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1.	Delldén, Carl Olof, 1800-1854 (författare) Om folk-rättens princip. Akademisk afhandling ... utgifven af Carl Olof Delldén, Phil. och J.U. Doctor ... och Hans Peter Gustafson, Kongl Stipend. Gottl. På gustavianska lärosalen d. 14 oct. 1843 ..., II 1843 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)
2.	Adeogun, Ramoni, et al. (författare) Polarimetric Wireless Indoor Channel Modeling Based on Propagation Graph 2019 Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X. ; 67:10, s. 6585-6595 Tidskriftsartikel (refereegranskat)abstract This paper generalizes a propagation graph model to polarized indoor wireless channels. In the original contribution, the channel is modeled as a propagation graph in which vertices represent transmitters, receivers, and scatterers, while edges represent the propagation conditions between vertices. Each edge is characterized by an edge transfer function accounting for the attenuation, delay spread, and the phase shift on the edge. In this contribution, we extend this modeling formalism to polarized channels by incorporating depolarization effects into the edge transfer functions and hence, the channel transfer matrix. We derive closed form expressions for the polarimetric power delay spectrum and cross-polarization ratio of the indoor channel. The expressions are derived considering average signal propagation in a graph and relate these statistics to model parameters, thereby providing a useful approach to investigate the averaged effect of these parameters on the channel statistics. Furthermore, we present a procedure for calibrating the model based on method of moments. Simulations were performed to validate the proposed model and the derived approximate expressions using both synthetic data and channel measurements at 15 GHz and 60 GHz. We observe that the model and approximate expressions provide good fit to the measurement data.
3.	Agardh, Carl-David, et al. (författare) Influence of treatment with diethylstilbestrol for carcinoma of prostate on platelet aggregation and plasma lipoproteins 1986 Ingår i: Urology. - : Elsevier BV. - 1527-9995 .- 0090-4295. ; 28:6, s. 469-471 Tidskriftsartikel (refereegranskat)abstract Treatment of prostatic carcinoma with estrogens is accompanied by an increased risk for thromboembolic and cardiovascular complications. The underlying mechanisms are still unknown. Patients treated with diethylstilbestrol (DES) were compared with patients given no estrogen treatment regarding factors (platelet aggregation in vitro and plasma lipoproteins) that have been suggested to contribute to increased thrombogenesis and cardiovascular risk. The results do not show any increase in in vitro platelet aggregation in patients treated with DES compared with those given no treatment. This indicates that hyperaggregability does not contribute to the increased incidence in thromboembolic events seen in DES-treated patients. This is in contrast to the increased platelet aggregation previously described in patients treated with polyestradiolphosphate + etinylestradiol. The changes in plasma lipoproteins observed during DES-treatment are generally considered beneficial from an atherogenic point of view and do not appear to cause the elevated incidence of cardiovascular disease in these patients.
4.	Agardh, Carl-David, et al. (författare) The influence of treatment with estrogens and estramustine phosphate on platelet aggregation and plasma lipoproteins in non-disseminated prostatic carcinoma 1984 Ingår i: Journal of Urology. - 1527-3792. ; 132:5, s. 1021-1024 Tidskriftsartikel (refereegranskat)abstract The treatment of prostatic carcinoma with estrogens is associated with an increased risk of cardiovascular as well as thromboembolic complications. In the present study, patients harboring highly or moderately differentiated prostatic carcinoma without signs of metastases were treated with either polyestradiolphosphate + etinylestradiol, estramustine phosphate or given no treatment. Subsequently, these patients were investigated regarding factors (platelet aggregation, plasma and platelet phospholipid composition and lipoprotein patterns) that might contribute to increased thrombogenesis and cardiovascular risk. The results indicate the presence of increased in vitro platelet aggregation in patients treated with polyestradiolphosphate + etinylestradiol compared to those treated with estramustine phosphate or given no treatment. A possible relationship between the availability of arachidonic acid in platelet membrane phospholipids and in vitro platelet aggregation is suggested. On the other hand the alterations in plasma lipoproteins observed during treatment are generally considered positive from an atherogenic point of view and do not seem relevant to the elevated incidence of cardiovascular disease in these patients.
5.	Bernland, Anders, et al. (författare) Estimation of Spherical Wave Coefficients from 3D Positioner Channel Measurements 2012 Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757. ; 11, s. 608-611 Tidskriftsartikel (refereegranskat)abstract Electromagnetic vector spherical waves have been used recently to model antenna-channel interaction and the available degrees of freedom in MIMO systems. However, there are no previous accounts of a method to estimate spherical wave coefficients from channel measurements. One approach for this, using a 3D positioner, is presented and analyzed in this letter. Measurement results are presented and discussed. It is concluded that estimates based on randomly positioned measurements within a volume are less sensitive to noise than those based only on measurements on the surface.
6.	Bernland, Anders, et al. (författare) Estimation of Spherical Wave Coefficients from 3D Positioner Channel Measurements 2012 Rapport (övrigt vetenskapligt/konstnärligt)abstract Electromagnetic vector spherical waves have been used recently to model antenna channel interaction and the available degrees of freedom in MIMO systems. However, there are no previous accounts of a method to estimate spherical wave coefficients from channel measurements. One approach, using a 3D positioner, is presented in this letter, both in theory and practice. Measurement results are presented and discussed. One conclusion is that using randomly positioned measurements within a volume is less sensitive to noise than using only measurements on the surface.
7.	Bondarik, Alexander, et al. (författare) PTFE and Quartz Based 60 GHz Patch Antennas 2012 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
8.	Boström, Gustaf, et al. (författare) Antidepressant use and mortality in very old people 2016 Ingår i: International psychogeriatrics. - : Cambridge University Press. - 1041-6102 .- 1741-203X. ; 28:7, s. 1201-1210 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: Antidepressant treatment may increase the risk of death. The association between antidepressants and mortality has been evaluated in community-dwelling older people, but not in representative samples of very old people, among whom dementia, multimorbidity, and disability are common.METHODS: Umeå 85+/GERDA study participants (n = 992) aged 85, 90, and ≥95 years were followed for up to five years. Cox proportional hazard regression models were used to analyze mortality risk associated with baseline antidepressant treatment, adjusted for potential confounders.RESULTS: Mean age was 89 years; 27% of participants had dementia, 20% had stroke histories, 29% had heart failure, and 16% used antidepressants. In age- and sex-adjusted analyses, antidepressant use was associated with a 76% increased mortality risk (hazard ratio [HR] = 1.76; 95% confidence interval [CI], 1.41-2.19). Adding adjustment for Geriatric Depression Scale score, HR was 1.62 (95% CI, 1.29-2.03). The association was not significant when adjusting for additional confounding factors (HR = 1.08; 95% CI, 0.85-1.38). Interaction analyses in the fully adjusted model revealed a significant interaction between sex and antidepressant use (HR: 1.76; 95% CI, 1.05-2.94). Among male and female antidepressant users, the HRs for death were 0.76 (95% CI, 0.47-1.24) and 1.28 (95% CI, 0.97-1.70), respectively.CONCLUSION: Among very old people, baseline antidepressant treatment does not seem to be independently associated with increased mortality risk. However, the risk may be different in men and women. This difference and the potential risk of initial treatment require further investigation in future cohort studies of very old people.
9.	Boström, Gustaf, et al. (författare) Effects of a high-intensity functional exercise program on depressive symptoms among people with dementia in residential care : a randomized controlled trial 2016 Ingår i: International Journal of Geriatric Psychiatry. - : Wiley. - 0885-6230 .- 1099-1166. ; 31:8, s. 868-878 Tidskriftsartikel (refereegranskat)abstract OBJECTIVES: The aim of this study is to evaluate the effect of a high-intensity functional exercise program on depressive symptoms among older care facility residents with dementia.METHODS: Residents (n = 186) with a diagnosis of dementia, age ≥ 65 years, Mini-Mental State Examination score ≥ 10, and dependence in activities of daily living were included. Participants were randomized to a high-intensity functional exercise program or a non-exercise control activity conducted 45 min every other weekday for 4 months. The 15-item Geriatric Depression Scale (GDS) and the Montgomery-Åsberg Depression Rating Scale (MADRS) were administered by blinded assessors at baseline, 4, and 7 months.RESULTS: No difference between the exercise and control activity was found in GDS or MADRS score at 4 or 7 months. Among participants with GDS scores ≥ 5, reductions in GDS score were observed in the exercise and control groups at 4 months (-1.58, P = 0.001 and -1.54, P = 0.004) and 7 months (-1.25, P = 0.01 and -1.45, P = 0.007). Among participants with MADRS scores ≥ 7, a reduction in MADRS score was observed at 4 months in the control group (-2.80, P = 0.009) and at 7 months in the exercise and control groups (-3.17, P = 0.003 and -3.34, P = 0.002).CONCLUSIONS: A 4-month high-intensity functional exercise program has no superior effect on depressive symptoms relative to a control activity among older people with dementia living in residential care facilities. Exercise and non-exercise group activities may reduce high levels of depressive symptoms.
