Hutchins w obronie interdyscyplinarnych badań nad poznaniem

The article presents the interdisciplinary approach of Edwin Hutchins, analyzing his conception of distributed cognition as probably the most important and lasting contribution of anthropology to the repertoire of theoretical tools in cognitive science. At the same time, this conception resulted in one of the most interesting relationships between cognitive science and social sciences. These relationships are made possible by the assumptions of Hutchins’ conception, which directly contribute to interdisciplinary collaboration. His account of distributed cognition has enormous potential, allowing the integration of research into cognitive and social processes. This is also because it breaks with methodological individualism

Magnetic resonance imaging assessment of cerebral small vessel disease intensification in patients with severe aortic valve stenosis

Purpose: To assess the prevalence of the neuroradiological indices of cerebral small vessel disease (CSVD) in patients with severe aortic valve stenosis (AS) in magnetic resonance imaging (MRI). Material and methods: 34 patients (age 60-90 years, 17 women and 17 men) with severe AS and 50 healthy controls (age 61-85 years, 29 women and 21 men) underwent MRI brain examinations, which were analysed for the neuroradiological indices of CSVD: hyperintensities in periventricular white matter (PVWM) and deep white matter (DWM), enlarged perivascular spaces (ePVS), lacunar strokes, and cerebral microbleeds (CMBs). Results: PVWM hyperintensities were found in 46% of volunteers and was significantly lower (p = 0.027), corresponding to AS patients (80%), the density of lesions was higher in the AS group than in controls (p = 0.019). DWM hyperintensities were found more often in AS patients (76%) than in controls (66%) (p = 0.303), but the densities were similar in both groups. Lacunar strokes were found in 35% of AS patients and 16% of controls (p = 0.042). The average number of lacunar strokes per person was 0.9 in the AS group and 0.3 in the controls (p = 0.035). The AS group showed higher variance in the number of strokes: SD = 1.96 vs. SD = 1.06 in controls. Both prevalence and density of the ePVS and CMBs did not differ significantly between the groups. Conclusions: Neuroradiological indices of the vascular disease do not provide an unequivocal clue to the pathogenesis of CSVD in patients with severe AS. Most observations imply that CSVD is primarily a consequence of cerebral hypoperfusion caused by AS

Brain neuroplasticity in multiple sclerosis patients in functional magnetic resonance imaging : part 1: comparison with healthy volunteers

Purpose: The aim of this study was to assess the activity of motor cortical areas and the resting brain activity in a group of multiple sclerosis (MS) patients compared to a group of healthy individuals according to task-based functional magnetic resonance imaging (t-fMRI), resting state functional MRI (rs-fMRI), and volumetric MRI studies. Material and methods: The study enrolled 28 MS patients and 20 healthy volunteers who underwent MRI examinations. Primary motor cortex (M1), premotor area (PMA), supplementary motor area, as well as resting state networks (RSN’s) and volumes of selected brain structures were subjected to a detailed analysis. Results: In MS patients, a motor task more often resulted in the activation of ipsilateral M1 cortex (observed in 39% of the studied group) as well as the PMA cortex (observed in 32% of MS patients). No differences in resting brain activity were found between the studied groups. Significant differences were observed in volumetric parameters of the total brain volume (healthy volunteers vs. MS patients, respectively): (1197 cm³ vs. 1150 cm³) and volumes of the grey matter (517 cm³ vs. 481 cm³), cerebellum (150 cm³ vs. 136 cm³), thalamus (16.3 cm³ vs. 12.6 cm³), putamen (8.9 cm³ vs. 7.7 cm³), and globus pallidus (4.57 cm³ vs. 3.57 cm³). Conclusions: In the MS patients, the motor task required significantly more frequent activation of the primary and secondary ipsilateral motor cortex compared to the group of healthy volunteers. The rs-fMRI study showed no differences in activity patterns within the RSN’s. Differences in the total cerebral volume and the volume of the grey matter, cerebellum, thalamus, putamen, and globus pallidus were observed

Brain neuroplasticity in multiple sclerosis patients in functional magnetic resonance imaging studies : part 2 : effect of aerobic training

Purpose: The aim of this study was to evaluate the effects of aerobic training on motor cortical areas in multiple sclerosis (MS) patients, based on task-based functional magnetic resonance imaging (t-fMRI) as well as on brain activity t rest, according to resting state functional MRI (rs-fMRI) studies. Material and methods: Multiple sclerosis patients were divided into 2 groups consisting of 14 participants each: the MS study group and the MS control group. All MS patients underwent clinical assessment and MRI examination, twice: in the MS study group at the time of inclusion in the study and after a 4-week period of aerobic training, whereas in the MS control group it happened at the time of inclusion and after a period of one month without exercise rehabilitation. The MRI study protocol included rs-fMRI and t-fMRI sequences, which were the grounds for an analysis of resting state networks (RSN) as well as peak level and cluster level parameters within motor cortex areas - the primary motor cortex, premotor area, and supplementary motor area, respectively. Results: In the MS study group, aerobic training improved the clinical condition and decreased the functional correlation between the sensorimotor network and the salience network. Also, significant decreases of the mean cluster level (72.42 vs. 38.35) and peak level values (10.89 vs. 7.64) were observed in the contralateral primary motor cortex in this group of patients between examinations. Conclusions: Aerobic training not only improves physical performance but also contributes to changes in brain activity - both within RSN and motor cortex areas in MS patients

