connectivity were measured in 35 healthy women (24.9±4.2 years) who had previously experienced OC-related negative affect. All participants were examined in the follicular phase of a baseline cycle and in the third week of the subsequent cycle during treatment with either a combined OC (30 μg ethinyl estradiol/0.15 mg levonorgestrel) or placebo. The latter time point targeted the midluteal phase in placebo users and steady-state ethinyl estradiol and levonorgestrel concentrations in OC users. Amygdala and salience network connectivity generally increased with both higher endogenous and synthetic hormone levels, although amygdala-parietal cortical connectivity decreased in OC users. When in the luteal phase, the naturally cycling placebo users demonstrated higher connectivity in both networks compared with the women receiving OCs. Our results support a causal link between the exogenous administration of synthetic hormones and amygdala and salience network connectivity. Furthermore, they suggest a similar, potentially stronger, association between the natural hormonal variations across the menstrual cycle and intrinsic network connectivity., Original Article; Supplementary information available for this article at http://www.nature.com/npp/journal/vaop/ncurrent/suppinfo/npp2017157s1.html
- Published
- 2018
- Full Text
- View/download PDF
160. The value of magnetic resonance spectroscopy as a supplement to MRI of the brain in a clinical setting
- Author
-
Hellström, Jussi, Romanos Zapata, Romina, Libard, Sylwia, Wikström, Johan, Ortiz-Nieto, Francisco, Alafuzoff, Irina, Raininko, Raili, Hellström, Jussi, Romanos Zapata, Romina, Libard, Sylwia, Wikström, Johan, Ortiz-Nieto, Francisco, Alafuzoff, Irina, and Raininko, Raili
- Abstract
BACKGROUND: There are different opinions of the clinical value of MRS of the brain. In selected materials MRS has demonstrated good results for characterisation of both neoplastic and non-neoplastic lesions. The aim of this study was to evaluate the supplemental value of MR spectroscopy (MRS) in a clinical setting. MATERIAL AND METHODS: MRI and MRS were re-evaluated in 208 cases with a clinically indicated MRS (cases with uncertain or insufficient information on MRI) and a confirmed diagnosis. Both single voxel spectroscopy (SVS) and chemical shift imaging (CSI) were performed in 105 cases, only SVS or CSI in 54 and 49 cases, respectively. Diagnoses were grouped into categories: non-neoplastic disease, low-grade tumour, and high-grade tumour. The clinical value of MRS was considered very beneficial if it provided the correct category or location when MRI did not, beneficial if it ruled out suspected diseases or was more specific than MRI, inconsequential if it provided the same level of information, or misleading if it provided less or incorrect information. RESULTS: There were 70 non-neoplastic lesions, 43 low-grade tumours, and 95 high-grade tumours. For MRI, the category was correct in 130 cases (62%), indeterminate in 39 cases (19%), and incorrect in 39 cases (19%). Supplemented with MRS, 134 cases (64%) were correct, 23 cases (11%) indeterminate, and 51 (25%) incorrect. Additional information from MRS was beneficial or very beneficial in 31 cases (15%) and misleading in 36 cases (17%). CONCLUSION: In most cases MRS did not add to the diagnostic value of MRI. In selected cases, MRS may be a valuable supplement to MRI.
- Published
- 2018
- Full Text
- View/download PDF
161. Interactive segmentation of glioblastoma for post-surgical treatment follow-up
- Author
-
Dhara, Ashis Kumar, Arids, Erik, Fahlström, Markus, Wikström, Johan, Larsson, Elna-Marie, Strand, Robin, Dhara, Ashis Kumar, Arids, Erik, Fahlström, Markus, Wikström, Johan, Larsson, Elna-Marie, and Strand, Robin
- Abstract
Best paper award
- Published
- 2018
- Full Text
- View/download PDF
162. Bifurcation of the intratemporal facial nerve : A rare anatomical anomaly
- Author
-
Christou, Constantina, Wikström, Johan, Strömbäck, Karin, Christou, Constantina, Wikström, Johan, and Strömbäck, Karin
- Abstract
The anatomical position of the facial nerve is a critical factor in determining surgical candidacy in patients with congenital aural atresia (CAA). All patients with CAA must preoperatively be evaluated using a grading score based on information gained from a high resolution CT scan. In patients not suitable for surgical reconstruction, implantation of novel hearing implants is increasingly used for hearing rehabilitation. We, here, describe a bifurcation of the intratemporal part of the facial nerve in a 5-year old boy with CAA undergoing implantation with a bone conductive hearing device.
- Published
- 2018
- Full Text
- View/download PDF
163. Cerebral osmolytes and plasma osmolality in pregnancy and preeclampsia : a proton magnetic resonance spectroscopy study
- Author
-
Nelander, Maria, Wikström, Anna-Karin, Weis, Jan, Bergman, Lina, Larsson, Anders, Sundström Poromaa, Inger, Wikström, Johan, Nelander, Maria, Wikström, Anna-Karin, Weis, Jan, Bergman, Lina, Larsson, Anders, Sundström Poromaa, Inger, and Wikström, Johan
- Abstract
Background: Cerebral complications contribute substantially to mortality in preeclampsia. Pregnancy calls for extensive maternal adaptations, some associated with increased propensity for seizures, but the pathophysiology behind the eclamptic seizures is not fully understood. Plasma osmolality and sodium levels are lowered in pregnancy. This could result in extrusion of cerebral organic osmolytes, including the excitatory neurotransmitter glutamate, but this remains to be determined. The hypothesis of this study was that cerebral levels of organic osmolytes are decreased during pregnancy, and that this decrease is even more pronounced in women with preeclampsia. Method: We used proton magnetic resonance spectroscopy to compare levels of cerebral organic osmolytes, in women with preeclampsia (n=30), normal pregnancy (n=32) and non-pregnant controls (n=16). Cerebral levels organic osmolytes were further correlated to plasma osmolality, and plasma levels of glutamate and sodium. Results: Compared to non-pregnant women, women with normal pregnancy and preeclampsia had lower levels of the cerebral osmolytes myo-inositol, choline and creatine (p=0.001 or less), and all these metabolites correlated with each other (p<0.05). Women with normal pregnancies and preeclampsia had similar levels of osmolytes, except for glutamate, which was significantly lower in preeclampsia. Cerebral and plasma glutamate levels were negatively correlated with each other (p<0.008), and cerebral myo-inositol, choline and creatine levels were all positively correlated with both plasma osmolality and sodium levels (p<0.05). Conclusion: Our results indicate that pregnancy is associated with extrusion of cerebral organic osmolytes. This includes the excitatory neurotransmitter glutamate, which may be involved in the pathophysiology of seizures in preeclampsia.
