| 1. |
- Andersson, Staffan, 1959, et al.
(författare)
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Effects of egg yolk testosterone on growth and immunity in a precocial bird
- 2004
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X. ; 17:3, s. 501-505
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Tidskriftsartikel (refereegranskat)abstract
- In oviparous vertebrates, maternal steroid allocation to eggs can have important fitness consequences for the offspring. However, elevated testosterone levels are not only associated with beneficial postnatal effects, such as enhanced growth and high social status, but may also entail costs by suppressing the immune system. In this study, testosterone levels in eggs of Chinese painted quail (Coturnix chinensis) were experimentally manipulated to evaluate its effects on growth and immunocompetence. Testosterone did not affect embryonic development, body size or growth during the first 20 days. However, elevated testosterone levels during embryonic development were immunosuppressive for chicks with inherently higher growth rate. Adaptive scenarios where only beneficial effects of increased testosterone levels are considered may therefore need to be re-evaluated.
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| 2. |
- Koch, Sarah, et al.
(författare)
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Impacts of changes in environmental exposures and health behaviours due to the COVID-19 pandemic on cardiovascular and mental health : A comparison of Barcelona, Vienna, and Stockholm
- 2022
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 304
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Tidskriftsartikel (refereegranskat)abstract
- Responses to COVID-19 altered environmental exposures and health behaviours associated with noncommunicable diseases. We aimed to (1) quantify changes in nitrogen dioxide (NO2), noise, physical activity, and greenspace visits associated with COVID-19 policies in the spring of 2020 in Barcelona (Spain), Vienna (Austria), and Stockholm (Sweden), and (2) estimated the number of additional and prevented diagnoses of myocardial infarction (MI), stroke, depression, and anxiety based on these changes. We calculated differences in NO2, noise, physical activity, and greenspace visits between pre-pandemic (baseline) and pandemic (counterfactual) levels. With two counterfactual scenarios, we distinguished between Acute Period (March 15th - April 26th, 2020) and Deconfinement Period (May 2nd - June 30th, 2020) assuming counterfactual scenarios were extended for 12 months. Relative risks for each exposure difference were estimated with exposure-risk functions. In the Acute Period, reductions in NO2 (range of change from -16.9 mu g/m3 to -1.1 mu g/m3), noise (from -5 dB(A) to -2 dB(A)), physical activity (from -659 MET*min/wk to -183 MET*min/wk) and greenspace visits (from -20.2 h/m to 1.1 h/m) were largest in Barcelona and smallest in Stockholm. In the Deconfinement Period, NO2 (from -13.9 mu g/m3 to -3.1 mu g/m3), noise (from -3 dB(A) to -1 dB(A)), and physical activity levels (from -524 MET*min/wk to -83 MET*min/wk) remained below pre-pandemic levels in all cities. Greatest impacts were caused by physical activity reductions. If physical activity levels in Barcelona remained at Acute Period levels, increases in annual diagnoses for MI (mean: 572 (95% CI: 224, 943)), stroke (585 (6, 1156)), depression (7903 (5202, 10,936)), and anxiety (16,677 (926, 27,002)) would be anticipated. To decrease cardiovascular and mental health impacts, reductions in NO2 and noise from the first COVID-19 surge should be sustained, but without reducing physical activity. Focusing on cities' connectivity that promotes active transportation and reduces motor vehicle use assists in achieving this goal.
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| 3. |
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| 4. |
- Lõhmus, Mare, 1972, et al.
(författare)
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Chronic administration of leptin in Asian Blue Quail
- 2006
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Ingår i: Journal of Experimental Zoology Part a-Comparative Experimental Biology. - : Wiley. - 1548-8969 .- 1552-499X. ; 305A:1, s. 13-22
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that leptin has the capacity to reduce food intake, cause body weight loss, and increase energy expenditure in several vertebrate species. In this study, we investigated the effects of chronically elevated leptin levels on behavior and physiology of Asian Blue Quail (Coturnix chinensis). Fifteen male quail were treated with chicken leptin dissolved in phosphate-buffered saline (PBS) via subcutaneously inserted osmotic pumps that released approximately 1 mu g/g body weight/day during a 14-day period. Another 15 males acted as controls and their pumps released PBS only. All males were housed together with two females. We observed a decrease in body weight and feeding behavior in leptin-treated birds, but not in control birds, after 2 days of treatment. Thereafter, all birds increased in weight. Males treated with leptin were more active and more likely to preen the day after the beginning of the treatment. Plasma cholesterol levels in leptin birds decreased during the first week of treatment and plasma triglycerides tended to remain lower compared to the controls during the whole 2-week period of treatment. Glucose levels appeared stable during the observation period. Leptin-treated males remained closer to accompanying females than did control males, and females together with leptin males took longer to lay their first egg compared to females together with control males. This is the first article showing the effect of leptin on cholesterol and triglyceride levels in birds. We also observed a change in the activity and male-female interaction pattern in tested quail.
