| 1. |
- Toth, Arnold, et al.
(författare)
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Microbleeds may expand acutely after traumatic brain injury
- 2016
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Ingår i: Neuroscience Letters. - : Elsevier. - 0304-3940 .- 1872-7972. ; 617, s. 207-212
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Susceptibility weighted imaging (SWI) is a very sensitive tool for the detection of microbleeds in traumatic brain injury (TBI). The number and extent of such traumatic microbleeds (TMBs) have been shown to correlate with the severity of the injury and the clinical outcome. However, the acute dynamics of TMBs have not been revealed so far. Since TBI is known to constitute dynamic pathological processes, we hypothesized that TMBs are not constant in their appearance, but may progress acutely after injury.Materials and methods: We present here five closed moderate/severe (Glasgow coma scale≤13) TBI patients who underwent SWI very early (average=23.4 h), and once again a week (average=185.8 h) after the injury. The TMBs were mapped at both time points by a conventional radiological approach and their numbers and volumes were measured with manual tracing tools by two observers. TMB counts and extents were compared between time points.Results: TMBs were detected in four patients, three of them displaying an apparent TMB change. In these patients, TMB confluence and apparent growth were detected in the corpus callosum, coronal radiation or subcortical white matter, while unchanged TMBs were also present. These changes caused a decrease in the TMB count associated with an increase in the overall TMB volume over time.Conclusion: We have found a compelling evidence that diffuse axonal injury-related microbleed development is not limited strictly to the moment of injury: the TMBs might expand in the acute phase of TBI. The timing of SWI acquisition may be relevant for optimizing the prognostic utility of this imaging biomarker.
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| 2. |
- Környei, Bálint S., et al.
(författare)
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Cerebral microbleeds may be less detectable by susceptibility weighted imaging MRI from 24 to 72 hours after traumatic brain injury
- 2021
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media S.A.. - 1662-4548 .- 1662-453X. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: A former rodent study showed that cerebral traumatic microbleeds (TMBs) may temporarily become invisible shortly after injury when detected by susceptibility weighted imaging (SWI). The present study aims to validate this phenomenon in human SWI.Methods: In this retrospective study, 46 traumatic brain injury (TBI) patients in various forms of severity were included and willingly complied with our strict selection criteria. Clinical parameters potentially affecting TMB count, Rotterdam and Marshall CT score, Mayo Clinic Classification, contusion number, and total volume were registered. The precise time between trauma and MRI [5 h 19 min to 141 h 54 min, including SWI and fluid-attenuated inversion recovery (FLAIR)] was individually recorded; TMB and FLAIR lesion counts were assessed. Four groups were created based on elapsed time between the trauma and MRI: 0-24, 24-48, 48-72, and >72 h. Kruskal-Wallis, ANOVA, Chi-square, and Fisher's exact tests were used to reveal differences among the groups within clinical and imaging parameters; statistical power was calculated retrospectively for each comparison.Results: The Kruskal-Wallis ANOVA with Conover post hoc analysis showed significant (p = 0.01; 1-β > 0.9) median TMB number differences in the subacute period: 0-24 h = 4.00 (n = 11); 24-48 h = 1 (n = 14); 48-72 h = 1 (n = 11); and 72 h ≤ 7.5 (n = 10). Neither clinical parameters nor FLAIR lesions depicted significant differences among the groups.Conclusion: Our results demonstrate that TMBs on SWI MRI may temporarily become less detectable at 24-72 h following TBI.
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| 3. |
- Kövesdi, Erzsébet, et al.
(författare)
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Posttraumatic administration of pituitary adenylate cyclase activating polypeptide in central fluid percussion injury in rats
- 2008
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Ingår i: Neurotoxicity research. - : Springer. - 1029-8428 .- 1476-3524. ; 13:2, s. 71-78
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Tidskriftsartikel (refereegranskat)abstract
- Several in vitro and in vivo experiments have demonstrated the neuroprotective effects of pituitary adenylate cyclase activating polypeptide (PACAP) in focal cerebral ischemia, Parkinson's disease and traumatic brain injury (TBI). The aim of the present study was to analyze the effect of PACAP administration on diffuse axonal injury (DAI), an important contributor to morbidity and mortality associated with TBI, in a central fluid percussion (CFP) model of TBI. Rats were subjected to moderate (2 Atm) CFP injury. Thirty min after injury, 100 mu g PACAP was administered intracerebroventricularly. DAI was assessed by immunohistochemical detection of beta-amyloid precursor protein, indicating impaired axoplasmic transport, and RMO-14 antibody, representing foci of cytoskeletal alterations (neurofilament compaction), both considered classical markers of axonal damage. Analysis of damaged, immunoreactive axonal profiles revealed significant axonal protection in the PACAP-treated versus vehicle-treated animals in the corticospinal tract, as far as traumatically induced disturbance of axoplasmic transport and cytoskeletal alteration were considered. Similarly to our former observations in an impact acceleration model of diffuse TBI, the present study demonstrated that PACAP also inhibits DAI in the CFP injury model. The finding indicates that PACAP and derivates can be considered potential candidates for further experimental studies, or purportedly for clinical trials in the therapy of TBI.