- Published
- 2018
- Full Text
- View/download PDF
164. John Hedlund och den moderna staten : Ett komparativt studie av John Hedlund och Billy Grahams förkunnelse av kristendomen i det moderna samhället.
- Author
-
Wikström, Johan and Wikström, Johan
- Abstract
Syftet med denna uppsats är att undersöka hur John Hedlund förhåller sig till det svenska samhället, hans s.k. ”teologi om världen”. Denna kommer att undersökas och analyseras med hjälp av tre frågor• Vilken är enligt Hedlund relationen mellan kristendomen och det moderna svenska samhället?• Hur ser Billy Graham på relationen mellan kristendomen och det amerikanska samhället?• Vilka likheter och skillnader finns i Hedlund och Graham när det gäller synen på kristendomen och samhället? Uppsatsen tar sitt avstamp år 1946. Utgångspunkten motiveras av att detta var ett viktigt brytningsår i Hedlunds verksamhet: han blev ”Nalenpastorn” med det svenska folket, och dessutom reste han detta år till USA för att studera de mötesserier som ”Youth for Christ” organiserade – dvs. den organisation som Graham då verkade för. Grahams Crusade i Los Angeles 1950 ses som det verkliga startskottet för hans karriär och redan senare samma år startade John Hedlund sin motsvarighet som han kallade för ”korståg”. Detta i kombination med både Sveriges och USA:s utveckling från efterkrigstiden och framåt gör tidpunkten till lämplig. Avgränsningen i slutet av denna uppsats sätts till de viktiga brytpunkter som både Sverige och USA kommer till mot slutet av 1980-talet. Jag menar att Sverige når en tydlig brytpunkt med Olof Palmes död 1986 medan det i det amerikanska fallet får bli kommunismens kollaps 1989.
- Published
- 2018
165. Employment forecasting using data from the Swedish Public Employment Service
- Author
-
Wikström, Johan and Wikström, Johan
- Abstract
The objective of this thesis is to forecast the number of people registered at the Swedish Public Employment Service (Arbetsförmedlingen) that will manage to get employment each month and examine how accurate the forecasts are. The Swedish Public Employment Service is a government-funded agency in Sweden working to keep the unemployment rate low. When someone is unemployed or looking for a new job, he or she can register at the Swedish Public Employment Service. Being able to forecast well how many are expected to get employment could be useful when planning and making decisions. It could also be used as an indicator of how well the Swedish Public Employment Service manages to perform and thus how well the tax money is used. The models employed for forecasting were the seasonal autoregressive integrated moving average (SARIMA) and the long short-term memory (LSTM). A persistence model is also used as a baseline. The persistence model is a very simple model and the other models are therefore expected to outperform it. For the LSTM model, the use of both univariate and multivariate approaches will be explored in order to examine if the model can be improved with more data. Results from the experiments performed showed that a multivariate LSTM performed the lowest root mean squared error (RMSE) and is therefore considered the best model. However, the robustness of the model over time needs further research., Syftet med detta arbete är att göra prognoser på hur många av de registrerade på Arbetsförmedlingen som kommer att få arbete en viss månad och undersöka hur noggranna dessa prognoser blir. Arbetsförmedlingen är en skattefinansierad myndighet i Sverige som arbetar med att hålla arbetslösheten låg. När någon är arbetslös eller letar efter ett arbete kan man registrera sig hos Arbetsförmedlingen. Att kunna göra bra prognoser på hur många som kommer att få arbete skulle kunna vara användbart vid planering och beslutfattande. Det skulle också kunna användas som en indikator på hur väl Arbetsförmedlingen använder skattepengarna. De modeller som har använts är seasonal autoregressive integrated moving average (SARIMA) och long short-term memory (LSTM). En persistensmodell används också som baslinje. Persistensmodellen är en enkel modell och därför förväntas de andra modellerna prestera bättre. För LSTM-modellen kommer användningen av både envariabla och flervariabla tillvägagångssätt att undersökas för att testa om mer data kan förbättra modellen. Resultat från experimenten visar att det var en LSTM-modell med flera variabler som presterade lägst root mean squared error (RMSE) och anses därför vara den bästa modellen. Det behövs dock ytterligare studier för att undersöka modellens stabilitet över tid.
- Published
- 2018
166. Quantification of aromatase binding in the female human brain using [11C]cetrozole positron emission tomography.
- Author
-
Jonasson, My, Nordeman, Patrik, Eriksson, Jonas, Wilking, Helena, Wikström, Johan, Takahashi, Kayo, Niwa, Takashi, Hosoya, Takamitsu, Watanabe, Yasuyoshi, Antoni, Gunnar, Sundström Poromaa, Inger, Lubberink, Mark, and Comasco, Erika
- Published
- 2020
- Full Text
- View/download PDF
167. The value of magnetic resonance spectroscopy as a supplement to MRI of the brain in a clinical setting
- Author
-
Hellström, Jussi, primary, Romanos Zapata, Romina, additional, Libard, Sylwia, additional, Wikström, Johan, additional, Ortiz-Nieto, Francisco, additional, Alafuzoff, Irina, additional, and Raininko, Raili, additional
- Published
- 2018
- Full Text
- View/download PDF
168. Assessment of cerebral perfusion and edema in preeclampsia with intravoxel incoherent motion MRI
- Author
-
Nelander, Maria, primary, Hannsberger, Daniel, additional, Sundström-Poromaa, Inger, additional, Bergman, Lina, additional, Weis, Jan, additional, Åkerud, Helena, additional, Wikström, Johan, additional, and Wikström, Anna-Karin, additional
- Published
- 2018
- Full Text
- View/download PDF
169. Cerebral Osmolytes and Plasma Osmolality in Pregnancy and Preeclampsia: A Proton Magnetic Resonance Spectroscopy Study
- Author
-
Nelander, Maria, primary, Wikström, Anna-Karin, additional, Weis, Jan, additional, Bergman, Lina, additional, Larsson, Anders, additional, Sundström-Poromaa, Inger, additional, and Wikström, Johan, additional
- Published
- 2018
- Full Text
- View/download PDF
170. Bifurcation of the intratemporal facial nerve: A rare anatomical anomaly
- Author
-
Christou, Constantina, primary, Wikström, Johan, additional, and Strömbäck, Karin, additional
- Published
- 2018
- Full Text
- View/download PDF
171. Serotonin, ATRX, and DAXX Expression in Pituitary Adenomas : Markers in the Differential Diagnosis of Neuroendocrine Tumors of the Sellar Region.
