| 1. |
- Aldrin-Kirk, Patrick, et al.
(författare)
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DREADD Modulation of Transplanted DA Neurons Reveals a Novel Parkinsonian Dyskinesia Mechanism Mediated by the Serotonin 5-HT6 Receptor
- 2016
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Ingår i: Neuron. - : Elsevier BV. - 0896-6273. ; 90:5, s. 955-968
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Tidskriftsartikel (refereegranskat)abstract
- Transplantation of DA neurons is actively pursued as a restorative therapy in Parkinson's disease (PD). Pioneering clinical trials using transplants of fetal DA neuroblasts have given promising results, although a number of patients have developed graft-induced dyskinesias (GIDs), and the mechanism underlying this troublesome side effect is still unknown. Here we have used a new model where the activity of the transplanted DA neurons can be selectively modulated using a bimodal chemogenetic (DREADD) approach, allowing either enhancement or reduction of the therapeutic effect. We show that exclusive activation of a cAMP-linked (Gs-coupled) DREADD or serotonin 5-HT6 receptor, located on the grafted DA neurons, is sufficient to induce GIDs. These findings establish a mechanistic link between the 5-HT6 receptor, intracellular cAMP, and GIDs in transplanted PD patients. This effect is thought to be mediated through counteraction of the D2 autoreceptor feedback inhibition, resulting in a dysplastic DA release from the transplant.
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| 2. |
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| 3. |
- Bolinder, Martin, et al.
(författare)
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Fånggrödor och rötrester i ICBM
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Målsättningen med detta utvecklingsprojekt var att göra en förstudie om tillgänglig statistik för fånggrödor och rötrester. Data med tidsserier för fånggrödor som används i andra modelleringsprojekt på SLU kan anpassas relativt enkelt för att inkluderas i kolbalansmodellen ICBM på länsnivå. För rötrester finns det också potentiella källor med tidsserier, men de skulle kräva lite mer förbehandling innan de kan användas. Båda dataserierna sträcker sig så pass långt bak i tiden att de representerar ganska bra den tidpunkten från och med att dessa två faktorer blir relevanta att ha med i markkolsmodelleringen. Modellparametrar (utöver areal fånggrödor och mängd rötrester), som man skulle behöva justera rör framför allt allometriska funktioner för fånggrödor och humifieringskoefficienten för biogödsel.
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| 4. |
- Bolinder, Martin, et al.
(författare)
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Implementing a new version of ICBM in NIR
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the sector Land Use, Land-Use Change and Forestry (LULUCF, CRF sector 4) within the national greenhouse gas inventory (NIR), Sweden is applying a Tier 3 method for estimating the loss or gain of soil organic carbon (SOC) stocks for cropland on mineral soils to a depth of 0.25 m. The Introductory Carbon Balance Model (ICBM) is used for calculating stock change rates in eight agricultural production regions and results are aggregated to the national level. Calculations involves yearly agricultural census data and daily weather records, as well as results from a national soil-monitoring program (SMP) on soil carbon contents. Initially, only data from the first sampling of the national SMP were used for initializing ICBM. Since the first soil inventory, two additional samplings within the SMP have become available. Simultaneously, we have also gained more knowledge about SOC dynamics. In a development project last year, we were re-analyzing the complete records of data from the last two decades of the SMP confirming that SOC stocks are increasing, and we were starting to calibrate a new version of ICBM. The purpose of the project this year was to implement the new ICBM version in the NIR system.The results show that the new version of ICBM simulates increasing SOC stocks for the period 1990 to 2018, which is thereby more consistent with estimates from the national SMP data than results obtained using the previous ICBM version. The ICBM and SMP assessment methods of SOC stock changes are complementing each other, and both have their inherent limitations. Our analysis with both methodologies are still not fully completed. There remain some fine-tuning in the new ICBM version. Furthermore, we are continuously working on improving the interpretation regarding SOC stocks in the current database from the national SMP. Maintaining the latter and repeating the sampling at least once more would also substantially improve the value of this database.
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| 5. |
- Bolinder, Martin, et al.