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| 4. |
- Toth, Arnold, et al.
(författare)
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Both hemorrhagic and non-hemorrhagic traumatic MRI lesions are associated with the microstructural damage of the normal appearing white matter
- 2018
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Ingår i: Behavioural Brain Research. - : Elsevier. - 0166-4328 .- 1872-7549. ; 340, s. 106-116
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic microbleeds (TMBs) and non-hemorrhagic lesions (NHLs) on MRI are regarded as surrogate markers of diffuse axonal injury. However, the actual relation between lesional and diffuse pathology remained unclear, since lesions were related to clinical parameters, largely influenced by extracranial factors. The aim of this study is to directly compare TMBs, NHLs and their regional features with the co-existing diffuse injury of the normal appearing white matter (NAWM) as measured by diffusion tensor imaging (DTI). Thirty-eight adults with a closed traumatic brain injury (12 mild, 4 moderate and 22 severe) who underwent susceptibility weighted imaging (SWI), Tl-, T2 weighted and FLAIR MRI and routine CT were included in the study. TMB (on SWI) and NHL (on T1-, T2 weighted and FLAIR images) features and Rotterdam scores were evaluated. DTI metrics such as fractional anisotropy (FA) and mean diffusivity (MD) were measured over different NAWM regions. Clinical parameters including age; Glasgow Coma Scale; Rotterdam score; TMB and NHL features were correlated to regional NAWM diffusivity using multiple regression. Overall NHL presence and basal ganglia area TMB load were significantly, negatively correlated with the subcortical NAWM FA values (partial r = -0.37 and -0.36; p = 0.006 and 0.025, respectively). The presence of any NHL, or TMBs located in the basal ganglia area indicates diffuse NAWM damage even after adjusting for clinical and CT parameters. To estimate DAI, a conventional lesional MRI pathology evaluation might at least in part substitute the use of quantitative DTI, which is yet not widely feasible in a clinical setting. (C) 2017 Elsevier B.V. All rights reserved.
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| 5. |
- Tuka, Bernadett, et al.
(författare)
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Release of PACAP-38 in episodic cluster headache patients - An exploratory study
- 2016
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Ingår i: Journal of Headache and Pain. - : Springer Science and Business Media LLC. - 1129-2369 .- 1129-2377. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Activation of the trigeminal-autonomic reflex, involving the trigeminal ganglion, the superior salivatory nucleus and the sphenopalatine ganglion (SPG) is crucial in the pathophysiology of cluster headache (CH). Since pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38) is present both in the SPG and the trigeminal ganglion (TG) and its role in migraine has been described, our aim was to determine the plasma PACAP-38 levels in different phases of episodic CH (ECH). Peripheral cubital fossa blood samples were taken during the ictal and inter-bout periods of male ECH patients and from age-matched healthy controls (n = 9). Plasma PACAP-38-like immunoreactivity (LI) was measured with specific and sensitive radioimmunoassay. Findings: Significantly lower plasma PACAP-38-LI was detected in the inter-bout period of ECH patients than in healthy controls. However, PACAP-38 was significantly elevated in the plasma during CH attacks as compared to the inter-bout phase in the same subjects (n =5). Conclusions: This exploratory study suggests that PACAP-38 may be released during the attacks of ECH. Further patients and long-term follow-up are necessary to reveal its function.
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| 6. |
- Chen, Yuxi, et al.
(författare)
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Global Three-Dimensional Simulation of Earth's Dayside Reconnection Using a Two-Way Coupled Magnetohydrodynamics With Embedded Particle-in-Cell Model : Initial Results
- 2017
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Ingår i: Journal of Geophysical Research - Space Physics. - : AMER GEOPHYSICAL UNION. - 2169-9380 .- 2169-9402. ; 122:10, s. 10318-10335
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Tidskriftsartikel (refereegranskat)abstract
- We perform a three-dimensional (3-D) global simulation of Earth's magnetosphere with kinetic reconnection physics to study the flux transfer events (FTEs) and dayside magnetic reconnection with the recently developed magnetohydrodynamics with embedded particle-in-cell model. During the 1 h long simulation, the FTEs are generated quasi-periodically near the subsolar point and move toward the poles. We find that the magnetic field signature of FTEs at their early formation stage is similar to a "crater FTE," which is characterized by a magnetic field strength dip at the FTE center. After the FTE core field grows to a significant value, it becomes an FTE with typical flux rope structure. When an FTE moves across the cusp, reconnection between the FTE field lines and the cusp field lines can dissipate the FTE. The kinetic features are also captured by our model. A crescent electron phase space distribution is found near the reconnection site. A similar distribution is found for ions at the location where the Larmor electric field appears. The lower hybrid drift instability (LHDI) along the current sheet direction also arises at the interface of magnetosheath and magnetosphere plasma. The LHDI electric field is about 8 mV/m, and its dominant wavelength relative to the electron gyroradius agrees reasonably with Magnetospheric Multiscale (MMS) observations.
