| 1. |
- Bengtsson, Fia, 1986-, et al.
(författare)
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Environmental drivers of Sphagnum growth in peatlands across the Holarctic region
- 2021
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Ingår i: Journal of Ecology. - : John Wiley & Sons. - 0022-0477 .- 1365-2745. ; 109:1, s. 417-431
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Tidskriftsartikel (refereegranskat)abstract
- The relative importance of global versus local environmental factors for growth and thus carbon uptake of the bryophyte genusSphagnum-the main peat-former and ecosystem engineer in northern peatlands-remains unclear. We measured length growth and net primary production (NPP) of two abundantSphagnumspecies across 99 Holarctic peatlands. We tested the importance of previously proposed abiotic and biotic drivers for peatland carbon uptake (climate, N deposition, water table depth and vascular plant cover) on these two responses. Employing structural equation models (SEMs), we explored both indirect and direct effects of drivers onSphagnumgrowth. Variation in growth was large, but similar within and between peatlands. Length growth showed a stronger response to predictors than NPP. Moreover, the smaller and denserSphagnum fuscumgrowing on hummocks had weaker responses to climatic variation than the larger and looserSphagnum magellanicumgrowing in the wetter conditions. Growth decreased with increasing vascular plant cover within a site. Between sites, precipitation and temperature increased growth forS. magellanicum. The SEMs indicate that indirect effects are important. For example, vascular plant cover increased with a deeper water table, increased nitrogen deposition, precipitation and temperature. These factors also influencedSphagnumgrowth indirectly by affecting moss shoot density. Synthesis. Our results imply that in a warmer climate,S. magellanicumwill increase length growth as long as precipitation is not reduced, whileS. fuscumis more resistant to decreased precipitation, but also less able to take advantage of increased precipitation and temperature. Such species-specific sensitivity to climate may affect competitive outcomes in a changing environment, and potentially the future carbon sink function of peatlands.
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| 2. |
- Granath, Gustaf, et al.
(författare)
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Environmental and taxonomic controls of carbon and oxygen stable isotope composition in Sphagnum across broad climatic and geographic ranges
- 2018
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Ingår i: Biogeosciences. - : Copernicus Publications. - 1726-4170 .- 1726-4189. ; 15:16, s. 5189-5202
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Tidskriftsartikel (refereegranskat)abstract
- Rain-fed peatlands are dominated by peat mosses (Sphagnum sp.), which for their growth depend on nutrients, water and CO2 uptake from the atmosphere. As the isotopic composition of carbon (C-12(,)13) and oxygen (O-16(,)18) of these Sphagnum mosses are affected by environmental conditions, Sphagnum tissue accumulated in peat constitutes a potential long-term archive that can be used for climate reconstruction. However, there is inadequate understanding of how isotope values are influenced by environmental conditions, which restricts their current use as environmental and palaeoenvironmental indicators. Here we tested (i) to what extent C and O isotopic variation in living tissue of Sphagnum is speciesspecific and associated with local hydrological gradients, climatic gradients (evapotranspiration, temperature, precipitation) and elevation; (ii) whether the C isotopic signature can be a proxy for net primary productivity (NPP) of Sphagnum; and (iii) to what extent Sphagnum tissue delta O-18 tracks the delta O-18 isotope signature of precipitation. In total, we analysed 337 samples from 93 sites across North America and Eurasia us ing two important peat-forming Sphagnum species (S. magellanicum, S. fuscum) common to the Holarctic realm. There were differences in delta C-13 values between species. For S. magellanicum delta C-13 decreased with increasing height above the water table (HWT, R-2 = 17 %) and was positively correlated to productivity (R-2 = 7 %). Together these two variables explained 46 % of the between-site variation in delta C-13 values. For S. fuscum, productivity was the only significant predictor of delta C-13 but had low explanatory power (total R-2 = 6 %). For delta O-18 values, approximately 90 % of the variation was found between sites. Globally modelled annual delta O-18 values in precipitation explained 69 % of the between-site variation in tissue delta O-18. S. magellanicum showed lower delta O-18 enrichment than S. fuscum (-0.83 %0 lower). Elevation and climatic variables were weak predictors of tissue delta O-18 values after controlling for delta O-18 values of the precipitation. To summarize, our study provides evidence for (a) good predictability of tissue delta O-18 values from modelled annual delta O-18 values in precipitation, and (b) the possibility of relating tissue delta C-13 values to HWT and NPP, but this appears to be species-dependent. These results suggest that isotope composition can be used on a large scale for climatic reconstructions but that such models should be species-specific.
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| 3. |
- Pierzynowski, Stefan, et al.
