| 59991. |
- Lehtiniemi, M., et al.
(författare)
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Predation of the introduced cladoceran Cercopagis pengoi on the calanoid copepod Eurytemora affinis in the Gulf of Finland, Baltic Sea.
- 2008
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Ingår i: MARINE ECOLOGY-PROGRESS SERIES. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 362, s. 193-200
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Tidskriftsartikel (refereegranskat)abstract
- We studied the potential of an introduced species, the predatory cladoceran Cercopagis pengoi, to influence native zooplankton populations in the Baltic Sea. Feeding rates (FRs) of different instars of C. pengoi on Eurytemora affinis, a dominant copepod species, were determined experimentally. The FRs of C. pengoi varied from 0.7 to 4.8 prey predator(-1) d(-1) and were significantly higher in older instars. Based on the experimental results and long-term zooplankton abundance data from the Gulf of Finland, we estimated the in situ predation rates. Our results imply that at maximum abundance, the C. pengoi population feeding in dense prey patches could consume as many as 10(5) E. affinis m(-3) d(-1). This could explain the observed drastic decrease in copepod abundances in the eastern Gulf of Finland, the region with the highest C. pengoi abundance after the expansion of this species. Such a decline may strengthen food competition between other zooplanktivores, i.e. planktivorous fish and mysids, feeding on the same copepod prey in regions where C, pengoi may reach high abundances. In the Gulf of Finland, especially in the eastern parts, a collapse of E. affinis, a key species in the pelagic system, would cause major changes in virtually all trophic levels, because the food web structure is simple with only a few species of zooplankton, planktivores, and piscivores.
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| 59992. |
- Lehtipalo, Katrianne, et al.
(författare)
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How Do Amines Affect the Growth of Recently Formed Aerosol Particles
- 2013
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Ingår i: NUCLEATION AND ATMOSPHERIC AEROSOLS. - : American Institute of Physics (AIP). - 9780735411524 ; , s. 295-297
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Konferensbidrag (refereegranskat)abstract
- Growth rates of recently born nanometer-scale particles were measured during the CLOUD experiments at CERN. Combining the data from several recently developed measurement techniques allowed us to follow the growth of the particles starting from molecules to molecular clusters and finally to climatically relevant particles. We studied the binary system with sulphuric acid and water, and the ternary systems with ammonia or dimethylamine added to the chamber, both in purely neutral situation, and with ionization from cosmic rays or the CERN particle beam.
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| 59993. |
- Lehtipalo, Katrianne, et al.
(författare)
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Multicomponent new particle formation from sulfuric acid, ammonia, and biogenic vapors
- 2018
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 4:12
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Tidskriftsartikel (refereegranskat)abstract
- A major fraction of atmospheric aerosol particles, which affect both air quality and climate, form from gaseous precursors in the atmosphere. Highly oxygenated organic molecules (HOMs), formed by oxidation of biogenic volatile organic compounds, are known to participate in particle formation and growth. However, it is not well understood how they interact with atmospheric pollutants, such as nitrogen oxides (NOx) and sulfur oxides (SOx) from fossil fuel combustion, as well as ammonia (NH3) from livestock and fertilizers. Here, we show how NOx suppresses particle formation, while HOMs, sulfuric acid, and NH3 have a synergistic enhancing effect on particle formation. We postulate a novel mechanism, involving HOMs, sulfuric acid, and ammonia, which is able to closely reproduce observations of particle formation and growth in daytime boreal forest and similar environments. The findings elucidate the complex interactions between biogenic and anthropogenic vapors in the atmospheric aerosol system.
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| 59994. |
- Lehtipalo, Katrianne, et al.
(författare)
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The effect of acid-base clustering and ions on the growth of atmospheric nano-particles
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.
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| 59995. |
- Lehtisalo, J., et al.