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| 7. |
- Daldorff, Lars K. S., et al.
(författare)
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Two-way coupling of a global Hall magnetohydrodynamics model with a local implicit particle-in-cell model
- 2014
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Ingår i: Journal of Computational Physics. - : Elsevier BV. - 0021-9991 .- 1090-2716. ; 268, s. 236-254
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Tidskriftsartikel (refereegranskat)abstract
- Computational models based on a fluid description of the plasma, such as magnetohydrodynamic (MHD) and extended magnetohydrodynamic (XMHD) codes are highly efficient, but they miss the kinetic effects due to the assumptions of small gyro radius, charge neutrality, and Maxwellian thermal velocity distribution. Kinetic codes can properly take into account the kinetic effects, but they are orders of magnitude more expensive than the fluid codes due to the increased degrees of freedom. If the fluid description is acceptable in a large fraction of the computational domain, it makes sense to confine the kinetic model to the regions where kinetic effects are important. This coupled approach can be much more efficient than a pure kinetic model. The speed up is approximately the volume ratio of the full domain relative to the kinetic regions assuming that the kinetic code uses a uniform grid. This idea has been advocated by [1] but their coupling was limited to one dimension and they employed drastically different grid resolutions in the fluid and kinetic models. We describe a fully two-dimensional two-way coupling of a Hall MHD model BATS-R-US with an implicit Particle-in-Cell (PIC) model iPIC3D. The coupling can be performed with identical grid resolutions and time steps. We call this coupled computational plasma model MHD-EPIC (MHD with Embedded PIC regions). Our verification tests show that MHD-EPIC works accurately and robustly. We show a two-dimensional magnetosphere simulation as an illustration of the potential future applications of MHD-EPIC.
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| 8. |
- Diószegi, Attila, 1962-, et al.
(författare)
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Modelling and simulation of heat conduction in 1-D polar spherical coordinates using control volume-based finite difference method
- 2016
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Ingår i: International journal of numerical methods for heat & fluid flow. - 0961-5539 .- 1758-6585. ; 26:1, s. 2-17
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Tidskriftsartikel (refereegranskat)abstract
- Purpose - The purpose of this paper is to obtain a finite difference method (FDM) solution using control volume for heat transport by conduction and the heat absorption by the enthalpy model in the sand mixture used in casting manufacturing processes. A mixture of sand and different chemicals (binders) is used as moulding materials in the casting processes. The presence of various compounds in the system improve the complexity of the heat transport due to the heat absorption as the binders are decomposing and transformed into gaseous products due to significant heat shock. Design/methodology/approach - The geometrical domain were defined in a 1D polar coordinate system and adapted for numerical simulation according to the control volume-based FDM. The simulation results were validated by comparison to the temperature measurements under laboratory conditions as the sand mould mixture was heated by interacting with a liquid alloy. Findings - Results of validation and simulation methods were about high correspondence, the numerical method presented in this paper is accurate and has significant potential in the simulation of casting processes. Originality/value - Both numerical solution (definition of geometrical domain in 1D polar coordinate system) and verification method presented in this paper are state-of-the-art in their kinds and present high scientific value especially regarding to the topic of numerical modelling of heat flow and foundry technology.
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| 9. |
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| 10. |
- Ma, Ying-Juan, et al.
(författare)
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3D global multi-species Hall-MHD simulation of the Cassini T9 flyby
- 2007
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 34:24, s. L24S10-
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Tidskriftsartikel (refereegranskat)abstract
- The wake region of Titan is an important component of Titan's interaction with its surrounding plasma and therefore a thorough understanding of its formation and structure is of primary interest. The Cassini spacecraft passed through the distant downstream region of Titan on 18: 59: 30 UT Dec. 26, 2005, which is referred to as the T9 flyby and provided a great opportunity to test our understanding of the highly dynamic wake region. In this paper we compare the observational data (from the magnetometer, plasma analyzer and Langmuir probe) with numerical results using a 7-species Hall MHD Titan model. There is a good agreement between the observed and modeled parameters, given the uncertainties in plasma measurements and the approximations inherent in the Hall MHD model. Our simulation results also show that Hall MHD model results fit the observations better than the non-Hall MHD model for the flyby, consistent with the importance of kinetic effects in the Titan interaction. Based on the model results, we also identify various regions near Titan where Hall MHD models are applicable.
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| 11. |
- Markidis, Stefano, et al.