(författare)
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New calibration of the ICBM model & analysis of soil organic carbon concentration from Swedish soil monitoring programs
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We are using the Introductory Carbon Balance Model (ICBM) within the national inventory reporting (NIR) system for estimating changes in soil organic carbon (SOC) stocks in Swedish arable land for mineral soils. The first version of ICBM was developing from a long-term experiment (LTE) in Ultuna Sweden, with a time-series of data from 1956 to 1991. The model is initialized using data from a soil database and information from Swedish soil monitoring programs (SMPs). For that purpose, it specifically uses data from the first inventory of the Swedish Environmental Protection Agency (SEPA) SMP conducted in the early 1990s. Since the 1990s, the SEPA SMP has conducted two further inventories in a 10-year cycles, with the last inventory completed in 2017. In complement to this SEPA SMP, the Swedish Board of Agriculture (SJV) was completing a spatially more detailed SMP in 2011 and 2012. In an earlier study, when the third inventory of SEPA was still not fully completed, we showed that SOC concentrations are increasing in Swedish arable mineral soils during the past two decades. Simulations with the current version of ICBM are not reproducing this long-term increasing trend.The main purposes of this project were to (i) calibrate a second version of ICBM by incorporating new knowledge gained from LTEs, (ii) evaluate the trends in SOC concentrations with the complete inventories (I, II and III) of SEPA, (iii) compare results from SEPAs last inventory (III) with that of SJV SMP conducted at approximately the same time period. A Bayesian approach was selected for calibrating the second version of ICBM, using an updated time series of data from Ultuna ending in 2017, and by also including experimental data (1996-2017) from a new sister experiment at Lanna in southern Sweden. For adequately comparing the SEPA and SJV SMPs, we were correcting data from the SJV samples so that we could express all results for SOC concentrations on a basis equivalent to dry combustion. Our analysis on the complete SEPA inventories are generally confirming our previous assessment. However, a more detailed exploration using data only from inventories II and III having identical sampling coordinates, clearly indicates that the increases in SOC concentrations were less in the last decade than in the previous one. Furthermore, when comparing SOC concentrations at different spatial scales, the positive trend in SOC concentrations is much more obvious on the scale of Swedish agricultural production regions (eight regions). Indeed, at the scale of the twenty-one Swedish counties, there are few significant differences and the increasing trend is unclear for many of the counties. This is reflecting difficulties related to the density of sampling points in the SEPA SMP; each of them roughly represents 1500 ha of arable land. Besides, only two decades or even only one decade since SEPA was regarding inventory II as a restart of their SMP, remain a short time period in detecting changes in SOC and highlight the importance of maintaining continuous SMPs.We found the comparisons between the SJV and SEPA SMPs useful but further work is necessary to refine the linkage. The overall changes in parameter values related to SOC dynamics for the calibrated second version of ICBM, will give simulations towards higher SOC stocks, compared to the current version. The main parameter explaining this differences is the increased contribution of below ground (i.e., roots) annual C inputs to soil contributing to the formation of more stable SOC. The approach we used here also offers the advantage of making a multi-site calibration and we could in the future, further refine parameter values by including other Swedish LTEs. Additionally, it allows us to include an estimate for uncertainty in the predictions of SOC stocks, which we could also develop for inclusion in the NIR system.
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| 6. |
- Burmeister, Jason J., et al.
(författare)
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In vivo electrochemical studies of optogenetic control of glutamate signaling measured using enzyme-based ceramic microelectrode arrays
- 2018
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Ingår i: Neuromethods. - New York, NY : Springer New York. - 0893-2336 .- 1940-6045. ; 130, s. 327-351
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Bokkapitel (refereegranskat)abstract
- Direct electrochemical measurements of glutamate release in vivo were combined with optogenetics in order to examine light-induced control of glutamate neurotransmission in the rodent brain. Self-referenced recordings of glutamate using ceramic-based microelectrode arrays (MEAs) in hippocampus and frontal cortex demonstrated precise optical control of light-induced glutamate release through channelrhodopsin (ChR2) expression in both rat hippocampus and frontal cortex. Although the virus was only injected unilaterally, bilateral and rostro-caudal expression was observed in slice imaging, indicating diffusion and active transport of the viral particles. Methodology for the optogenetic control of glutamate signaling in the rat brain is thoroughly explained with special attention paid to MEA enzyme coating and cleaning for the benefit of other investigators. These data support that optogenetic control of glutamate signaling is robust with certain advantages as compared to other methods to modulate the in vivo control of glutamate signaling.
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| 7. |
- Devotta, Ashwin Moris, 1984-, et al.
(författare)
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A modified Johnson-Cook model for ferritic-pearlitic steel in dynamic strain aging regime
- 2019
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Ingår i: Metals. - : MDPI. - 2075-4701. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the flow stress behavior of ferritic-pearlitic steel (C45E steel) is investigated through isothermal compression testing at different strain rates (1 s-1, 5 s-1, and 60 s-1) and temperatures ranging from 200 to 700 °C. The stress-strain curves obtained from experimental testing were post-processed to obtain true stress-true plastic strain curves. To fit the experimental data to well-known material models, Johnson-Cook (J-C) model was investigated and found to have a poor fit. Analysis of the flow stress as a function of temperature and strain rate showed that among other deformation mechanisms dynamic strain aging mechanism was active between the temperature range 200 and 400 °C for varying strain rates and J-C model is unable to capture this phenomenon. This lead to the need to modify the J-C model for the material under investigation. Therefore, the original J-C model parameters A, B and n are modified using the polynomial equation to capture its dependence on temperature and strain rate. The results show the ability of the modified J-C model to describe the flow behavior satisfactorily while dynamic strain aging was operative. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
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| 8. |
- Eynian, Mahdi, 1980-, et al.
(författare)
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New methods for in-process identification of modal parameters in milling
- 2018
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Ingår i: Procedia CIRP. - : Elsevier. - 2212-8271 .- 2212-8271. ; 77, s. 469-472
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Tidskriftsartikel (refereegranskat)abstract
- Chatter vibrations encountered in machining can degrade surface finish and damage the machining hardware. Since chatter originates from unstable interaction of the machining process and the machining structure, information about vibration parameters of the machining structure should be used to predict combinations of cutting parameters that allow stable machining. While modal test methods, for example those with impact hammers, are widely used to identify structural parameters; the need for sophisticated test equipment is prohibitive in their use. Furthermore, dynamic properties of critical components of a machine tool may change as they get affected by cutting loads, material removal and spindle rotation. Recently few algorithms have been proposed that identify the in-process dynamic parameters by frequency measurements, thus avoiding these problems. In this paper, some of these algorithms are reviewed and their capabilities and limitations in processing am experimental data set are compared and discussed. © 2018 The Authors. Published by Elsevier Ltd.
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| 9. |
- Lundblad, Mattias, et al.
(författare)
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KP-LULUCF
- 2019
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Ingår i: National inventory report Sweden 2019 : greenhouse gas emission inventories 1990-2017. ; , s. 457-483
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Bokkapitel (refereegranskat)
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| 10. |
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