(författare)
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Exogenous pancreatic-like enzymes are recovered in the gut and improve growth of exocrine pancreatic insufficient pigs
- 2012
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 1525-3163 .- 0021-8812. ; 90, s. 324-326
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Tidskriftsartikel (refereegranskat)abstract
- The exocrine pancreatic insufficient (EPI) pigs grow less due to different disturbances in feed digestion, absorption, and retention. Use of pancreatic-like enzymes of microbial origin in pigs may improve feed use and performance in slow-growing pigs. The aim was to study gut recovery and effectiveness of pancreatic-like enzymes of microbial origin supplementation on pig performance. Six male pigs 10 to 12 kg BW underwent pancreatic duct ligation surgery to induce total exocrine pancreatic insufficiency (EPI). Three cannulas to access the gastrointestinal tract content were installed in stomach, duodenum, and ileum in EPI pigs and in 3 control (healthy) pigs. One month after surgery, enzymes were given before feeding and digesta samples were collected for analyses. The BW of EPI pigs did not increase during 1 mo following surgery (11.7 vs. 11.6 kg BW); however, BW increased after 1 wk of enzyme supplementation (12.1 kg BW). Coefficient of fat and N absorption increased (P < 0.05) in EPI pigs after enzyme supplementation. Activity of amylase, lipase, and protease in chyme samples of EPI pigs was very low compared to controls. In EPI pigs after enzyme supplementation, amylase activity increased from 5.32 to 72.9 units/mL but remained lower than that of healthy pigs (162.7 units/mL). Lipase activity increased from 79.1 to 421.6 units/mL, which was similar to that of controls (507.3 units/mL). Proteolytic activity increased from 7.8 to 69.7 units/mL but still did not reach control pigs (164.3 units/mL). In conclusion, exogenous microbial enzymes mimic endogenous pancreatic enzymes being recovered along the lumen of the gastrointestinal tract. These enzymes might be a useful tool to stimulate growth of slower-growing pigs after the weaning period.
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| 4. |
- Wolinski, J., et al.
(författare)
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Effect of feeding colostrum versus exogenous immunoglobulin G on gastrointestinal structure and enteric nervous system in newborn pigs
- 2012
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 1525-3163 .- 0021-8812. ; 90, s. 327-329
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Tidskriftsartikel (refereegranskat)abstract
- Colostrum is an indispensable source of antibodies (IgG) protecting the newborn pig against infection. We studied the effect of feeding colostrum and purified IgG on early structure and development of the gastrointestinal tract (GIT). Newborn littermate pigs were fed either colostrum, an elemental diet (ED), or an ED supplemented with purified serum IgG (ED + IgG) for 24 h or then only ED up to 72 h. Afterwards, pigs were slaughtered. Colostrum-fed pigs or ED supplemented with IgG (ED + IgG) increased thickness (P < 0.001) of stomach mucosa and muscularis (P < 0.05) compared to the ED group not receiving IgG. Feeding an ED supplemented with IgG improved morphology of the GIT towards that of colostrum-fed piglets and indicates a beneficial effect of IgG on GIT development in neonatal pigs. Immunohistochemical studies indicate that ED feeding may influence the expression of nitric oxide synthase in jejunal myenteric (but not submucous) neurons of newborn pigs.
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| 5. |
- Al-Garawi, A., et al.
(författare)
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Influenza A facilitates sensitization to house dust mite in infant mice leading to an asthma phenotype in adulthood
- 2011
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Ingår i: Mucosal Immunology. - : Elsevier BV. - 1933-0219. ; 4:6, s. 682-694
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Tidskriftsartikel (refereegranskat)abstract
- The origins of allergic asthma, particularly in infancy, remain obscure. Respiratory viral infections and allergen sensitization in early life have been associated with asthma in young children. However, a causal link has not been established. We investigated whether an influenza A infection in early life alters immune responses to house dust mite (HDM) and promotes an asthmatic phenotype later in life. Neonatal (8-day-old) mice were infected with influenza virus and 7 days later, exposed to HDM for 3 weeks. Unlike adults, neonatal mice exposed to HDM exhibited negligible immune responsiveness to HDM, but not to influenza A. HDM responsiveness in adults was associated with distinct Ly6c(+) CD11b(+) inflammatory dendritic cell and CD8 alpha(+) plasmacytoid (pDC) populations that were absent in HDM-exposed infant mice, suggesting an important role in HDM-mediated inflammation. Remarkably, HDM hyporesponsiveness was overcome when exposure occurred concurrently with an acute influenza infection; young mice now displayed robust allergen-specific immunity, allergic inflammation, and lung remodeling. Remodeling persisted into early adulthood, even after prolonged discontinuation of allergen exposure and was associated with marked impairment of lung function. Our data demonstrate that allergen exposure coincident with acute viral infection in early life subverts constitutive allergen hyporesponsiveness and imprints an asthmatic phenotype in adulthood.