10.	Bourdoux, Andre, et al. (författare) D1.2 MaMi Channel Characteristics: Measurement Results 2015 Rapport (övrigt vetenskapligt/konstnärligt)abstract This deliverable presents channel measurement results for the scenariosOpen exhibition and Crowded auditiorium. The measurement procedureand equipment are described. Massive MIMO (MaMi) channel characteristicsand key parameters are extracted and used in an extended COST 2100channel model for MaMi. The initial validation performed shows that themodel is capable of reproducing the statistics in terms of temporal behaviorof the user separability, singular value spread, capacity and sum-rate anddirectional characteristics. The model can be used for system and link levelMaMi simulations.
11.	Burman, Maria, et al. (författare) Body Mass Index, Mini Nutritional Assessment, and their Association with Five-Year Mortality in Very Old People 2015 Ingår i: The Journal of Nutrition, Health & Aging. - Paris : Springer. - 1279-7707 .- 1760-4788. ; 19:4, s. 461-467 Tidskriftsartikel (refereegranskat)abstract OBJECTIVES: to investigate the prevalence of malnutrition and the association between Body Mass Index (BMI), Mini Nutritional Assessment (MNA) and five-year mortality in a representative population of very old (>85 years) people.DESIGN: A prospective cohort study.SETTING: A population-based study of very old people in northern Sweden and western Finland, living in institutional care or in the community.PARTICIPANTS: Out of 1195 potential participants, 832 were included (mean age 90.2±4.6 years).MEASUREMENTS: Nutritional status was assessed using BMI and MNA and the association of those two variables with five-year mortality was analyzed.RESULTS: The mean BMI value for the whole population was 25.1±4.5 kg/m2, with no difference between genders (P=0.938). The mean MNA score was 22.5±4.6 for the whole sample, and it was lower for women than for men (P<0.001). Thirteen percent were malnourished (MNA<17) and 40.3% at risk of malnutrition (MNA 17-23.5) according to MNA. Also, 34.8% of those with a MNA score <17 still had a BMI value ≥22.2 kg/m2. A BMI value <22.2 kg/m2 and a MNA score<17 were associated with lower survival. The association with mortality seemed to be J-shaped for BMI, and linear for MNA.CONCLUSIONS: Malnutrition according to MNA was common, but a substantial portion of those with a low MNA score still had a high BMI value, and vice versa. The association with mortality appeared to be J-shaped for BMI, and linear for MNA. The MNA seems to be a good measurement of malnutrition in very old people, and BMI might be misleading and could underestimate the prevalence of malnutrition, especially in women.
12.	Burman, Maria, et al. (författare) Is malnutrition a risk factor for incident urinary tract infection among older people in residential care facilities? 2018 Ingår i: Journal of Nursing Home Research. - : SERDI. - 2496-0799. ; 4, s. 49-55 Tidskriftsartikel (refereegranskat)abstract Background: Malnutrition and urinary tract infections (UTI) are common among older people living in residential care facilities.Objectives: To determine whether malnutrition is a risk factor for incident urinary tract infection in people aged ≥65 years living in residential care facilities.Design, Setting, and Participants: A prospective cohort study of people living in residential care facilities in northern Sweden (N=373). Data from the Frail Older People-Activity and Nutrition and Umeå Dementia and Exercise studies were used.Measurements: Malnutrition was assessed using the Mini Nutritional Assessment (MNA). Risk factors for UTI were explored using univariate and multivariate Cox proportional hazard regression analyses. Maximum follow-up time was 9 months.Results: The incidence of UTI was 460/1000 person-years; 85/276=30.8% of women and 16/97=16.5% of men contracted UTIs. History of UTI (hazard ratio [HR] 2.804, 95% confidence interval [CI] 1.824–4.311), heart failure (HR 2.101, 95% CI 1.368–3.225), hypertension (HR 1.656, 95% CI 1.095–2.504), and low Mini-Mental State Examination (MMSE) score (HR 0.937, 95% CI 0.892–0.985) were associated independently with higher risk of incident UTI in multivariate analyses. Malnutrition was not associated with UTI in the whole sample or in women; MNA score was associated with UTI in men in univariate analysis (HR 0.841, 95% CI 0.750–0.944).Conclusion: The incidence of UTI was high in residential care facilities and individuals with histories of UTI, heart failure, hypertension, or cognitive impairment were more likely to be affected. Malnutrition was not a risk factor for UTI in the whole sample or in women, but may constitute a risk for UTI among men.
13.	Burman, Maria, et al. (författare) Obesity may increase survival, regardless of nutritional status : a Swedish cohort study in nursing homes 2022 Ingår i: BMC Geriatrics. - : BioMed Central. - 1471-2318. ; 22:1 Tidskriftsartikel (refereegranskat)abstract Background: To investigate the associations between the body mass index (BMI), Mini Nutritional Assessment-Short Form (MNA-SF) scores, and 2-year mortality.Methods: A nationwide cohort study using data from a national quality register of older (age ≥ 65 years) nursing home residents (N = 47,686). Individuals were categorized according to BMI as underweight (< 18.5 kg/m2), normal-weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (class I, 30.0-34.9 kg/m2; class II, 35.0-39.9 kg/m2; class III, ≥ 40.0 kg/m2). Participants' nutritional status were categorized as good (MNA-SF score 12-14), at risk of malnutrition (MNA-SF score 8-11), or malnutrition (MNA-SF score 0-7). Associations with mortality were analysed using Cox proportional-hazards models.Results: At baseline, 16.0% had obesity, and 14.6% were malnourished. During 2 years of follow-up, 23,335 (48.9%) individuals died. Compared with normal-weight individuals, mortality was greater among underweight individuals [hazard ratio (HR) 1.62, 95% confidence interval (CI) 1.55-1.69] and lesser among individuals with class I (HR 0.63, 95% CI 0.60-0.66), class II (HR 0.62, 95% CI 0.56-0.68), and class III (HR 0.80, 95% CI 0.69-0.94) obesity. Compared with individuals with good nutritional status, mortality was increased for those with malnutrition (HR 2.98,95% CI 2.87-3.10). Lower mortality among obese individuals was also seen in subgroups defined according to MNA-SF scores.Conclusions: Among older nursing home residents, obesity, including severe obesity, was associated with lower 2-year mortality. Higher BMIs were associated with better survival, regardless of nutritional status according to MNA-SF.
14.	Burman, Maria, et al. (författare) Prevalence of obesity and malnutrition in four cohorts of very old adults, 2000–2017 2022 Ingår i: The Journal of Nutrition, Health & Aging. - : Springer. - 1279-7707 .- 1760-4788. ; 26:7, s. 706-713 Tidskriftsartikel (refereegranskat)abstract Objectives: Investigate trends in the prevalence of obesity and malnutrition among very old adults (age ≥ 85 years) between 2000 and 2017.Design, Setting, Participants, Measurements: A study with data from the Umeå 85+/Gerontological regional database population-based cohort study of very old adults in northern Sweden. Every 5 years from 2000–2002 to 2015–2017, comprehensive assessments of participants were performed during home visits (N=1602). Body mass index (BMI) classified participants as underweight (<18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2), and obese (≥30.0 kg/m2). Mini Nutritional Assessment (MNA) scores classified participants as malnourished (0 to <17), at risk of malnutrition (17–23.5), and having good nutritional status (24–30). Prevalence and trends were examined using analysis of variance and chi-squared tests, including subgroup analyses of nursing home residents.Results: Between 2000–2002 and 2015–2017, the mean BMI increased from 24.8± 4.7 to 26.0± 4.7 kg/m2. The prevalence of obesity and underweight were 13.4% and 7.6%, respectively, in 2000–2002 and 18.3% and 3.0%, respectively, in 2015–2017. The mean MNA score increased between 2000–2002 and 2010–2012 (from 23.2± 4.7 to 24.2± 3.6), and had decreased (to 23.3± 4.2) by 2015–2017. The prevalence of malnutrition was 12.2%, 5.1%, and 8.7% in 2000–2002, 2010–2012, and 2015–2017, respectively. Subgroup analyses revealed similar BMI and MNA score patterns among nursing home residents.Conclusions: Among very old adults, the mean BMI and prevalence of obesity seemed to increase between 2000–2002 and 2015–2017. Meanwhile, the nutritional status (according to MNA scores) seemed to improve between 2000–2002 and 2010–2012, it declined by 2015–2017.
