| 1. |
- Alerstam, Thomas, et al.
(författare)
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Flight speeds among bird species : allometric and phylogenetic effects.
- 2007
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Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 5:8, s. e197-
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Tidskriftsartikel (refereegranskat)abstract
- Flight speed is expected to increase with mass and wing loading among flying animals and aircraft for fundamental aerodynamic reasons. Assuming geometrical and dynamical similarity, cruising flight speed is predicted to vary as (body mass)(1/6) and (wing loading)(1/2) among bird species. To test these scaling rules and the general importance of mass and wing loading for bird flight speeds, we used tracking radar to measure flapping flight speeds of individuals or flocks of migrating birds visually identified to species as well as their altitude and winds at the altitudes where the birds were flying. Equivalent airspeeds (airspeeds corrected to sea level air density, Ue) of 138 species, ranging 0.01-10 kg in mass, were analysed in relation to biometry and phylogeny. Scaling exponents in relation to mass and wing loading were significantly smaller than predicted (about 0.12 and 0.32, respectively, with similar results for analyses based on species and independent phylogenetic contrasts). These low scaling exponents may be the result of evolutionary restrictions on bird flight-speed range, counteracting too slow flight speeds among species with low wing loading and too fast speeds among species with high wing loading. This compression of speed range is partly attained through geometric differences, with aspect ratio showing a positive relationship with body mass and wing loading, but additional factors are required to fully explain the small scaling exponent of Ue in relation to wing loading. Furthermore, mass and wing loading accounted for only a limited proportion of the variation in Ue. Phylogeny was a powerful factor, in combination with wing loading, to account for the variation in Ue. These results demonstrate that functional flight adaptations and constraints associated with different evolutionary lineages have an important influence on cruising flapping flight speed that goes beyond the general aerodynamic scaling effects of mass and wing loading.
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| 2. |
- Askling, Helena H, et al.
(författare)
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Serologic Analysis of Returned Travelers with Fever, Sweden
- 2009
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Ingår i: Emerging Infectious Diseases. - Atlanta, GA, USA : U.S. Department of Health and Human Services * Centers for Disease Control and Prevention. - 1080-6040 .- 1080-6059. ; 15:11, s. 1805-1808
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Tidskriftsartikel (refereegranskat)abstract
- We studied 1,432 febrile travelers from Sweden who had returned from malaria-endemic areas during March 2005-March 2008. In 383 patients, paired serum samples were blindly analyzed for influenza and 7 other agents. For 21% of 115 patients with fever of unknown origin, serologic analysis showed that influenza was the major cause.
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| 3. |
- Bengtsson, Boel, et al.
(författare)
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Test-retest variability for standard automated perimetry and short-wavelength automated perimetry in diabetic patients
- 2008
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Ingår i: Acta Ophthalmologica. - : Wiley-Blackwell. - 1755-375X .- 1755-3768 .- 1395-3907. ; 86:2, s. 170-6
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To assess limits for significant improvement or deterioration of visual fields in diabetic patients based on short-term test-retest variability in subjects with different degrees of retinopathy.METHODS: Fifty patients with diabetic retinopathy ranging from level 10 to 75 [according to the Early Treatment Diabetic Retinopathy Study (ETDRS) severity scale] were tested repeatedly with both standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP) with short intervals. The association between visual field loss and degree of retinopathy outside fovea was analysed. Test-retest variability of global and local visual field indices and prediction limits for significant change were calculated.RESULTS: The amount of visual field loss was significantly associated to the degree of retinopathy, with a correlation coefficient of -0.51 for SAP (P = 0.0003) and -0.45 for SWAP (P = 0.002). Global test-retest variability was smaller with SAP than with SWAP (P < 0.0001). For both SAP and SWAP, local test-retest variability was considerably smaller at test points with normal sensitivity than at test points with reduced sensitivity (P < 0.0001). Paracentral test points within 10 degrees of eccentricity had less variability than peripheral points (P < 0.0001), implying that smaller change is required to reach statistically significant improvement or deterioration at initially normal and paracentral points than at depressed points and peripherally located test points.CONCLUSION: Our results propose that SAP, as well as SWAP, can be useful for monitoring visual function outside fovea in diabetic patients with various degrees of retinopathy. We report a preference for SAP because of less variability generally. Limits for significant improvement or deterioration have been assessed but need future validation in a longitudinal study.
