| 1. |
- Fatima, Ambrin, et al.
(författare)
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Monoallelic and bi-allelic variants in NCDN cause neurodevelopmental delay, intellectual disability, and epilepsy
- 2021
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Ingår i: American Journal of Human Genetics. - : Cell Press. - 0002-9297 .- 1537-6605. ; 108:4, s. 739-748
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Tidskriftsartikel (refereegranskat)abstract
- Neurochondrin (NCDN) is a cytoplasmatic neural protein of importance for neural growth, glutamate receptor (mGluR) signaling, and synaptic plasticity. Conditional loss of Ncdn in mice neural tissue causes depressive-like behaviors, impaired spatial learning, and epileptic seizures. We report on NCDN missense variants in six affected individuals with variable degrees of developmental delay, intellectual disability (ID), and seizures. Three siblings were found homozygous for a NCDN missense variant, whereas another three unrelated individuals carried different de novo missense variants in NCDN. We assayed the missense variants for their capability to rescue impaired neurite formation in human neuroblastoma (SH-SY5Y) cells depleted of NCDN. Overexpression of wild-type NCDN rescued the neurite-phenotype in contrast to expression of NCDN containing the variants of affected individuals. Two missense variants, associated with severe neurodevelopmental features and epilepsy, were unable to restore mGluR5-induced ERK phosphorylation. Electrophysiological analysis of SH-SY5Y cells depleted of NCDN exhibited altered membrane potential and impaired action potentials at repolarization, suggesting NCDN to be required for normal biophysical properties. Using available transcriptome data from human fetal cortex, we show that NCDN is highly expressed in maturing excitatory neurons. In combination, our data provide evidence that bi-allelic and de novo variants in NCDN cause a clinically variable form of neurodevelopmental delay and epilepsy, highlighting a critical role for NCDN in human brain development.
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| 2. |
- Kim, Yong Suk, et al.
(författare)
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Greenhouse gas emissions after a prescribed fire in white birch-dwarf bamboo stands in northern Japan, focusing on the role of charcoal
- 2011
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Ingår i: European Journal of Forest Research. - : Springer Science and Business Media LLC. - 1612-4669 .- 1612-4677. ; 130:6, s. 1031-1044
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Tidskriftsartikel (refereegranskat)abstract
- Forest fires affect both carbon (C) and nitrogen (N) cycling in forest ecosystems, and thereby influence the soil-atmosphere exchange of major greenhouse gases (GHGs): carbon dioxide (CO(2)), methane (CH(4)), and nitrous oxide (N(2)O). To determine changes in the soil GHG fluxes following a forest fire, we arranged a low-intensity surface fire in a white birch forest in northern Japan. We established three treatments, having four replications each: a control plot (CON), a burned plot (BURN), and a plot burned with removal of the resulting charcoal (BURN-CHA). Soil GHG fluxes and various properties of the soil were determined on four or five occasions during a period that spanned two growing seasons. We observed increased concentrations of ammonium-N (NH(4)-N) in BURN and BURN-CHA after the fire, while nitrate-N (NO(3)-N) concentration was only increased in BURN-CHA after the fire. The soil CO(2) flux was significantly higher in CON than in BURN or BURN-CHA, but there was no difference in soil CH(4) uptake between the three treatments. Moreover, the N(2)O flux from BURN-CHA soil was slightly greater than in CON or BURN. In BURN-CHA, the soil N(2)O flux peaked in August, but there was no peak in BURN. We found temporal correlations between soil GHG fluxes and soil variables, e.g. soil temperature or NO(3)-N. Our results suggest that environmental changes following fire, including the increased availability of N and the disappearance of the litter layer, have the potential to change soil GHG fluxes. Fire-produced charcoal could be significant in reducing soil N(2)O flux in temperate forests.
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| 3. |
- Makoto, Kobayashi, et al.
