Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2022
Authors
Miyuru GunathilakeAbstract
No abstract has been registered
Authors
Yong Q. Tian Qian Yu Hunter J. Carrick Brian L. Becker Remegio Confesor Mark Francek Olivia C. AndersonAbstract
No abstract has been registered
Abstract
Understanding the mechanisms of ecological community dynamics and how they could be affected by environmental changes is important. Population dynamic models have well known ecological parameters that describe key characteristics of species such as the effect of environmental noise and demographic variance on the dynamics, the long-term growth rate, and strength of density regulation. These parameters are also central for detecting and understanding changes in communities of species; however, incorporating such vital parameters into models of community dynamics is challenging. In this paper, we demonstrate how generalized linear mixed models specified as intercept-only models with different random effects can be used to fit dynamic species abundance distributions. Each random effect has an ecologically meaningful interpretation either describing general and species-specific responses to environmental stochasticity in time or space, or variation in growth rate and carrying capacity among species. We use simulations to show that the accuracy of the estimation depends on the strength of density regulation in discrete population dynamics. The estimation of different covariance and population dynamic parameters, with corresponding statistical uncertainties, is demonstrated for case studies of fish and bat communities. We find that species heterogeneity is the main factor of spatial and temporal community similarity for both case studies.
Editors
Randi HesjedalAbstract
No abstract has been registered
Abstract
Knowledge of the temporal variation in reproductive success and its key driving factors is crucial in predicting animal population persistence. Few studies have examined the effects of a range of explanatory factors operating simultaneously on the same population over a long period. Based on 41 years of monitoring (1979–2019), we tested prevailing hypotheses about drivers of annual variation in breeding success in two sympatric species of boreal forest grouse—the capercaillie (Tetrao urogallus) and the black grouse (T. tetrix)—in a 45 km2 boreal forest landscape. From counts in early August, we measured breeding success (chicks/hen) along with potential determining factors. We formulated five main hypotheses on causes of variation (hen condition, chick weather, chick food, predation, demographic characteristics) and derived 13 associated explanatory variables for analysis. We first tested the five hypotheses separately and then used model selection (AICc) to rank the best predictive models irrespective of hypotheses. Lastly, we used path analysis to illuminate potential causal relationships. Barring demographic characteristics, all hypotheses were supported, most strongly for chick food and predation. Among predictor variables, chick food (insect larvae and bilberry fruit crops), vole and fox abundances, the winter-NAO index, and temperature after hatching, had the strongest effect sizes in both species. Precipitation after hatching had no detectable effect. Model selection indicated bottom-up factors to be more important than predation, but confounding complicated interpretation. Path analysis suggested that the high explanatory power of bilberry fruiting was due not only to its direct positive effect on chick food quality but also to an indirect positive effect on vole abundance, which buffers predation. The two components of breeding success—proportion of hens with broods and number of chicks per brood—were uncorrelated, the former having the strongest effect. The two components had different ecological correlates that often varied asynchronously, resulting in overall breeding success fluctuating around low to moderate levels. Our study highlights the complexity of key explanatory drivers and the importance of considering multiple hypotheses of breeding success. Although chick food appeared to equal or surpass predation in explaining the annual variation in breeding success, predation may still be the overall limiting factor. Comparative and experimental studies of confounded variables (bilberry fruiting, voles, and larvae) are needed to disentangle causes of variation in breeding success of boreal forest grouse.
Abstract
Using decades of satellite observations, Finnish and Norwegian scientists calculated the warming effect caused by changes in the snow and ice cover of the Arctic and Antarctic regions.
Authors
Mari Røken Kristin Forfang Yngvild Wasteson Anita Haug Haaland Hans Geir Eiken Snorre Hagen Ane Mohn BjellandAbstract
Aims To investigate and compare antimicrobial resistance genes (ARGs) in faeces from cohabiting dogs and owners. Methods and Results DNA from faecal samples from 35 dogs and 35 owners was screened for the presence of 34 clinically relevant ARGs using high throughput qPCR. In total, 24 and 25 different ARGs were present in the dog and owner groups, respectively. The households had a mean of 9.9 ARGs present, with dogs and owners sharing on average 3.3 ARGs. ARGs were shared significantly more in households with dogs over 6 years old (3.5, interquartile range 2.75–5.0) than in households with younger dogs (2.5, interquartile range 2.0–3.0) (p = 0.02). Dogs possessed significantly more mecA and aminoglycoside resistance genes than owners. Conclusions Dogs and owners can act as reservoirs for a broad range of ARGs belonging to several antimicrobial resistance classes. A modest proportion of the same resistance genes were present in both dogs and owners simultaneously, indicating that ARG transmission between the dog and human gut is of minor concern in the absence of antimicrobial selection. Significance and Impact of the Study This study provides insight into the common dog and human gut resistomes, contributing to an improved knowledge base in risk assessments regarding ARG transmission between dogs and humans.