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| 4. |
- Cardell, L O, et al.
(författare)
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Genes regulating molecular and cellular functions in noninfectious nonallergic rhinitis.
- 2009
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Ingår i: Allergy. - : Wiley. - 1398-9995 .- 0105-4538. ; 64:9, s. 1301-8
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Tidskriftsartikel (refereegranskat)abstract
- Chronic noninfectious, nonallergic rhinitis (NINAR) is a complex syndrome with a principally unknown pathophysiology. New technology has made it possible to examine differentially expressed genes and according to network theory, genes connected by their function that might have key roles in the disease.
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| 5. |
- Hellgren, Johan, 1965, et al.
(författare)
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A validation study of nasal spectroscopy: Rhinolux.
- 2007
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Ingår i: European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery. - : Springer Science and Business Media LLC. - 0937-4477. ; 264:9, s. 1009-12
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Tidskriftsartikel (refereegranskat)abstract
- This study is the first to validate the Rhinolux against acoustic rhinometry in detecting nasal mucosal swelling when changing body position from sitting to supine. The Rhinolux (Rhios GmbH, Germany) is a new device using a light-absorption technique called nasal spectroscopy and to measure changes in nasal blood volume as a sign of nasal mucosal swelling in real time. The relationship between the changes in nasal blood volume measured with the Rhinolux and changes in nasal mucosal swelling has however, not previously been validated objectively. To evaluate this relationship we compared the Rhinolux to acoustic rhinometry following the change in body position from sitting to supine. The study population consisted of 20 healthy subjects (7 women, 13 men, mean age 34.7 +/- 9.3 years). The Rhinolux was applied sitting in the upright position followed by 5 min in the supine position. Acoustic rhinometry was measured sitting in the upright position and after 5 min in the supine position. In seven subjects the measurements were repeated on three different days to assess the repeatability. The mean change from baseline in minimal cross sectional area DeltaMCA measured with acoustic rhinometry was -0.12(+/-0.19) cm2 (right + left side), P = 0.013 but DeltaE (change in light extinction from baseline) measured with the Rhinolux was unchanged 0.02(+/-0.18) optical densities (OD), P = 0.56. There was no correlation between DeltaE and DeltaMCA r = 0.028, P = 0.9. The mean DeltaE result from repeated measurements on different days was 0.05(+/-0.08) OD, P = 0.09 and the DeltaMCA was -0.1(+/-0.11) cm2, P = 0.02. This study showed that the changes in nasal blood volume measured with the Rhinolux did not reflect changes in nasal mucosal swelling measured with acoustic rhinometry when changing body position from sitting to supine. The results indicate that the utility of the Rhinolux in assessing nasal mucosal reactions has to be evaluated further.
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| 6. |
- Hellgren, Johan, 1965, et al.
(författare)
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Altered positional regulation of nasal patency in patients with obstructive sleep apnoea syndrome.
- 2009
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Ingår i: European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery. - : Springer Science and Business Media LLC. - 1434-4726. ; 266:1, s. 83-7
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Tidskriftsartikel (refereegranskat)abstract
- We assessed the regulation of nasal patency supine in subjects with obstructive sleep apnoea syndrome (OSAS) compared to healthy controls. Healthy subjects increase nasal obstruction when changing body position from sitting to supine, possibly due to increased hydrostatic pressure in the head supine. Limited data indicate that this response is altered in patients with OSAS, suggesting that supine nasal patency is actively regulated. This study examined the nasal response to recumbent body position using acoustic rhinometry in OSAS patients and healthy controls. Twenty subjects (16 men and 4 women, mean age 55 +/- 16 years), with diagnosed OSAS [mean apnoea hypopnoea index (AHI) 46 +/- 22 events/h] without nasal obstruction and continuous positive airway pressure (CPAP)-naive, underwent measurement of intra-nasal cross sectional area by acoustic rhinometry at sitting and after 5 min supine. Twenty healthy controls (13 men, 7 women, mean age 35 +/- 9 years) were also included in the study. In the patients with OSAS, the mean minimal cross sectional area (MCA, left + right nasal cavity) was unchanged between sitting (1.18 +/- 0.41 cm(2)) and supine (1.21 +/- 0.35 cm(2), P = 0.5). In the healthy controls, the mean MCA decreased from 1.06 +/- 0.18 to 0.94 +/- 0.21 cm(2) supine, P = 0.01. This study showed that the normal decrease in nasal patency following a change in body position from sitting to supine is absent in patients with OSAS. The results indicate that there is an active regulation of supine nasal patency.
