| 1. |
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| 2. |
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| 3. |
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| 4. |
- Bergman, Åke, et al.
(författare)
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Science and policy on endocrine disrupters must not be mixed : a reply to a "common sense" intervention by toxicology journal editors
- 2013
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- The "common sense" intervention by toxicology journal editors regarding proposed European Union endocrine disrupter regulations ignores scientific evidence and well-established principles of chemical risk assessment. In this commentary, endocrine disrupter experts express their concerns about a recently published, and is in our considered opinion inaccurate and factually incorrect, editorial that has appeared in several journals in toxicology. Some of the shortcomings of the editorial are discussed in detail. We call for a better founded scientific debate which may help to overcome a polarisation of views detrimental to reaching a consensus about scientific foundations for endocrine disrupter regulation in the EU.
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| 5. |
- Chavez, Johanna, et al.
(författare)
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Unexpectedly low UV-sensitivity in a bird, the budgerigar.
- 2014
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Ingår i: Biology letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- Photoreceptor adaptation ensures appropriate visual responses during changing light conditions and contributes to colour constancy. We used behavioural tests to compare UV-sensitivity of budgerigars after adaptation to UV-rich and UV-poor backgrounds. In the latter case, we found lower UV-sensitivity than expected, which could be the result of photon-shot noise corrupting cone signal robustness or nonlinear background adaptation. We suggest that nonlinear adaptation may be necessary for allowing cones to discriminate UV-rich signals, such as bird plumage colours, against UV-poor natural backgrounds.
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| 6. |
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| 7. |
- Haller, Nicola, et al.
(författare)
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Stimulus motion improves spatial contrast sensitivity in budgerigars (Melopsittacus undulatus).
- 2014
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Ingår i: Vision Research. - : Elsevier BV. - 1878-5646 .- 0042-6989. ; 102, s. 19-25
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Tidskriftsartikel (refereegranskat)abstract
- Birds are generally thought to have excellent vision with high spatial resolution. However, spatial contrast sensitivity of birds for stationary targets is low compared to other animals with similar acuity, such as mammals. For fast flying animals body stability and coordination are highly important, and visual motion cues are known to be relevant for flight control. We have tested five budgerigars (Melopsittacus undulatus) in behavioural discrimination experiments to determine whether or not stimulus motion improves contrast sensitivity. The birds were trained to distinguish between a homogenous grey field and sine-wave gratings of spatial frequencies between 0.48 and 6.5 cycles/degree, and Michelson contrasts between 0.7% and 99%. The gratings were either stationary or drifting with velocities between 0.9 and 13 degrees/s. Budgerigars were able to discriminate patterns of lower contrast from grey when the gratings were drifting, and the improvement in sensitivity was strongest at lower spatial frequencies and higher drift velocities. Our findings indicate that motion cues can have positive effects on visual perception of birds. This is similar to earlier results on human vision. Contrast sensitivity, tested solely with stationary stimuli, underestimates the sensory capacity of budgerigars flying through their natural environments.
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| 8. |
- Kelber, Almut, et al.
(författare)
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Limits of colour vision in dim light
- 2010
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Ingår i: Opthalmic and Physiological Optics. - : Wiley. - 1475-1313 .- 0275-5408. ; 30:5, s. 454-459
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Konferensbidrag (refereegranskat)abstract
- Humans and most vertebrates have duplex retinae with multiple cone types for colour vision in bright light, and one single rod type for achromatic vision in dim light. Instead of comparing signals from multiple spectral types of photoreceptors, such species use one highly sensitive receptor type thus improving the signal-to-noise ratio at night. However, the nocturnal hawkmoth Deilephila elpenor, the nocturnal bee Xylocopa tranquebarica and the nocturnal gecko Tarentola chazaliae can discriminate colours at extremely dim light intensities. To be able to do so, they sacrifice spatial and temporal resolution in favour of colour vision. We review what is known about colour vision in dim light, and compare colour vision thresholds with the optical sensitivity of the photoreceptors in selected animal species with lens and compound eyes.
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| 9. |
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| 10. |
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| 11. |
- Lind, Katharina, et al.
