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1.
  • Danielsson, Åke, et al. (author)
  • A controlled randomized trial of budesonide versus prednisolone retention enemas in active distal ulcerative colitis
  • 1987
  • In: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 22:8, s. 987-992
  • Journal article (peer-reviewed)abstract
    • Sixty-four patients with active distal ulcerative colitis participated in a multicentre, randomized, investigator-blind trial to compare the effect of budesonide enema, 2 mg/100 ml, with prednisolone disodium phosphate enema, 31.25 mg/100 ml. Budesonide is a new potent corticosteroid with a rapid first-pass elimination. The patients were treated for 4 weeks, and the efficacy of the drugs were evaluated by sigmoidoscopy, histology, and subjective symptoms after 2 and 4 weeks. After 4 weeks of treatment 16 of 31 patients (52%) receiving budesonide enema had healed endoscopically, compared with 8 of 33 (24%) (p = 0.045) receiving prednisolone enema. Budesonide was superior to prednisolone in terms of both significantly improved sigmoidoscopic and histologic scores and subjective symptoms evaluated by visual analogue scales. The patients receiving prednisolone had a significant depression of endogenous cortisol levels during the treatment period, but not the patients receiving budesonide. Budesonide enema seems to be a promising therapy for active distal ulcerative colitis and causes no adverse reactions
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2.
  • af Sillén, Ulrika, et al. (author)
  • Self-rated health in relation to age and gender: influence on mortality risk in the Malmö Preventive Project.
  • 2005
  • In: Scandinavian Journal of Public Health. - : SAGE Publications. - 1651-1905 .- 1403-4948. ; 33:3, s. 9-183
  • Journal article (peer-reviewed)abstract
    • Aims: A study was undertaken to examine whether poor self-rated health (SRH) can independently predict all-cause mortality during 22-year follow-up in middle-aged men and women. Subjects and methods: Data are derived from a population-based study in Malmo¨ , Sweden. This included baseline laboratory testing and a self-administered questionnaire. The question on global SRH was answered by 15,590 men (mean age 46.4 years) and 10,089 women (49.4 years). Social background characteristics (occupation, marital status) were based on data from national censuses. Mortality was retrieved from national registers. Results: At screening 4,261 (27.3%) men and 3,085 (30.6%) women reported poor SRH. Among subjects rating their SRH as low, 1,022 (24.0%) men and 228 (7.4%) women died during follow-up. Corresponding figures for subjects rating their SRH as high were 1801 (15.9%) men and 376 (5.4%) women. An analysis of survival in subjects reporting poor SRH revealed an age-adjusted hazard risk ratio (HR, 95%CI) for men HR 1.5 (1.4–1.7), and for women HR 1.4 (1.2–1.6). The corresponding HR after adjusting for possible social confounders was for men HR 1.3 (1.1–1.4), and women HR 1.1 (0.9–1.4). When additional adjustment was made for biological risk factors the association for men was still significant, HR 1.2 (1.1–1.3). Conclusion: Poor SRH predicts increased long-term mortality in healthy, middle-aged subjects. For men the association is independent of both social background and selected biological variables. The adjustment for biological variables can be questioned as they might represent mediating mechanisms in a possible causal chain of events.
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5.
  • Andersson, C, et al. (author)
  • The three ZNT8 autoantibody variants together improve the diagnostic sensitivity of childhood and adolescent type 1 diabetes
  • 2011
  • In: Autoimmunity. - : Taylor & Francis. - 0891-6934 .- 1607-842X. ; 44:5, s. 394-405
  • Journal article (peer-reviewed)abstract
    • Aims: We tested whether autoantibodies to all three ZnT8RWQ variants, GAD65, insulinoma-associated protein 2 (IA-2), insulin and autoantibodies to islet cell cytoplasm (ICA) in combination with human leukocyte antigen (HLA) would improve the diagnostic sensitivity of childhood type 1 diabetes by detecting the children who otherwise would have been autoantibody-negative.Methods: A total of 686 patients diagnosed in 1996–2005 in Skåne were analyzed for all the seven autoantibodies [arginin 325 zinc transporter 8 autoantibody (ZnT8RA), tryptophan 325 zinc transporter 8 autoantibody (ZnT8WA), glutamine 325 Zinc transporter 8 autoantibody (ZnT8QA), autoantibodies to glutamic acid decarboxylase (GADA), Autoantibodies to islet-antigen-2 (IA-2A), insulin autoantibodies (IAA) and ICA] in addition to HLA-DQ genotypes.Results: Zinc transporter 8 autoantibody to either one or all three amino acid variants at position 325 (ZnT8RWQA) was found in 65% (449/686) of the patients. The frequency was independent of age at diagnosis. The ZnT8RWQA reduced the frequency of autoantibody-negative patients from 7.5 to 5.4%—a reduction by 28%. Only 2 of 108 (2%) patients who are below 5 years of age had no autoantibody at diagnosis. Diagnosis without any islet autoantibody increased with increasing age at onset. DQA1-B1*X-0604 was associated with both ZnT8RA (p = 0.002) and ZnT8WA (p = 0.01) but not with ZnT8QA (p = 0.07). Kappa agreement analysis showed moderate (>0.40) to fair (>0.20) agreement between pairs of autoantibodies for all combinations of GADA, IA-2A, ZnT8RWQA and ICA but only slight ( < 0.19) agreement for any combination with IAA.Conclusions: This study revealed that (1) the ZnT8RWQA was common, independent of age; (2) multiple autoantibodies were common among the young; (3) DQA1-B1*X-0604 increased the risk for ZnT8RA and ZnT8WA; (4) agreement between autoantibody pairs was common for all combinations except IAA. These results suggest that ZnT8RWQA is a necessary complement to the classification and prediction of childhood type 1 diabetes as well as to randomize the subjects in the prevention and intervention of clinical trials.
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6.
  • Andersson, Kristoffer, 1976, et al. (author)
  • Fabrication and characterization of field-plated buried-gate SiC MESFETs
  • 2006
  • In: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 27:7, s. 573-575
  • Journal article (peer-reviewed)abstract
    • Silicon carbide (SiC) MESFETs were fabricated using a standard SiC MESFET structure with the application of the "buried-channel" and field-plate (FP) techniques in the process. FPs combined with a buried-gate are shown to be favorable concerning output power density and power-added efficiency (PAE), due to higher breakdown voltage and decreased output conductance. A very high power density of 7.8 W/mm was measured on-wafer at 3 GHz for a two-finger 400-/spl mu/m gate periphery SiC MESFET. The PAE for this device was 70% at class AB bias. Two-tone measurements at 3 GHz /spl plusmn/ 100 kHz indicate an optimum FP length for high linearity operation.
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7.
  • Andersson, Martin N., et al. (author)
  • Diet and ambient temperature interact to shape plasma fatty acid composition, basal metabolic rate and oxidative stress in great tits
  • 2018
  • In: The Journal of experimental biology. - : The Company of Biologists. - 1477-9145 .- 0022-0949. ; 221
  • Journal article (peer-reviewed)abstract
    • Diet and ambient temperature affect animal physiology, survival and reproductive success. However, knowledge of how these environmental factors interact to shape physiological processes and life-history traits of birds and other animals is largely lacking. By exposing adult great tits (Parus major) to two contrasting diets (saturated or unsaturated fatty acids; SFAs and UFAs, respectively) and ambient temperatures (3°C versus 20°C) that the birds encounter in nature, we investigated the effects of these two factors on several physiological parameters. Our results show that diet and ambient temperature interact to affect the composition of plasma fatty acids, basal metabolic rate (BMR) and oxidative stress, which are thought to affect the life-history and survival of individuals. Specifically, birds provided the SFA-rich diet had higher mass-specific BMR and oxidative stress (levels of lipid peroxidation) after exposure to low compared with high ambient temperature, whereas the opposite pattern was evident for birds with a UFA-rich diet. Surprisingly, birds on the SFA diet had higher relative levels of monounsaturated fatty acids compared with the UFA-fed birds at low ambient temperature, whereas the opposite, and expected, pattern was found at the high temperature. Although the present study focuses on the physiological implications of the diet×temperature interaction, our results might also be important for the leading theories of ageing, which currently do not take interactions between environmental factors into account. In addition, the present results are important for wildlife management, especially with regards to anthropogenic feeding of wild animals across variable and changing climatic conditions.