15.	Fossum, Magdalena, et al. (författare) Isolation and in vitro cultivation of human urothelial cells from bladder washings of adult patients and children 2003 Ingår i: Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery. - : Informa UK Limited. - 0284-4311 .- 1651-2073. ; 37, s. 41-45 Tidskriftsartikel (refereegranskat)
16.	Gustafson, Carl (författare) 60 GHz Wireless Propagation Channels: Characterization, Modeling and Evaluation 2014 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract To be able to connect wirelessly to the internet is nowadays a part of everyday life and the number of wireless devices accessing wireless networks worldwide are increasing rapidly. However, with the increasing number of wireless devices and applications and the amount available bandwidth, spectrum shortage is an issue. A promising way to increase the amount of available spectrum is to utilize frequency bands in the mm-wave range of 30-300 GHz that previously have not been used for typical consumer applications. The 60 GHz band has been pointed out as a good candidate for short range, high data rate communications, as the amount of available bandwidth is at least 5 GHz worldwide, with most countries having 7 GHz of bandwidth available in this band. This large bandwidth is expected to allow for wireless communication with bit rates up to 7 Gbit/s, which can be compared to the typical WLAN systems of today that typically provide bit rates up to 0.6 Gbit/s. However, the performance of any wireless system is highly dependent on the properties and characteristics of the wireless propagation channel. This thesis focuses on indoor short range wireless propagation channels in the 60 GHz band and contains a collection of papers that characterizes, models and evaluates different aspects that are directly related to the propagation channel properties. Paper I investigates the directional properties of the indoor 60 GHz wireless radio channel based on a set of indoor measurements in a conference room. In the paper, the signal pathways and propagation mechanisms for the strongest paths are identified. The results show that first and second order interactions account for the major contribution of the received power. The results also show that finer structures, such as ceiling lamps, can be significant interacting objects. Paper II presents a cluster-based double-directional channel model for 60 GHz indoor multiple-input multiple-output (MIMO) systems. This paper is a direct continuation of the results in paper I. The model supports arbitrary antenna elements and array configurations and is validated against measurement data. The validation shows that the channel model is able to efficiently reproduce the statistical properties of the measured channels. The presented channel model is also compared with the 60 GHz channel models developed for the industry standards IEEE802.15.3c and IEEE802.11ad. Paper III characterizes the effect of shadowing due to humans and other objects. Measurements of the shadowing gain for human legs, metallic sheets, as well as metallic and plastic cylinders are presented. It is shown that the shadowing gain of these objects are fairly similar and that the shadowing due to the metal cylinder can be determined based on the geometrical theory of diffraction. Next, the shadowing due to a water-filled human body phantom is compared with the shadowing due to real humans. The results show that the water-filled phantom has shadowing properties similar to those of humans and is therefore suitable for use in 60 GHz human body shadowing measurements. Paper IV presents a novel way of estimating the cluster decay and fading. Previously, the cluster decay has usually been determined by performing a simple linear regression, without considering the effects of the noise floor and cluster fading. The paper presents an estimation method which takes these effects into account and jointly estimates both the cluster decay and cluster fading. It is shown that this estimation method can greatly improve the estimated parameters. Paper V evaluates the capacity improvement capability of spatial multiplexing and beamforming techniques for 60 GHz systems in an indoor environment. In this paper, beamforming refers to conventional gain focusing in the direction of the strongest propagation path. The paper uses a capacity metric that only depends on the multi-path richness of the propagation channel and the antenna aperture size. In the paper, it is shown that, when the link budget is limited due to electrically small antennas and long Tx-Rx separation distances, beamforming approximates the capacity of spatial multiplexing. However, spatial multiplexing is a worthwhile option when Rx SNR is favorable and a higher peak data rate is required. Paper VI describes different methods for the clustering of wireless multi-path components. In the literature, the clustering method that is predominantly used is the K-means algorithm, or a power-weighted version of K-means, called K-power means. In this paper, we point out that K-means is a special case of a Gaussian mixture model (GMM). The paper presents a clustering method based on a GMM. This method is able to handle arbitrary cluster spreads in the different dimensions better than the K-means algorithm. A power-weighted version of the GMM is also presented. In addition to this, a mixture model based on asymmetric Laplace distributions is also presented, with and without power-weighting. Paper VII is based on channel measurements in a small and a large room, where the Tx and Rx arrays have dual polarized elements. Using these measurements, the cross-polarization ratio (XPR) of the multi-path components are characterized. This gives valuable information on how the MPCs are affected by the propagation channel. A statistical description of the XPR is also needed for the development of a propagation channel model that supports polarization. The paper also investigates the eigenvalue spreads for single and dual polarized elements. Furthermore, the measurements include LOS and NLOS measurement, where the NLOS scenarios include water-filled human presented in paper III. The results show that the capacity can be greatly improved if dual-polarized elements are used, and that the XPR values are in general higher compared to lower frequencies.
17.	Gustafson, Carl, et al. (författare) Archimedean spiral antenna for underground soil measurements in Greenland 2010 Ingår i: [Host publication title missing]. - 9781424464319 Konferensbidrag (refereegranskat)abstract In this paper, we present a thin single-arm Archimedean spiral antenna designed to be used in underground soil measurements to characterize the dielectric properties of soil during freezing and thawing processes. The designed antenna works in low permittivity, low-loss frozen soil as well as in high permittivity, high-loss marshy soil and operates over the frequency range 1–3 GHz. The antennas has been successfully used for measurements of soil properties in situ.
18.	Gustafson, Carl, et al. (författare) Characterization of 60 GHz Shadowing by Human Bodies and Simple Phantoms 2012 Ingår i: Radioengineering. - 1210-2512. ; 21:4, s. 979-984, s. 473-477 Tidskriftsartikel (refereegranskat)abstract The 60 GHz band is very promising for high data rate (>1 Gb/s) wireless systems operating at short ranges. However, due to the short wavelengths in this frequency band, the shadowing effects cuased by human bodies and furniture are severe and need to be modeled properly. In this paper, we present an experimental, measurement-based characterization of the reflection and shadowing effects in the 60 GHz band caused by human bodies and various phantoms, in order to find simple phantoms suitable for use in human shadowing measurements. It is shown that a waterfilled human phantom serves as a good choice for this purpose.
19.	Gustafson, Carl, et al. (författare) Directional analysis of measured 60 GHz indoor radio channels using SAGE 2011 Ingår i: [Host publication title missing]. - 1550-2252. - 9781424483327 Konferensbidrag (refereegranskat)abstract Abstract in Undetermined Directional properties of the radio channel are of high importance for the development of reliable wireless systems operating in the 60 GHz frequency band. Using transfer functions measured from 61 to 65 GHz in a conference room we have extracted estimates of the multi-path component parameters using the SAGE algorithm. In the paper we compare results for line-of-sight (LOS) scenarios and the corresponding non-line-of-sight (NLOS) scenarios and present values of the direction spread at the Tx and the Rx.
20.	Gustafson, Carl-Johan, et al. (författare) Employing human keratinocytes cultured on macroporous gelatin spheres to treat full thickness-wounds : an in vivo study on athymic rats. 2007 Ingår i: Burns. - : Elsevier BV. - 0305-4179 .- 1879-1409. ; 33:6, s. 726-35 Tidskriftsartikel (refereegranskat)abstract Providing cutaneous wounds with sufficient epidermis to prevent infections and fluid loss is one of the most challenging tasks associated with surgical treatment of burns. Recently, application of cultured keratinocytes in this context has allowed this challenge to be met without several of the limitations connected with the use of split-thickness skin grafts. The continuous development of this novel approach has now revealed that transplantation of cultured autologous keratinocytes as single-cell suspensions exhibits several advantages over the use of cultured epidermal grafts. However, a number of methodological problems remain to be solved, primarily with regards to the complexity of culturing these cells; loss of viability and other negative effects during their preparation and transportation; the relatively long period of time required following transplantation to obtain a sufficiently protective epidermis. In the present investigation we attempted to eliminate these limitations by culturing the keratinocytes on macroporous gelatin spheres. Accordingly, the efficacies of normal human keratinocytes in single-cell suspension or growing on macroporous gelatin spheres, as well as of split-thickness skin grafts in healing wounds on athymic rats were compared. Human keratinocytes were found to adhere and proliferate efficiently both on the surface and within the pores of such spheres. Transplantation of such cells adherent to the spheres resulted in significantly more rapid formation of a stratified epidermis than did transplantation of single-cell suspensions or spheres alone. Twenty-three days after transplantation, the epidermis formed from the cells bound to the spheres was not as thick as the epidermis on wounds covered with split-thickness skin grafts, but significantly thicker than on wounds to which single-cell suspensions, spheres alone or no transplant at all was applied. Furthermore, fluorescence in situ hybridisation revealed that the transplanted keratinocytes, both those adherent to gelatin spheres and those in single-cell suspension, were components of the newly formed epidermis. These findings indicate that application of biodegradable macroporous spheres may prove to be of considerable value in designing cell-based therapies for the treatment of acute and persistent wounds.