Research on the post-weld explosive hardening of AA7075-T651 friction stir welded butt joints

In this paper, the post-weld explosive hardening of a 5 mm AA7075-T651 plate welded via FSW was performed. To investigate the possibility of increasing FSW joint mechanical properties, the welded plate was explosively treated with four various explosive materials (ammonal, emulsion explosive, FOX-7, and PBX) in two different hardening systems. As part of the investigation, the observations of the surface and macrostructure of the treated plates were described. The obtained microhardness distribution allowed us to register the increase in hardness of the SZ up to 6%, but no increase in hardness of the LHZ was reported. In most cases, the influence of explosive treatment on the mechanical properties of the welded joint was disadvantageous as ultimate tensile strength and ductility were reduced. The only positive effect which was observed is the increase in the value of yield strength up to 27% corresponding to 77 MPa, achieved by explosive materials with detonation velocity below 3000 m/s

Edwin Hutchins: In defense of interdisciplinary research on cognition

The article presents the interdisciplinary approach of Edwin Hutchins, analyzing his conception of distributed cognition as probably the most important and lasting contribution of anthropology to the repertoire of theoretical tools in cognitive science. At the same time, this conception resulted in one of the most interesting relationships between cognitive science and social sciences. These relationships are made possible by the assumptions of Hutchins’ conception, which directly contribute to interdisciplinary collaboration. His account of distributed cognition has enormous potential, allowing the integration of research into cognitive and social processes. This is also because it breaks with methodological individualism

Research on microstructure and mechanical properties of explosively welded stainless steel/commercially pure Ti plate

Surface protection by the application of explosive welding is one of the meaningful methods used in many chemical devices like reactor condensers, heat exchangers, steam turbines and other processing apparatus. Due to the wide range of explosively welded applications, the problem of the useful lifetime of the products obtained by this method becomes important and should be well understood. Process of explosive welding is related to enormous pressure and high detonation velocity, which causes intense energy release in a short time, which favors to produce solid wavy bond featured with high metallurgical quality. Due to strain hardening in the bond zone, significant changes in microstructures and mechanical properties were observed. In this paper, 316L stainless steel explosively welded with commercially pure titanium was investigated to show the correlations and changes between microstructures and mechanical properties before and after annealing. Application of post-weld heat treatment contributes to stress relieving and improves the mechanical properties, which is closely related to microstructure recrystallization and hardness decrease adjacent to joint.</jats:p

Ecofriendly Water-Soluble Binders for Precision Ceramic Moulds in Aerospace Turbine Casting: Process Development and Performance Evaluation

The paper presents the development of an ecofriendly ceramic moulding system for the precision casting of aircraft turbine components from nickel superalloys using water-soluble binders. The motivation was to eliminate hydrolysed ethyl silicate (HES) due to its environmental and occupational hazards. Two water-based binders (K + M)&mdash;Keysol (for the primary layer) and Matrixsol (for the backup layers)&mdash;were evaluated against the standard HES-based system. A comprehensive comparative analysis was conducted including microstructure, phase composition, wettability, mechanical, thermal, and gas permeability properties. The developed K + M ceramic moulds achieved a bending strength of 12.4 MPa after annealing, average surface roughness (Ra) below 5 &micro;m, and open porosity of 29.1%, indicating excellent strength and permeability. Thermal conductivity increased from 0.3 W/mK to 2.0 W/mK between 22 &deg;C and 1400 &deg;C. The wetting angle of water-based binders was higher (Keysol: ~36&deg;) compared to HES (~5&deg;), resulting in more stable surface morphology. Gas permeability was maintained at 5.6 &times; 10&minus;9 cm2 at 1100 &deg;C, ensuring effective degassing during casting. The results demonstrate that the K + M system can replace HES in production while improving safety and reducing environmental impact, making it suitable for industrial-scale implementation in the aerospace sector

Research on microstructure and mechanical properties of explosively welded stainless steel/commercially pure Ti plate

Surface protection by the application of explosive welding is one of the meaningful methods used in many chemical devices like reactor condensers, heat exchangers, steam turbines and other processing apparatus. Due to the wide range of explosively welded applications, the problem of the useful lifetime of the products obtained by this method becomes important and should be well understood. Process of explosive welding is related to enormous pressure and high detonation velocity, which causes intense energy release in a short time, which favors to produce solid wavy bond featured with high metallurgical quality. Due to strain hardening in the bond zone, significant changes in microstructures and mechanical properties were observed. In this paper, 316L stainless steel explosively welded with commercially pure titanium was investigated to show the correlations and changes between microstructures and mechanical properties before and after annealing. Application of post-weld heat treatment contributes to stress relieving and improves the mechanical properties, which is closely related to microstructure recrystallization and hardness decrease adjacent to joint