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8.
  • Barbosa, Edna J L, 1961, et al. (author)
  • Extracellular water and blood pressure in adults with growth hormone (GH) deficiency: a genotype-phenotype association study.
  • 2014
  • In: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8
  • Journal article (peer-reviewed)abstract
    • Growth hormone deficiency (GHD) in adults is associated with decreased extracellular water volume (ECW). In response to GH replacement therapy (GHRT), ECW increases and blood pressure (BP) reduces or remains unchanged. Our primary aim was to study the association between polymorphisms in genes related to renal tubular function with ECW and BP before and 1 year after GHRT. The ECW measures using bioimpedance analysis (BIA) and bioimpedance spectroscopy (BIS) were validated against a reference method, the sodium bromide dilution method (Br(-)).
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9.
  • Barbosa, Edna J L, 1961, et al. (author)
  • Genotypes associated with lipid metabolism contribute to differences in serum lipid profile of GH-deficient adults before and after GH replacement therapy.
  • 2012
  • In: European journal of endocrinology / European Federation of Endocrine Societies. - 1479-683X .- 0804-4643. ; 167:3, s. 353-62
  • Journal article (peer-reviewed)abstract
    • bjective: GH deficiency (GHD) in adults is associated with an altered serum lipid profile that responds to GH replacement therapy (GHRT). This study evaluated the influence of polymorphisms in genes related to lipid metabolism on serum lipid profile before and after 1 year of GHRT in adults. Design and methods: In 318 GHD patients, total cholesterol (TC) serum concentrations, LDL-C, HDL-C, and triglycerides (TG) were assessed. Using a candidate gene approach, 20 single nucleotide polymorphisms (SNPs) were genotyped. GH dose was individually titrated to obtain normal serum IGF1 concentrations. Results: At baseline, the minor alleles of cholesteryl ester transfer protein (CETP) gene SNPs rs708272 and rs1800775 were associated with higher serum TC and apolipoprotein E (APOE) gene SNP rs7412 with lower TC concentrations; CETP SNPs rs708272, rs1800775, and rs3764261 and apolipoprotein B (APOB) gene SNP rs693 with higher serum HDL-C; APOE SNP rs7412, peroxisome proliferator-activated receptor gamma (PPARG) gene SNP rs10865710 with lower LDL-C, and CETP SNP rs1800775 with higher LDL-C; and APOE/C1/C4/C2 cluster SNP rs35136575 with lower serum TG. After treatment, APOB SNP rs676210 GG genotype was associated with larger reductions in TC and LDL-C and PPARG SNP rs10865710 CC genotype with greater TC reduction. All associations remained significant when adjusted for age, sex, and BMI. Conclusions: In GHD adults, multiple SNPs in genes related to lipid metabolism contributed to individual differences in baseline serum lipid profile. The GH treatment response in TC and LDL-C was influenced by polymorphisms in the APOB and PPARG genes.
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10.
  • Bengtsson, Kenneth, et al. (author)
  • Så kan Sverige bli ledande nation i resurseffektivitet
  • 2016
  • In: Dagens Nyheter. - 1101-2447. ; :2016-04-30
  • Journal article (pop. science, debate, etc.)abstract
    • Ny rapport. Det svenska näringslivet kan bli mer hållbart, resurssmart och därmed internationellt konkurrenskraftigt. Men för det behövs en tydlig politisk avsiktsförklaring och riktlinjer. Vi har listat sex områden där policyutveckling brådskar, skriver företrädare för näringsliv, forskning och myndigheter i en gemensam uppmaning.
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13.
  • Broggi, Juli, et al. (author)
  • Carry-over effects on reproduction in food-supplemented wintering great tits
  • 2022
  • In: Journal of Avian Biology. - : Wiley. - 0908-8857 .- 1600-048X. ; 2022:8
  • Journal article (peer-reviewed)abstract
    • Bird winter-feeding has become a popular backyard activity around the world, particularly in northern regions of Europe and America with cold winters. However, the short- and long-term ecological consequences of such artificial feeding remain inconclusive. In seasonal environments, timing of breeding is a crucial aspect that can strongly influence reproductive output and ultimately fitness. Individual condition at the start of the breeding season is especially important in determining breeding success, by influencing the onset of and investment in breeding. However, empirical evidence on the effects of winter feeding on avian breeding performance remain equivocal. We studied onset of reproduction (laying date) and breeding investment (clutch size) over seven consecutive seasons in a population of wild great tits Parus major in southern Sweden. During the first three years of study, no experimental manipulation was undertaken, while over the last four years the study area was exposed to either supplemented or unmanipulated winter feeding conditions. Breeding was positively affected by supplementary feeding during winter, as birds breeding in the supplemented area increased their clutch size compared to birds from the control area, although laying date remained unaffected by winter feeding. Since differences in clutch size were absent during the three years prior to the experimental manipulation, the results suggest that winter supplementary feeding, and not inherent differences between the two areas, was the reason for the observed effect. Both breeding parameters varied over the years of study, although the effects of the experimental manipulation on clutch size remained consistent, which suggests a carry-over effect of winter feeding on subsequent breeding performance.
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14.
  • Broggi, Juli, et al. (author)
  • Mass or pace? Seasonal energy management in wintering boreal passerines
  • 2019
  • In: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 189:2, s. 339-351
  • Journal article (peer-reviewed)abstract
    • Research on winter energy management in small vertebrates has focused on the regulation of body mass (BM) within a framework of starvation-predation trade-off. Winter-acclimatized birds exhibit a seasonal increase in both BM and basal metabolic rate (BMR), although the patterns of co-variation between the two traits remain unknown. We studied this co-variation in three different species of wild titmice, great, blue and willow tits, originating from two boreal regions at different latitudes. Seasonal change in BM and BMR was inter-dependent, particularly in the great tit; however, by contrast, no seasonal change was observed in the willow tit. BMR changed non-linearly in concert with BM with a peak in midwinter for both blue and great tits, whereas such non-linear pattern in willow tit was opposite and independent of BM. Surprisingly, BMR appears to be more sensitive to ambient temperatures than BM in all three species studied. Energy management is a multifaceted strategy that cannot be fully understood without considering reserve levels and energy expenditure simultaneously. Thus, our study indicates that the prevailing conceptual framework based on variation in BM alone is insufficient to understand seasonal energy management in small wintering passerines.
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15.
  • Cha, Eunjung, 1985, et al. (author)
  • Cryogenic low-noise InP HEMTs: A source-drain distance study
  • 2016
  • In: 2016 Compound Semiconductor Week, CSW 2016. - 9781509019649 ; , s. Article number 7528576-
  • Conference paper (peer-reviewed)abstract
    • The scaling effect of the source-drain distance was investigated in order to improve the performance of low-noise InP HEMTs at cryogenic temperatures 4-15 K. The highest dc transconductance at an operating temperature of 4.8 K and low bias power was achieved at a source-drain distance of 1.4 mu m. The extracted HEMT minimum noise temperature was 0.9 K at 5.8 GHz for a 3-stage 4-8 GHz hybrid low-noise amplifier at 10 K.