(författare)
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Association of long-term dietary fat intake, exercise, and weight with later cognitive function in the Finnish Diabetes Prevention Study
- 2016
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Ingår i: The Journal of Nutrition, Health & Aging. - : Springer Science and Business Media LLC. - 1279-7707 .- 1760-4788. ; 20:2, s. 146-154
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate associations of long-term nutrient intake, physical activity and obesity with later cognitive function among the participants in the Finnish Diabetes Prevention Study, in which a lifestyle intervention was successful in diabetes prevention. Design: An active lifestyle intervention phase during middle age (mean duration 4 years) and extended follow-up (additional 9 years) with annual lifestyle measurements, followed by an ancillary cognition assessment. Setting: 5 research centers in Finland. Participants: Of the 522 middle-aged, overweight participants with impaired glucose tolerance recruited to the study, 364 (70%) participated in the cognition assessment (mean age 68 years). Measurements: A cognitive assessment was executed with the CERAD test battery and the Trail Making Test A on average 13 years after baseline. Lifestyle measurements included annual clinical measurements, food records, and exercise questionnaires during both the intervention and follow-up phase. Results: Lower intake of total fat (p=0.021) and saturated fatty acids (p=0.010), and frequent physical activity (p=0.040) during the whole study period were associated with better cognitive performance. Higher BMI (p= 0.012) and waist circumference (p= 0.012) were also associated with worse performance, but weight reduction prior to the cognition assessment predicted worse performance as well (decrease vs. increase, p= 0.008 for BMI and p= 0.002 for waist). Conclusions: Long-term dietary fat intake, BMI, and waist circumference have an inverse association with cognitive function in later life among people with IGT. However, decreases in BMI and waist prior to cognitive assessment are associated with worse cognitive performance, which could be explained by reverse causality.
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| 59996. |
- Lehtisalo, Jenni, et al.
(författare)
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Changes in Lifestyle, Behaviors, and Risk Factors for Cognitive Impairment in Older Persons During the First Wave of the Coronavirus Disease 2019 Pandemic in Finland : Results From the FINGER Study
- 2021
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Ingår i: Frontiers in Psychiatry. - : Frontiers Media SA. - 1664-0640. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Aims: This study aimed to describe how the first phase of the coronavirus disease 2019 (COVID-19) pandemic affected older persons from the general Finnish population who are at risk of developing or have cognitive impairment, specifically, to describe whether participants experienced a change in risk factors that are relevant for the prevention of cognitive decline including diet, physical activity, access to medical care, socially and cognitively stimulating activities, and emotional health and well-being.Method: A postal survey was sent in June 2020 to 859 participants from the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER), an ongoing longitudinal study. The survey was developed to assess the effect of the COVID-19 pandemic and related infection-control measures on daily life, specifically commitment to distancing measures, access to health care and social services, daily activities, and changes in cognitive and social activities.Results: By September 2020, 613 (71%) participants responded (mean age = 77.7 years, 32% lived alone, and 80% had at least one chronic condition). Three quarters adopted some distancing practices during the first months of the pandemic. Older participants were more likely to practice total isolation than younger ones (29 vs. 19%; p = 0.003). Non-acute health-care visits were canceled for 5% of the participants who needed appointments, but cancellations in dental health care (43%), home aid (30%), and rehabilitative services (53%) were more common. Pandemic-related changes were reported in social engagements, for example, less contact with friends (55%) and family (31%), or less frequent attendance in cultural events (38%) or associations (25%), although remote contact with others increased for 40%. Feelings of loneliness increased for 21%, particularly those who were older (p = 0.023) or living alone (p < 0.001). Physical activity reduced for 34%, but dietary habits remained stable or improved. Pandemic-related changes in lifestyle and activities were more evident among those living alone.Conclusions: Finnish older persons generally reported less negative changes in lifestyles and behaviors during the pandemic than expected. Older people and those living alone seemed more susceptible to negative changes. It is important to compare how coping strategies may compare with other European countries to identify factors that may help older individuals to maintain healthy lifestyles during future waves of COVID-19.
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| 59997. |
- Lehtisalo, Jenni, et al.