(författare)
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Induction of an Antiviral State and Attenuated Coxsackievirus Replication in Type III Interferon-Treated Primary Human Pancreatic Islets
- 2013
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Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 87:13, s. 7646-7654
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Tidskriftsartikel (refereegranskat)abstract
- Type III interferons (IFNs), also called lambda interferons (IFN-lambda), comprise three isoforms, IFN-lambda 1 (interleukin-29 [IL-29]), IFN-lambda 2 (IL-28A), and IFN-lambda 3 (IL-28B). Only limited information is available on their expression and biological functions in humans. Type I and type II IFNs protect human pancreatic islets against coxsackievirus infection, and this is important since such viruses have been proposed to play a role in the development of human type 1 diabetes. Here we investigated whether type III IFN is expressed during infection of human islet cells with coxsackievirus and if type III IFN regulates permissiveness to such infections. We show that human islets respond to a coxsackievirus serotype B3 (CVB3) infection by inducing the expression of type III IFNs. We also demonstrate that islet endocrine cells from nondiabetic individuals express the type III IFN receptor subunits IFN-lambda R1 and IL-10R2. Pancreatic alpha cells express both receptor subunits, while pancreatic beta cells express only IL-10R2. Type III IFN stimulation elicited a biological response in human islets as indicated by the upregulated expression of antiviral genes as well as pattern recognition receptors. We also show that type III IFN significantly reduces CVB3 replication. Our studies reveal that type III IFNs are expressed during CVB3 infection and that the expression of the type III IFN receptor by the human pancreatic islet allows this group of IFNs to regulate the islets' permissiveness to infection. Our novel observations suggest that type III IFNs may regulate viral replication and thereby contribute to reduced tissue damage and promote islet cell survival during coxsackievirus infection.
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| 12. |
- Lind, Marcus, 1976, et al.
(författare)
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Changes in HbA(1c) and frequency of measuring HbA(1c) and adjusting glucose-lowering medications in the 10 years following diagnosis of type 2 diabetes: a population-based study in the UK
- 2014
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 57:8, s. 1586-1594
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Tidskriftsartikel (refereegranskat)abstract
- Aim/hypothesis The aim of this work was to study levels of HbA(1c) and patterns of adjusting glucose-lowering drugs in patients with impaired glycaemic control over 10 years after diagnosis of type 2 diabetes. Methods We studied 4,529 individuals in The Health Improvement Network Database newly diagnosed with type 2 diabetes in the year 2000. Results From 6 months to 10 years after diagnosis, the HbA(1c) increased from 7.04% (53.4 mmol/mol) to 7.49% (58.3 mmol/mol) (average annual change: 0.047% [0.51 mmol/mol]). The greatest annual change occurred between 6 months and 2 years (0.21% [2.30 mmol/mol] increase per year, p < 0.001), followed by the 2-5 year time period (0.033% [0.36 mmol/mol] increase per year, p < 0.001). No significant increase in HbA(1c) occurred between 5 and 10 years (p = 0.20). In multivariable analyses, patients who were younger (p < 0.001), with higher BMI (p = 0.033) and who were current insulin users (p = 0.024) at diagnosis had greater increases in HbA(1c) between 6 months and 2 years. For individuals with HbA(1c) above 7.0% (53 mmol/mol) the mean time to next measurement of HbA(1c) was 0.53 years and increase in doses or changes to other glucose-lowering medications were performed in 26% of cases. Conclusions/interpretation HbA(1c) increases by approximately 0.5% (5 mmol/mol) over 10 years after diagnosis of type 2 diabetes, with the main increase appearing in the first years after diagnosis. More frequent monitoring of HbA(1c) and adjustments of glucose-lowering drugs may be essential to prevent the decline.
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| 13. |
- Lind, Marcus, 1976, et al.