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16.
  • Chapman, Ben, et al. (author)
  • To boldly go: individual differences in boldness influence migratory tendency.
  • 2011
  • In: Ecology Letters. - : Wiley. - 1461-023X. ; 14, s. 871-876
  • Journal article (peer-reviewed)abstract
    • Ecology Letters (2011) ABSTRACT: Partial migration, whereby only a fraction of the population migrates, is thought to be the most common type of migration in the animal kingdom, and can have important ecological and evolutionary consequences. Despite this, the factors that influence which individuals migrate and which remain resident are poorly understood. Recent work has shown that consistent individual differences in personality traits in animals can be ecologically important, but field studies integrating personality traits with migratory behaviour are extremely rare. In this study, we investigate the influence of individual boldness, an important personality trait, upon the migratory propensity of roach, a freshwater fish, over two consecutive migration seasons. We assay and individually tag 460 roach and show that boldness influences migratory propensity, with bold individuals being more likely to migrate than shy fish. Our data suggest that an extremely widespread personality trait in animals can have significant ecological consequences via influencing individual-level migratory behaviour.
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17.
  • Culina, Antica, et al. (author)
  • Connecting the data landscape of long-term ecological studies : The SPI-Birds data hub
  • 2021
  • In: Journal of Animal Ecology. - : John Wiley & Sons. - 0021-8790 .- 1365-2656. ; 90:9, s. 2147-2160
  • Journal article (peer-reviewed)abstract
    • The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database ()-a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration.
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18.
  • Cöster, Maria, et al. (author)
  • Validity, reliability, and responsiveness of a self-reported foot and ankle score (SEFAS)
  • 2012
  • In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 83:2, s. 197-203
  • Journal article (peer-reviewed)abstract
    • Background and purpose A questionnaire was introduced by the New Zealand Arthroplasty Registry for use when evaluating the outcome of total ankle replacement surgery. We evaluated the reliability, validity, and responsiveness of the modified Swedish version of the questionnaire (SEFAS) in patients with osteoarthritis or inflammatory arthritis before and/or after their ankle was replaced or fused. Patients and methods The questionnaire was translated into Swedish and cross-culturally adapted according to a standardized procedure. It was sent to 135 patients with ankle arthritis who were scheduled for or had undergone surgery, together with the foot and ankle outcome score (FAOS), the short form 36 (SF-36) score, and the EuroQol (EQ-5D) score. Construct validity was evaluated with Spearman's correlation coefficient when comparing SEFAS with FAOS, SF-36, and EQ-5D, content validity by calculating floor and ceiling effects, test-retest reliability with intraclass correlation coefficient (ICC), internal consistency with Cronbach's alpha (n = 62), agreement by Bland-Altman plot, and responsiveness by effect size and standardized response mean (n = 37). Results For construct validity, we correlated SEFAS with the other scores and 70% or more of our predefined hypotheses concerning correlations could be confirmed. There were no floor or ceiling effects. ICC was 0.92 (CI 95%: 0.88-0.95), Cronbach's alpha 0.96, effect size was 1.44, and the standardized response mean was 1.00. Interpretation SEFAS is a self-reported foot and ankle score with good validity, reliability and responsiveness, indicating that the score can be used to evaluate patients with osteoarthritis or inflammatory arthritis of the ankle and outcome of surgery.
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19.
  • Ekberg, Marie, et al. (author)
  • Hospital admission rates among men and women with symptoms of chronic bronchitis and airflow limitation corresponding to the GOLD stages of chronic obstructive pulmonary disease - A population-based study
  • 2008
  • In: Respiratory Medicine. - : Elsevier BV. - 1532-3064 .- 0954-6111. ; 102:1, s. 109-120
  • Journal article (peer-reviewed)abstract
    • Chronic obstructive pulmonary disease is a major cause of increased morbidity and mortality. The aim of this study was to investigate hospital admission rates among individuals with symptoms of chronic bronchitis and among those with airflow limitation corresponding to GOLD stages 1-4. Method: Between 1974 and 1992, 22 044 middle-aged individuals participated in a health screening, which included spirometry (without broncho-dilation), as well as recording of respiratory symptoms and smoking habits. Information on hospital admissions until 31 December 2002 was obtained from local and national registers. The hospital admission rates due to all causes, obstructive Lung disease and cardiovascular disease were analysed among individuals with symptoms of chronic bronchitis and among those with airflow limitation corresponding to GOLD stages 1-4 using ordinal regression with adjustment for age and with individuals with normal lung function and without symptoms of chronic bronchitis as reference group. Results: Symptoms of chronic bronchitis and GOLD stages 1-4 showed increased hospital admission rates (hospital admission rates due to obstructive lung disease excluded) among smokers of both genders. Furthermore, symptoms of chronic bronchitis showed increased hospital admission rates due to obstructive lung disease among smoking women. There were also increased hospital admission rates due to obstructive lung disease among smokers of GOLD stages 1-4 and increased hospital admission rates due to cardiovascular disease among female smokers of GOLD stage 2. Conclusion: Among smokers, symptoms of chronic bronchitis as well airflow limitation corresponding to GOLD stages 1-4 conveyed a substantial morbidity with increased hospital admission rates due to all causes. The burden of disease is most likely underestimated among individuals with symptoms of chronic bronchitis and chronic obstructive pulmonary disease.
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20.
  • Ekberg, Marie, et al. (author)
  • Mortality in GOLD stages of COPD and its dependence on symptoms of chronic bronchitis
  • 2005
  • In: Respiratory Research. - : Springer Science and Business Media LLC. - 1465-9921 .- 1465-993X. ; 6, s. 98-106
  • Journal article (peer-reviewed)abstract
    • Background: The GOLD classification of COPD severity introduces a stage 0 ( at risk) comprising individuals with productive cough and normal lung function. The aims of this study were to investigate total mortality risks in GOLD stages 0 - 4 with special focus on stage 0, and furthermore to assess the influence of symptoms of chronic bronchitis on mortality risks in GOLD stages 1 - 4. Method: Between 1974 and 1992, a total of 22 044 middle-aged individuals participated in a health screening, which included a spirometry as well as recording of respiratory symptoms and smoking habits. Individuals with comorbidity at baseline ( diabetes, stroke, cancer, angina pectoris, or heart infarction) were excluded from the analyses. Hazard ratios (HR 95% CI) of total mortality were analyzed in GOLD stages 0 - 4 with individuals with normal lung function and without symptoms of chronic bronchitis as a reference group. HR: s in smoking individuals with symptoms of chronic bronchitis within the stages 1 - 4 were calculated with individuals with the same GOLD stage but without symptoms of chronic bronchitis as reference. Results: The number of deaths was 3674 for men and 832 for women based on 352 324 and 150 050 person-years respectively. The proportion of smokers among men was 50% and among women 40%. Self reported comorbidity was present in 4.6% of the men and 6.6% of the women. Among smoking men, Stage 0 was associated with an increased mortality risk, HR; 1.65 ( 1.32 - 2.08), of similar magnitude as in stage 2, HR; 1.41 ( 1.31 - 1.70). The hazard ratio in stage 0 was significantly higher than in stage 1 HR; 1.13 ( 0.98 - 1.29). Among male smokers with stage 1; HR: 2.04 ( 1.34 - 3.11), and among female smokers with stage 2 disease; HR: 3.16 ( 1.38 - 7.23), increased HR: s were found in individuals with symptoms of chronic bronchitis as compared to those without symptoms of chronic bronchitis. Conclusion: Symptoms fulfilling the definition of chronic bronchitis were associated with an increased mortality risk among male smokers with normal pulmonary function ( stage 0) and also with an increased risk of death among smoking individuals with mild to moderate COPD ( stage 1 and 2).