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| 7. |
- Hellgren, Johan, 1965, et al.
(författare)
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Nonallergic occupational rhinitis
- 2007
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Ingår i: Clin Allergy Immunol. - 1075-7910. ; 19, s. 241-8
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Hellgren, Johan, 1965
(författare)
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Occupational rhinosinusitis.
- 2008
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Ingår i: Current allergy and asthma reports. - 1529-7322. ; 8:3, s. 234-9
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Tidskriftsartikel (refereegranskat)abstract
- In contrast to most allergic rhinitis and nasal hyperresponsiveness, occupational rhinosinusitis offers a unique and effective measure-control of exposure-to reduce its medical impact on patients. Prospective data from adolescents introduced to the work environment show that working in high-risk environments results in a higher incidence of rhinitis compared with those not employed in such settings. Data also show that the highest incidence of occupational rhinosinusitis is found during the first months of exposure to irritants and sensitizers, emphasizing the importance of early prevention. The study of occupational rhinosinusitis is complicated by factors related to poor definitions, clear-cut differentiation from other nasal inflammatory disease, and the industrial, economic, and political considerations in the implementation of preventive measures. This review focuses on new insights on occupational rhinosinusitis, including the impact on health-related quality of life.
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| 9. |
- Hellgren, Johan, 1965, et al.
(författare)
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Perennial non-infectious rhinitis--an independent risk factor for sleep disturbances in Asthma.
- 2007
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 101:5, s. 1015-20
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Tidskriftsartikel (refereegranskat)abstract
- Aim of the studyTo evaluate if perennial non-infectious rhinitis is associated with sleep disturbances in asthma.Materials and methodsThis is a questionnaire based study in a random population sample from Denmark, Estonia, Iceland, Norway and Sweden aged 30–54 yr. A total of 1127 individuals reporting asthma from an original random population sample of 16,191 were analysed regarding their quality of sleep in relation to perennial non-infectious rhinitis. Perennial non-infectious rhinitis was defined as having nasal symptoms such as nasal blockage and secretion in the absence of common cold, always. Asthma was defined as both ever having had asthma and having physician diagnosed asthma. Odds ratios (OR) for difficulties inducing sleep, difficulties maintaining sleep, early morning awakenings and daytime sleepiness were calculated in a multiple logistic regression controlling for other risk factors for sleep disturbances such as snoring, wheeze, obesity and smoking.ResultsThe response rate was 74%. A total of 189 (17%) of the subjects with asthma reported perennial non-infectious rhinitis. Perennial non-infectious rhinitis was associated with an increased OR for difficulties maintaining sleep (1.6 (95% confidence interval (CI) 1.1–2.3)), early morning awakenings (1.5 (95% CI 1.1–2.2)) and daytime sleepiness (1.8 (95% CI 1.2–2.9)). The result show that perennial non-infectious rhinitis is an independant risk factor for sleep disturbances in asthma.
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| 10. |
- Hellgren, Johan, 1965
(författare)
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Quality of life in nonallergic rhinitis.
- 2007
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Ingår i: Clinical allergy and immunology. - 1075-7910. ; 19, s. 383-7
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Tidskriftsartikel (refereegranskat)abstract
- Health-related quality-of-life questionnaires are instruments to assess the burden of a disease as perceived by the patient. Few data are available on the health-related quality of life of patients with nonallergic rhinitis, but data from studies of patients with allergic rhinitis show that rhinitis predominantly affects mental quality of life. This burden of rhinitis is associated with impaired sleep, excessive daytime sleepiness, concentration problems, and increased irritability.
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