- Author
-
Casar Borota, Olivera, Botling, Johan, Granberg, Dan, Stigare, Jerker, Wikström, Johan, Boldt, Henning Bünsow, Kristensen, Bjarne Winther, Ponten, Fredrik, Trouillas, Jacqueline, Casar Borota, Olivera, Botling, Johan, Granberg, Dan, Stigare, Jerker, Wikström, Johan, Boldt, Henning Bünsow, Kristensen, Bjarne Winther, Ponten, Fredrik, and Trouillas, Jacqueline
- Abstract
Differential diagnosis based on morphology and immunohistochemistry between a clinically nonfunctioning pituitary neuroendocrine tumor (NET)/pituitary adenoma and a primary or secondary NET of nonpituitary origin in the sellar region may be difficult. Serotonin, a frequently expressed marker in the NETs, has not been systematically evaluated in pituitary NETs. Although mutations in ATRX or DAXX have been reported in a significant proportion of pancreatic NETs, the mutational status of ATRX and DAXX and their possible pathogenetic role in pituitary NETs are unknown. Facing a difficult diagnostic case of an invasive serotonin and adrenocorticotroph hormone immunoreactive NET in the sellar region, we explored the immunohistochemical expression of serotonin, ATRX, and DAXX in a large series of pituitary endocrine tumors of different types from 246 patients and in 2 corticotroph carcinomas. None of the pituitary tumors expressed serotonin, suggesting that serotonin immunoreactive sellar tumors represent primary or secondary NETs of nonpituitary origin. Normal expression of ATRX and DAXX in pituitary tumors suggests that ATRX and DAXX do not play a role in the pathogenesis of pituitary endocrine tumors that remain localized to the sellar and perisellar region. A lack of ATRX or DAXX in a sellar NET suggests a nonpituitary NET, probably of pancreatic origin. One of the 2 examined corticotroph carcinomas, however, demonstrated negative ATRX immunolabeling due to an ATRX gene mutation. Further studies on a larger cohort of pituitary carcinomas are needed to clarify whether ATRX mutations may contribute to the metastatic potential in a subset of pituitary NETs.
- Published
- 2017
- Full Text
- View/download PDF
172. Diagnosis of Placental Mesenchymal Dysplasia with a focus on magnetic resonance imaging (MRI)
- Author
-
Marusik, C, Frykholm, C, Ericson, Katharina, Wikström, Johan, Axelsson, Ove, Marusik, C, Frykholm, C, Ericson, Katharina, Wikström, Johan, and Axelsson, Ove
- Published
- 2017
- Full Text
- View/download PDF
173. Extended anatomical grading in diffuse axonal injury using MRI : Hemorrhagic lesions in the substantia nigra and mesencephalic tegmentum indicate poor long-term outcome
- Author
-
Abu Hamdeh, Sami, Marklund, Niklas, Lannsjö, Marianne, Howells, Tim, Raininko, Raili, Wikström, Johan, Enblad, Per, Abu Hamdeh, Sami, Marklund, Niklas, Lannsjö, Marianne, Howells, Tim, Raininko, Raili, Wikström, Johan, and Enblad, Per
- Abstract
Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. In this study, three magnetic resonance imaging (MRI) sequences were used to quantify the anatomical distribution of lesions, to grade DAI according to the Adams grading system, and to evaluate the value of lesion localization in combination with clinical prognostic factors to improve outcome prediction. Thirty patients (mean 31.2 years ±14.3 standard deviation) with severe DAI (Glasgow Motor Score [GMS] <6) examined with MRI within 1 week post-injury were included. Diffusion-weighted (DW), T2*-weighted gradient echo and susceptibility-weighted (SWI) sequences were used. Extended Glasgow outcome score was assessed after 6 months. Number of DW lesions in the thalamus, basal ganglia, and internal capsule and number of SWI lesions in the mesencephalon correlated significantly with outcome in univariate analysis. Age, GMS at admission, GMS at discharge, and low proportion of good monitoring time with cerebral perfusion pressure <60 mm Hg correlated significantly with outcome in univariate analysis. Multivariate analysis revealed an independent relation with poor outcome for age (p = 0.005) and lesions in the mesencephalic region corresponding to substantia nigra and tegmentum on SWI (p = 0.008). We conclude that higher age and lesions in substantia nigra and mesencephalic tegmentum indicate poor long-term outcome in DAI. We propose an extended MRI classification system based on four stages (stage I—hemispheric lesions, stage II—corpus callosum lesions, stage III—brainstem lesions, and stage IV—substantia nigra or mesencephalic tegmentum lesions); all are subdivided by age (≥/<30 years).
- Published
- 2017
- Full Text
- View/download PDF
174. Emotional anticipation after delivery - a longitudinal neuroimaging study of the postpartum period
- Author
-
Gingnell, Malin, Toffoletto, Simone, Wikström, Johan, Engman, Jonas, Bannbers, Elin, Comasco, Erika, Sundström Poromaa, Inger, Gingnell, Malin, Toffoletto, Simone, Wikström, Johan, Engman, Jonas, Bannbers, Elin, Comasco, Erika, and Sundström Poromaa, Inger
- Abstract
Neuroimaging research has begun to unveil the mechanisms behind emotion processing during the postpartum period, which, in turn, may be of relevance for the development of postpartum depression. The present study sought to longitudinally investigate the neural correlates of emotion anticipation during the postpartum period in healthy women. Functional magnetic resonance imaging was employed to measure the blood oxygen level-dependent signal in the brain in response to anticipation of negative emotional stimuli and during processing of images with positive or negative valence. The participating women were scanned twice: the first scan occurred during the first 48 hours after delivery, and the second was performed 4-6 weeks after delivery. The early postpartum period was characterized by higher anterior cingulate cortex reactivity during anticipation of negative emotional stimuli than the late postpartum period. This was accompanied by a negative relationship with insular reactivity during the early postpartum period and a trend towards an increase in insular reactivity in the late postpartum period. Thus, during the first four weeks of the postpartum period, a diminished top-down regulatory feedback on emotion-related areas of the brain was noted. This finding suggests a physiologically important adaptation during the healthy postpartum period.