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21.
  • Ellis, Vincenzo A., et al. (author)
  • Explaining prevalence, diversity and host specificity in a community of avian haemosporidian parasites
  • 2020
  • In: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 129:9, s. 1314-1329
  • Journal article (peer-reviewed)abstract
    • Many hypotheses attempt to explain parasite–host associations, but rarely are they examined together in a single community. For hosts, key traits are the proportion of infected individuals (prevalence) and the diversity of parasites infecting them. A key parasite trait is host specificity, ranging from specialists infecting one or a few closely related species to generalists infecting many species. We tested 10 hypotheses to explain host-parasite associations; five ‘host-centric’ (e.g. prevalence is related to host abundance) and five ‘parasite-centric’ (e.g. parasite abundance is related to host specificity). We analyzed a community of 67 locally transmitted avian haemosporidian parasite lineages (genera Plasmodium, Haemoproteus or Leucocytozoon), sampled from 2726 birds (64 species) in southern Sweden. Among host-centric hypotheses, Haemoproteus and Leucocytozoon prevalence and Haemoproteus diversity were related to host habitat preferences, whereas there were no relationships with host abundance or body mass. Haemoproteus and Leucocytozoon prevalences were more similar among closely related than among distantly related host species. Haemoproteus prevalence and diversity were lower in host species with few close relatives (‘evolutionarily distinct’ hosts). Among parasite-centric hypotheses, most lineages, even relative generalists, infected closely related host species more often than expected by chance. However, the host species of Haemoproteus and Leucocytozoon lineages overlapped less among lineages than expected by chance. Specialists did not reach higher prevalences than generalists on single host species. However, the abundance of Haemoproteus lineages was related to host specificity with generalists more common than specialists; this was driven by three closely related generalists. Host specificity of parasites was unrelated to the abundance or evolutionarily distinctiveness of their hosts. Parasite communities are likely structured by many factors and cannot be explained by hypotheses focusing solely on hosts or parasites. However, we found consistent effects of host phylogenetic relationships, plausibly a result of evolutionarily conserved host immune systems limiting parasite distributions.
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22.
  • Galeev, Roman, et al. (author)
  • Genome-wide RNAi Screen Identifies Cohesin Genes as Modifiers of Renewal and Differentiation in Human HSCs
  • 2016
  • In: Cell Reports. - : Elsevier BV. - 2211-1247. ; 14:12, s. 2988-3000
  • Journal article (peer-reviewed)abstract
    • To gain insights into the regulatory mechanisms of hematopoietic stem cells (HSCs), we employed a genome-wide RNAi screen in human cord-blood derived cells and identified candidate genes whose knockdown maintained the HSC phenotype during culture. A striking finding was the identification of members of the cohesin complex (STAG2, RAD21, STAG1, and SMC3) among the top 20 genes from the screen. Upon individual validation of these cohesin genes, we found that their knockdown led to an immediate expansion of cells with an HSC phenotype in vitro. A similar expansion was observed in vivo following transplantation to immunodeficient mice. Transcriptome analysis of cohesin-deficient CD34(+) cells showed an upregulation of HSC-specific genes, demonstrating an immediate shift toward a more stem-cell-like gene expression signature upon cohesin deficiency. Our findings implicate cohesin as a major regulator of HSCs and illustrate the power of global RNAi screens to identify modifiers of cell fate.
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23.
  • Haghighi, Mona, et al. (author)
  • A Comparison of Rule-based Analysis with Regression Methods in Understanding the Risk Factors for Study Withdrawal in a Pediatric Study
  • 2016
  • In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
  • Journal article (peer-reviewed)abstract
    • Regression models are extensively used in many epidemiological studies to understand the linkage between specific outcomes of interest and their risk factors. However, regression models in general examine the average effects of the risk factors and ignore subgroups with different risk profiles. As a result, interventions are often geared towards the average member of the population, without consideration of the special health needs of different subgroups within the population. This paper demonstrates the value of using rule-based analysis methods that can identify subgroups with heterogeneous risk profiles in a population without imposing assumptions on the subgroups or method. The rules define the risk pattern of subsets of individuals by not only considering the interactions between the risk factors but also their ranges. We compared the rule-based analysis results with the results from a logistic regression model in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Both methods detected a similar suite of risk factors, but the rule-based analysis was superior at detecting multiple interactions between the risk factors that characterize the subgroups. A further investigation of the particular characteristics of each subgroup may detect the special health needs of the subgroup and lead to tailored interventions.
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24.
  • Hansson, L-A, et al. (author)
  • A synthesis of animal movement across scales
  • 2014
  • In: Animal Movement Across Scales. - : Oxford University Press. - 9780199677184 ; , s. 259-267
  • Book chapter (peer-reviewed)abstract
    • This chapter aims at synthesizing the knowledge presented in the chapters of the book’s three sections by addressing evolutionary compromises, dispersal, gene flow, and assisted movements. How climate change and other environmental changes at different scales may affect animal movement, migration, and dispersal in the future are also summarized here. Moreover, how the different senses are utilized for navigation and orientation and how these may lead to different movement and migration patterns are also discussed. Finally, how the recent technical revolution has affected animal movement research is addressed and the view on future perspectives of animal movement research is also provided.
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25.
  • Henricson, Anders, et al. (author)
  • 10-year survival of total ankle arthroplasties A report on 780 cases from the Swedish Ankle Register
  • 2011
  • In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 82:6, s. 655-659
  • Journal article (peer-reviewed)abstract
    • Background and purpose There is an ongoing need to review large series of total ankle replacements (TARs) for monitoring of changes in practice and their outcome. 4 national registries, including the Swedish Ankle Register, have previously reported their 5-year results. We now present an extended series with a longer follow-up, and with a 10-year survival analysis. Patients and methods Records of uncemented 3-component TARs were retrospectively reviewed, determining risk factors such as age, sex, and diagnosis. Prosthetic survival rates were calculated with exchange or removal of components as endpoint-excluding incidental exchange of the polyethylene meniscus. Results Of the 780 prostheses implanted since 1993, 168 (22%) had been revised by June 15, 2010. The overall survival rate fell from 0.81 (95% CI: 0.79-0.83) at 5 years to 0.69 (95% CI: 0.67-0.71) at 10 years. The survival rate was higher, although not statistically significantly so, during the latter part of the period investigated. Excluding the STAR prosthesis, the survival rate for all the remaining designs was 0.78 at 10 years. Women below the age of 60 with osteoarthritis were at a higher risk of revision, but age did not influence the outcome in men or women with rheumatoid arthritis. Revisions due to technical mistakes at the index surgery and instability were undertaken earlier than revisions for other reasons. Interpretation The results have slowly improved during the 18-year period investigated. However, we do not believe that the survival rates of ankle replacements in the near future will approach those of hip and knee replacements-even though improved instrumentation and design of the prostheses, together with better patient selection, will presumably give better results.
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26.
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27.
  • Holmberg, Anna H, et al. (author)
  • Risk factors for hip fractures in a middle-aged population: a study of 33,000 men and women.