(författare)
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The Association between HbA1c, Fasting Glucose, 1-Hour Glucose and 2-Hour Glucose during an Oral Glucose Tolerance Test and Cardiovascular Disease in Individuals with Elevated Risk for Diabetes
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:10
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To determine the association between HbA1c, fasting plasma glucose (FPG), 1-hour (1 hPG) and 2-hour (2 hPG) glucose after an oral glucose tolerance test (OGTT) and cardiovascular disease in individuals with elevated risk for diabetes. Design: We studied the relationship between baseline, updated mean and updated (last) value of HbA1c, FPG, 1 hPG and 2 hPG after an oral 75 g glucose tolerance test (OGTT) and acute CVD events in 504 individuals with impaired glucose tolerance (IGT) at baseline enrolled in the Finnish Diabetes Prevention Study. Participants: 504 individuals with IGT were followed with yearly evaluations with OGTT, FPG and HbA1c. Results: Over a median follow-up of 9.0 years 34 (6.7%) participants had a CVD event, which increased to 52 (10.3%) over a median follow-up of 13.0 years when including events that occurred among participants following a diagnosis of diabetes. Updated mean HbA1c, 1 hPG and 2 hPG, HR per 1 unit SD of 1.57 (95% CI 1.16 to 2.11), p = 0.0032, 1.51 (1.03 to 2.23), p = 0.036 and 1.60 (1.10 to 2.34), p = 0.014, respectively, but not FPG (p = 0.11), were related to CVD. In analyses of the last value prior to the CVD event the same three glycaemic measurements were associated with the CVD events, with HRs per 1 unit SD of 1.45 (1.06 to 1.98), p = 0.020, 1.55 (1.04 to 2.29), p = 0.030 and 2.19 (1.51 to 3.18), p < 0.0001, respectively but only 2 hPG remained significant in pairwise comparisons. Including the follow-up period after diabetes onset updated 2 hPG (p = 0.003) but not updated mean HbA1c (p = 0.08) was related to CVD. Conclusions and Relevance: Current 2 hPG level in people with IGT is associated with increased risk of CVD. This supports its use in screening for prediabetes and monitoring glycaemic levels of people with prediabetes.
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| 14. |
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| 15. |
- Lind, Olle
(författare)
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Bird Vision: Spatial acuity and colour discrimination in bright and dim light
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Birds use vision to guide navigation, foraging and mate choice, and studies of the limitations in bird visual perception are most helpful for the understanding of bird ecology. Here, I present four studies of bird vision in bright and dim light. Paper I is a quantification of how sensitive colour vision modelling is to variation in data, such as the spectral sensitivity of photoreceptors and receptor noise, which are used as model parameters. In Papers II and III, I have studied budgerigars (Melopsittacu undulatus), which are strictly diurnal, and Bourke’s parrots (Neopsephotus bourkii) that are diurnal but also active during twilight. Paper II shows that the intensity limit of colour vision and the optical sensitivity of single photoreceptors are similar in both species. Both parrots need more light to see colours (between 0.1-0.4 cd/m2) than other vertebrates (e.g. 0.01 cd/m2 for humans). In Paper II, it was also found that Bourke’s parrots have larger eyes and retinas with a higher density of rods compared to budgerigars. In Paper III, I investigated whether this gives Bourke’s parrots enhanced spatial vision in dim light. This does not seems to be the case, the spatial acuity is similar in both species at light intensities between 0.08 cd/m2 and 73 cd/m2. So far, there are no indications of superior visual capacities in dim light in Bourke’s parrots compared to budgerigars. In Paper IV, I have studied how colour vision in birds mediates spatial information. Colour patterns function as signals in bird communication, such as the plumage coloration of a courting bird. Much is known about birds’ perception of colour contrast, but the spatial tuning of colour vision in birds has been completely unknown. Here, I present, for the first time, a contrast sensitivity function for isoluminant colour patterns in an animal besides humans, the budgerigar. Paper IV shows that colour vision is used for the detection of colour contrast in larger fields while achromatic vision is used to detect fine detail. Similar finding has been made in humans suggesting that this is a general property of vertebrate vision. With Paper IV, it is now possible to account for both colour contrast and the spatial arrangement of colours in patterns when exploring bird communication.
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| 16. |
- Lind, Olle, et al.
(författare)
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Brightness Discrimination in Budgerigars (Melopsittacus undulatus)
- 2013
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Birds have excellent spatial acuity and colour vision compared to other vertebrates while spatial contrast sensitivity is relatively poor for unknown reasons. Contrast sensitivity describes the detection of gratings of varying spatial frequency. It is unclear whether bird brightness discrimination between large uniform fields is poor as well. Here we show that budgerigars (Melopsittacus undulatus) need a Michelson contrast of 0.09 to discriminate between large spatially separated achromatic fields in bright light conditions. This is similar to the peak contrast sensitivity of 10.2 (0.098 Michelson contrast) for achromatic grating stimuli established in earlier studies. The brightness discrimination threshold described in Weber fractions is 0.18, which is modest compared to other vertebrates.