(författare)
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Kinetic Modeling in the Magnetosphere
- 2021
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Ingår i: Magnetospheres in the Solar System. - : Wiley. ; , s. 607-615
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents the state of the art of kinetic modeling techniques for simulating plasma kinetic dynamics in magnetospheres. We describe the key numerical techniques for enabling large-scale kinetic simulations of magnetospheres: parameter scaling, implicit Particle-in-Cell schemes and fluid-kinetic coupling. We show an application of these techniques to study particle acceleration and heating in asymmetric magnetic reconnection in the Ganymede magnetosphere.
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| 12. |
- Michanek, Peter, et al.
(författare)
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Effect of infrared and red monochromatic light on equine wound healing
- 2020
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Ingår i: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 53, s. 143-148
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Tidskriftsartikel (refereegranskat)abstract
- Background Light-emitting diodes (LEDs) are commonly used for treating a variety of disorders in horses, including wounds. Despite its claim to shorten healing times, there is a lack of scientific documentation regarding its effects.Objectives To investigate if treatment with pulsating visible red light (lambda approximate to 637 nm) and near-infrared (NIR) light (lambda approximate to 956 nm) affects wound healing.Study design Randomised blinded controlled experimental study.Methods A circular skin wound (o = 2 cm) was created on each side of the neck in eight healthy horses. One randomly chosen wound received light treatment and the other served as an untreated control. Treatment duration was 4 minutes and 40 seconds (red light 95 seconds, 2.3 mW/cm(2); NIR light 185 seconds, 6.4 mW/cm(2)) and was performed once daily on day 0-4, 7-11, 14-18 and 21-25. The wounds were photographed and evaluated using digital photoplanimetry on day 0, 1, 2, 3, 4, 7, 14, 21, 28 and 35. The degree of swelling was assessed with diagnostic ultrasound on the same days except the last recording was performed on day 36 instead of 35. Days to total healing was recorded. ANOVA was used for statistical analysis (P < .05).Results The wound area (P = .2-.9) and degree of swelling (P = .2-1.0) did not differ between treated and control groups on any day. There was a significant difference (P = .03) in healing time between control (49.0, 95% CI = 35.4-62.6 days) and treated wounds (51.8, 95% CI = 38.7-64.8 days).Main limitations The wounds were treated until day 25 and this study does not investigate the effect of a longer treatment period than 25 days.Conclusions The results of this study do not indicate any clinically relevant positive effect of pulsating visible red light and NIR light on the healing of experimental skin wounds in horses, compared with no treatment.
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| 13. |
- Ostrowska, Justyna, et al.
(författare)
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Computed tomography characteristics of equine paranasal sinus cysts
- 2020
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Ingår i: Equine Veterinary Journal. - : Wiley. - 0425-1644 .- 2042-3306. ; 52, s. 538-546
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Tidskriftsartikel (refereegranskat)abstract
- Background Computed tomography (CT) is commonly used to investigate equine paranasal sinus disease, however, only limited information is available in the literature about the detailed CT appearance of equine paranasal sinus cysts.Objectives To investigate if paranasal sinus cysts have specific characteristics in CT images that allow differentiation from other sinus diseases.Study design Retrospective observational study.Methods Evaluation and comparison of CT studies of eight horses with surgically and/or histopathologically confirmed paranasal sinus cysts and 10 horses with other confirmed paranasal sinus diseases.Results A discrete hyperattenuating wall-like structure was detected in the periphery of the sinus lesion in precontrast acquisition in 7/8 horses with paranasal sinus cysts. A similar wall-like structure was detected in 3/10 horses with other sinus diseases, however, in contrast to horses with paranasal sinus cysts, two of these also had hyperattenuating regions within the contents of the sinus lesion. Bone destruction and formation affecting cancellous and cortical bone and dental disease were frequent in horses with paranasal sinus cysts. No significant difference in attenuation values was found when the fluid/soft tissue attenuation contents of lesions in horses with paranasal sinus cysts (mean 28.9 +/- SD 9.2 HU) were compared with other sinus diseases when ethmoid haematomas were excluded (30.4 +/- 12.9 HU, P = .8).Main limitations Low number of cases.Conclusions Detection of a hyperattenuating cystic wall is a helpful feature for identifying paranasal sinus cysts in CT images of horses. In contrast, measurement of attenuation values of the soft tissue/fluid contents of the sinus lesions was not helpful in identifying paranasal sinus cysts.
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| 14. |
- Ostrowska, Justyna, et al.