- Published
- 2017
- Full Text
- View/download PDF
175. Homozygous GRID2 missense mutation predicts a shift in the D-serine binding domain of GluD2 in a case with generalized brain atrophy and unusual clinical features
- Author
-
Ali, Zafar, Zulfiqar, Shumaila, Klar, Joakim, Wikström, Johan, Ullah, Farid, Khan, Ayaz, Abdullah, Uzma, Baig, Shahid, Dahl, Niklas, Ali, Zafar, Zulfiqar, Shumaila, Klar, Joakim, Wikström, Johan, Ullah, Farid, Khan, Ayaz, Abdullah, Uzma, Baig, Shahid, and Dahl, Niklas
- Abstract
BACKGROUND: Spinocerebellar ataxias comprise a large and heterogeneous group of disorders that may present with isolated ataxia, or ataxia in combination with other neurologic or non-neurologic symptoms. Monoallelic or biallelic GRID2 mutations were recently reported in rare cases with cerebellar syndrome and variable degree of ataxia, ocular symptoms, hypotonia and developmental delay. CASE PRESENTATION: We report on a consanguineous family with autosomal recessive childhood onset of slowly progressive cerebellar ataxia and delayed psychomotor development in three siblings. MRI of an adult and affected family member revealed slightly widened cerebral and cerebellar sulci, suggesting generalized brain atrophy, and mild cerebellar atrophy. Using whole exome sequencing we identified a novel homozygous missense variant [c.2128C > T, p.(Arg710Trp)] in GRID2 that segregates with the disease. The missense variant is located in a conserved region encoding the extracellular serine-binding domain of the GluD2 protein and predicts a change in conformation of the protein. CONCLUSION: The widespread supratentorial brain abnormalities, absence of oculomotor symptoms, increased peripheral muscle tone and the novel missense mutation add to the clinical and genetic variability in GRID2 associated cerebellar syndrome. The neuroradiological findings in our family indicate a generalized neurodegenerative process to be taken into account in other families segregating complex clinical features and GRID2 mutations., Zafar Ali, Shumaila Zulfiqar and Joakim Klar contributed equally
- Published
- 2017
- Full Text
- View/download PDF
176. Cerebral Magnesium Levels in Preeclampsia; A Phosphorus Magnetic Resonance Spectroscopy Study
- Author
-
Nelander, Maria, Weis, Jan, Bergman, Lina, Larsson, Anders, Wikström, Anna-Karin, Wikström, Johan, Nelander, Maria, Weis, Jan, Bergman, Lina, Larsson, Anders, Wikström, Anna-Karin, and Wikström, Johan
- Abstract
BACKGROUND: Magnesium sulfate (MgSO4) is used as a prophylaxis for eclamptic seizures. The exact mechanism of action is not fully established. We used phosphorus magnetic resonance spectroscopy (31P-MRS) to investigate if cerebral magnesium (Mg2+) levels differ between women with preeclampsia, normal pregnant, and nonpregnant women. METHODS: This cross-sectional study comprised 28 women with preeclampsia, 30 women with normal pregnancies in corresponding gestational week (range: 23-41 weeks) and 11 nonpregnant healthy controls. All women underwent 31P-MRS from the parieto-occipital region of the brain and were interviewed about cerebral symptoms. Differences between groups were assessed by analysis of variance and Tukey's post-hoc test. Correlations between Mg2+ levels and specific neurological symptoms were estimated with Spearman's rank test. RESULTS: Mean maternal cerebral Mg2+ levels were lower in women with preeclampsia (0.12 mM ± 0.02) compared to normal pregnant controls (0.14 mM ± 0.03) (P = 0.04). Nonpregnant and normal pregnant women did not differ in Mg2+ levels. Among women with preeclampsia, lower Mg2+ levels correlated with presence of visual disturbances (P = 0.04). Plasma levels of Mg2+ did not differ between preeclampsia and normal pregnancy. CONCLUSIONS: Women with preeclampsia have reduced cerebral Mg2+ levels, which could explain the potent antiseizure prophylactic properties of MgSO4. Within the preeclampsia group, women with visual disturbances have lower levels of Mg2+ than those without such symptoms.
- Published
- 2017
- Full Text
- View/download PDF
177. Magnetic Resonance Compatibility of a Transponder Aimed for Radiotherapy Positioning – A Phantom Study
- Author
-
Wikström, Johan, Isacsson, Ulf, Bengt, Johansson, Lennernäs, Bo, Wikström, Johan, Isacsson, Ulf, Bengt, Johansson, and Lennernäs, Bo
- Abstract
Background/Aim: Electromagnetic Positioning Systems (EMP) is a new position-ing technique in four-dimensional radiotherapy. Patients with implanted transponders may be referred for magnetic resonance imaging (MRI) making it important to establish the MR safety. Materials and Methods: Oranges were prepared with transponders and imaged on a 3T MR scanner with different sequences. Computed tomography (CT) was performed as comparison. MR artifacts were assessed. An estimation of the maximum transponder de-flection force and heating was made. Results: The mean measured displacement of transponders was 0.1 mm (range=0.03-0.3 mm). Artifacts were observed adjacent to transponders using all sequences. The deflection force on the transponder in the gantry was less than 38 mN. No heating was observed. Conclusion: The absence of any substantial movement, the weak measured deflection force and absence of observed heating speaks for the safe use of MR imaging with transponder 3T. Local artefacts makes evaluation impossible adjacent to transponders.
- Published
- 2017
- Full Text
- View/download PDF
178. SNX10 gene mutation leading to osteopetrosis with dysfunctional osteoclasts
- Author
-
Stattin, Eva-Lena, Henning, Petra, Klar, Joakim, McDermott, Emma, Stecksen-Blicks, Christina, Sandström, Per-Erik, Kellgren, Therese G, Rydén, Patrik, Hallmans, Göran, Lönnerholm, Torsten, Ameur, Adam, Helfrich, Miep H, Coxon, Fraser P, Dahl, Niklas, Wikström, Johan, Lerner, Ulf H, Stattin, Eva-Lena, Henning, Petra, Klar, Joakim, McDermott, Emma, Stecksen-Blicks, Christina, Sandström, Per-Erik, Kellgren, Therese G, Rydén, Patrik, Hallmans, Göran, Lönnerholm, Torsten, Ameur, Adam, Helfrich, Miep H, Coxon, Fraser P, Dahl, Niklas, Wikström, Johan, and Lerner, Ulf H
- Abstract
Autosomal recessive osteopetrosis (ARO) is a heterogeneous disorder, characterized by defective osteoclastic resorption of bone that results in increased bone density. We have studied nine individuals with an intermediate form of ARO, from the county of Västerbotten in Northern Sweden. All afflicted individuals had an onset in early infancy with optic atrophy, and in four patients anemia was present at diagnosis. Tonsillar herniation, foramen magnum stenosis, and severe osteomyelitis of the jaw were common clinical features. Whole exome sequencing, verified by Sanger sequencing, identified a splice site mutation c.212 + 1 G > T in the SNX10 gene encoding sorting nexin 10. Sequence analysis of the SNX10 transcript in patients revealed activation of a cryptic splice site in intron 4 resulting in a frame shift and a premature stop (p.S66Nfs * 15). Haplotype analysis showed that all cases originated from a single mutational event, and the age of the mutation was estimated to be approximately 950 years. Functional analysis of osteoclast progenitors isolated from peripheral blood of patients revealed that stimulation with receptor activator of nuclear factor kappa-B ligand (RANKL) resulted in a robust formation of large, multinucleated osteoclasts which generated sealing zones; however these osteoclasts exhibited defective ruffled borders and were unable to resorb bone in vitro.