Authors
Jennifer Mildenberger Janne Kristin Stangeland Céline ReboursAbstract
No abstract has been registered
Authors
Maryam Mirahmad Shahrzad Mohseni Ozra Tabatabaei-Malazy Fataneh Esmaeili Sudabeh Alatab Roodabeh Bahramsoltani Hanieh-Sadat Ejtahed Husseyn Qulami Zahra Bitarafan Babak Arjmand Elahe NazeriAbstract
Background Inflammation is a double-edged sword in the pathophysiology of chronic diseases, such as type 2 diabetes mellitus (T2DM). The global rise in the prevalence of T2DM in one hand, and poor disease control with currently-available treatments on the other hand, along with an increased tendency towards the use of natural products make scientists seek herbal medicines for the management of diabetes and its complications by reducing C-reactive protein (CRP) as an inflammatory marker. Purpose To systematically review the literature to identify the efficacy of various medicinal plants with antioxidative and anti-inflammatory properties considering their effect on CRP in animal models of T2DM. Study design systematic review. Methods Electronic databases including PubMed, Scopus, Web of Science and Cochran Library were searched using the search terms “herbal medicine”, “diabetes”, “c-reactive protein”, “antioxidants” till August 2021. The quality of evidence was assessed using the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE's) tool. The study protocol was registered in PROSPERO with an ID number CRD42020207190. A manual search to detect any articles not found in the databases was also made. The identified studies were then critically reviewed and relevant data were extracted and summarized. Results Among total of 9904 primarily-retrieved articles, twenty-three experimental studies were finally included. Our data indicated that numerous herbal medicines, compared to placebo or hypoglycemic medications, are effective in treatment of diabetes and its complications through decreasing CRP concentrations and oxidative stresses levels. Medicinal plants including Psidium guajava L., Punica granatum L., Ginkgo biloba L., Punica granatum L., Dianthus superbusn L.. Moreover, Eichhornia crassipes (Mart.) Solms, Curcuma longa L., Azadirachta indica A. Juss., Morus alba L., and Ficus racemosa L. demonstrated potential neuroprotective effects in animal models of diabetes. Conclusion Hypoglycemic medicinal plants discussed in this review seem to be promising regulators of CRP, and oxidative stress. Thus, these plants are suitable candidates for management of diabetes’ complications. Nevertheless, further high-quality in vivo studies and clinical trials are required to confirm these effects.
Authors
Darius Kviklys Jonas Viškelis Mindaugas Liaudanskas Valdimaras Janulis Kristina Laužikė Giedrė Samuolienė Nobertas Uselis Juozas LanauskasAbstract
Modern apple orchard systems should guarantee homogeneity of fruit internal and external qualities and fruit maturity parameters. However, when orchards reach productive age, a variation of these parameters takes place and mostly it is related to uneven light distribution within the tree canopy. The aim of the study was to evaluate the canopy position’s effect on fruit internal and external quality parameters. This is the first study where all the main fruit quality and maturation parameters were evaluated on the same trees and were related to the light conditions and photosynthetic parameters. Four fruit positions were tested: top of the apple tree, lower inside part of the canopy, and east and west sides of the apple tree. Fruit quality variability was significant for fruit size, blush, colour indices, total sugar content, dry matter concentration, accumulation of secondary metabolites and radical scavenging activity. Fruit position in the canopy did not affect flesh firmness and fruit maturity parameters such as the starch index, Streif index and respiration rate. At the Lithuanian geographical location (55°60′ N), significantly, the highest fruit quality was achieved at the top of the apple tree. The tendency was established that apple fruits from the west side of the canopy have better fruit quality than from the east side and it could be related to better light conditions at the west side of the tree. Inside the canopy, fruits were distinguished only by the higher accumulation of triterpenic compounds and higher content of malic acid. Light is a main factor of fruit quality variation, thus all orchard management practices, including narrow two-dimensional tree canopies and reflecting ground covers which improve light penetration through the tree canopy, should be applied.