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| 17. |
- Lind, Olle, et al.
(författare)
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Luminance-dependence of spatial vision in budgerigars (Melopsittacus undulatus) and Bourke's parrots (Neopsephotus bourkii).
- 2012
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Ingår i: Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology. - : Springer Science and Business Media LLC. - 1432-1351. ; 198, s. 69-77
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Tidskriftsartikel (refereegranskat)abstract
- Budgerigars (Melopsittacus undulatus) and Bourke's parrots (Neopsephotus bourkii) are closely related birds with different activity patterns. Budgerigars are strictly diurnal while Bourke's parrots are active in dim twilight. Earlier studies show that the intensity threshold of colour vision is similar in both species while Bourke's parrots have larger eyes with a higher density of rods than budgerigars. In this study, we investigate whether this could be an adaptation for better spatial vision in dim light. We used two alternative forced-choice experiments to determine the spatial acuity of both species at light intensities ranging from 0.08 to 73 cd/m(2). We also determined the spatial contrast sensitivity function (CSF) for bright light in Bourke's parrots and compare it to existing data for budgerigars. The spatial acuity of Bourke's parrots was found to be similar to that of budgerigars at all light levels. Also the CSF of Bourke's parrots is similar to that of budgerigars with a sensitivity peak located between 2.1 and 2.6 cycles/degree. Our findings do not support the hypothesis that Bourke's parrots have superior spatial acuity in dim light compared to budgerigars and the adaptive value of the relatively rod-rich and large eyes of Bourke's parrots remains unclear.
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| 18. |
- Lind, Olle, et al.
(författare)
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The contribution of single and double cones to spectral sensitivity in budgerigars during changing light conditions.
- 2014
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Ingår i: Journal of Comparative Physiology A. - : Springer Science and Business Media LLC. - 1432-1351 .- 0340-7594. ; 200:3, s. 197-207
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Tidskriftsartikel (refereegranskat)abstract
- Bird colour vision is mediated by single cones, while double cones and rods mediate luminance vision in bright and dim light, respectively. In daylight conditions, birds use colour vision to discriminate large objects such as fruit and plumage patches, and luminance vision to detect fine spatial detail and motion. However, decreasing light intensity favours achromatic mechanisms and eventually, in dim light, luminance vision outperforms colour vision in all visual tasks. We have used behavioural tests in budgerigars (Melopsittacus undulatus) to investigate how single cones, double cones and rods contribute to spectral sensitivity for large (3.4°) static monochromatic stimuli at light intensities ranging from 0.08 to 63.5 cd/m(2). We found no influences of rods at any intensity level. Single cones dominate the spectral sensitivity function at intensities above 1.1 cd/m(2), as predicted by a receptor noise-limited colour discrimination model. Below 1.1 cd/m(2), spectral sensitivity is lower than expected at all wavelengths except 575 nm, which corresponds to double cone function. We suggest that luminance vision mediated by double cones restores visual sensitivity when single cone sensitivity quickly decreases at light intensities close to the absolute threshold of colour vision.
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| 19. |
- Lind, Olle, et al.
(författare)
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The spatial tuning of achromatic and chromatic vision in budgerigars
- 2011
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Ingår i: Journal of Vision. - : Association for Research in Vision and Ophthalmology (ARVO). - 1534-7362. ; 11:7
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Tidskriftsartikel (refereegranskat)abstract
- Birds are assumed to use half of their cones (double cones) to detect fine spatial detail while their other half (single cones) is used for color vision. However, the spatial resolution of the color pathway in birds has never been studied. We determined the spatial contrast sensitivity to achromatic and isoluminant red-green and blue-green color gratings in budgerigars (Melopsittacus undulatus). Contrast sensitivity to achromatic gratings has band-pass characteristics while that for red-green and blue-green gratings has low-pass properties. Maximum sensitivity is lower to blue-green than to red-green gratings and the acuity for both color gratings is less than half (ca. 4.5 cycles/degree) of that for achromatic gratings (ca. 10 cycles/degree). This suggests that achromatic vision in birds, as in humans and bees, is tuned for detecting fine detail while chromatic vision is tuned for viewing larger fields. Similar to humans, blue-sensitive cones contribute little to spatial vision. Moreover, budgerigars detected gratings having both achromatic and chromatic contrasts more reliably at high spatial frequencies than gratings with either of these contrasts, suggesting that the single and double cone pathways are incompletely separated. The study demonstrates the importance of the spatial dimension of color vision; fine patterns remain unresolved even if they present large color contrasts.