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| 5. |
- Lohmus, Mare, et al.
(författare)
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Climate change : what will it do to fish-parasite interactions?
- 2015
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Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 116:2, s. 397-411
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Forskningsöversikt (refereegranskat)abstract
- Climate change-related factors are predicted to affect aquatic environments in many ways. Fish physiology, immunology, behaviour, and parasite-avoidance strategies are likely to be affected by climate change and this may lead to ecosystem-level changes. Parasitic organisms that exploit fish are also likely to be affected by climate change, both directly and via climate effects on their hosts. It is possible that climate change will alter the prerequisites for parasite transfer, for example, through changes in phenological relationships, and/or change the direction and pressure of selection in host-parasite relationships. Our review indicates strong multifactorial effects of climate change on fish-parasite systems. Increased water temperature is, on the one hand, predicted to enhance parasite metabolism, resulting in more rapid spread of parasites; on the other hand, the occurrence of some parasites could also decrease if the optimal temperature for growth and transmission is exceeded.
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| 6. |
- Lõhmus, Mare, et al.
(författare)
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Combined Exposure to Birch Pollen and Thunderstorms Affects Respiratory Health in Stockholm, Sweden—A Time Series Analysis
- 2022
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 19:10, s. 5852-5852
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Tidskriftsartikel (refereegranskat)abstract
- Background: Thunderstorm asthma is a term used to describe surges in acute respiratory illnesses following a thunderstorm and is often attributed to an intense exposure to aeroallergens. Several episodes of thunderstorm asthma have been observed worldwide; however, no such cases have been described in Sweden. In Sweden, the most prominent exposure to air-borne pollen occurs during the blooming of the birch. We aimed to explore the associations between respiratory health and the combined exposure to thunderstorms and birch pollen. Methods: We investigated the association between the daily numbers of outpatient visits due to respiratory cases and the combined exposure to thunderstorms and birch pollen during the period of 1 May–31 September in 2001–2017, in Stockholm County, Sweden, by using time series analysis with log linear models. Results: We detected noticeable increases in the number of outpatient visits on both the same day (max 26%; 95% CI 1.16–1.37) and the day after (max 50%; 95% CI 1.32–1.70) the occurrence of a thunderstorm, when the concentrations of birch pollen and the number of lightning discharges were within the highest categories. Conclusions: It is possible that co-exposure to heavy thunderstorms and high concentrations of birch pollen affects the respiratory health of the Stockholm population. To the best of our knowledge, this is the first study addressing the thunderstorm-related respiratory illnesses in Sweden and the effects of birch pollen. Our study may be important for future public health advice related to thunderstorm asthma.
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| 7. |
- Lõhmus, Mare, et al.
(författare)
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Disruption of seasonality in growth hormone-transgenic coho salmon (Oncorhynchus kisutch) and the role of cholecystokinin in seasonal feeding behavior.
- 2008
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Ingår i: Hormones and behavior. - : Elsevier BV. - 1095-6867 .- 0018-506X. ; 54:4, s. 506-13
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Tidskriftsartikel (refereegranskat)abstract
- Seasonal variation in daily food intake is a well-documented phenomenon in many organisms including wild-type coho salmon where the appetite is noticeably reduced during periods of decreased day length and low water temperature. This reduction may in part be explained by altered production of cholecystokinin (CCK) and growth hormone (GH). CCK is a hormone produced in the brain and gut that mediates a feeling of satiety and thus has an inhibitory effect on food intake and foraging behaviour. Growth hormone (GH) enhances feeding behaviour and consequently growth, but its production is reduced during winter. The objectives of this study were: first, to compare the seasonal feeding behaviour of wild and GH-transgenic coho salmon; second, to determine the behavioural effect of blocking the action of CCK (by using devazepide) on the seasonal food intake; and third, to measure CCK expression in brain and gut tissues between the two genotypes across seasons. We found that, in contrast to wild salmon, food intake in transgenic salmon was not reduced during winter indicating that seasonal control of appetite regulation has been disrupted by constitutive production of GH in transgenic animals. Blocking of CCK increased food intake in both genotypes in all seasons. The increase was stronger in wild genotypes than transgenic fish; however blocking CCK in wild-type fish in winter did not elevate appetites to levels observed in the summer. The response to devazepide was generally faster in transgenic than in wild salmon with more rapid effects observed during summer than during winter, possibly due to a higher temperature in summer. Overall, a seasonal effect on CCK mRNA levels was observed in telencephalon with levels during winter being higher compared to the summer in wild fish, but with no seasonal effect in transgenic fish. No differences in seasonal CCK expression were found in hypothalamus. Higher levels of CCK were detected in the gut of both genotypes in winter compared to summer. Thus, CCK appears to mediate food intake among seasons in both wild-type and GH-transgenic salmon, and an altered CCK regulation may be responsible at least in part for the seasonal regulation of food intake.