(författare)
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Computed tomography characteristics of equine paranasal sinus cysts—a case series
- 2016
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Ingår i: Veterinary Radiology and Ultrasound. - 1058-8183 .- 1740-8261. ; 57, s. 654-654
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- COMPUTEDTOMOGRAPHYCHARACTERISTICSOFEQUINEPARANASALSINUSCYSTS-ACASESERIESJ.Ostrowska,T.T´oth,L.Lindstr¨om,K.Hansson,M.Uhlhorn,C.J.Ley.FromtheUniversityAnimalHospital(Ostrowska,T´oth,Uhlhorn),DepartmentofClinicalSciences(Hansson,Ley),andDepartmentofBiomedicalSciencesandVeterinaryPublicHealth,SwedishUni-versityofAgriculturalSciences,UppsalaSE-75007,Sweden(Lindstr¨om).Introduction/Purpose:Differentiatingparanasalsinuscysts(PSC)fromotherparanasalsinusdiseasesinhorsesbasedondiagnosticimagingischallenging.TheaimofthisstudywastoidentifythepatternofCTfeatures,typicalforPSC,byretrospectivecomparisontootherdiseasesoftheequineparanasalsinuses. Methods:NineCTscansofeighthorses(diseasereoccurredafter1yearinonehorse)withtypicalsurgicalappearanceofPSC(sevenconfimedwithhistopathology)wereretrospectivelyre-viewed(group-1).Imagingfndingswerecomparedtoagroupof11horseswithparanasalsinusdiseaseofotherorigin(twoneoplasia,sevenchronicsinusits/granuloma,twopro-gressiveethmoidhematoma),withallhorsesinthisgrouphavingsurgery/necropsyandculture/histopathologyconfimationofthediagnosis(group-2).Thirteenofthehorsesre-ceivedcontrast;IVIohexol300mgI/ml,20ml/s,400ml/horse,scannedapproximately2and7minpostcontrast.MeanHounsfielUnits(HU)valuesofthesofttissue/fluidensitylesionswereobtainedforthreeregionsofinterestinthreedifferentslices.Studentt-testforindependentsamples,P<0.05consideredsignificantwasusedtocomparemeandensityofthecysticcontentwithfreesinusfluiingroup-1andsofttissue/fluidensitylesionsingroup-2.Results:Insixhorsesthepresumedwallofthecystwasatleastpartiallymineralized.Subtlepost-contrastenhancementofthecysticwallwasseenintwohorsesinwhichthemineralizedwallwasabsent.Presenceoffocalorspicule-like,peripheralmineralizationswereseenintwogroup-1horsesandinonegroup-2horsewithaparanasalsinusgranuloma.Allcystswerefillewithsofttissue/fluidensity(mean±SD,25±11HU),exceptonethatcontainedonlyair.Nosignificandifferencewasfoundbetweenthemeandensityofthecysticcontentandthesofttissue/fluidensitylesionsingroup-2(mean±SD,25±11vs.42±23HU,P=0.06),orbetweenthefreesinusfluisurroundingthecysts(mean±SD,25±11HUvs.34±17HU,P=0.2).Corticaldestructionwasdetectedinfourgroup-1andtwogroup-2horses.Sevenhorsesineachgrouphadcancellousbonethinning/destruction,whichalwaysinvolvedatleasttheinfraorbitalcanal.Bonedistortionwasmostfrequent/severeingroup-1horsesandboneproductionwasmostcommoningroup-2horseswithsinusitis.Discussion/Conclusions:ParanasalsinuscystsoftenhavemineralizationinthecystwallandthisfeaturemaybeusefultodifferentiatePSCfromotherparanasalsinusesdiseasesinCTimages.DespitethebenigncharacterofPSCcorticaldestructioniscommoninhorseswithPSC.ThereisconsiderableoverlapbetweenHUvaluesofthecontentsofPSCandthefluid/tissupresentinotherparanasalsinusdiseases.
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| 15. |
- Pethő, Dávid, et al.
(författare)
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Ferryl hemoglobin and heme induce Α1‐microglobulin in hemorrhaged atherosclerotic lesions with inhibitory function against hemoglobin and lipid oxidation
- 2021
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 22:13
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Tidskriftsartikel (refereegranskat)abstract
- Infiltration of red blood cells into atheromatous plaques and oxidation of hemoglobin (Hb) and lipoproteins are implicated in the pathogenesis of atherosclerosis. α1‐microglobulin (A1M) is a radical‐scavenging and heme‐binding protein. In this work, we examined the origin and role of A1M in human atherosclerotic lesions. Using immunohistochemistry, we observed a significant A1M immunoreactivity in atheromas and hemorrhaged plaques of carotid arteries in smooth muscle cells (SMCs) and macrophages. The most prominent expression was detected in macrophages of organized hemorrhage. To reveal a possible inducer of A1M expression in ruptured lesions, we exposed aortic endothelial cells (ECs), SMCs and macrophages to heme, Oxy‐ and FerrylHb. Both heme and FerrylHb, but not OxyHb, upregulated A1M mRNA expression in all cell types. Importantly, only FerrylHb induced A1M protein secretion in aortic ECs, SMCs and macrophages. To assess the possible function of A1M in ruptured lesions, we analyzed Hb oxidation and heme‐catalyzed lipid peroxidation in the presence of A1M. We showed that recombinant A1M markedly inhibited Hb oxidation and heme‐driven oxidative modification of low‐density lipoproteins as well plaque lipids derived from atheromas. These results demonstrate the presence of A1M in atherosclerotic plaques and suggest its induction by heme and FerrylHb in the resident cells.