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| 20. |
- Lind, Olle, et al.
(författare)
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Ultraviolet sensitivity and colour vision in raptor foraging
- 2013
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Ingår i: Journal of Experimental Biology. - : The Company of Biologists. - 1477-9145 .- 0022-0949. ; 216:10, s. 1819-1826
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Tidskriftsartikel (refereegranskat)abstract
- Raptors have excellent vision, yet it is unclear how they use colour information. It has been suggested that raptors use ultraviolet (UV) reflections from vole urine to find good hunting grounds. In contrast, UV plumage colours in songbirds such as blue tits are assumed to be 'hidden' communication signals, inconspicuous to raptors. This ambiguity results from a lack of knowledge about raptor ocular media transmittance, which sets the limit for UV sensitivity. We measured ocular media transmittance in common buzzards (Buteo buteo), sparrowhawks (Accipiter nisus), red kites (Milvus milvus) and kestrels (Falco tinnunculus) so that, for the first time, raptor UV sensitivity can be fully described. With this information, and new measurements of vole urine reflectance, we show that (i) vole urine is unlikely to provide a reliable visual signal to hunting raptors and (ii) blue tit plumage colours are more contrasting to blue tits than to sparrowhawks because of UV reflectance. However, as the difference between blue tit and sparrowhawk vision is subtle, we suggest that behavioural data are needed to fully resolve this issue. UV cues are of little or no importance to raptors in both vole and songbird interactions and the role of colour vision in raptor foraging remains unclear.
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| 21. |
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| 22. |
- Lind, Olle, et al.
(författare)
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Ultraviolet vision in birds: the importance of transparent eye media.
- 2014
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Ingår i: Royal Society of London. Proceedings B. Biological Sciences. - : The Royal Society. - 1471-2954. ; 281:1774
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Tidskriftsartikel (refereegranskat)abstract
- Ultraviolet (UV)-sensitive visual pigments are widespread in the animal kingdom but many animals, for example primates, block UV light from reaching their retina by pigmented lenses. Birds have UV-sensitive (UVS) visual pigments with sensitivity maxima around 360-373 nm (UVS) or 402-426 nm (violet-sensitive, VS). We describe how these pigments are matched by the ocular media transmittance in 38 bird species. Birds with UVS pigments have ocular media that transmit more UV light (wavelength of 50% transmittance, λT0.5, 323 nm) than birds with VS pigments (λT0.5, 358 nm). Yet, visual models predict that colour discrimination in bright light is mostly dependent on the visual pigment (UVS or VS) and little on the ocular media. We hypothesize that the precise spectral tuning of the ocular media is mostly relevant for detecting weak UV signals, e.g. in dim hollow-nests of passerines and parrots. The correlation between eye size and UV transparency of the ocular media suggests little or no lens pigmentation. Therefore, only small birds gain the full advantage from shifting pigment sensitivity from VS to UVS. On the other hand, some birds with VS pigments have unexpectedly low UV transmission of the ocular media, probably because of UV blocking lens pigmentation.
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| 23. |
- Lind, Ylva, 1954-, et al.