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| 6. |
- Chu, Derek K, et al.
(författare)
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Indigenous enteric eosinophils control DCs to initiate a primary Th2 immune response in vivo.
- 2014
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 211:8, s. 1657-1672
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Tidskriftsartikel (refereegranskat)abstract
- Eosinophils natively inhabit the small intestine, but a functional role for them there has remained elusive. Here, we show that eosinophil-deficient mice were protected from induction of Th2-mediated peanut food allergy and anaphylaxis, and Th2 priming was restored by reconstitution with il4(+/+) or il4(-/-) eosinophils. Eosinophils controlled CD103(+) dendritic cell (DC) activation and migration from the intestine to draining lymph nodes, events necessary for Th2 priming. Eosinophil activation in vitro and in vivo led to degranulation of eosinophil peroxidase, a granule protein whose enzymatic activity promoted DC activation in mice and humans in vitro, and intestinal and extraintestinal mouse DC activation and mobilization to lymph nodes in vivo. Further, eosinophil peroxidase enhanced responses to ovalbumin seen after immunization. Thus, eosinophils can be critical contributors to the intestinal immune system, and granule-mediated shaping of DC responses can promote both intestinal and extraintestinal adaptive immunity.
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| 7. |
- Halkier, Henrik, et al.
(författare)
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Destination development in Western Siberia : tourism governance and evolutionary economic geography
- 2019
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Ingår i: Tourism Geographies. - : Routledge. - 1461-6688 .- 1470-1340. ; 21:2, s. 261-283
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Tidskriftsartikel (refereegranskat)abstract
- Tourism development has often been identified as a tool for balancing negative effects of economic restructuring, especially in peripheral regions. Tourism-based activities often utilize the availability of abundant nature, but although most English language studies of destination development are presented from western contexts, examples from post-Soviet Russia are rare. Western Siberia is a periphery with access to natural resources and heavy industrialization but remotely located from domestic (Russian) and international markets, where tourism is often considered a saviour, especially for the regional economies. Stakeholders in this Russian resource periphery face challenges in managing governance and cooperation in destinations development due to frequent institutional, economic and social changes. Using evolutionary economic geography and based on primary sources and interview data, tourism development and stakeholder relations are assessed in three Western Siberia regions: Tomsk, Kemerovo and Altai Krai. Findings show that for tourism to make a significant contribution, it must be more central to the economic development agenda in all three regions. However, it is currently only achieving a permanent high-profile in one of them, being crowded out by other (mostly primary) industries in the other two. Although the specific tourism governance set-up varies between the three regions, it is clear that public tourism governance still sits somewhat uneasily between state control and the market economy. Tourism receives substantial public subsidies, especially in large-scale investment projects, which depend on federal support within a governance system where decentralization seems to be somewhat limited and unstable. As a result, the tourism path development in the Siberian periphery is highly dependent on state intervention and success in other sectors.
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| 8. |
- Mosiichuk, N., et al.
(författare)
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Uricemia in juvenile pigs model : Effect of nephrectomy and potassium oxonate
- 2019
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Ingår i: Journal of Animal and Feed Sciences. - : The Kielanowski Institute of Animal Physiology and Nutrition, PAS. - 1230-1388. ; 28:3, s. 254-262
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Tidskriftsartikel (refereegranskat)abstract
- Uric acid is the end product of dietary and endogenous purine metabolism in humans and higher primates. In all lower mammalian species it is converted to allantoin by liver uricase. The aim of this study was to investigate the uric acid turnover in pig model after nephrectomy surgery, fructose-enriched diet and potassium oxonate application. The first experiment was performed using 4 intact control pigs and 8 nephrectomized (5/6 nephrectomy) pigs. Both groups were fed high-fat diet enriched with 20% of fructose for 3 weeks. During the second experiment, as another approach to induce hyperuricemia, potassium oxonate solution (POx) was administered intravenously to 4 healthy pigs, once or twice per day. In the third preliminary experiment one healthy and two nephrectomized (9/10 nephrectomy) pigs were infused with POx to induce hyperuricemia. Results showed that 5/6 nephrecotomy did not affect plasma uric acid concentration for 25 days following surgery. The consumption of the high-fat diet enriched with 20% of fructose did not result in the rise of plasma uric acid, either in healthy or nephrectomized pigs. Administration of POx solution to healthy and 9/10 nephrectomized pigs resulted in significantly increased plasma uric acid concentrations for 18 h and 24 h, respectively, following a single POx infusion. The present study expands today available data on uric acid metabolism in pigs as a model for exploring uricemia in human with kidney dysfunction.