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| 16. |
- Pettkó-Szandtner, Aladár, et al.
(författare)
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Activation of an alfalfa cyclin-dependent kinase inhibitor by calmodulin-like domain protein kinase.
- 2006
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Ingår i: Plant Journal. - 0960-7412. ; 46:1, s. 111-23
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Tidskriftsartikel (refereegranskat)abstract
- Kip-related proteins (KRPs) play a central role in the regulation of the cell cycle and differentiation through modulation of cyclin-dependent kinase (CDK) functions. We have identified a CDK inhibitor gene from Medicago truncatula (Mt) by a yeast two-hybrid screen. The KRPMt gene was expressed in all plant organs and cultured cells, and its transcripts accumulated after abscisic acid and NaCl treatment. The KRPMt protein exhibits seven conserved sequence domains and a PEST motif that is also detected in various Arabidopsis KRPs. In the yeast two-hybrid test, the KRPMt protein interacted with CDK (Medsa;CDKA;1) and D-type cyclins. However, in the pull-down assays, B-type CDK complexes were also detectable. Recombinant KRPMt differentially inhibited various alfalfa CDK complexes in phosphorylation assays. The immunoprecipitated Medsa;CDKA;1/A;2 complex was strongly inhibited, whereas the mitotic Medsa;CDKB2;1 complex was the most sensitive to inhibition. Function of Medsa;CDKB1;1 complex was not inhibited by the KRPMt protein. The mitotic Medsa;CYCB2 and Medsa;CYCA2;1 complexes responded weakly to this inhibitor protein. Kinase complexes from G2/M cells showed increased sensitivity towards the inhibitor compared with those isolated from G1/S-phase cells. In vitro phosphorylation of Medicago retinoblastoma-related protein was also reduced in the presence of KRPMt. Phosphorylation of this inhibitor protein by the recombinant calmodulin-like domain protein kinase (MsCPK3) resulted in enhanced inhibition of CDK function. The data presented emphasize the selective sensitivity of various cyclin-dependent kinase complexes to this inhibitor protein, and suggest a role for CDK inhibitors and CPKs in cross-talk between Ca2+ signalling and regulation of cell-cycle progression in plants.
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| 17. |
- Skov Hansen, Sabrina, et al.
(författare)
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A large cyst in the distal femur of a horse
- 2020
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Ingår i: Equine Veterinary Education. - : Wiley. - 0957-7734 .- 2042-3292. ; 33, s. e67-e72
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Tidskriftsartikel (refereegranskat)abstract
- A 10-year-old Warmblood gelding presented with a left hindlimb lameness. Diagnostic analgesia located the lameness to the stifle. Radiography showed an unusually large cyst in the distal femur. Diagnostic arthroscopy of the stifle did not reveal any significant abnormalities. An extra-articular transcortical approach to the cyst was performed for drainage, curettage, and provision of an autologous, cancellous bone graft, gentamicin-impregnated collagen fleeces and injectable steroid. The horse returned to a higher level of competitive dressage than prior to surgery. This report describes a large cyst in the distal femur of a horse.
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| 18. |
- Skov Hansen, Sabrina, et al.
(författare)
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The influence of tenoscopic approaches on radiocarpal joint perforation during carpal sheath tenoscopy in horses
- 2020
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Ingår i: Veterinary Surgery. - : Wiley. - 0161-3499 .- 1532-950X. ; 49, s. 274-280
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Tidskriftsartikel (refereegranskat)abstract
- Objective To report the frequency of radiocarpal joint (RCJ) perforation during two proximolateral carpal sheath (CS) approaches and to investigate whether the presence or absence of a natural communication between the RCJ and CS. Study design Experimental, randomized, controlled study. Sample population Twelve adult horses and 12 cadaver front limbs. Methods Proximolateral CS tenoscopy was performed on both carpi of 12 horses under general anaesthesia. Limbs were randomly assigned into two groups. In group 1, the instrument portal was centered at the level of the distal radial physeal remnant (PR). In group 2, the instrument portal was centered 2 cm proximal to the PR. Immediately after tenoscopy, dye-coloured fluid was instilled arthroscopically into the dorsolateral RCJ, and the open tenoscopic portals were evaluated for leakage. Twelve cadaver front limbs were examined for naturally occuring RCJ and CS communication by using positive-contrast computed tomography (CT). Frequency of perforations were compared with McNemar's test for two matched proportions. Results In group 1, 10 of 12 RCJ were perforated during tenoscopy, and, in group 2, four of 12 RCJ were perforated (P = 0.03). No diffusion of contrast from the RCJ to the CS was detected by CT. Conclusion Perforation of the RCJ was common when CS instrument portals were placed at the level of the PR. No natural communication was detected between the RCJ and CS. Clinical significance Carpal sheath tenoscopic instrument portals may need to be placed >2 cm proximal to the PR to prevent inadvertent RCJ perforation, especially in horses undergoing tenoscopic treatment of a septic CS.