(författare)
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Stability of fatty acid composition in seal blubber during long-term storage
- 2012
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Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 461, s. 283-291
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Tidskriftsartikel (refereegranskat)abstract
- This study was performed to evaluate the stability of the fatty acid (FA) composition of blubber from Baltic grey seals Halichoerus grypus archived at −25°C in the Swedish Environmental Specimen Bank (SESB). Possible alterations of FA compositions with storage time and temperature were evaluated. Blubber from 5 seals was kept at +2°C and at −20°C and sampled for up to 6 mo and 33 mo, respectively. Furthermore, FA profile stability was evaluated in blubber stored in the SESB for 4 and 6 yr. This was done by re-sampling and re-analyzing blubber samples from SESB. In both parts of the study, a principal component analysis was performed on 48 FAs comprising 98 to 99% of the total FAs in blubber of Baltic grey seals. We found no indication of a critically altered FA composition, neither in blubber stored at +2°C for 6 mo nor in blubber stored at −20°C for 33 mo. The re-analysis of samples stored in SESB for ~4 to 6 yr only differed for a few FAs in some samples. The most remarkable differences were a slight increase in some long-chain unsaturated FAs (18:2n-6, 20:3n-3, 20:4n-3, 22:4n-3). As an increase in long-chain polyunsaturated FAs due to storage is highly unlikely, we believe that this is probably more due to the sampling technique than to a critically altered FA composition due to storage. Our results suggest that archived seal blubber may be safely used in retrospective analyses of diet using an FA signature analysis technique.
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| 24. |
- Mitkus, Mindaugas, et al.
(författare)
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Retinal ganglion cell topography and spatial resolution of two parrot species: budgerigar (Melopsittacus undulatus) and Bourke's parrot (Neopsephotus bourkii).
- 2014
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Ingår i: Journal of Comparative Physiology A. - : Springer Science and Business Media LLC. - 1432-1351 .- 0340-7594. ; 200:5, s. 371-384
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Tidskriftsartikel (refereegranskat)abstract
- Retinal ganglion cell (RGC) isodensity maps indicate important regions in an animal's visual field. These maps can also be combined with measures of focal length to estimate the theoretical visual acuity. Here we present the RGC isodensity maps and anatomical spatial resolving power in three budgerigars (Melopsittacus undulatus) and two Bourke's parrots (Neopsephotus bourkii). Because RGCs were stacked in several layers, we modified the Nissl staining procedure to assess the cell number in the whole-mounted and cross-sectioned tissue of the same retinal specimen. The retinal topography showed surprising variation; however, both parrot species had an area centralis without discernable fovea. Budgerigars also had a putative area nasalis never reported in birds before. The peak RGC density was 22,300-34,200 cells/mm(2) in budgerigars and 18,100-38,000 cells/mm(2) in Bourke's parrots. The maximum visual acuity based on RGCs and focal length was 6.9 cyc/deg in budgerigars and 9.2 cyc/deg in Bourke's parrots. These results are lower than earlier behavioural estimates. Our findings illustrate that retinal topography is not a very fixed trait and that theoretical visual acuity estimations based on RGC density can be lower than the behavioural performance of the bird.
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| 25. |
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| 26. |
- Roth, Lina, et al.
(författare)
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The Impact of Domestication on the Chicken Optical Apparatus
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:6, s. e65509-
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Tidskriftsartikel (refereegranskat)abstract
- Domestication processes tend to release animals from natural selection and favour traits desired by humans, such as food-production and co-operative behaviour. A side effect of such selective breeding is the alteration of unintended traits. In this paper, we investigate how active selection for egg production in chickens has affected the visual system, in particular the optical sensitivity that relates to the ability of chickens to see in dim light. We measured eye dimensions as well as the pupil diameter at different light intensities (the steady state pupil dynamics), in adult male and female White Leghorns and the closest relatives to their ancestor, the Red Junglefowls. With this information, we calculated the focal length and optical sensitivity (f-number) of the eyes. Males have larger eyes than females in both breeds and White Leghorn eyes are larger than those of Red Junglefowls in both sexes. The steady state pupil dynamics is less variable, however, the combination of pupil dynamics and eye size gives a higher optical sensitivity in Red Junglefowl eyes than in White Leghorns at light intensities below approximately 10 cd/m2. While eye size and focal length match the larger body size in White Leghorns compared to Red Junglefowls, the steady state pupil dynamics do not. The reason for this is likely to be that eye morphology and the neuro-muscular control of the pupil have been affected differently by the strong selection for egg production and the simultaneous release of the selection pressure for high performing vision. This study is the first description of how optical sensitivity has changed in a domesticated species and our results demonstrate important considerations regarding domestication processes and sensory ability.