  • 2005
  • In: Osteoporosis International. - : Springer Science and Business Media LLC. - 1433-2965 .- 0937-941X. ; 16:Sep22, s. 2185-2194
  • Journal article (peer-reviewed)abstract
    • Knowledge about subjects who sustain hip fractures in middle age is poor. This study prospectively investigated risk factors for hip fracture in middle age and compared risk factors for cervical and trochanteric hip fractures. The Malmo Preventive Project consists of 22,444 men, mean age 44 years, and 10,902 women, mean age 50 years at inclusion. Baseline assessment included multiple examinations and lifestyle information. Follow-up was up to 16 years with regard to occurrence of fracture. One hundred thirty-five women had one low-energy hip fracture each, 93 of which were cervical and 42 trochanteric. One hundred sixty-three men had 166 hip fractures, of which 81 were cervical and 85 trochanteric. In the final Cox regression model for women, the risk factors with the strongest associations with hip fracture were diabetes (risk ratio (RR) 3.89, 95% confidence interval (CI) 1.69-8.93, p=0.001) and poor self-rated health (RR 1.74, 95% CI 1.22-2.48, p=0.002). A history of previous fracture (RR 4.76, 95%CI 2.74-8.26, p=0.0001) was also a significant risk factor. In men, diabetes had the strongest association with hip fracture (RR 6.13, 95%CI 3.19-11.8, p=0.001). Smoking (RR 2.20, 95%CI 1.54-3.15, p=0.001), high serum gamma-glutamyl transferase (RR 1.84, 95%CI 1.50-2.26, p=0.001), poor self-rated health (RR 1.49, 95%CI 1.06-2.10, p=0.02) and reported sleep disturbances (RR 1.52, 95%CI 1.03-2.27, p=0.04) were other significant risk factors. The strongest risk factor for hip fracture for both women and men in middle age was diabetes. Many risk factors were similar for men and women, although the risk ratio differed. The risk factor pattern for cervical versus trochanteric fractures differed in both men and women. The findings indicate that those suffering a hip fracture before the age of 75 have a shorter life expectancy, suggesting that hip fractures affect the less healthy segment of the population.
  •  
28.
  • Holmberg, Anna H, et al. (author)
  • The Association Between Hyperglycemia and Fracture Risk in Middle Age. A prospective, population-based study of 22 444 men and 10 902 women.
  • 2008
  • In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 1945-7197 .- 0021-972X. ; 93:3, s. 815-822
  • Journal article (peer-reviewed)abstract
    • Aims: Type 1 diabetes mellitus is associated with increased fracture risk, whereas the risk associated with type 2 diabetes is less obvious. Elevated fasting blood glucose (FBG) and high 2-hour glucose during an oral glucose tolerance test (OGTT) indicate impaired glucose tolerance or diabetes. The associations between FBG, 2-h glucose and the risk of fracture were investigated. Methods: The Malmö Preventive Project consists of 22 444 men (44 +/- 6.6 yrs) and 10 902 women (50 +/- 7.4 yrs), with a follow-up of 19 (+/-3.9)years and 15 (+/-4.5) years for incident fractures. Baseline assessment included multiple examinations and lifestyle information. A logistic regression model was used. Adjustments were made for age, BMI, and smoking. Results: Low-energy fractures were recorded in 1246 men and 1236 women. A 2-h glucose measurement between 4.3 and 6.2 mmol/L in men (2(nd) and 3(rd) quartiles), and above 6.5 mmol/L in women (3(rd) and 4(th) quartiles), adjusted for age, BMI, and smoking, was significantly associated with decreased risk of multiple fractures, in men (ORs 0.57-0.71) and women (ORs 0.38-0.66). In women, a 2-h glucose measurement above 7.5 mmol/L was associated with a decreased risk of osteoporotic fractures (OR 0.57, CI 95% 0.44-0.74). Conclusions: In middle-aged men and women, elevated 2-h glucose levels were associated with decreased risks of multiple and osteoporotic fractures, independent of age, BMI, and smoking. A high 2-h glucose level is characterized by peripheral insulin resistance with a high insulin level. Our findings indirectly suggest a positive effect on bone from hyperglycemia.
  •  
29.
  • Janson, Per-Olof, 1940, et al. (author)
  • Acromegaly and Cushing's syndrome due to ectopic production of GHRH and ACTH by a thymic carcinoid tumour: in vitro responses to GHRH and GHRP-6.
  • 1998
  • In: Clinical endocrinology. - 0300-0664. ; 48:2, s. 243-50
  • Journal article (peer-reviewed)abstract
    • A 50-year-old male presented with diabetes mellitus and Cushing's syndrome associated with a large mediastinal mass. The levels of serum cortisol were high (1500-1800 nmol/l) without diurnal variation. Plasma ACTH levels (200-250 ng/l) and urinary excretion of cortisol were also increased. The levels of these hormones did not change in response to stimulation with corticotrophin releasing hormone (CRH) or suppression with high doses of dexamethasone. The patient had an elevated baseline GH level (7.3 mU/l), and the levels of immunoreactive GH-releasing hormone (GHRH) in eight plasma samples were markedly increased (600-1500 ng/l). Circulating levels of IGF-1, chromogranin A and neuropeptide Y (NPY) were also increased. Computer-assisted tomography and octreotide scintigraphy revealed a large mediastinal tumour and metastases in the left supraclavicular fossa. During treatment with octreotide, the baseline GH level was decreased (to 4.4 mU/l), while the GH pulse height was unchanged. Surgical removal of most of the tumour tissue resulted in a further decrease in the baseline serum GH level to a value (1.6 mU/l) about 20% of that before treatment, while the pulse height and mean GH were affected to a lesser extent. Postoperatively, circulating levels of cortisol and IGF-1 decreased, and the patient exhibited clinical improvement. Histological examination showed a neuroendocrine tumour with characteristics consistent with a foregut carcinoid of thymic origin. Immunoreactive GHRH, ACTH and NPY, but not immunoreactive GH, were detected in 80-90% of the tumour cells and the three peptides appeared to be co-localized. In primary culture, cells from this tumour displayed calcium influx in response to GHRH or GH releasing peptide-6 (GHRP-6), while there were not such responses by cells from another carcinoid not producing GHRH, ACTH or NPY. These results demonstrate a rare case of ectopic production of GHRH, ACTH and NPY, and indicate that the tumour cells were responsive to GHRH and GHRP-6 as well as octreotide.
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30.
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31.
  • Kamrad, Ilka, et al. (author)
  • Poor prosthesis survival and function after component exchange of total ankle prostheses
  • 2015
  • In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 86:4, s. 407-411
  • Journal article (peer-reviewed)abstract
    • BACKGROUND AND PURPOSE: In failed total ankle replacements (TARs), fusion is often the procedure of preference; the outcome after exchanging prosthetic components is debated. We analyzed prosthetic survival, self-reported function, and patient satisfaction after component exchange. Patients and methods We identified patients in the Swedish Ankle Registry who underwent exchange of a tibial and/or talar component between January 1, 1993 and July 1, 2013 and estimated prosthetic survival by Kaplan-Meier analysis. We evaluated the patient-reported outcome measures (PROMs) SEFAS, EQ-5D, EQ-VAS, SF-36, and patient satisfaction by direct questions.RESULTS: 69 patients underwent revision TAR median 22 (0-110) months after the primary procedure. 24 of these failed again after median 26 (1-110) months. Survival analysis of revision TAR showed a 5-year survival rate of 76% and a 10-year survival of 55%. 29 patients with first revision TAR in situ answered the PROMs at mean 8 (1-17) years after revision and had the following mean scores: SEFAS 22, SF-36 physical 37 and mental 49, EQ-5D index 0.6, and EQ-VAS 64. 15 of the patients were satisfied, 5 were neither satisfied nor dissatisfied, and 9 were dissatisfied.INTERPRETATION: Revision TAR had a 10-year survival of 55%, which is lower than the 10-year survival of 74% for primary TAR reported from the same registry. Only half of the patients were satisfied. Future studies should show which, if any, patients benefit from revision TAR and which patients should rather be fused directly.
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32.