21.	Gustafson, Carl-Johan (författare) In vitro and in vivo studies on biodegradable matrices for autotransplantation 2006 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Tissue engineering (TE), one of the most rapidly growing fields of life science, is an interdisciplinary area in which technical, biological and medical expertise co-fertilize on another with the ultimate aim of restoring, maintaining or improving tissues and/or organs. This purpose links TE closely to research concerning reconstructive plastic surgery. At present, TE utilizes two major approaches: I. Autologous cells are cultivated outside the body - in vitro - and returned as autotransplants to the patient; and II. Autologous cells are stimulated to regenerate in the patient - in vivo - usually together with a suitable carrier structure or substances that regulates cell function. This approach is referred to as guided tissue regeneration. With regards to full thickness skin wounds, such as deep burn wounds, the belief today is that optimal treatment must achieve restoration of both the dermal and the epidermal regions of the skin. At present, the treatment considered to be the gold standards for treatment of full thickness wounds only restore the epidermis of the wound, with either split thickness skin grafts or cultured keratinocytes. This thesis focuses on approaches allowing restoration of both the dermis and the epidermis. In order to achieve this, different dermal matrices have been characterised and evaluated. A suitable dermal matrix should fulfil a number of demands: I. It should be biodegradable; II. Epithelial cells should be able to attach to this matrix; III. Epithelial cells should be able to migrate and proliferate on the matrix; IV. The dermal matrix should stimulate regeneration of an autologous neodermis (i.e. ingrowth of fibroblasts and angiogenesis); V. It should be possible to store the matrix for long period of time without loss of function; and VI. Production, use and storage of the matrix should be cost-effective. In Paper I and II cell-free dermis was used as a carrier for epithelial cells cultured in vitro. Cell-free dermis fulfils most of the demands enumerated above, and reliable techniques for the cultivation of both keratinocytes and urothelial cells for autotransplantation were developed. A disadvantage associated with the use cell-free dermis is its limited ability to be maintained as a ready-to-use product, primarily due to the complicated and, to date, costly process of production. In Paper III the possibility to harvest urothelial cells with a non-invasive technique was investigated. The majority of patients suffering from hypospadia are children. To be able to harvest cells for transplantation through bladder-washing, without loss of proliferative capacity would be a great advantage. In search for a more convenient product, a poly urethane urea scaffold (PUUR) was investigated in paper IV. An in vitro study followed by a pilot study - in vivo - on healthy volunteers, revealed that the PUUR scaffold possesses great potential as template for dermal regeneration. Unfortunately, this scaffold is not rapidly degraded in vivo. In paper V the suitability of a three-dimensional system consisting of biodegradable macroporous gelatine spheres as carriers for transplantation of keratinocytes into full-thickness wounds was examined in an in vivo study, involving nude rats. Gelatine is an autologous material and thus, biodegradable and the small size of the spheres allow them to be injected with a syringe at location where they are needed. In addition, the pores greatly increase the number of keratinocytes that can be cultured on these spheres. In comparison to treatment with cultured keratinocytes in single-cell solution, macroporous gelatine spheres coated with keratinocytes promoted an earlier wound closure and better skin quality. Accordingly, such spheres represent a highly promising and interesting matrix for dermal regeneration and for co-cultivation with epithelial cells.
22.	Gustafson, Carl, et al. (författare) Modeling the cluster decay in mm-wave channels 2014 Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014. - 9788890701849 ; , s. 803-807 Konferensbidrag (refereegranskat)abstract © 2014 European Association on Antennas and Propagation.The cluster power is an important parameter for cluster-based wireless channel models. This paper addresses modeling and estimation of the cluster power for wireless channels. A novel way of estimating the cluster decay and cluster fading, where the effects of the noise floor is taken into account, is presented. Due to the noise floor present in the measurement, only a limited number of clusters are available when estimating the cluster decay. It is shown that the estimated cluster decay and cluster fading can be improved if the effects of the noise floor and cluster fading are modeled and taken into account in the estimation step. If the noise floor is not taken into account in the estimation of the cluster decay, the resulting model can overestimate the RMS delay spread. Further, the paper includes estimates of the cluster decay and fading based on measured clusters for an indoor wireless mm-Wave channel in a conference room environment.
23.	Gustafson, Carl, et al. (författare) Modeling the Polarimetric mm-wave Propagation Channel using Censored Measurements 2016 Ingår i: Proceedings - IEEE Global Communications Conference, GLOBECOM. - 2334-0983 .- 2576-6813. - 9781509013289 ; , s. Article number 7842003- Konferensbidrag (refereegranskat)abstract This paper presents results based on polarimetric radio channel measurements at 60 GHz in a small room and in an empty, unfurnished, medium-sized room. The measurements in the small meeting room were performed using dual-polarized virtual antenna array elements at both the transmitter and receiver sides and includes LOS and NLOS scenarios. In the unfurnished room, a directional horn antenna was scanned in the azimuth plane and the Rx antenna was an omnidirectional antenna. Based on these measurements, the paper presents experimental parameter estimates for a novel model of the polarimetric propagation paths, that includes the power-decay as well as a correlated fading for the different polarization components. This work also includes an estimation method that takes measurement limitations caused by the noise floor and the limited cross-polarization discrimination of the antennas into account using censored samples.
24.	Gustafson, Carl, et al. (författare) On mm-Wave Multi-path Clustering and Channel Modeling 2014 Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X. ; 62:3, s. 1445-1455 Tidskriftsartikel (refereegranskat)abstract Efficient and realistic mm-wave channel models are of vital importance for the development of novel mm-wave wireless technologies. Though many of the current 60 GHz channel models are based on the useful concept of multi-path clusters, only a limited number of 60 GHz channel measurements have been reported in the literature for this purpose. Therefore, there is still a need for further measurement based analyses of multi-path clustering in the 60 GHz band. This paper presents clustering results for a double-directional 60 GHz MIMO channel model. Based on these results, we derive a model which is validated with measured data. Statistical cluster parameters are evaluated and compared with existing channel models. It is shown that the cluster angular characteristics are closely related to the room geometry and environment, making it infeasible to model the delay and angular domains independently. We also show that when using ray tracing to model the channel, it is insufficient to only consider walls, ceiling, floor and tables; finer structures such as ceiling lamps, chairs and bookshelves need to be taken into account as well.
25.	Gustafson, Carl, et al. (författare) Statistical Modeling and Estimation of Censored Pathloss Data 2015 Ingår i: IEEE Wireless Communications Letters. - 2162-2337 .- 2162-2345. ; 4:5, s. 569-572 Tidskriftsartikel (refereegranskat)abstract Pathloss is typically modeled using a log-distance power law with a large-scale fading term that is log-normal. However, the received signal is affected by the dynamic range and noise floor of the measurement system used to sound the channel, which can cause measurement samples to be truncated or censored. If the information about the censored samples is not included in the estimation method, as in ordinary least squares estimation, it can result in biased estimation of both the pathloss exponent and the large scale fading. This can be solved by applying a Tobit maximum-likelihood estimator, which provides consistent estimates for the pathloss parameters. This letter provides information about the Tobit maximum-likelihood estimator and its asymptotic variance under certain conditions.
26.	Gustafson, Carl, et al. (författare) The COST IRACON Geometry-Based Stochastic Channel Model for Vehicle-to-Vehicle Communication in Intersections 2020 Ingår i: IEEE Transactions on Vehicular Technology. - 0018-9545. ; 69:3, s. 2365-2375 Tidskriftsartikel (refereegranskat)abstract Vehicle-to-vehicle (V2V) wireless communications can improve traffic safety at road intersections and enable congestion avoidance. However, detailed knowledge about the wireless propagation channel is needed for the development and realistic assessment of V2V communication systems. We present a novel geometry-based stochastic MIMO channel model with support for frequencies in the band of 5.2-6.2 GHz. The model is based on extensive high-resolution measurements at different road intersections in the city of Berlin, Germany. We extend existing models, by including the effects of various obstructions, higher order interactions, and by introducing an angular gain function for the scatterers. Scatterer locations have been identified and mapped to measured multi-path trajectories using a measurement-based ray tracing method and a subsequent RANSAC algorithm. The developed model is parameterized, and using the measured propagation paths that have been mapped to scatterer locations, model parameters are estimated. The time variant power fading of individual multi-path components is found to be best modeled by a Gamma process with an exponential autocorrelation. The path coherence distance is estimated to be in the range of 0-2 m. The model is also validated against measurement data, showing that the developed model accurately captures the behavior of the measured channel gain, Doppler spread, and delay spread. This is also the case for intersections that have not been used when estimating model parameters.