(författare)
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Effects of fire-derived charcoal on soil properties and seedling regeneration in a recently burned Larix gmelinii/Pinus sylvestris forest
- 2011
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Ingår i: Journal of Soils and Sediments. - Heidelberg : Springer Berlin/Heidelberg. - 1439-0108 .- 1614-7480. ; 11:8, s. 1317-1322
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Fire is a primary form of disturbance in boreal ecosystems. Charcoal is an important by-product of forest fire and has been reported to have the potential to influence the plant community establishing after fire. To date, however, no study has effectively tested the relationship between charcoal and plant regeneration in the actual post-fire forests. To determine the contribution of charcoal to soil properties and plant regeneration after forest fires, we conducted in situ investigations concerning the relationship between charcoal and the plant-soil system. Materials and methods: We conducted a field investigation in a recently burnt Gmelin larch (Larix gmelinii)/Scots pine (Pinus sylvestris) forest in the Russian Far East to investigate charcoal contents, pH, water contents, and nutrient availability in soil together with the regeneration of larch and pine seedlings. Results and discussion: Positive correlations were found between charcoal contents and soil pH, water contents, and available P contents. Additionally, charcoal contents and the number of pine seedlings were positively correlated. There was, however, no significant relationship between charcoal content and extractable NH(4) (+) content or the number of larch seedlings. These results suggest that while charcoal influences are somewhat obscure in the field, charcoal significantly contributes to the amelioration of water and nutrient availability together with the success of regeneration of pine seedling. Conclusions: Charcoal produced during fire events in Gmelin larch and Scots pine forests of eastern Russia has a modest influence on soil properties, but has the potential to improve regeneration in these fire-prone ecosystems.
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| 4. |
- Makoto, Kobayashi, et al.
(författare)
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The growth of Larix gmelinii seedlings as affected by charcoal produced at two different temperatures
- 2011
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Ingår i: Biology and Fertility of Soils. - : Springer Science and Business Media LLC. - 0178-2762 .- 1432-0789. ; 47:4, s. 467-472
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Tidskriftsartikel (refereegranskat)abstract
- Fires burn forest with spatially heterogeneous intensity and charcoals generated at various temperatures during fires exhibit variable physical and chemical characteristics. These variable properties of charcoal may, in turn, influence germination and growth of tree seedlings. To examine the effects of different charcoal properties on the growth of Gmelin larch (Larix gmelinii) seedlings, we conducted an experiment with larch-branch-derived charcoals produced at 400A degrees C (low charcoal) and 800A degrees C (high charcoal); charcoal was combined with sand at three different rates (5%, 20% and 50%, v/v charcoal in sand). The high charcoal had no significant effects on any measured property while the low charcoal application stimulated growth and the effect increased with the addition rate. The low charcoal application resulted in the greater available P content, a lower N/P in needles and the greater growth of seedlings than high charcoal application. The growth of seedlings was not affected by the application of the high charcoal at any rate probably because the high charcoal inhibited the seedling growth due to its high pH. These results indicate that charcoal produced at different temperatures during forest fires can affect the growth of Gmelin larch seedlings differently.
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| 5. |
- Quentin, Audrey G, et al.
(författare)
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Non-structural carbohydrates in woody plants compared among laboratories.
- 2015
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Ingår i: Tree physiology. - : Oxford University Press (OUP). - 1758-4469 .- 0829-318X. ; 35:11, s. 1146-1165
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Tidskriftsartikel (refereegranskat)abstract
- Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also asked whether any differences among laboratories were related to the extraction and quantification methods used to determine starch and sugar concentrations. These questions were addressed by sending sub-samples collected from five woody plant tissues, which varied in NSC content and chemical composition, to 29 laboratories. Each laboratory analyzed the samples with their laboratory-specific protocols, based on recent publications, to determine concentrations of soluble sugars, starch and their sum, total NSC. Laboratory estimates differed substantially for all samples. For example, estimates for Eucalyptus globulus leaves (EGL) varied from 23 to 116 (mean = 56) mg g(-1) for soluble sugars, 6-533 (mean = 94) mg g(-1) for starch and 53-649 (mean = 153) mg g(-1) for total NSC. Mixed model analysis of variance showed that much of the variability among laboratories was unrelated to the categories we used for extraction and quantification methods (method category R(2) = 0.05-0.12 for soluble sugars, 0.10-0.33 for starch and 0.01-0.09 for total NSC). For EGL, the difference between the highest and lowest least squares means for categories in the mixed model analysis was 33 mg g(-1) for total NSC, compared with the range of laboratory estimates of 596 mg g(-1). Laboratories were reasonably consistent in their ranks of estimates among tissues for starch (r = 0.41-0.91), but less so for total NSC (r = 0.45-0.84) and soluble sugars (r = 0.11-0.83). Our results show that NSC estimates for woody plant tissues cannot be compared among laboratories. The relative changes in NSC between treatments measured within a laboratory may be comparable within and between laboratories, especially for starch. To obtain comparable NSC estimates, we suggest that users can either adopt the reference method given in this publication, or report estimates for a portion of samples using the reference method, and report estimates for a standard reference material. Researchers interested in NSC estimates should work to identify and adopt standard methods.
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