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| 9. |
- Pierzynowski, Stefan, et al.
(författare)
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Behavioral changes in response to feeding pancreatic-like enzymes to exocrine pancreatic insufficiency pigs.
- 2012
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 1525-3163 .- 0021-8812. ; 90:Suppl 4, s. 439-441
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Tidskriftsartikel (refereegranskat)abstract
- Behavioral changes during pancreatic enzyme therapy have never been studied. The present study investigated behavioral changes in exocrine pancreatic insufficiency (EPI) pigs when their feed was supplemented with pancreatic-like enzymes of microbial origin. A crossover design study was used to test the effect of enzyme supplementation in 2 × 4 EPI pigs that underwent pancreatic duct ligation (PDL). After 40 d of adaptation, the study commenced, comprising 2 control and 2 enzyme feeding periods of 10 d each in sequence. On days 7 and 10 of each experimental period, behavior was monitored for 24 h and feed consumption and BW were recorded. Behavioral observations focused on the pigs' activity- lying down or passive, or sitting, or standing or active-and were expressed as percentage activity for 24 h. During the adaptation period, BW gain was completely inhibited after PDL whereas for the entire study period, the body weight increased from 10.5 ± 1.1 to 14.0 ± 1.4 kg (P < 0.01). Exocrine pancreatic insufficiency pigs were more active when fed the enzymes (21 vs. 18% per 24 h; P < 0.01). Microbial enzyme supplementation not only improved the growth of the EPI pigs but it also increased their activity. This behavior change contradicts the generally accepted norm that satiety evokes by digestion and subsequent nutrients absorption reduces human or animal motility.
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| 10. |
- Socha-Banasiak, A., et al.
(författare)
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The pig as a model for premature infants - The importance of immunoglobulin supplementation for growth and development
- 2017
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Ingår i: Journal of Biological Regulators and Homeostatic Agents. - 0393-974X. ; 31:1, s. 87-92
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Tidskriftsartikel (refereegranskat)abstract
- Preterm human neonates, contrary to preterm piglets, obtain immunoglobulins from their mothers via the placenta during intrauterine development. However, one should note that the majority of trans-placental transfer of immunoglobulins in humans takes place during the last trimester of pregnancy. It is also known that the feeding of limited amounts of colostrum or systemic infusion of small amounts of serum improves the survival of preterm and full-term piglets. Full-term piglets deprived of their mother's immunoglobulins exhibit strong apathy and develop watery diarrhoea, often resulting in death. The aim of the current study was to determine if provision of immunoglobulins using different approaches would be beneficial for survival outcomes. To reach the immunological sufficient level we infused immunoglobulins intravenously in amount mimicking the blood level in piglets fed with sow colostrum. Intravenous infusion of immunoglobulins in both preterm and full-term newborn piglets fully ensured their survival, growth and blood immunoglobulin G and protein levels similar to those observed in piglets fed colostrum. Piglets completely deprived of immunoglobulins exhibited significantly lower blood levels of immunoglobulins and protein compared to colostrum-fed animals. Piglets infused with only serum exhibited significantly lower blood immunoglobulin G level compared to those infused with immunoglobulins. In conclusion, based on the data obtained, we suggest that passive immune support provided by colostrum intake or early systemic infusion of Ig's in sufficient amounts is key to ensuring the general well-being of preterm and full-term new born piglets, used as an animal model for the human infant.
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| 11. |
- Szczurek, P., et al.
(författare)
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Effects of dietary supplementation with pancreatic-like enzymes of microbial origin (PLEM) and silicon dioxide (SiO2) on the performance of piglets fed creep feed
- 2016
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 94:7 Supp.3, s. 62-65
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that during the suckling period pancreatic secretion is low. The aim of the study was to investigate the effects of dietary supplementation with pancreatic-like enzymes of microbial origin (PLEM) and SiO2, as an antibacterial factor, on the performance of piglets fed creep feed during weaning and thereafter. The experiment was performed on piglets from 30 litters. The piglets were divided into 5 groups (n = 63–66) and weaned at the age of 28 d old. The control group received standard creep feed (Days 7–28), and groups P1 and P2 and groups PA1 and PA2 received creep feed with SiO2supplemented with protease (P1 and P2) or with protease+amylase (PA1 and PA2) during Days 7–13 (P1 and PA1) or Days 14–20 (P2 and PA2) before weaning. Dietary supplementation with PLEM and SiO2led to a significant (P < 0.05) increase in ADG in the treated piglets compared to the control with the best results obtained in group P2. To summarize, creep feed supplemented with PLEM improves productivity parameters of piglets under standard rearing conditions.
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