27.	Gustafson, Carl, et al. (författare) Tobit Maximum-likelihood estimation of Censored Pathloss Data 2015 Rapport (övrigt vetenskapligt/konstnärligt)abstract Pathloss is typically modeled using a log-distance power law with a large-scale fading term that is log-normal. However, the received signal is affected by the dynamic range and noise floor of the measurement system used to sound the channel, which can cause measurement samples to be truncated or censored. If the information about the censored samples are not included in the estimation method, as in ordinary least squares estimation, it can result in biased estimation of both the pathloss exponent and the large scale fading. This is solved by applying a Tobit maximum-likelihood estimator, which provides consistent estimates for the pathloss parameters. This technical report provides information about the Tobit maximum-likelihood estimator estimator and its asymptotic variance under certain conditions.
28.	Haneda, Katsuyuki, et al. (författare) 60 GHz Spatial Radio Transmission: Multiplexing or Beamforming? 2013 Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X. ; 61:11, s. 5735-5743 Tidskriftsartikel (refereegranskat)abstract This paper compares the capacity improvement capability of spatial multiplexing and beamforming techniques for 60 GHz spatial transmissions in a multi-carrier radio system such as orthogonal frequency division multiplexing. The term beamforming in this paper refers to the conventional gain focusing, for the strongest propagation path, by narrow antenna beams. Our channel capacity metric depends only on the multipath richness of the propagation channel and the antenna aperture size, but is otherwise independent of the realization of antenna elements on the aperture. Our analysis also reveals the spatial degrees-of-freedom (SDoF) of the radio channel, which is the maximum number of antenna elements on the aperture for efficient spatial multiplexing. We evaluate the capacity and SDoF of single-polarized 60 GHz radio channels measured in a conference room environment. Our results show that the radio channel offers multiple SDoFs both in line-of-sight (LOS) and non-LOS (NLOS) scenarios such that spatial multiplexing can improve the channel capacity, provided that the receive signal-to-noise ratio (SNR) is sufficiently high to utilize them. Under 10 dBm of the transmit power, the high receive SNR is guaranteed when the antenna aperture size is larger than 12 in LOS and 92 in NLOS scenarios, respectively.
29.	Haneda, Katsuyuki, et al. (författare) Spatial Degrees-of-Freedom of 60 GHz Multiple-Antenna Channels 2013 Ingår i: [Host publication title missing]. - 1550-2252. Konferensbidrag (refereegranskat)abstract This paper studies the potential of spatial multiplexing for measured 60 GHz radio channels by estimating the number of eigenchannels. It is well-known that the number of available eigenchannels is dependent on a propagation channel condition as well as antenna array conguration. We evaluate a spatial degrees- of-freedom (SDoF) metric that depends on the propagation conditions and the antenna aperture size, but is otherwise independent of the realization of antenna elements on the aperture. The SDoF metric is a measure of the effective number of antenna elements for spatial multiplexing. We evaluate the SDoF for 60 GHz multiple-input multiple-output channels measured in a conference room environment under a line-of- sight (LOS) condition. Our analysis reveals that the SDoF is more than one for a transmit- receive antenna separation of more than 2 m, which indicates that spatial multiplexing can work in such LOS scenarios. Our results indicate that using only 10 antenna elements at each of the transmit and receive antenna aperture is sufficient for effective spatial multiplexing performance in the considered propagation scenario. Furthermore, by using just 5 antennas at each aperture, eigenchannels down to −15 dB relative magnitude can still be captured.
30.	Hornsten, Carl, et al. (författare) The prevalence of stroke and the association between stroke and depression among a very old population 2012 Ingår i: Archives of gerontology and geriatrics (Print). - : Elsevier BV. - 0167-4943 .- 1872-6976. ; 55:3, s. 555-559 Tidskriftsartikel (refereegranskat)abstract There are few studies comparing those who have had and have not had a stroke among those aged 80 years and over, the very old. The aim of this paper was to investigate the prevalence of stroke and the association between stroke and depression in a very old population. This paper is based on cross-sectional data from a population-based study performed between 2005 and 2007. Half of those aged 85 years, all 90-, and 95-year-olds and older in eight urban and rural municipalities in northern Sweden and Finland were invited to participate. A sample of 601 individuals who participated fully in the study was selected. Data were collected through assessments, structured interviews and investigation of medical charts. A specialist in geriatric medicine determined disease status for depression based on medical records and results from the Geriatric Depression Scale (GDS)-15, the Montgomery A Asberg Depression Rating Scale (MADRS) and the Organic Brain Syndrome (OBS) scale, and for stroke based on medical records and reported disease. The prevalence of stroke was 21.5%. The prevalence of depression was 50.4% among those with stroke compared to 34.3% among those without stroke (OR 1.944, p < 0.001). In a logistic regression model adjusted for several demographic variables, diseases and functional level, stroke was independently associated with depression (OR 1.644, p = 0.038). A large proportion of those with depression, both with and without stroke, were not receiving antidepressant medication. In conclusion, the stroke prevalence was high and stroke showed a strong association with depression among very old people. (c) 2012 Elsevier Ireland Ltd. All rights reserved.
31.	Huss, Fredrik, 1971-, et al. (författare) Characterisation of a new degradable polymer scaffold for regeneration of the dermis : In vitro and in vivo human studies 2008 Ingår i: Organogenesis. - 1547-6278. ; 4:3, s. 195-200 Tidskriftsartikel (refereegranskat)abstract Full thickness skin wounds in humans heal with scars, but without regeneration of the dermis. A degradable poly(urethane urea) scaffold (PUUR), Artelon® is already used to reinforce soft tissues in orthopaedics, and for treatment of osteoarthritis of the hand, wrist and foot. In this paper we have done in vitro experiments followed by in vivo studies to find out whether the PUUR is biocompatible and usable as a template for dermal regeneration. Human dermal fibroblasts were cultured on discs of PUUR, with different macrostructures (fibrous and porous). They adhered to and migrated into the scaffolds, and produced collagen. The porous scaffold was judged more suitable for clinical applications and 4 mm Ø, 2 mm-thick discs of porous scaffold (12% w/w or 9% w/w polymer solution) were inserted intradermally in four healthy human volunteers. The implants were well tolerated and increasing ingrowth of fibroblasts was seen over time in all subjects. The fibroblasts stained immunohistochemically for procollagen and von Willebrand factor, indicating neocollagenesis and angiogenesis within the scaffolds. The PUUR scaffold may be a suitable material to use as a template for dermal regeneration. ©2008 Landes Bioscience.
32.	Huss, Fredrik R.M., et al. (författare) New degradable polymer scaffold for regeneration of the dermis In vitro and in vivo studies Annan publikation (övrigt vetenskapligt/konstnärligt)
33.	Hörnsten, Carl, et al. (författare) High blood pressure as a risk factor for incident stroke among very old people : a population-based cohort study 2016 Ingår i: Journal of Hypertension. - 0263-6352 .- 1473-5598. ; 34:10, s. 2059-2065 Tidskriftsartikel (refereegranskat)abstract INTRODUCTION: High blood pressure (BP) increases the risk of stroke, but there is limited evidence from studies including very old people. The aim was to investigate risk factors for incident stroke among very old people.METHODS: A prospective population-based cohort study was performed among participants aged at least 85 years in northern Sweden. The 955 participants were tested at their homes. BP was measured manually after 5-min supine rest. Incident stroke data were collected from medical charts guided by hospital registry, death records, and 5-year reassessments. Cox proportional hazards models were used.RESULTS: The stroke incidence was 33.8/1000 person-years (94 stroke events) during a mean follow-up period of 2.9 years. In a comprehensive multivariate model, atrial fibrillation [hazard ratio 1.85, 95% confidence interval (CI) 1.07-3.19] and higher SBP (hazard ratio 1.19, 95% CI 1.08-1.30 per 10-mmHg increase) were associated with incident stroke overall. However, higher SBP was not associated with incident stroke in participants with SBP less than 140 mmHg (hazard ratio 0.90, 95% CI 0.53-1.53 per 10-mmHg increase). In additional multivariate models, DBP at least 90 mmHg (hazard ratio 2.45, 95% CI 1.47-4.08) and SBP at least 160 mmHg (vs. <140 mmHg; hazard ratio 2.80, 95% CI 1.53-5.14) were associated with incident stroke. The association between BP and incident stroke was not affected by interactions related to sex, dependence in activities of daily living, or cognitive impairment.CONCLUSION: High SBP (≥160 mmHg) and DBP (≥90 mmHg) and atrial fibrillation appeared to be risk factors for incident stroke among very old people.