- Published
- 2017
- Full Text
- View/download PDF
179. Guidelines for the use of magnetic resonance imaging in diagnosing and monitoring the treatment of multiple sclerosis : recommendations of the Swedish Multiple Sclerosis Association and the Swedish Neuroradiological Society
- Author
-
Vågberg, M, Axelsson, M, Birgander, R, Burman, Joachim, Cananau, C, Forslin, Y, Granberg, T, Gunnarsson, M, von Heijne, A, Jönsson, L, Karrenbauer, V D, Larsson, Elna-Marie, Lindqvist, T, Lycke, J, Lönn, L, Mentesidou, E, Müller, S, Nilsson, P, Piehl, F, Svenningsson, A, Vrethem, M, Wikström, Johan, Vågberg, M, Axelsson, M, Birgander, R, Burman, Joachim, Cananau, C, Forslin, Y, Granberg, T, Gunnarsson, M, von Heijne, A, Jönsson, L, Karrenbauer, V D, Larsson, Elna-Marie, Lindqvist, T, Lycke, J, Lönn, L, Mentesidou, E, Müller, S, Nilsson, P, Piehl, F, Svenningsson, A, Vrethem, M, and Wikström, Johan
- Abstract
Multiple sclerosis (MS) is associated with inflammatory lesions in the brain and spinal cord. The detection of such inflammatory lesions using magnetic resonance imaging (MRI) is important in the consideration of the diagnosis and differential diagnoses of MS, as well as in the monitoring of disease activity and predicting treatment efficacy. Although there is strong evidence supporting the use of MRI for both the diagnosis and monitoring of disease activity, there is a lack of evidence regarding which MRI protocols to use, the frequency of examinations, and in what clinical situations to consider MRI examination. A national workshop to discuss these issues was held in Stockholm, Sweden, in August 2015, which resulted in a Swedish consensus statement regarding the use of MRI in the care of individuals with MS. The aim of this consensus statement is to provide practical advice for the use of MRI in this setting. The recommendations are based on a review of relevant literature and the clinical experience of workshop attendees. It is our hope that these recommendations will benefit individuals with MS and guide healthcare professionals responsible for their care.
- Published
- 2017
- Full Text
- View/download PDF
180. A missense variant in ITPR1 provides evidence for autosomal recessive SCA29 with asymptomatic cerebellar hypoplasia in carriers.
- Author
-
Klar, Joakim, Ali, Zafar, Farooq, Muhammad, Khan, Kamal, Wikström, Johan, Iqbal, Maria, Zulfiqar, Shumaila, Faryal, Sanam, Baig, Shahid Mahmood, Dahl, Niklas, Klar, Joakim, Ali, Zafar, Farooq, Muhammad, Khan, Kamal, Wikström, Johan, Iqbal, Maria, Zulfiqar, Shumaila, Faryal, Sanam, Baig, Shahid Mahmood, and Dahl, Niklas
- Abstract
Spinocerebellar ataxias (SCA) comprise a heterogeneous group of inherited neurological disorders characterized by a range of symptoms from both cerebellar and extra cerebellar structures. We investigated the cause of autosomal recessive, congenital SCA in six affected family members from a large consanguineous family. Using whole-exome sequencing, we identified a homozygous ITPR1 missense variant [c.5360T>C; p.(L1787P)] segregating in all affected individuals. Heterozygous carriers were asymptomatic despite cerebellar hypoplasia. Variants in the ITPTR1 gene have previously been associated exclusively with autosomal dominant SCA15 and SCA29 with slow or no progression. The L1787 residue is highly conserved and the leucine to proline substitution has a predicted destabilizing effect on the protein structure. Additionally, the L1787P variant is located in a domain separated from previously described and dominant-acting missense variants consistent with a distinct effect on IP3R1 tetramer structure and function. Taken together, we show for the first time that a biallelic ITPR1 missense variant may cause an autosomal recessive and infantile onset SCA29, albeit with subclinical cerebellar hypoplasia in carriers. Our findings add to the genetic complexity of SCA29 and broaden the correlations between ITPR1 variants and their clinical expression.
- Published
- 2017
- Full Text
- View/download PDF
181. Overview of neuroradiology.
- Author
-
Larsson, Elna-Marie, Wikström, Johan, Larsson, Elna-Marie, and Wikström, Johan
- Abstract
Neuroradiology with computed tomography (CT) and magnetic resonance imaging (MRI) is essential for the initial evaluation of patients with a clinical suspicion of brain and spine disorders. Morphologic imaging is required to obtain a probable diagnosis to support the treatment decisions in pre- and perinatal disorders, vascular diseases, traumatic injuries, metabolic disorders, epilepsy, infection/inflammation, neurodegenerative disorders, degenerative spinal disease, and tumors of the central nervous system. Different postprocessing tools are increasingly used for three-dimensional visualization and quantification of lesions. Additional information is provided by angiographic methods and physiologic CT and MRI techniques, such as diffusion MRI, perfusion CT/MRI, MR spectroscopy, functional MRI, tractography, and nuclear medicine imaging methods. Positron emission tomography (PET) is now integrated with CT (PET/CT), and PET/MR scanners have recently also been introduced. These hybrid techniques facilitate the co-registration of lesions with different modalities, and give new possibilites for functional imaging. Repeated imaging is increasingly performed for treatment monitoring. The improved imaging techniques together with the neuropathologic diagnosis after biopsy or surgery allow more personalized treatment of the patient. Neuroradiology also includes endovascular treatment of aneurysms and arteriovenous malformations as well as thrombectomy in acute stroke. This catheter-based treatment has replaced invasive neurosurgery in many cases.
- Published
- 2017
- Full Text
- View/download PDF
182. Anti-analysis techniques to weaken author classification accuracy in compiled executables
- Author
-
Muir, Macaully and Wikström, Johan
- Subjects
Datavetenskap (datalogi) ,Computer Sciences - Abstract
Programming languages such as C/C++ allow for great flexibility in how code can be written. This leads to pro- grammers developing their own “code style” that can be used to identify them among a group of other programmers, in a setting such as a programming competition. Recent research has shown that some of the identifying stylistic features present in source code survive the compilation pro- cess, and that authorship classification can be performed on the compiled executables alone. This was originally per- formed by Rosenblum et al. in their 2011 paper on the subject. This thesis takes the approach of Rosenblum et al. and in- vestigates how the author classification process is a ected by changes in the compilation process of the training dataset, specifically di erent levels of optimisation (-O1 to -O3) and static linkage. We find that full optimisation yields a 10% drop in accuracy in datasets with 413 and 20 authors re- spectively. Static linkage results in a significant drop in accuracy in datasets with 20 and 10 authors, respectively. In both cases, the classifiers still perform significantly bet- ter than random chance and as such these methods cannot guarantee anonymity to the programmer. It is not clear how these results translate to other datasets, although there is reason to believe they would be reproducible using other classifiers found in the literature.