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| 27. |
- Telles, Francismeire Jane, et al.
(författare)
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Out of the blue: the spectral sensitivity of hummingbird hawkmoths.
- 2014
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Ingår i: Journal of Comparative Physiology A. - : Springer Science and Business Media LLC. - 1432-1351 .- 0340-7594. ; 200:6, s. 537-546
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Tidskriftsartikel (refereegranskat)abstract
- The European hummingbird hawkmoth Macroglossum stellatarum is a diurnal nectar forager like the honeybee, and we expect similarities in their sensory ecology. Using behavioural tests and electroretinograms (ERGs), we studied the spectral sensitivity of M. stellatarum. By measuring ERGs in the dark-adapted eye and after adaptation to green light, we determined that M. stellatarum has ultraviolet (UV), blue and green receptors maximally sensitive at 349, 440 and 521 nm, and confirmed that green receptors are most frequent in the retina. To determine the behavioural spectral sensitivity (action spectrum) of foraging moths, we trained animals to associate a disk illuminated with spectral light, with a food reward, and a dark disk with no reward. While the spectral positions of sensitivity maxima found in behavioural tests agree with model predictions based on the ERG data, the sensitivity to blue light was 30 times higher than expected. This is different from the honeybee but similar to earlier findings in the crepuscular hawkmoth Manduca sexta. It may indicate that the action spectrum of foraging hawkmoths does not represent their general sensory capacity. We suggest that the elevated sensitivity to blue light is related to the innate preference of hawkmoths for blue flowers.
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| 28. |
- Waling, Maria, 1981-, et al.
(författare)
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A one-year intervention has modest effects on energy and macronutrient intakes of overweight and obese Swedish children.
- 2010
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Ingår i: The Journal of nutrition. - : Elsevier BV. - 1541-6100 .- 0022-3166. ; 140:10, s. 1793-8
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Tidskriftsartikel (refereegranskat)abstract
- To decrease BMI in overweight and obese children, improved dietary intake and increased physical activity are key elements. Our objective was to evaluate the impact of a 1-y food and physical activity intervention on energy and macronutrient intake in overweight and obese children. A randomized open trial was conducted with 92 overweight or obese 10.4 ± 1.08-y-old children. The intervention included 14 group sessions with different themes regarding food and physical activity. Dietary intake was assessed with diet history interviews covering 14 d at baseline and 4-d food records after 1 y and was evaluated according to national dietary recommendations. The control group participated in the same measurements as the intervention group but did not take part in group sessions. After 1 y, both groups had decreased their energy intake (EI) relative to total energy expenditure, but the effect was more pronounced for the intervention group than for the control group. At 1 y follow-up, a larger proportion of children in the intervention group compared with the control group met the recommended intake of refined sugar (P = 0.019). However, the groups did not differ in the proportion children who met the recommended intake of dietary fiber. Further, SFA intake relative to total EI did not differ between the groups at 1 y follow-up. In conclusion, despite a rather comprehensive intervention, only modest effects were achieved with respect to reduced EI and improved macronutrient intake.
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| 29. |
- Öhlund, Inger, 1954-, et al.
(författare)
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BMI at 4 years of age is associated with previous and current protein intake and with paternal BMI
- 2010
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Ingår i: European Journal of Clinical Nutrition. - : Springer Science and Business Media LLC. - 0954-3007 .- 1476-5640. ; 64:2, s. 138-145
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Objectives:To evaluate possible associations between body mass index (BMI) at 4 years of age, current and previous dietary intakes and parental BMI.Methods:A follow-up of dietary intake and anthropometry in 127 4-year-old children corresponding to 54% of children who completed an initial intervention study at 18 months of age.Results:Fourteen percent of the girls and 13% of the boys were overweight (age-adjusted BMI>/=25) and 2% of the girls and 3% of the boys were obese (age-adjusted BMI>/=30). Thirty-four percent and 9% of the fathers and 19 and 7% of the mothers were overweight and obese, respectively. BMI at 6-18 months was a strong predictor of BMI at 4 years. Univariate regression analyses revealed that intake of protein in particular, and also of total energy and carbohydrates at 17/18 months and at 4 years, was positively associated with BMI at 4 years. Although BMI at 6-18 months was the strongest predictor of BMI at 4 years, in the final multivariate models of the child's BMI, protein intake at 17-18 months and at 4 years, energy intake at 4 years and the father's-but not the mother's-BMI were also independent contributing factors.Conclusions:Among these healthy children, BMI at 4 years of age tracked from 6 to 18 months of age and were associated with previous and current protein intake as well as parental BMI, particularly that of the father.