34.	Hörnsten, Carl, et al. (författare) High blood pressure as a risk factor for incident stroke among very old people: a population-based cohort study Annan publikation (övrigt vetenskapligt/konstnärligt)
35.	Hörnsten, Carl, et al. (författare) Measurement error of the Mini-Mental State Examination among individuals with dementia that reside in nursing homes 2021 Ingår i: European Journal of Ageing. - : Springer. - 1613-9372 .- 1613-9380. ; 18:1, s. 109-115 Tidskriftsartikel (refereegranskat)abstract Few studies have investigated the measurement error of the Mini-Mental State Examination (MMSE) in the same unit of measurement, also known as absolute reliability. This measurement can help determine whether an observed score change for an individual is likely to represent true change. The aim of this study was to investigate the absolute reliability of the MMSE among individuals with dementia that reside in nursing homes. Among 88 participants, 19 (21.6%) were men, 35 (39.8%) had Alzheimer's disease, 35 (39.8%) had vascular dementia, and the mean age was 84.0 years (range 65-98). The participants were tested and retested with the MMSE within 1-6 days. Both tests were administered by the same assessor at the same time of day. The mean MMSE score was 13.7 (range 0-28). The absolute difference between MMSE scores varied from 0 to 6 points, and the differences did not correlate with the corresponding score means (p = 0.874). The smallest detectable change (SDC) between two measurements was 4.00. The SDC was independent of depression, impaired vision and hearing, delirium within the last week, dementia type and age. However, the SDC was 5.56 among men and 3.50 among women (p = 0.003). In conclusion, for individuals with dementia that reside in nursing homes, it seems like their MMSE score needs to change by four or more points between two measurements in order for their score change to be reliably higher than the measurement error.
36.	Hörnsten, Carl, 1985- (författare) Stroke and depression in very old age 2016 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Background The prevalence and incidence of stroke are known to increase with age, which, combined with demographic change, means that very old patients with stroke are a growing patient group. Risk factors for incident stroke among very old people have not been widely investigated. The impact of depression on mortality in very old people who have had a stroke also remains unclear. The aim of this thesis was to investigate the risk factors for incident stroke, the epidemiology of stroke and depression, and the consequences of having had a stroke regarding the risk of depression and mortality among very old people.Methods A randomly selected half of 85-, all 90-, and all ≥95-year-olds in certain municipalities in Västerbotten County, Sweden, and Pohjanmaa County, Finland were targeted in a population-based cohort study from 2000-2012. The 65-, 70-, 75-, and 80-year-olds in all the rural and random samples from the urban municipalities in the same counties were furthermore targeted in a survey in 2010.In the cohort study patients were assessed in their homes, by means of the 15-item Geriatric Depression Scale (GDS-15) and other assessment scales, as well as blood pressure measurements, several physical tests, and a review of medical diagnoses appearing in the medical charts. Incident stroke data were collected from medical charts guided by hospital registry records, cause of death records, and reassessments after 5 years. Depression was defined as a GDS-15 score ≥5. A clinical definition of all depressive disorders, based on assessment scale scores and review of medical charts was also used. A specialist in geriatric medicine evaluated the diagnoses. The survey included yes/no questions about stroke and depression status, and the 4-item Geriatric Depression Scale. Associations with mortality and incident stroke were tested using Cox proportional-hazard models. Results In the ≥85-year-olds examined in 2005-2007 (n=601), the stroke prevalence was 21.5%, the prevalence of all depressive disorders was 37.8% and stroke was independently associated with depressive disorders (odds ratio 1.644, p=0.038). The prevalence of depression according to GDS-15 scores was 43.2% in people with stroke compared with 25.0% in people without stroke (p=0.001). However, in ≥85-year-olds examined in Sweden from 2000-2012 (n=955), from all past data collections in the study, depression was not independently associated with incident stroke. In ≥65-year-olds who responded to a survey in 2010 (n=6098), the stroke prevalence rose with age from 4.7% among the 65- to 11.6% among the 80-year-olds (p<0.001). The prevalence of depression rose from 11.0% among the 65- to 18.1% among the 80-year-olds (p<0.001). In the group with stroke, depression was independently associated with dependence in personal activities of daily living and having a life crisis the preceding year, while in the non-stroke group, depression was independently associated with several additional demographic, social and health factors.In ≥85-year-olds examined in 2005-2007 with valid GDS-15 tests (n=452), having had a stroke was associated with increased 5-year mortality [hazard ratio (HR) 1.53, 95% confidence interval (CI) 1.15-2.03]. Having had a stroke and depression was associated with increased 5-year mortality compared with having only stroke (HR 1.90, 95% CI 1.15-3.13), having only depression (HR 1.59, 95% CI 1.03-2.45), and compared with having neither stroke nor depression (HR 2.50, 95% CI 1.69-3.69). Having only stroke without a depression did not increase mortality compared with having neither stroke nor depression.In ≥85-year-olds examined in Sweden from 2000-2012 (n=955), from all past data collections in the study, the stroke incidence was 33.8/1000 person-years during a mean follow-up period of about three years. In a comprehensive multivariate model, atrial fibrillation (HR 1.85, 95% CI 1.07–3.19) and higher systolic blood pressure (SBP; HR 1.19, 95% CI 1.08–1.30 per 10-mmHg increase) were associated with incident stroke overall. In additional multivariate models, diastolic blood pressure (DBP) ≥90 mmHg (HR 2.45, 95% CI 1.47–4.08) and SBP ≥160 mmHg (v. <140 mmHg; HR 2.80, 95% CI 1.53–5.14) were associated with incident stroke.Conclusion The prevalence of both stroke and depression increased with age, and rates were especially high among very old people. Having had a stroke was independently associated with a higher prevalence of depression among very old people, however, depression was not independently associated with a higher incidence of stroke. Having had a stroke was associated with increased all-cause mortality among very old people, but only among those who were also depressed. High SBP (≥160 mmHg), DBP (≥90 mmHg) and atrial fibrillation were the only consistent independent risk factors for incident stroke among very old people.
37.	Hörnsten, Carl, et al. (författare) The association between stroke, depression, and 5-year mortality among very old people 2013 Ingår i: Stroke. - : Lippincott Williams & Wilkins. - 0039-2499 .- 1524-4628. ; 44:9, s. 2587-2589 Tidskriftsartikel (refereegranskat)abstract Background and Purpose: Depression after stroke has been associated with increased mortality, but little is known about this association among very old people.Methods: A population-based study among people ≥85 years of age was conducted in northern Sweden and Finland, comprising cross-sectional assessments and subsequent survival data. The 452 individuals who had completed the Geriatric Depression Scale-15 assessment were selected. Depression was defined as a score of ≥5 on the geriatric depression scale.Results: Of those with a history of stroke, 38 of 88 (43.2%) people were depressed, and 11 of the 38 (28.9%) were treated with antidepressants, compared with 91 of 364 (25.0%) depressed (P=0.001) and 17 of 91 (18.7%) treated with antidepressants among those without stroke. Having a history of stroke and ongoing depression was associated with increased 5-year mortality compared with having only stroke (hazard ratio, 1.90; confidence interval, 1.15–3.13), having only depression (hazard ratio, 1.59; confidence interval, 1.03–2.45), and compared with having neither stroke nor depression (hazard ratio, 2.50; confidence interval, 1.69–3.69). Having only stroke without depression did not increase mortality compared with having neither stroke nor depression.Conclusions: A history of stroke was associated with increased mortality among very old people but only among those who were also depressed. Depression seemed to be underdiagnosed and undertreated.
38.	Hörnsten, Carl, et al. (författare) The prevalence of stroke and depression and factors associated with depression in elderly people with and without stroke 2016 Ingår i: BMC Geriatrics. - : BioMed Central. - 1471-2318. ; 16 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract Background: Few studies have investigated factors associated with depression among elderly people with and without stroke concurrently, using identical settings, procedures and study variables. The aim was to investigate the prevalence of stroke and depression and to compare the factors associated with depression in people with and without stroke. Methods: A postal mail survey was sent to 65-, 70-, 75- and 80-year-olds in northern Sweden and Finland in 2010 (n = 6098). Stroke was defined as answering "yes" to the question "Have you had a stroke?" Depression was defined as answering "yes" to the question "Are you depressed?" or having a Geriatric Depression Scale-4 score >= 2. Dependence in personal activities of daily living was defined as not showering without human assistance. Associations were tested with log-binomial regression. Results: The overall stroke prevalence was 7.0 +/- 0.3 % and increased from 4.7 +/- 0.4 % among 65-year-olds to 11.6 +/- 1.0 % among 80-year-olds (p < 0.001). The overall depression prevalence was 12.8 +/- 0.4 % and increased from 11.0 +/- 0.6 % among 65-year-olds to 18.1 +/- 1.2 % among 80-year-olds (p < 0.001). Depression was more common among people with stroke (Prevalence Ratio 1.77, 95 % Confidence Interval 1.48-2.12). In the non-stroke group, depression was independently associated with diabetes, dependence in instrumental activities of daily living, living alone, not having someone to talk to, poor finances, pain problems and having a life crisis in the preceding year. In the group with stroke, depression was independently associated with dependence in personal activities of daily living and having a life crisis the preceding year. Conclusions: Depression in people without stroke appeared to be independently associated with a broader range of external factors than depression in people with stroke.