- Published
- 2016
183. Konsten att kommunicera på Facebook : En kvalitativ studie om engagemang kopplat till format och budskap
- Author
-
Lundberg, Linn and Wikström, Johan
- Subjects
engagemang ,Communication Studies ,Kommunikationsvetenskap ,Facebook ,relationsmarknadsföring ,kvantitativ innehållsanalys ,Sociala medier ,marknadskommunikation - Abstract
Studiens resultat pekar på att text/länkformatet är det format som genererar mest engagemang hos mottagarna på Facebook och att de inläggen som är personliga/informativa uppskattas mest bland mottagarna på Facebook. Videoinlägg är generellt det inläggsformat som är minst effektivt samtidigt som det är ett format som delas ungefär lika ofta som andra typer av inläggsformat. Bildinlägg är i stort sett lika engagerande som text/länk-inläggen och bekräftar således tidigare forskning om att bildinlägg är en effektiv metod för att skapa engagemang. Studiens resultat visar också på att reklambaserade och uppmanande inlägg har en mindre effekt än personliga och informativa inlägg.
- Published
- 2016
184. Mobilt Testande : -en jämförelse av kognitiva testpoäng från mobil respektive icke-mobil enhet
- Author
-
Wikström, Johan
- Subjects
Tillämpad psykologi ,Applied Psychology - Abstract
Ökad användning av mobila enheter, samt organisationers önskan att effektivt testa och engagera arbetssökande driver utvecklingen av mobilanpassade test framåt. Forskning kring mobila enheters inverkan på testresultat är tvetydig med positiva och negativa utfall. Mobila enheter verkar ha negativ inverkan på testpoäng från kognitiva test. En effekt som kan bero på de begränsningar (mindre skärm, pekskärm) som mobila enheter har. Mått på kognitiva förmågor används ofta vid urval, om olika enheter ger upphov till differens i testpoäng behöver detta utredas. I en experimentell studie (N=51) undersöktes huruvida mobila enheter har negativ inverkan på resultat från kognitiva test. I upprepade mätningar genomförde deltagarna kognitiva test på mobil och icke-mobil enhet. Studien visar att mobila enheter inte har en negativ påverkan på testresultatet. Diskussionen behandlar möjliga förklaringar till resultat utifrån urval och testdesign, tar upp begränsningar i studien samt siar om MT framtid.
- Published
- 2016
185. Homozygous GRID2 missense mutation predicts a shift in the D-serine binding domain of GluD2 in a case with generalized brain atrophy and unusual clinical features
- Author
-
Ali, Zafar, primary, Zulfiqar, Shumaila, additional, Klar, Joakim, additional, Wikström, Johan, additional, Ullah, Farid, additional, Khan, Ayaz, additional, Abdullah, Uzma, additional, Baig, Shahid, additional, and Dahl, Niklas, additional
- Published
- 2017
- Full Text
- View/download PDF
186. Hormonal Cycle and Contraceptive Effects on Amygdala and Salience Resting-State Networks in Women with Previous Affective Side Effects on the Pill
- Author
-
Engman, Jonas, primary, Sundström Poromaa, Inger, additional, Moby, Lena, additional, Wikström, Johan, additional, Fredrikson, Mats, additional, and Gingnell, Malin, additional
- Published
- 2017
- Full Text
- View/download PDF
187. OP 39 Cerebral osmolytes and osmolality in pregnancy and preeclampsia
- Author
-
Nelander, Maria, primary, Wikström, Anna-Karin, additional, Weis, Jan, additional, Bergman, Lina, additional, Larsson, Anders, additional, Sundström-Poromaa, Inger, additional, and Wikström, Johan, additional
- Published
- 2017
- Full Text
- View/download PDF
188. SNX10 gene mutation leading to osteopetrosis with dysfunctional osteoclasts
- Author
-
Stattin, Eva-Lena, primary, Henning, Petra, additional, Klar, Joakim, additional, McDermott, Emma, additional, Stecksen-Blicks, Christina, additional, Sandström, Per-Erik, additional, Kellgren, Therese G., additional, Rydén, Patrik, additional, Hallmans, Göran, additional, Lönnerholm, Torsten, additional, Ameur, Adam, additional, Helfrich, Miep H., additional, Coxon, Fraser P., additional, Dahl, Niklas, additional, Wikström, Johan, additional, and Lerner, Ulf H., additional
- Published
- 2017
- Full Text
- View/download PDF
189. A missense variant in ITPR1 provides evidence for autosomal recessive SCA29 with asymptomatic cerebellar hypoplasia in carriers
- Author
-
Klar, Joakim, primary, Ali, Zafar, additional, Farooq, Muhammad, additional, Khan, Kamal, additional, Wikström, Johan, additional, Iqbal, Maria, additional, Zulfiqar, Shumaila, additional, Faryal, Sanam, additional, Baig, Shahid Mahmood, additional, and Dahl, Niklas, additional
- Published
- 2017
- Full Text
- View/download PDF
190. Emotional anticipation after delivery – a longitudinal neuroimaging study of the postpartum period
- Author
-
Gingnell, Malin, primary, Toffoletto, Simone, additional, Wikström, Johan, additional, Engman, Jonas, additional, Bannbers, Elin, additional, Comasco, Erika, additional, and Sundström-Poromaa, Inger, additional
- Published
- 2017
- Full Text
- View/download PDF
191. Cerebral Magnesium Levels in Preeclampsia; A Phosphorus Magnetic Resonance Spectroscopy Study
- Author
-
Nelander, Maria, primary, Weis, Jan, additional, Bergman, Lina, additional, Larsson, Anders, additional, Wikström, Anna-Karin, additional, and Wikström, Johan, additional
- Published
- 2017
- Full Text
- View/download PDF
192. Extended Anatomical Grading in Diffuse Axonal Injury Using MRI: Hemorrhagic Lesions in the Substantia Nigra and Mesencephalic Tegmentum Indicate Poor Long-Term Outcome
- Author
-
Abu Hamdeh, Sami, primary, Marklund, Niklas, additional, Lannsjö, Marianne, additional, Howells, Tim, additional, Raininko, Raili, additional, Wikström, Johan, additional, and Enblad, Per, additional
- Published
- 2017
- Full Text
- View/download PDF
193. 176: Cerebral magnesium levels in preeclampsia; a phosphorus magnetic resonance spectroscopy study
- Author
-
Nelander, Maria, primary, Weis, Jan, additional, Bergman, Lina, additional, Wikström, Anna-Karin, additional, and Wikström, Johan, additional
- Published
- 2017
- Full Text
- View/download PDF
194. Utvärdering av övervakade maskininlärningsalgoritmer för att förutsäga framgång inom sportfiske
- Author
-
Wikström, Johan
- Subjects
Datavetenskap (datalogi) ,sport fishing ,recreational fishing ,Computer Sciences ,linear regression ,supervised machine learning ,sportfiske ,fiske ,artificial neural networks ,fishing ,random forest - Abstract