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| 19. |
- Svidró, József Tamás, 1984-, et al.
(författare)
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Heat absorption capacity and binder degradation characteristics of 3D printed cores investigated by inverse Fourier thermal analysis
- 2015
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Ingår i: Transactions Of The American Foundry Society. - : The American Foundry Society. - 9780874334340 ; , s. 135-143
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Konferensbidrag (refereegranskat)abstract
- The application of 3D printing techniques is a recently developing area used within foundry technology. Digital production of sand molds and cores eliminates the need for hard tooling, drastically reduces lead times and offers design freedoms not possible in the traditional pattern making. Even though mold and core making technologies are refined from both scientific and practical points of view, casting defects may still occur in the final products. Thus, molding material related casting research is required to generate state-of-the-art methods and understandings to avoid the formation of casting defects. In this paper, a pioneering method is presented which is suitable to determine novel thermophysical and heat transfer properties of various types of molding materials. These properties are strongly connected to the cooling capacity and the gas evolution features of the cores used in casting production. The method is based on temperature measurements inside spherical shaped core sand specimens and evaluated by a special application of Fourier thermal analysis. Temperature measurements were performed in test samples produced by two different 3D core printing systems. The registered temperature data were processed by Fourier thermal analysis to calculate the thermal properties and the decomposition characteristics of the 3D printed cores. The experiments were executed under different heating conditions analogous to aluminium and cast iron production.
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| 20. |
- Svidró, József Tamás, et al.
(författare)
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The novel application of Fourier thermal analysis in foundry technologies
- 2014
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Ingår i: Journal of thermal analysis and calorimetry (Print). - : Springer Science and Business Media LLC. - 1388-6150 .- 1588-2926. ; 115:1, s. 331-338
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Tidskriftsartikel (refereegranskat)abstract
- The process of casting in sand moulds is used for a large volume of castings manufactured in the world. Internal channels and complex geometries of these products are formed by the placement of cores within the mould cavity. Resin-bound sand mixtures are essential ingredients in engine component manufacturing. In this study, a state-of-the-art application of Fourier thermal analysis in foundry technologies is presented. Investigation of decomposition phenomena of resin-bound moulding materials during casting production is a brand new area to use the potential of thermal sciences. Temperature measurements in test samples of standard types of moulding mixtures were performed. The registered cooling curves were processed by a numerical iteration algorithm to determine the amount of heat absorbed during degradation of the moulding material. Thermogravimetric analysis (TG) and differential thermal analysis (DTA) of sand mixtures were carried out to compare the results of the Fourier thermal analysis with TG and DTA curves.
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| 21. |
- Svidró, Judit, et al.
(författare)
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The influence of thermal expansion of unbonded foundry sands on the deformation of resin bonded cores
- 2017
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Ingår i: Archives of Metallurgy and Materials. - : De Gruyter Open. - 1733-3490 .- 2300-1909. ; 62:2, s. 795-798
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Tidskriftsartikel (refereegranskat)abstract
- Depending on the preparation and the applied materials, moulds and cores can be of high rigidity or can be flexible. Although, chemically bonded moulding materials have relatively good flexibility, their high temperature behaviour determines the dimensional accuracy, the stresses in the castings and can induce several casting defects, such as rattail, veining, etc. The phenomenon is based on two major effects: the thermal expansion of the unbonded foundry sands and the deformation of the sand mixtures. The main objective of the present work was to study the relationship between these two effects, and to improve the knowledge related to the thermo-mechanical interactions between the casting and the mould. Dilatometric analysis of unbonded sand samples were performed and compared to the results of hot distortion tests of moulding mixture specimens. The results showed, that the thermal expansion of foundry sand largely influences the hot distortion behaviour, but depending on the type of binder used.
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| 22. |
- Szamosi, Zoltan, et al.
(författare)
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Explosion Characteristics of Torrefied Wheat Straw, Rape Straw, and Vine Shoots Fuels
- 2017
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 31:11, s. 12192-12199
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Tidskriftsartikel (refereegranskat)abstract
- Torrefaction is a method for upgrading raw biomass to produce solid fuels that exhibit higher energy density relative to that of the raw material. In countries that produce significant amounts of agricultural residues, torrefaction may facilitate the utilization of waste in the energy sector by adding value to the raw fuel and opening pathways for new applications. In typical scenarios for utilization as fuel, both the raw and torrefied materials are stored in granular form. Dependent upon the properties of the granular material, the risk of dust explosion may be significant. Torrefaction changes the physical and chemical properties of the biomass and, therefore, affect explosion risk and severity. This work investigates the dust explosion characteristics of raw and torrefied agricultural wastes typically produced in Central European countries. The objective is to provide a characterization of these fuels in terms of explosion properties and make recommendations on storage design and safety. Three residues were studied: wheat straw, rape straw, and vine shoots. The samples were characterized in terms of their particle size, proximate and ultimate compositions, calorific properties, thermogravimetric behavior, and standard explosion characteristics. Torrefaction increased the explosivity of all three residues. Of the three samples, wheat straw was the least explosive, which is explained by the lowest amount of open cellular pores generated during torrefaction. Scanning electron microscopy imaging and thermogravimetry results suggested that the amount of open pores is the most significant contributor to the increase of explosivity caused by torrefaction, as opposed to increasing brittleness and fragmentation. For plants switching from using raw residues to torrefied fuels, the required area of typical explosion panels increases by 18-21% in the case of wheat and rape straw and by 26-30% in the case of vine shoots.