(författare)
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Diabetes, glycaemia, and cognitiona secondary analysis of the Finnish Diabetes Prevention Study
- 2016
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Ingår i: Diabetes/Metabolism Research Reviews. - : Wiley. - 1520-7552 .- 1520-7560. ; 32:1, s. 102-110
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Tidskriftsartikel (refereegranskat)abstract
- Background: Type 2 diabetes is linked with cognitive dysfunction and dementia in epidemiological studies, but these observations are limited by lack of data on the exact timing of diabetes onset. We investigated diabetes, dysglycaemia, and cognition in the Finnish Diabetes Prevention Study, in which the timing and duration of diabetes are well documented.Methods: The Finnish Diabetes Prevention Study comprised middle-aged, overweight participants with impaired glucose tolerance but no diabetes at baseline (n=522), randomized to lifestyle intervention or a control group. After an intervention period (mean duration 4years) and follow-up (additional 9years), cognitive assessment with the CERAD test battery and Trail Making Test A (TMT) was executed twice within a 2-year interval. Of the 364 (70%) participants with cognitive assessments, 171 (47%) had developed diabetes.Results: Cognitive function did not differ between those who developed diabetes and those who did not. Lower mean 2-h glucose at an oral glucose tolerance test (OGTT) and HbA(1C) during the intervention period predicted better performance in the TMT (p=0.012 and 0.024, respectively). Those without diabetes or with short duration of diabetes improved in CERAD total score between the two assessments (p=0.001) whereas those with long duration of diabetes did not (p=0.844).Conclusions: Better glycemic control among persons with baseline impaired glucose tolerance predicted better cognitive performance 9years later in this secondary analysis of the Finnish Diabetes Prevention Study population. In addition, learning effects in cognitive testing were not evident in people with long diabetes duration.
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| 59998. |
- Lehtisalo, Jenni, et al.
(författare)
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Dietary changes and cognition over 2 years within a multidomain intervention trial-The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER)
- 2019
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Ingår i: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 15:3, s. 410-417
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Association between healthy diet and better cognition is well established, but evidence is limited to evaluate the effect of dietary changes adopted in older age.Methods: We investigated the role of dietary changes in the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) with 1260 at-risk participants (60-77 years) who were randomized to intensive multidomain intervention (including dietary counseling) or regular health advice for 2 years. Parallel process latent growth curves of adherence to dietary recommendations and cognitive performance were analyzed.Results: Adherence to healthy diet at baseline predicted improvement in global cognition, regardless of intervention allocation (P = .003). Dietary improvement was associated with beneficial changes in executive function, especially in the intervention group (P = .008; P = .051 for groups combined).Discussion: Dietary changes initiated during the intervention were related to changes in executive function in 2 years. Long-term diet appeared more influential for global cognition.
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| 59999. |
- Lehtisalo, Jenni, et al.
(författare)
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Nutrient intake and dietary changes during a 2-year multi-domain lifestyle intervention among older adults : secondary analysis of the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) randomised controlled trial
- 2017
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Ingår i: British Journal of Nutrition. - 0007-1145 .- 1475-2662. ; 118:4, s. 291-302
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Tidskriftsartikel (refereegranskat)abstract
- Advancing age increases the risk for diseases and health concerns like cognitive decline, constituting a major public health challenge. Lifestyle, especially healthy diet, affects many risk factors related to chronic diseases, and thus lifestyle interventions among older adults may be beneficial in promoting successful ageing. We completed a randomised 2-year multi-domain lifestyle intervention trial aiming at prevention of cognitive decline among 631 participants in the intervention and 629 in the control group, aged 60-77 years at baseline. Dietary counselling was one of the intervention domains together with strength exercise, cognitive training and management of CVD risk factors. The aim of this paper was to describe success of the intervention -that is, how an intervention based on national dietary recommendations affected dietary habits as a part of multi-intervention. Composite dietary intervention adherence score comprising nine distinct goals (range 0-9 points from none to achieving all goals) was 5.0 at baseline, and increased in the intervention group after the 1st (P< 0.001) and 2nd (P = 0.005) year. The difference in change compared with the control group was significant at both years (P < 0.001 and P= 0.018). Intake of several vitamins and minerals decreased in the control group but remained unchanged or increased in the intervention group during the 2 years. Well-targeted dietary counselling may prevent age-related decline in diet quality and help in preventing cognitive decline.
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| 60000. |
- Lehtiö, Lari, et al.
(författare)
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Structural basis for inhibitor specificity in human poly(ADP-ribose) polymerase-3.
- 2009
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Ingår i: Journal of medicinal chemistry. - : American Chemical Society (ACS). - 1520-4804 .- 0022-2623. ; 52:9, s. 3108-11
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Tidskriftsartikel (refereegranskat)abstract
- Poly(ADP-ribose) polymerases (PARPs) activate DNA repair mechanisms upon stress- and cytotoxin-induced DNA damage, and inhibition of PARP activity is a lead in cancer drug therapy. We present a structural and functional analysis of the PARP domain of human PARP-3 in complex with several inhibitors. Of these, KU0058948 is the strongest inhibitor of PARP-3 activity. The presented crystal structures highlight key features for potent inhibitor binding and suggest routes for creating isoenzyme-specific PARP inhibitors.
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