This report examines three different machine learning algorithms and their effectiveness for predicting recreational fishing success. Recreational fishing is a huge pastime but reliable methods of predicting fishing success have largely been missing. This report compares random forest, linear regression and multilayer perceptron to a reasonable baseline model for predicting fishing success. Fishing success is defined as the expected weight of the fish caught. Previous reports have mainly focused on commercial fishing or limited the research to examining the impact of a single variable. In this exploratory study, multiple attributes and multiple algorithms are examined to determine if supervised machine learning is a viable tool to predict recreational fishing success. Recreational fishing success can potentially be predicted by a large number of attributes, which may be different for different species. In this report, data is fetched from multiple sources and combined into a unified data format. The primary source of data is a database from the fishing app FishBrain, containing data of over 250000 logged catches. Another is the World Weather Online API which supplies weather data. The report focuses on the four most common species in the database, largemouth bass, Micropterus salmoides, northern pike, Esox lucius, rainbow trout, Oncorhynchus mykiss and European perch, Perca fluviatilis with a focus on largemouth bass since it has the most data available. Algorithms are evaluated using the Weka data mining software. Hyperparameters are found using cross-validation and some data is used as a test set to validate the results after cross-validation. Results are measured as the error compared to a baseline algorithm. Random forest is the most effective algorithm in the experiments, reducing error compared to the baseline for all the examined fish species. It is also found that no single variable affects the chosen metric of fishing success much, but rather a combination of most of the examined variables is needed to give optimal predictions. In conclusion, the random forest algorithm can be used to predict fishing success across multiple species. It performs significantly better than linear regression, multilayer perceptron and the baseline on crossvalidation and on the testing set. I denna rapport evalueras tre olika maskininlärningsalgoritmer och deras effektivitet för att förutsäga framgång inom sportfiske. Sport- fiske är en mycket populär hobby, men pålitliga metoder att förutsäga framgångsrikt sportfiske saknas. Denna rapport jämför random forest, linjär regression och flerlagers neurala nätverk mot en rimlig baselinealgorithm för att förutsäga framgång inom sportfiske. Framgång defineras som fiskens förväntade vikt i kg. Tidigare undersökningar har huvudsakligen fokuserat på kommersiellt fiske eller begränsat undersökningen till påverkan av en enskild variabel. I denna studie undersöks flera attribut och algoritmer för att avgöra om övervakad maskininlärning är ett användbart verktyg för att förutsäga framgång inom sportfiske. Framgång inom sportfiske kan potentiellt påverkas av ett stort antal attribut som kan vara olika för olika arter. I denna studie hämtas data från ett flertal källor som kombineras i ett unifierat dataformat. Den primära datakällan är en databas tillhörande sportfiskeappen FishBrain som innehåller över 250000 loggade fångster. En annan källa är World Weather Online:s API som bidrar med väderdata. Rapporten fokuserar på de fyra vanligaste arterna i databasen, largemouth bass, Micropterus salmoides, gädda, Esox lucius, regnbågsöring, Oncorhynchus mykiss och europeisk abborre, Perca fluviatilis med ett särskilt fokus på largemouth bass eftersom den har mest data tillgängligt. Algoritmerna evalueras med hjälp av data mining-verktyget Weka. Hyperparametrar bestäms med hjälp av korsvalidering och en delmängd av datan separeras och används för att validera resultaten efter korsvalidering. Resultaten mäts relativt en baseline-algoritm. Random forest är den mest effektiva algoritmen i experimenten och reducerar felet jämfört med baseline-algoritmen för alla undersökta fiskarter. Inget enskilt attribut påverkar slutresultatet mycket utan det behövs en kombination av flera attribut för att ge optimala prediktioner. Slutsatsen blir att random forest kan användas för att förutsäga framgång inom sportfiske för flera olika fiskarter. Den presterar signifikant bättre än linjär regression, flerlagers neuralt nätverk och baselinealgoritmen på korsvalidering och på testdelmängden.
- Published
- 2015
195. Festiketten : Developement of an E-commerce Web Application for custom designed bottle labels
- Author
-
Berner, Ellen, Björkrot, Emil, Grip, Didrik, Jonsson, Alma, Kozma, Andreas, Wikblad, Ludwig, Wikström, Johan, and Österlund, Mathias
- Subjects
Computer and Information Sciences ,Data- och informationsvetenskap - Abstract
The report examines how an online store for custom designed bottle labels can be developed as a web application, and aims to contribute to the existing research on web design. The development is based on the vision” to provide custom labels through an online store which puts the icing on the cake for your special occasion”, with persons in the age 25-40 who are planning a wedding or another large event as target group. The technical methods which can be used are presented in the report and what impact they had on the competitive aspects of the online store. Design strategies for building user trust are discussed among others, as essential parts of e-commerce according to the presented theory. Furthermore, the report presents more concrete technical methods for increasing the competitiveness such as faster loading times and search engine optimization. Especially loading times plays a central role for the success of a web application according to the related theory. The methods which has been used and why, considering the collected theory, are presented in the report. The conclusions of the report states that an online store successfully can be developed using an agile methodology such as Scrum and that it can take benefits from being implemented as a single page application. Developing a design tool for custom bottle labels proved to be a difficult balancing act between customization and simplicity. Denna rapport undersöker hur en e-butik för försäljning av egendesignade flasketiketter kan utvecklas som webbapplikation, och syftar till att bidra till den existerande forskningen kring webbutveckling. Utvecklandet utgår från visionen "att genom en e-butik tillhandahålla personliga etiketter som sätter guldkant på ditt evenemang", med personer i 25-40 årsåldern som planerar bröllop eller någon annan större fest som målgrupp. I rapporten presenteras de tekniska metoder som kan användas, och vad de har för påverkan på de konkurrensmässiga aspekterna av e-butiken. Bland annat behandlas designstrategier för att skapa förtroende hos användaren, en essentiell del i e-handel enligt den teori som presenteras i rapporten. Vidare presenteras även mer konkreta tekniska aspekter för att utöka konkurrenskraften såsom snabbare laddningstider och sökmotoroptimering. Framförallt spelar laddningstider en central roll för webbapplikationers framgång enligt den framtagna teorin. De metoder som valts utifrån den framtagna teorin och varför presenteras sedan i rapporten. Slutsatserna blir att en e-butik med fördel kan vara en single-page applikation och utvecklas agilt enligt Scrum. Att utveckla ett designverktyg för personliga flasketiketter visade sig vara en svår balansgång mellan valfrihet och enkelhet.