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| 8. |
- Lohmus, Mare, et al.
(författare)
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Dress for success : human facial expressions are important signals of emotions
- 2009
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Ingår i: Annales Zoologici Fennici. - 0003-455X .- 1797-2450. ; 46:1, s. 75-80
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Tidskriftsartikel (refereegranskat)abstract
- In order to test how emotions affect individual neutral facial expressions and the reliability of humans to read these expressions, we photographed faces of 25 women wearing clothes in which they felt attractive, unattractive, or comfortable while expressing an emotionally neutral face. Men found the faces of women in attractive clothes the most attractive, whereas the faces of women in comfortable and unattractive clothes were ranked as intermediate and least attractive, respectively, even though the clothes were not visible in the photographs. Our results demonstrate that despite very subtle effects, the emotional state of women is perceived by men and that the two sexes are concordant on the signal sent and received. We show a close connection between exterior attributes, confidence, and how a person is perceived by others.
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| 9. |
- Lõhmus, Mare, 1972, et al.
(författare)
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Dress for success: even unseen clothing increases female facial attractiveness
- 2009
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Ingår i: Annales Zoologici Fennici. ; 46, s. 75-80
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Tidskriftsartikel (refereegranskat)abstract
- Human facial expressions are important signals of emotions. In order to test how emotions affect individual neutral facial expressions and the reliability of humans to read these expressions, we photographed faces of 25 women wearing clothes in which they felt attractive, unattractive, or comfortable while expressing an emotionally neutral face. Men found the faces of women in attractive clothes the most attractive, whereas the faces of women in comfortable and unattractive clothes were ranked as intermediate and least attractive, respectively, even though the clothes were not visible in the photographs. Our results demonstrate that despite very subtle effects, the emotional state of women is perceived by men and that the two sexes are concordant on the signal sent and received. We show a close connection between exterior attributes, confidence, and how a person is perceived by others.
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| 10. |
- Lõhmus, Mare, et al.
(författare)
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Effects of chronic leptin administration on nitric oxide production and immune responsiveness of greenfinches
- 2011
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Ingår i: Comparative Biochemistry and Physiology A. - : Elsevier BV. - 1095-6433 .- 1531-4332. ; 158:4, s. 560-565
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Tidskriftsartikel (refereegranskat)abstract
- Leptin and nitric oxide (NO) are both important messengers in intra- and intercellular communication systems in vertebrates. Several studies have demonstrated an involvement of both substances in the immune response. Here we tested the effects of chronic leptin and anti-leptin treatments on the NO production and phytohaemagglutinin- (PHA) induced cutaneous inflammatory response in a wild passerine, the greenfinch (Carduelis chloris). Plasma leptin levels of individual birds were consistent in time but could be still temporarily increased by administration of recombinant chicken leptin. Increase of plasma leptin was also induced by administration of anti-leptin, which can be most likely explained by increased endogenous leptin production due to disruption of signalling pathways. Contrary to previous findings in mammals, leptin administration reduced systemic NO production. Leptin increased cutaneous swelling response to PHA. This immune-enhancing effect was observable despite the similar plasma leptin levels of leptin-treated and control birds at the time of measurement of immune responses, i.e., 9 days after start of the treatments. This provides evidence for a delayed or long-term potentiation of the cells and cytokines involved. The effects of leptin administration on NO production and immune responsiveness were age-dependent, which indicates the complexity of underlying regulatory mechanisms.
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