  • Kanatsuna, N, et al. (author)
  • Doubly reactive INS-IGF2 autoantibodies in children with newly diagnosed autoimmune (type 1) diabetes
  • 2015
  • In: Scandinavian Journal of Immunology. - : Wiley-Blackwell. - 0300-9475 .- 1365-3083. ; 82:4, s. 361-369
  • Journal article (peer-reviewed)abstract
    • The splice variant INS-IGF2 entails the preproinsulin signal peptide, the insulin B-chain, eight amino acids of the C-peptide and 138 unique amino acids from an ORF in the IGF2 gene. The aim of this study was to determine whether levels of specific INS-IGF2 autoantibodies (INS-IGF2A) were related to age at diagnosis, islet autoantibodies, HLA-DQ or both, in patients and controls with newly diagnosed type 1 diabetes. Patients (n = 676), 0-18 years of age, diagnosed with type 1 diabetes in 1996-2005 and controls (n = 363) were analysed for specific INS-IGF2A after displacement with both cold insulin and INS-IGF2 to correct for non-specific binding and identify double reactive sera. GADA, IA-2A, IAA, ICA, ZnT8RA, ZnT8WA, ZnT8QA and HLA-DQ genotypes were also determined. The median level of specific INS-IGF2A was higher in patients than in controls (P < 0.001). Irrespective of age at diagnosis, 19% (126/676) of the patients had INS-IGF2A when the cut-off was the 95th percentile of the controls (P < 0.001). The risk of INS-IGF2A was increased among HLA-DQ2/8 (OR = 1.509; 95th CI 1.011, 2.252; P = 0.045) but not in 2/2, 2/X, 8/8, 8/X or X/X (X is neither 2 nor 8) patients. The association with HLA-DQ2/8 suggests that this autoantigen may be presented on HLA-DQ trans-heterodimers, rather than cis-heterodimers. Autoantibodies reactive with both insulin and INS-IGF2A at diagnosis support the notion that INS-IGF2 autoimmunity contributes to type 1 diabetes.
  •  
33.
  • Khalili, Payam, et al. (author)
  • Smoking as a modifier of the systolic blood pressure-induced risk of cardiovascular events and mortality : a population-based prospective study of middle-aged men
  • 2002
  • In: Journal of Hypertension. - : Ovid Technologies (Wolters Kluwer Health). - 0263-6352 .- 1473-5598. ; 20:9, s. 1759-1764
  • Journal article (peer-reviewed)abstract
    • Objective To examine to what degree smoking habits modulate the relationship between systolic blood pressure (SBP) and risk for cardiovascular morbidity (first event) and mortality in middle-aged men. Design and methods In all, 22 444 middle-aged men were recruited from a population-based screening study (mean attendance rate 71%). Risk factor intervention was offered to about 20% of participants. Subjects were followed in local and national registers for cardiovascular morbidity and mortality during more than 17 years of follow-up. Lifestyle variables were investigated at baseline, including smoking habits. Event rates were calculated in relation to quintiles (Q1-Q5) of baseline SBP in untreated subjects, subdivided into categories of smoking habits, but also for 915 previously known, treated hypertensive (tHT) patients at baseline. Results We found an increasing incidence of first cardiovascular event (CE) with increasing SBP levels, ranging from 63.5 CE/10 000 person-years (Q1) to 62.3, 70.5,82.3 and 115.1 CE/10 000 person-years (Q2-Q5). The corresponding figure in tHTs; was 153 CE/10 000 person-years. If further subdivided into smokers/ex-smokers/non-smokers, the relative risks (RR) of smokers were 1.9 [95% confidence interval (Cl): 1.5-2.4], 2.1 (1.8-2.5), 2.3 (1.8-2.9), 1.8 (1.5-2.1), and 1.7 (1.5-2.0) compared to present non-smokers, in relation to SBP (Q1-Q5). In tHTs; the RR was 1.4 (1.1-1.8). Cardiovascular mortality rates differed in relation to SBP and smoking habits, from 40.3 (present non-smokers) and 70.7 (smokers) deaths/10 000 person-years in Q1, to 54.2 and 134.0 deaths/10 000 person-years in Q5. In tHTs the corresponding figures were 81.6 and 149.4 deaths/10 000 person-years, respectively. No difference in risk was found for never-smokers compared to ex-smokers in relation to SBP. The risk in moderate/heavy smokers (> 10 cigarettes/day) compared to other smokers (less than or equal to 10 cigarettes/day) was significantly (P < 0.005) increased only in Q5. Conclusion Increasing systolic blood pressure levels in middle-aged men is associated with an increasing risk of future cardiovascular events and mortality, an association modified by smoking habits. Patients with treated hypertension in the 1970-1980s were also at an increased risk in spite of healthcare efforts. This calls for a more comprehensive multiple risk factor approach for the management and reduction of cardiovascular risk in these patients. (C) 2002 Lippincott Williams Wilkins.
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34.
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35.
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36.
  • Lindström, Åke, et al. (author)
  • Birds doing it the octopus way : fright moulting and distraction of predators
  • 1988
  • In: Ornis Scandinavica. - : JSTOR. - 0030-5693. ; 19:2, s. 165-166
  • Journal article (peer-reviewed)abstract
    • "Fright moulting" has been recorded in several orders of birds and interpreted as a way of escaping a predator when already caught. Two observations suggest that the behaviour may have another function, viz. when an aerial predator chases the prey. By shedding body feathers in the air the bird creates a cloud behind it; this might confuse the predator in the same way as the ink of octopuses confuse their predators.
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37.
  •  
38.
  • Löfberg, Robert, et al. (author)
  • Oral budesonide versus prednisolone in patients with extensive and left sided ulcerative colitis
  • 1996
  • In: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 110:6, s. 1713-1718
  • Journal article (peer-reviewed)abstract
    • BACKGROUND & AIMS: Systemic glucocorticosteroids (GCSs) have proven efficacy in active ulcerative colitis but cause undesired systemic side effects. Therefore, new GCSs with high topical activity and a high rate of metabolism may be of clinical value in this condition. The aim of this study was to explore the efficacy and safety of the topically acting GCS budesonide in an oral controlled-release formulation in extensive or left-sided, mild to moderately active ulcerative colitis. METHODS: A 9-week, randomized, double-blind, controlled trial was performed, and treatments with 10 mg budesonide or 40 mg prednisolone daily, both gradually tapered, were compared. Endoscopic improvement and effect on endogenous plasma cortisol were assessed. RESULTS: Thirty-four patients were administered budesonide, and 38 patients were administered prednisolone. Mean endoscopic scores improved significantly in both groups but without difference between the groups. Five patients in the budesonide group and 7 patients in the prednisolone group deteriorated and were withdrawn from the study. Morning plasma cortisol levels were suppressed in the prednisolone group (entry, 449 nmol/L; 2 weeks, 116 nmol/L; 4 weeks, 195 nmol/L) but were unchanged in the budesonide group. CONCLUSIONS: The GCS budesonide administered in an oral controlled-release formulation seems to give an overall treatment result in active ulcerative colitis approaching that of prednisolone but without suppression of plasma cortisol levels. This concept merits further evaluation.
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39.