- Published
- 2015
196. MRI estimated placental perfusion in fetal growth assessment
- Author
-
Sohlberg, Sara, Mulic-Lutvica, Ajlana, Olovsson, Matts, Weis, Jan, Axelsson, Ove, Wikström, Johan, and Wikström, Anna-Karin
- Subjects
Perfusion ,Magnetic resonance imaging ,Placenta ,Obstetrics, Gynecology and Reproductive Medicine ,Intrauterine growth restriction ,Reproduktionsmedicin och gynekologi ,Small for gestational age ,Perfusion fraction ,Radiologi och bildbehandling ,Radiology, Nuclear Medicine and Medical Imaging - Abstract
Objective This study aimed to evaluate placental perfusion fraction estimated by magnetic resonance imaging (MRI) in vivo as a marker of placental function. Methods The study population included 35 pregnant women, of whom 13 had preeclampsia, examined at gestational weeks 22 to 40. Each woman underwent, within a 24 hour period: a MRI diffusion-weighted sequence (from which we calculated the placental perfusion fraction); venous blood sampling; and an ultrasound examination including estimation of fetal weight, amniotic fluid index and Doppler velocity measurements. We compared the perfusion fraction in pregnancies with and without fetal growth restriction and estimated correlations between the perfusion fraction and ultrasound estimates and plasma markers with linear regression. The associations between the placental perfusion fraction and ultrasound estimates were modified by the presence of preeclampsia (p
- Published
- 2015
197. Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures.
- Author
-
Hamdeh, Sami Abu, Marklund, Niklas, Lewén, Anders, Howells, Tim, Raininko, Raili, Wikström, Johan, and Enblad, Per
- Published
- 2019
- Full Text
- View/download PDF
198. Pregnancy hypertensive disease and risk of dementia and cardiovascular disease in women aged 65 years or older : a cohort study
- Author
-
Nelander, Maria, Cnattingius, S, Åkerud, Helena, Wikström, Johan, Pedersen, N L, Wikström, Anna-Karin, Nelander, Maria, Cnattingius, S, Åkerud, Helena, Wikström, Johan, Pedersen, N L, and Wikström, Anna-Karin
- Abstract
OBJECTIVE: The primary aim was to study pregnancy hypertensive disease and subsequent risk of dementia. The second aim was to study if the increased risks of cardiovascular disease (CVD) and stroke after pregnancy hypertensive disease persist in an elderly population. DESIGN: Cohort study. SETTING: Sweden. POPULATION OR SAMPLE: 3232 women 65 years or older (mean 71 years) at inclusion. METHODS: Cox proportional hazards regression analyses were used to calculate risks of dementia, CVD and/or stroke for women exposed to pregnancy hypertensive disease. Exposure data were collected from an interview at inclusion during the years 1998-2002. Outcome data were collected from the National Patient Register and Cause of Death Register from the year of inclusion until the end of 2010. Age at inclusion was set as a time-dependent variable, and adjustments were made for body mass index, education and smoking. MAIN OUTCOME MEASURES: Dementia, CVD, stroke. RESULTS: During the years of follow-up, 7.6% of the women exposed to pregnancy hypertensive disease received a diagnosis of dementia, compared with 7.4% among unexposed women (HR 1.19; 95% CI 0.79 to 1.73). The corresponding rates for CVD were 22.9% for exposed women and 19.0% for unexposed women (HR 1.29; 95% CI 1.02 to 1.61), and for stroke 13.4% for exposed women and 10.7% for unexposed women (HR 1.36; 95% CI 1.00 to 1.81). CONCLUSIONS: There was no increased risk of dementia after self-reported pregnancy hypertensive disease in our cohort. We found that the previously reported increased risk of CVD and stroke after pregnancy hypertensive disease persists in an older population.
- Published
- 2016
- Full Text
- View/download PDF
199. Human fertilizer and the productivity of farming households
- Author
-
Pettersson, Jan, Wikström, Johan, Pettersson, Jan, and Wikström, Johan
- Abstract
Ecological sanitation offers both sanitation and fertilizer through recycling of nutrients. Human fertilizer provides a close to free addition of nutrients in household farming and may, therefore, decrease the downward risk of fertilizer adoption. We study an ecological sanitation investment program in southern Mali, where just over 150 beneficiaries got a urine diverting dry toilet installed. Our results suggest that the average household in our study is able to produce amounts of N, P, and K equivalent to around a fourth of its yearly expenditures on artificial fertilizers, corresponding to a yearly addition of nutrients or a yearly reduction in fertilizer expenditures to a value of about 50 Euro. However, the quantity and quality of N, P, and K actually retained is found to be only a fraction of this potential amount. Using propensity score matching methods, we find an increase in maize yields among beneficiary households, but no effect on the yields of other crops. Moreover, households substitute artificial fertilizer with human fertilizer at 10-15% of the average household use of artificial fertilizers. Thus, the substitution may worsen an already bad soil nutrient balance. Higher retention levels are needed for solutions to prove financially viable.
- Published
- 2016
- Full Text
- View/download PDF
200. The effect of combined hormonal contraceptives use on brain reactivity during response inhibition
- Author
-
Gingnell, Malin, Bannbers, Elin, Engman, Jonas, Frick, Andreas, Moby, Lena, Wikström, Johan, Sundström-Poromaa, Inger, Gingnell, Malin, Bannbers, Elin, Engman, Jonas, Frick, Andreas, Moby, Lena, Wikström, Johan, and Sundström-Poromaa, Inger
- Abstract
Objectives Cognitive control, which can be described as the ability to moderate impulses, has not previously been investigated in users of combined hormonal contraception (CHC). Given the suggested modulatory role of ovarian steroids in prefrontal dopaminergic function, which in turn taps into cognitive control, this randomised, double-blinded, placebo-controlled oral contraceptive trial set out to investigate the brain activity pattern during response inhibition in CHC users. Methods Thirty-four women were randomised to one treatment cycle with a levonorgestrel-containing CHC or placebo. The women performed a Go/NoGo task to measure brain activity during response inhibition by use of event-related functional magnetic resonance imaging (fMRI) prior to and during the CHC/placebo treatment cycle. Results No differences between CHC and placebo users in number of correct inhibitions were found during treatment, but only women on CHC significantly improved their performance between the baseline and treatment assessments. During the treatment cycle CHC users displayed decreased activity in the right middle frontal gyrus in comparison with placebo users. No other significant activations were evident between treatment groups or within groups. Conclusion Overall, CHC use had marginal effects on brain activity during response inhibition. If anything, the findings of the study may suggest reduced effort or increased efficiency in maintaining orbitofrontal cortex inhibitory cognitive control when using a combined oral contraceptive.
- Published
- 2016
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.