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| 23. |
- Székely, Éva, et al.
(författare)
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Synthesizing expressive speech from amateur audiobook recordings
- 2012
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Ingår i: Spoken Language Technology Workshop (SLT). ; , s. 297-302
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Konferensbidrag (refereegranskat)abstract
- Freely available audiobooks are a rich resource of expressive speech recordings that can be used for the purposes of speech synthesis. Natural sounding, expressive synthetic voices have previously been built from audiobooks that contained large amounts of highly expressive speech recorded from a profes- sionally trained speaker. The majority of freely available au- diobooks, however, are read by amateur speakers, are shorter and contain less expressive (less emphatic, less emotional, etc.) speech both in terms of quality and quantity. Synthesiz- ing expressive speech from a typical online audiobook there- fore poses many challenges. In this work we address these challenges by applying a method consisting of minimally su- pervised techniques to align the text with the recorded speech, select groups of expressive speech segments and build expres- sive voices for hidden Markov-model based synthesis using speaker adaptation. Subjective listening tests have shown that the expressive synthetic speech generated with this method is often able to produce utterances suited to an emotional mes- sage. We used a restricted amount of speech data in our exper- iment, in order to show that the method is generally applicable to most typical audiobooks widely available online.
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| 24. |
- Székely, Tamás, et al.
(författare)
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The causes and implications of sex role diversity in shorebird breeding systems
- 2024
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Ingår i: Ibis. - 0019-1019. ; 166:2, s. 357-385
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Forskningsöversikt (refereegranskat)abstract
- Males and females often exhibit different behaviours during mate acquisition, pair-bonding and parenting, and a convenient label to characterize these behaviours is sex role. The diverse roles that male and female shorebirds (plovers, sandpipers and allies) exhibit in mating and parenting have played a key role in advancing mainstream theories in avian ecology and behavioural biology including sexual selection, sexual conflict and parental cooperation. Recent advances in shorebird research have also highlighted the significance of the social environment in driving sex role behaviours by linking the adult sex ratio with breeding behaviour and population demography. Here we review the key advances in sex role research using shorebirds as an ecological model system. We identify knowledge gaps and argue that shorebirds have untapped potential to accelerate diverse research fields including evolutionary genomics, movement ecology, social networks and environmental changes. Future studies of sex roles will benefit from individual-based monitoring using advanced tracking technologies, and from multi-team collaborations that are facilitated by standardized data collection methodologies across different species in the field. These advances will not only contribute to our understanding of reproductive strategies, but they will also have knock-on effects on predicting population resilience to environmental changes and on prioritizing species for conservation.
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| 25. |
- Teixeira, Fernando, et al.
(författare)
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Evidence of non-site-specific agricultural management effects on the score of visual soil quality indicators
- 2023
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Ingår i: Soil use and management. - : Wiley. - 0266-0032 .- 1475-2743. ; 39:1, s. 474-484
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates 11 agricultural management practices (AMPs) and their effects on seven visual soil quality indicators and soil aggregate stability. The survey carried out across eight pedoclimatic zones in Europe and China was based on visual soil assessments (New Zealand VSA method) performed on soils subject to different soil management practices and nearby similar soils, under similar farming features, without the distinctive soil management practice (control). Fisher's exact test was used to test if the management treatment was independent of the score of each visual soil quality indicator and to test if the management treatment produced a higher frequency of the score ‘good’. The results showed a statistically significant (α < .05) higher frequency of the score ‘good’ for ‘soil structure and consistency’ and/or ‘soil porosity’ for six AMPs. For no-till AMP, the null hypothesis can also be rejected for ‘susceptibility to erosion’ and ‘soil stability’ and for ‘mulching + permanent soil cover’ AMP, for the ‘presence of tillage pan’ and ‘soil colour’. The hypothesis that the management treatment was independent of the score of each indicator was rejected for ‘soil structure and consistency’ of three AMPs, for ‘soil porosity’ of three AMPs, for ‘soil colour’ of one AMP and for the ‘presence of tillage pan’ of one AMP. This study demonstrates that farming systems sharing a common influential soil management practice at different locations and with different soil types significantly affect the score of some visual soil quality indicators.
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