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| 30. |
- Öhlund, Inger, et al.
(författare)
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Serum 25-Hydroxyvitamin D Levels in Preschool-Age Children in Northern Sweden Are Inadequate After Summer and Diminish Further During Winter
- 2013
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Ingår i: Journal of Pediatric Gastroenterology and Nutrition - JPGN. - 0277-2116 .- 1536-4801. ; 56:5, s. 551-555
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objective: Despite studies indicating that vitamin D intake among Swedish children does not meet the recommendation, little is known of their vitamin D status. The aim of the present study was to examine vitamin D status in preschool-age children in relation to vitamin D intake, season, body mass index, and skin color. Methods: Preschool-age children (n = 90; mean age 54 +/- 7.1 months), all living in northern Sweden (latitude 63 degrees north), half of them with fair skin, half with darker complexion, were recruited from well-baby clinics. The study group was examined first in August-September (late summer) and then the following January-February (winter). Skin type, vitamin D intake, anthropometrics, serum 25-hydroxyvitamin D (S-25[OH] D), and serum parathyroid hormone were assessed. Results: Mean +/- SD S-25(OH) Din summer and winter were 60 +/- 15 nmol/L and 55 +/- 16 nmol/L, respectively (P < 0.001). Fifteen percent and 10% had S-25(OH) D >= 75 nmol/L, and 25% and 40% had S-25(OH) D < 50 nmol/L, respectively. The mean vitamin D intake was higher in dark-skinned compared with fair-skinned children. In spite of this, S-25(OH) D in dark-skinned children was lower compared with fair-skinned children during both seasons. The dietary intake of vitamin D was positively associated with S-25(OH) D levels. Conclusions: Vitamin D status is inadequate in preschool-age children living in northern Sweden, especially in dark-skinned children and during the winter despite vitamin D intakes meeting the recommendations, prompting strategies to improve intake of vitamin D in this population.
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| 31. |
- Öhlund, Inger, et al.
(författare)
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Serum lipid and apolipoprotein levels in 4-year-old children are associated with parental levels and track over time
- 2011
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Ingår i: European Journal of Clinical Nutrition. - London : Nature Publishing Group. - 0954-3007 .- 1476-5640. ; 65:4, s. 463-469
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Tidskriftsartikel (refereegranskat)abstract
- Background/Objectives: There are only a few studies linking dietary fat intake to serum lipid levels in young children. Our objective was to prospectively evaluate serum lipid levels from infancy to early childhood, and to explore their possible association with dietary, growth and parental factors.Subjects/Methods: Children (n=127) followed from early infancy were examined for serum lipid levels, anthropometry and dietary intake at 4 years of age. We also studied possible associations with parental anthropometric and blood biochemistry data collected from 122 mothers' and 118 fathers' when children were 4 years of age.Results: Serum concentrations of total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC) and the apolipoprotein B/apolipoprotein A-1 ratio (apo B/apo A-1) showed significant tracking from infancy to 4 years. Furthermore, children's TC levels correlated with paternal TC level from 6 months to 4 years, but with maternal only at 4 years. In girls, both LDLC and HDLC correlated with parental LDLC and HDLC. In all children, intake of saturated fatty acids (SAFAs) was higher than recommended, and in 90% of the children polyunsaturated fatty acid (PUFA) intake was lower than recommended.Conclusions: Serum lipid levels values tracked from infancy to 4 years and were associated with parental values. Higher serum lipid levels at 4 years compared with 6-18 months of age may result from changes in the quality of dietary fat. We therefore suggest that intake of dietary fat in 4-year-old children should be more focused on quality. Furthermore, as there were strong associations between the child and parental serum lipid levels this supports the view that family-based rather than individual intervention is preferable.
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