39.	Imsland, Freyja, et al. (författare) Regulatory mutations in TBX3 disrupt asymmetric hair pigmentation underlying Dun camouflage colour in horses 2016 Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 48:2, s. 152-158 Tidskriftsartikel (refereegranskat)abstract Dun is a wild-type coat color in horses characterized by pigment dilution with a striking pattern of dark areas termed primitive markings. Here we show that pigment dilution in Dun horses is due to radially asymmetric deposition of pigment in the growing hair caused by localized expression of the T-box 3 (TBX3) transcription factor in hair follicles, which in turn determines the distribution of hair follicle melanocytes. Most domestic horses are non-dun, a more intensely pigmented phenotype caused by regulatory mutations impairing TBX3 expression in the hair follicle, resulting in a more circumferential distribution of melanocytes and pigment granules in individual hairs. We identified two different alleles (non-dun1 and non-dun2) causing non-dun color. non-dun2 is a recently derived allele, whereas the Dun and non-dun1 alleles are found in ancient horse DNA, demonstrating that this polymorphism predates horse domestication. These findings uncover a new developmental role for T-box genes and new aspects of hair follicle biology and pigmentation.
40.	Johnsson, Martin, et al. (författare) A sexual ornament in chickens is affected by pleiotropic alleles at HAO1 and BMP2, selected during domestication. 2012 Ingår i: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404 .- 1553-7390. ; 8:8 Tidskriftsartikel (refereegranskat)abstract Domestication is one of the strongest forms of short-term, directional selection. Although selection is typically only exerted on one or a few target traits, domestication can lead to numerous changes in many seemingly unrelated phenotypes. It is unknown whether such correlated responses are due to pleiotropy or linkage between separate genetic architectures. Using three separate intercrosses between wild and domestic chickens, a locus affecting comb mass (a sexual ornament in the chicken) and several fitness traits (primarily medullary bone allocation and fecundity) was identified. This locus contains two tightly-linked genes, BMP2 and HAO1, which together produce the range of pleiotropic effects seen. This study demonstrates the importance of pleiotropy (or extremely close linkage) in domestication. The nature of this pleiotropy also provides insights into how this sexual ornament could be maintained in wild populations.
41.	Johnzon, Carl-Fredrik, et al. (författare) The Effect of Lipopolysaccharide-Induced Experimental Bovine Mastitis on Clinical Parameters, Inflammatory Markers, and the Metabolome : A Kinetic Approach 2018 Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 9 Tidskriftsartikel (refereegranskat)abstract Mastitis is an inflammatory condition of the mammary tissue and represents a major problem for the dairy industry worldwide. The present study was undertaken to study how experimentally induced acute bovine mastitis affects inflammatory parameters and changes in the metabolome. To this end, we induced experimental mastitis in nine cows by intramammary infusion of 100 pg purified Escherichia call lipopolysaccharide (LPS) followed by kinetic assessments of cytokine responses (by enzyme-linked immunosorbent assay), changes in the metabolome (assessed by nuclear magnetic resonance), clinical parameters (heat, local pain perception, redness, swelling, rectal temperature, clot formation, and color changes in the milk), and milk somatic cell counts, at several time points post LPS infusion. Intramammary LPS infusion induced clinical signs of mastitis, which started from 2 h post infusion and had returned to normal levels within 24-72 h. Milk changes were seen with a delay compared with the clinical signs and persisted for a longer time. In parallel, induction of IL-6 and TNF-alpha were seen in milk, and there was also a transient elevation of plasma IL-6 whereas plasma TNF-alpha was not significantly elevated. In addition, a robust increase in CCL2 was seen in the milk of LPS-infused cows, whereas G-CSF, CXCL1, and histamine in milk were unaffected. By using a metabolomics approach, a transient increase of plasma lactose was seen in LPS-induced cows. In plasma, significant reductions in ketone bodies (3-hydroxybutyrate and acetoacetate) and decreased levels of short-chain fatty acids, known to be major products released from the gut microbiota, were observed after LPS infusion; a profound reduction of plasma citrate was also seen. Intramammary LPS infusion also caused major changes in the milk metabolome, although with a delay in comparison with plasma, including a reduction of lactose. We conclude that the LPS-induced acute mastitis rapidly affects the plasma metabolome and cytokine induction with similar kinetics as the development of the clinical signs, whereas the corresponding effects in milk occurred with a delay.
42.	Karttunen, Aki, et al. (författare) Censored Multipath Component Cross-Polarization Ratio Modeling 2017 Ingår i: IEEE Wireless Communications Letters. - 2162-2337. ; 6:1, s. 82-85 Tidskriftsartikel (refereegranskat)abstract In wireless channel measurements, the relatively weak cross-polarized multipath components (MPCs) are typically severely affected by the measurement noise level. As shown in this letter, the typical cross-polarization ratio (XPR) model parameter estimation, which ignores the existence of censored samples, may lead to significant errors. We demonstrate how to achieve accurate parameter estimates with a maximum likelihood estimator that properly takes into account both the measured XPRs and the censored samples. Also, a new XPR model is presented in which the average XPR is modeled as a function of the MPC excess loss. The new model is shown to be insensitive to the channel measurement noise level. A practical example with measured data in an indoor environment at 60 GHz demonstrates the utility of the approach.
43.	Karttunen, Aki, et al. (författare) Path loss models with distance-dependent weighted fitting and estimation of censored path loss data 2016 Ingår i: IET Microwaves, Antennas and Propagation. - : Institution of Engineering and Technology (IET). - 1751-8725 .- 1751-8733. ; 10:14, s. 1467-1474 Tidskriftsartikel (refereegranskat)abstract Path loss models are the most fundamental part of wireless propagation channel models. Path loss is typically modelled as a (single-slope or multi-slope) power-law dependency on distance plus a log-normally distributed shadowing attenuation. Determination of the parameters of this model is usually done by fitting the model to results from measurements or ray tracing. The authors show that the typical least-square fitting to those data points is inherently biased to give the best fitting to the link distances that happen to have more evaluation points. A weighted fitting method is developed that emphasises the accuracy at the distance range that is consciously chosen by the user as most important for a system simulation. As a further important point that is typically not taken into account for path loss parameter extraction, the authors show that typically measurement data (but also ray tracing) is censored, i.e. path loss values above a certain threshold cannot be measured. The authors present examples of weighted fitting models, and models with and without the censored data, for 28 GHz channels in urban macrocells, and show that these effects have a significant impact on the extracted parameters and that the fitting accuracy can be improved with the presented methods.
44.	Li, Xuhong, et al. (författare) Robust Phase-Based Positioning Using Massive MIMO with Limited Bandwidth 2018 Ingår i: 28th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2017.. - 9781538635292 - 9781538635322 Konferensbidrag (refereegranskat)abstract This paper presents a robust phase-based positioningframework using a massive multiple-input multiple-output(MIMO) system. The phase-based distance estimates of MPCstogether with other parameters are tracked with an ExtendedKalman Filter (EKF), the state dimension of which varies withthe birth-death processes of paths. The iterative maximumlikelihoodestimation algorithm (RIMAX) and the modeling ofdense multipath component (DMC) in the framework furtherenhance the quality of parameter tracking by providing anaccurate initial state and the underlying noise covariance.The tracked MPCs are fed into a time-of-arrival (TOA) selfcalibrationpositioning algorithm for simultaneous trajectoryand environment estimation. Throughout the positioning process,no prior knowledge of the surrounding environment andbase station position is needed. The performance is evaluatedwith the measurement of a 2D complex movement, which wasperformed in a sports hall with an antenna array with 128 portsas base station using a standard cellular bandwidth of 40 MHz.The positioning result shows that the mean deviation of theestimated user equipment trajectory from the ground truth is13 cm. In summary, the proposed framework is a promisinghigh-resolution radio-based positioning solution for current andnext generation cellular systems.