  • Moller, Anders Pape, et al. (author)
  • Clutch-size variation in Western Palaearctic secondary hole-nesting passerine birds in relation to nest box design
  • 2014
  • In: Methods in Ecology and Evolution. - 2041-210X. ; 5:4, s. 353-362
  • Journal article (peer-reviewed)abstract
    • Secondary hole-nesting birds that do not construct nest holes themselves and hence regularly breed in nest boxes constitute important model systems for field studies in many biological disciplines with hundreds of scientists and amateurs involved. Those research groups are spread over wide geographic areas that experience considerable variation in environmental conditions, and researchers provide nest boxes of varying designs that may inadvertently introduce spatial and temporal variation in reproductive parameters. We quantified the relationship between mean clutch size and nest box size and material after controlling for a range of environmental variables in four of the most widely used model species in the Western Palaearctic: great tit Parus major, blue tit Cyanistes caeruleus, pied flycatcher Ficedula hypoleuca and collared flycatcher F.albicollis from 365 populations and 79610 clutches. Nest floor area and nest box material varied non-randomly across latitudes and longitudes, showing that scientists did not adopt a random box design. Clutch size increased with nest floor area in great tits, but not in blue tits and flycatchers. Clutch size of blue tits was larger in wooden than in concrete nest boxes. These findings demonstrate that the size of nest boxes and material used to construct nest boxes can differentially affect clutch size in different species. The findings also suggest that the nest box design may affect not only focal species, but also indirectly other species through the effects of nest box design on productivity and therefore potentially population density and hence interspecific competition.
  •  
40.
  • Moller, Anders Pape, et al. (author)
  • Effects of interspecific coexistence on laying date and clutch size in two closely related species of hole-nesting birds
  • 2018
  • In: Journal of Animal Ecology. - : WILEY. - 0021-8790 .- 1365-2656. ; 87:6, s. 1738-1748
  • Journal article (peer-reviewed)abstract
    • Coexistence between great tits Parus major and blue tits Cyanistes caeruleus, but also other hole-nesting taxa, constitutes a classic example of species co-occurrence resulting in potential interference and exploitation competition for food and for breeding and roosting sites. However, the spatial and temporal variations in coexistence and its consequences for competition remain poorly understood. We used an extensive database on reproduction in nest boxes by great and blue tits based on 87 study plots across Europe and Northern Africa during 1957-2012 for a total of 19,075 great tit and 16,729 blue tit clutches to assess correlative evidence for a relationship between laying date and clutch size, respectively, and density consistent with effects of intraspecific and interspecific competition. In an initial set of analyses, we statistically controlled for a suite of site-specific variables. We found evidence for an effect of intraspecific competition on blue tit laying date (later laying at higher density) and clutch size (smaller clutch size at higher density), but no evidence of significant effects of intraspecific competition in great tits, nor effects of interspecific competition for either species. To further control for site-specific variation caused by a range of potentially confounding variables, we compared means and variances in laying date and clutch size of great and blue tits among three categories of difference in density between the two species. We exploited the fact that means and variances are generally positively correlated. If interspecific competition occurs, we predicted a reduction in mean and an increase in variance in clutch size in great tit and blue tit when density of heterospecifics is higher than the density of conspecifics, and for intraspecific competition, this reduction would occur when density of conspecifics is higher than the density of heterospecifics. Such comparisons of temporal patterns of means and variances revealed evidence, for both species, consistent with intraspecific competition and to a smaller extent with interspecific competition. These findings suggest that competition associated with reproductive behaviour between blue and great tits is widespread, but also varies across large spatial and temporal scales.
  •  
41.
  • Moller, Anders P., et al. (author)
  • Variation in clutch size in relation to nest size in birds
  • 2014
  • In: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4:18, s. 3583-3595
  • Journal article (peer-reviewed)abstract
    • Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests, yet our current understanding of clutch size-nest size relationships is limited to small-scale studies performed over short time periods. Here, we quantified the relationship between clutch size and nest size, using an exhaustive database of 116 slope estimates based on 17,472 nests of 21 species of hole and non-hole-nesting birds. There was a significant, positive relationship between clutch size and the base area of the nest box or the nest, and this relationship did not differ significantly between open nesting and hole-nesting species. The slope of the relationship showed significant intraspecific and interspecific heterogeneity among four species of secondary hole-nesting species, but also among all 116 slope estimates. The estimated relationship between clutch size and nest box base area in study sites with more than a single size of nest box was not significantly different from the relationship using studies with only a single size of nest box. The slope of the relationship between clutch size and nest base area in different species of birds was significantly negatively related to minimum base area, and less so to maximum base area in a given study. These findings are consistent with the hypothesis that bird species have a general reaction norm reflecting the relationship between nest size and clutch size. Further, they suggest that scientists may influence the clutch size decisions of hole-nesting birds through the provisioning of nest boxes of varying sizes.
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42.
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43.
  • Nilsson, Anna, et al. (author)
  • Basal metabolic rate and energetic cost of thermoregulation among migratory and resident blue tits
  • 2011
  • In: Oikos. - : Wiley. - 1600-0706 .- 0030-1299. ; 120:12, s. 1784-1789
  • Journal article (peer-reviewed)abstract
    • Metabolic rates may be informative of adaptations to migration or wintering at high latitudes and may therefore be particularly interesting in partial migrants requiring adaptations to both migration and residency. To study the extent of physiological adaptations in migratory and resident blue tits Cyanistes caeruleus during the period of autumn migration in southern Sweden, we measured basal metabolic rate (BMR) and cost of thermoregulation at 0 degrees C (CTR0). In contrast to other migrants en route, migratory blue tits had lower BMR than residents. As migratory blue tits travel extraordinarily slowly on autumn migration and residents suffer from harsher climate and severe competition, residents may need dynamic adjustments that involve larger metabolic costs than migrants. Resident males had lower CTR0 than migrants and resident females. Resident males are socially dominant, which suggests that they have priority of access to food sources during summer and early autumn. They also spend more time on moult, which would give them the time and energy needed for molting into a plumage of higher insulation quality than is possible for migrants and resident females.
  •  
44.
  • Nilsson, Anna, et al. (author)
  • Diffuse, short and slow migration among Blue Tits
  • 2008
  • In: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7206 .- 2193-7192. ; 149:3, s. 365-373
  • Journal article (peer-reviewed)abstract
    • The knowledge of migration systems in long-distance regular migrants is in many cases extensive. Our understanding of the migratory characteristics of partial migrants, on the other hand, is far more rudimentary. We investigated migratory characteristics of partially migratory Blue Tits Cyanistes caeruleus using ringing recoveries of Swedish birds, to answer questions about geographic migration patterns, age-specific migrations, migration speeds and synchrony of movements. Median migration distance of Swedish Blue Tits was 82 km, with a main autumn direction in the sector between S and W (large directional scatter). Northerly and southerly populations did not differ in migration directions or distances, suggesting chain migration to be the general pattern. A larger proportion of adult Blue Tits remained near the breeding grounds during winter than was the case for juveniles. Some of the migrating birds (17%) seemed not to return in spring but stayed to breed closer to the winter area. Swedish Blue Tits show an exceptionally slow migration speed (median 13 km/day), among the slowest speeds recorded for any migrant bird. The Blue Tit represents an extreme case of diffuse, short and slow bird migration.
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45.
  • Nilsson, Anna, et al. (author)
  • Do partial and regular migrants differ in their responses to weather?
  • 2006
  • In: The Auk. - 0004-8038. ; 123:2, s. 537-547
  • Journal article (peer-reviewed)abstract
    • Partial migration is often considered a transitory stage between migration and residency, and whether partial migrants take weather conditions into account during migration is largely unknown. To assess whether partial migrants differ from regular migrants in their responses to weather, we compared the migratory intensity of a partial migrant, the Blue Tit (Cyanistes caeruleus), with more regular migrants in relation to weather at a migratory passage site in southern Sweden (Falsterbo) during the years 1993-2002. The regular migrants in the study were Linnet (Carduelis cannabina), Common Chaffinch (Fringilla coelebs), Brambling (F. montifringilla), and European Robin (Erithactis rubecula). The Blue Tit differed from the regular migrants mainly in showing a striking negative correlation between migratory activity and cloud cover. Also, weather had the highest explanatory power for migratory intensity in the Blue Tit. This suggests that the Blue Tit is more sensitive to weather conditions on migration than the regular migrants and that it preferably awaits days with wholly or partly clear skies before migrating past Falsterbo. As a consequence, Blue Tits usually restrict their migratory flights to the safest occasions, with relatively calm weather, good visibility, and all orientation cues (solar as well as magnetic) available.