45.	Liao, Qingbi, et al. (författare) Channel Capacity Analysis of Different Mobile Antenna Array Topologies in the Outdoor Urban Environment for 5G mm Wave System 2017 Ingår i: 2017 IEEE Antennas and Propagation Society International Symposium, Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538632840 ; , s. 1473-1474 Konferensbidrag (refereegranskat)abstract The 15 and 28 GHz frequency bands have been identified as interesting candidates for future 5G cellular communication systems. In this paper, based on ray-tracing simulations, we investigate the channel capacities at 15 and 28 GHz for a number of different array processing techniques, including beamforming, spatial multiplexing, and two types of hybrid beamforming. This is done for an 8 x 32 multiple input multiple output system, for the single user case. The hybrid beamforming techniques combines the beamforming and spatial multiplexing techniques, in order to reduce the number of analog-to-digital converters and thereby reducing the system complexity, while still maintaining multiplexing capabilities for improved system capacities. The achieved channel capacities the hybrid beamforming techniques with up to four parallel streams outperforms pure beamforming, but does not reach capacities close to that of full spatial multiplexing. This indicates that the outdoor channel can support multiplexing of more than four parallel data streams to a single user.
46.	Liao, Qingbi, et al. (författare) Simulations and Measurements of 15 and 28 GHz Indoor Channels with Different Array Configurations 2017 Ingår i: 2017 INTERNATIONAL WORKSHOP ON ANTENNA TECHNOLOGY. - : IEEE. - 9781509051779 ; , s. 256-259 Konferensbidrag (refereegranskat)abstract There are many different frequency bands above 6 GHz and into the mm-wave range above 30 GHz that are possible candidates for use in future 5G cellular systems. In this paper, we present some results for wireless channels at 15 and 28 GHz in an indoor scenario. The results are based on both measurements and ray tracing simulations. Basic comparisons of measured and simulated power-delay profiles, angle of departure and received power are presented to give an insight to the possibilities and limitations of utilizing ray tracing to characterize the indoor wireless channel at 15 and 28 GHz. We show that it is important to consider human body shadowing as well as finer structures and details in the ray tracing environment model in order to achieve reasonable results. Lastly, we also perform ray tracing simulations to assess the performance of a number of different array signal processing techniques, including beamforming, hybrid beamforming and spatial multiplexing.
47.	Llano-Diez, Monica, et al. (författare) Muscle wasting and the temporal gene expression pattern in a novel rat intensive care unit model 2011 Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 12, s. 602- Tidskriftsartikel (refereegranskat)abstract BACKGROUND: Acute quadriplegic myopathy (AQM) or critical illness myopathy (CIM) is frequently observed in intensive care unit (ICU) patients. To elucidate duration-dependent effects of the ICU intervention on molecular and functional networks that control the muscle wasting and weakness associated with AQM, a gene expression profile was analyzed at time points varying from 6 hours to 14 days in a unique experimental rat model mimicking ICU conditions, i.e., post-synaptically paralyzed, mechanically ventilated and extensively monitored animals. RESULTS: During the observation period, 1583 genes were significantly up- or down-regulated by factors of two or greater. A significant temporal gene expression pattern was constructed at short (6h-4 days), intermediate (5-8 days) and long (9-14 days) durations. A striking early and maintained up-regulation (6h-14d) of muscle atrogenes (muscle ring-finger 1/tripartite motif-containing 63 and F-box protein 32/atrogin-1) was observed, followed by an upregulation of the proteolytic systems at intermediate and long durations (5-14d). Oxidative stress response genes and genes that take part in amino acid catabolism, cell cycle arrest, apoptosis, muscle development, and protein synthesis together with myogenic factors were significantly up-regulated from 5 to 14 days. At 9-14 d, genes involved in immune response and the caspase cascade were up-regulated. At 5-14d, genes related to contractile (myosin heavy chain and myosin binding protein C), regulatory (troponin, tropomyosin), developmental, caveolin-3, extracellular matrix, glycolysis/gluconeogenesis, cytoskeleton/sarcomere regulation and mitochondrial proteins were down-regulated. An activation of genes related to muscle growth and new muscle fiber formation (increase of 3 myogenic factors and JunB and down-regulation of myostatin) and up-regulation of genes that code protein synthesis and translation factors were found from 5 to 14 days. CONCLUSIONS: Novel temporal patterns of gene expression have been uncovered, suggesting a unique, coordinated and highly complex mechanism underlying the muscle wasting associated with AQM in ICU patients and providing new target genes and avenues for intervention studies.
48.	Martínez Barrio, Álvaro, et al. (författare) The genetic basis for ecological adaptation of the Atlantic herring revealed by genome sequencing 2016 Ingår i: eLIFE. - 2050-084X. ; 5 Tidskriftsartikel (refereegranskat)abstract Ecological adaptation is of major relevance to speciation and sustainable population management, but the underlying genetic factors are typically hard to study in natural populations due to genetic differentiation caused by natural selection being confounded with genetic drift in subdivided populations. Here, we use whole genome population sequencing of Atlantic and Baltic herring to reveal the underlying genetic architecture at an unprecedented detailed resolution for both adaptation to a new niche environment and timing of reproduction. We identify almost 500 independent loci associated with a recent niche expansion from marine (Atlantic Ocean) to brackish waters (Baltic Sea), and more than 100 independent loci showing genetic differentiation between spring- and autumn-spawning populations irrespective of geographic origin. Our results show that both coding and non-coding changes contribute to adaptation. Haplotype blocks, often spanning multiple genes and maintained by selection, are associated with genetic differentiation.
49.	Nelson, Christian, et al. (författare) Geometry Based Channel Models with Cross- and Autocorrelation for Vehicular Network Simulations 2018 Ingår i: 2018 IEEE 87th Vehicular Technology Conference (VTC Spring). - Piscataway, NJ : IEEE. - 2577-2465. - 9781538663554 - 9781538663547 - 9781538663561 Konferensbidrag (refereegranskat)abstract Realistic network simulations are necessary to assess the performance of any communication system. In this paper, we describe an implementation of a channel model for vehicle-to-vehicle (V2V) communication in the OMNeT++/Plexe simulation environment. The model is based on previous extensive measurements in a V2V multilink highway scenario and cover line-of-sight (LOS) as well as obstructed LOS (OLOS) scenarios, which occurs when one or more vehicles obstruct the LOS component. The implementation captures both the temporal autocorrelation and the joint multilink cross-correlation processes to achieve a realistic behavior. Preliminary results show that the implementation now generates stochastic large-scale fading with an autocorrelation function that agrees well with measured data. A representation of the cross-correlation process is now implemented through proper channel model selection since the geometry and location of objects are known in Plexe. We also show the impact of the suggested V2V physical layer (PHY) on the performance evaluation results observed at the facilities layer. As a metric, we use the data age, which is a measure how old the information about a vehicle is. When considering the autocorrelation in simulations, the experienced data-age increases. Examples show an increase of the 10% percentile data-age from 0.1s to 1.5s, which may affect the application performance significantly in critical situations. © 2018 IEEE.
50.	Niklasson, Johan, et al. (författare) High morale is associated with increased survival in the very old 2015 Ingår i: Age and Ageing. - : Oxford University Press (OUP). - 0002-0729 .- 1468-2834. ; 44:4, s. 630-636 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: high morale is defined as future-oriented optimism. Previous research suggests that a high morale independently predicts increased survival among old people, though very old people have not been specifically studied.OBJECTIVE: to investigate whether high morale is associated with increased survival among very old people.SUBJECTS: the Umeå 85+/GErontological Regional DAtabase-study (GERDA) recruited participants aged 85 years and older in northern Sweden and western Finland during 2000-02 and 2005-07, of whom 646 were included in this study.METHODS: demographic, functional- and health-related data were collected in this population-based study through structured interviews and assessments carried out during home visits and from reviews of medical records. The 17-item Philadelphia Geriatric Center Morale Scale (PGCMS) was used to assess morale.RESULTS: the 5-year survival rate was 31.9% for participants with low morale, 39.4% for moderate and 55.6% for those with high morale. In an unadjusted Cox model, the relative risk (RR) of mortality was higher among participants with low morale (RR = 1.86, P < 0.001) and moderate morale (RR = 1.59, P < 0.001) compared with participants with high morale. Similar results were found after adjustment for age and gender. In a Cox model adjusted for several demographic, health- and function-related confounders, including age and gender, mortality was higher among participants with low morale (RR = 1.36, P = 0.032) than those with high morale. There was a similar but non-significant pattern towards increased mortality in participants with moderate morale (RR = 1.21, P value = 0.136).CONCLUSION: high morale is independently associated with increased survival among very old people.

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