  •  
46.
  • Nilsson, Anna L K, et al. (author)
  • Energy reserves, information need and a pinch of personality determine decision-making on route in partially migratory blue tits
  • 2016
  • In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:10
  • Journal article (peer-reviewed)abstract
    • In facultative partial migrants some individuals in a population are migratory and others are resident and individuals decide each year anew which strategy to choose. While the proportion of birds migrating is in part determined by environmental conditions and competitive abilities, the timing of individual departure and behaviours on route are little understood. Individuals encounter different environmental conditions when migrating earlier or later. Based on cost/ benefit considerations we tested whether behaviours on route were affected by time constraints, personality and/or age in a partially migrating population of Blue tits (Cyanistes caeruleus). We captured female Blue tits on migration at the Southern tip of Sweden during early, peak and late migration and measured latency to feed in an unfamiliar environment, exploration of a novel object and hesitation to feed beside a novel object (neophobia). Lean birds and birds with long wings started feeding earlier when released into the cage indicating that foraging decisions were mainly determined by energetic needs (lean and large birds). However, juveniles commenced feeding later with progression of the migratory season in concordance with predictions about personality effects. Furthermore, lean birds started to explore earlier than birds with larger fat reserves again indicating an effect of maintaining threshold energy reserves. Moreover, late migrating juveniles, started to explore earlier than early migrating juveniles possibly due to time constraints to find high-quality foraging patches or a suitable winter home. Finally, neophobia did not change over the migratory season indicating that this behaviour is not compromised by time constraints. The results overall indicate that decisions on route are mainly governed by energetic requirements and current needs to learn about the environment and only to a small extent by differences in personality.
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47.
  • Nilsson, Anna L. K., et al. (author)
  • Migratory and resident blue tits Cyanistes caeruleus differ in their reaction to a novel object
  • 2010
  • In: Naturwissenschaften. - : Springer Science and Business Media LLC. - 1432-1904 .- 0028-1042. ; 97:11, s. 981-985
  • Journal article (peer-reviewed)abstract
    • Individuals differ consistently in their behavioural reactions towards novel objects and new situations. Reaction to novelty is one part of a suit of individually consistent behaviours called coping strategies or personalities and is often summarised as bold or shy behaviour. Coping strategies could be particularly important for migrating birds exposed to novel environments on their journeys. We compared the average approach latencies to a novel object among migrants and residents in partially migratory blue tits Cyanistes caeruleus. In this test, we found migrating blue tits to have shorter approach latencies than had resident ones. Behavioural reactions to novelty can affect the readiness to migrate and short approach latency may have an adaptive value during migration. Individual behaviour towards novelty might be incorporated among the factors associated with migratory or resident behaviour in a partially migratory population.
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48.
  • Nilsson, Anna, et al. (author)
  • The effect of climate change on partial migration - the blue tit paradox
  • 2006
  • In: Global Change Biology. - : Wiley. - 1354-1013. ; 12:10, s. 2014-2022
  • Journal article (peer-reviewed)abstract
    • Climate change has proven to affect various aspects of the migration of birds. In response to milder winters making the habitat more profitable and increasing the survival of residents, the migratory fraction of partially migratory populations has been predicted to decline. We studied the blue tit Parus caeruleus, a common partial migrant in southern Sweden. The numbers migrating at Falsterbo, a migratory passage site in SW Sweden, has increased during the last decades, in parallel with increasing winter and annual temperatures. Migration data from Falsterbo were compared with yearly indices of the size of the breeding population as estimated by the Swedish National Bird Monitoring Programme. Over the study period 1975-2004, also the breeding population has increased in size. The proportion of blue tits migrating each year did not change over the study period, or possibly even increased slightly, which is in contrast to how climate change has been predicted to influence populations containing both migratory and resident individuals. The most important factors determining the intensity of blue tit migration in a given year was the size of an important winter food source, the beech mast crop (more migrants at lower crops) and the size of the breeding population (more migrants at higher densities).
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49.
  • Nilsson, Jessica, et al. (author)
  • Comparison of the 2,2-azinobis-3-ethylbenzotiazoline-6-sulfonic acid (ABTS) and ferric reducing anti-oxidant power (FRAP) methods to asses the total antioxidant capacity in extracts of fruit and vegetables
  • 2005
  • In: Molecular Nutrition and Food Research. - : Wiley. - 1613-4133 .- 1613-4125. ; 49:3, s. 239-246
  • Journal article (peer-reviewed)abstract
    • A comparison was made on the use of two spectrophotometric methods, the ferric reducing antioxidant power (FRAP) method and the 2,2 '-azinobis-3-ethylbenzotiazoline-6-sulfonic acid (ABTS) method, for the measurement of the total antioxidant capacity (TAC) of plant foods. The correlations of TAC measured by the two methods were highly significant in both water-soluble (r(2) = 0.90) and water-insoluble extracts (r(2) = 0.98) from 13 strawberry samples. Also a corresponding comparison of TAC in extracts from 14 plant species showed high correlation coefficients, r(2) = 0.98 for water-soluble extracts and r(2) = 0.88 for water-insoluble extracts. The ratio of TAC values obtained with the two methods (ABTS/FRAP) varied between 0.7 and 3.3 for different plant extracts indicating that they contained antioxidants with varying reactivity in the two methods. TACs in six pure antioxidant substances were ranked in the following order by both methods: quercetin > ferulicacid > catechin > rutin > caffeicacid > Trolox = chlorogenic acid. The two methods showed similar TAC values for quercetin, rutin, caffeic acid and chlorogenic acid while ferulic acid and catechin gave higher results with the ABTS method than with the FRAP method, and such differences probably explain the varying ratios of ABTS/FRAP obtained in foods. Regarding storage TAC in water-soluble strawberry extracts stored at -20 or -80 degrees C was stable for at least five months while storage at 4 degrees C decreased the TAC value with 40% during five weeks of storage. The study showed that both the ABTS and FRAP methods can be used for convenient monitoring of the antioxidant capacities in fruit and vegetables, and that different antioxidants had varying reactivity in the two methods.
  •  
50.
  • Nilsson, Johan, et al. (author)
  • Experimental reduction of incubation temperature affects both nestling and adult blue tits Cyanistes caeruleus
  • 2008
  • In: Journal of Avian Biology. - 0908-8857. ; 39:5, s. 553-559
  • Journal article (peer-reviewed)abstract
    • Incubation was for a long time considered to be a period of decreased activity and low cost for parents. It was therefore ignored as a potential factor affecting life-history trade-offs in birds. Lately this view has started to change, and studies now show that there might be considerable costs connected to incubation. We experimentally reduced the nest temperature during incubation in blue tits Cyanistes caeruleus, thus increasing the energetic cost of incubation, to test the importance of incubation as a component of reproductive costs and for nestling quality. While most other studies use brood size manipulation to manipulate reproductive costs, we were able to separate treatment effects acting during the incubation period from those acting on later reproductive performance by applying a cross-foster design. We were also able to isolate the effects of decreased incubation temperature on the nestlings from treatment effects acting on incubating females. We found no experimental effect on the length of the incubation period or on hatching success. The lower temperature during incubation, however, caused lower growth rates in nestlings and reduced chick rearing capacity in adults. We conclude that incubation is a costly period, with the potential to affect both the trade-off between current and future reproduction and the one between parental effort and offspring quality within the current breeding attempt.
  •  
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