Preparing to grasp emotionally laden stimuli de Oliveira, Laura Alice Santos; Imbiriba, Luís Aureliano; Russo, Maitê Mello ...
PloS one,
09/2012, Volume:
7, Issue:
9
Journal Article
Peer reviewed
Open access
Contemporary theories of motor control propose that motor planning involves the prediction of the consequences of actions. These predictions include the associated costs as well as the rewarding ...nature of movements' outcomes. Within the estimation of these costs and rewards would lie the valence, that is, the pleasantness or unpleasantness of a given stimulus with which one is about to interact. The aim of this study was to test if motor preparation encompasses valence.
The readiness potential, an electrophysiological marker of motor preparation, was recorded before the grasping of pleasant, neutral and unpleasant stimuli. Items used were balanced in weight and placed inside transparent cylinders to prompt a similar grip among trials. Compared with neutral stimuli, the grasping of pleasant stimuli was preceded by a readiness potential of lower amplitude, whereas that of unpleasant stimuli was associated with a readiness potential of higher amplitude.
We show for the first time that the sensorimotor cortex activity preceding the grasping of a stimulus is affected by its valence. Smaller readiness potential amplitudes found for pleasant stimuli could imply in the recruitment of pre-set motor repertoires, whereas higher amplitudes found for unpleasant stimuli would emerge from a discrepancy between the required action and their aversiveness. Our results indicate that the prediction of action outcomes encompasses an estimate of the valence of a stimulus with which one is about to interact.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Muscular activity influences the craniofacial skeletal morphology.•Muscle function depends, in part, on genetic variations.•Variants in ACTN3 influence the sagittal and vertical craniofacial ...patterns.•Variants in MYO1H influence the sagittal craniofacial pattern.•Patient’s ethnicity could modify these associations.
This study aimed to evaluate the association of genetic variants inACTN3 and MYO1H with craniofacial skeletal patterns in Brazilians.
This cross-sectional study enrolled orthodontic and orthognathic patients selected from 4 regions of Brazil. Lateral cephalograms were used and digital cephalometric tracings and analyzes were performed for craniofacial phenotype determination. Participants were classified according to the skeletal malocclusion in Class I, II or III; and according to the facial type in Mesofacial, Dolichofacial or Brachyfacial. Genomic DNA was extracted from saliva samples containing exfoliated buccal epithelial cells and analyzed for genetic variants inACTN3 (rs678397 and rs1815739) and MYO1H (rs10850110) by real-time PCR. Chi-square or Fisher’s exact tests were used for statistical analysis (α = 5%).
A total of 646 patients were included in the present study. There was statistically significant association of the genotypes and/or alleles distributions with the skeletal malocclusion (sagittal skeletal pattern) and facial type (vertical pattern) for the variants assessed inACTN3 (P < 0.05). For the genetic variant evaluated in MYO1H, there was statistically significant difference between the genotypes frequencies for skeletal Class I and Class II (P < 0.05). The reported associations were different depending on the region evaluated.
ACTN3 and MYO1H are associated with sagittal and vertical craniofacial skeletal patterns in Brazilian populations.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The understanding of human postural control has advanced with the introduction of optimization process modeling. These models, however, only provide control parameters, rather than analytical ...descriptors of optimization processes. Here, we use a newly developed direct (pattern) search algorithm to investigate changes in postural optimization process in poststroke individuals.
This cross-sectional study investigated the optimization properties of postural stability during upright standing in poststroke individuals.
Twenty-nine poststroke and 15 healthy age-matched individuals underwent posturography with a force platform while standing for 60 s for acquisition of center-of-pressure data. Poststroke individuals were grouped depending on their weight-bearing (WB) pattern and their balance capability assessed through Berg Balance Scale (BBS). The optimization properties of postural stability were computed assuming the minimization of postural sway as cost function.
The asymmetric WB poststroke group showed larger convergence rate toward the local minimum of postural sway than the symmetric WB group. Additionally, the low-balance capability group exhibited smaller values for averaged local minima and global minimum of postural sway coordinates compared with high-balance capability group. Significant correlations were found for BBS and the local minima and global minimum (Pearson's r ranged 0.378-0.424, P < 0.05).
In summary, the optimization properties describing postural dynamic stability, steadiness, and global reference are altered in poststroke individuals with asymmetric WB pattern and low-balance capability.
Postural sway and heart rate were recorded in young men viewing emotionally engaging pictures. It was hypothesized that they would show a human analog of “freezing” behavior (i.e., immobility and ...heart rate deceleration) when confronted with a sustained block of unpleasant (mutilation) images, relative to their response to pleasant/arousing (sport action) or neutral (objects) pictures. Volunteers stood on a stabilometric platform during picture viewing. Significantly reduced body sway was recorded during the unpleasant pictures, along with increased mean power frequency (indexing muscle stiffness). Heart rate during unpleasant pictures also showed the expected greater deceleration. This pattern resembles the “freezing” and “fear bradycardia” seen in many species when confronted with threatening stimuli, mediated by neural circuits that promote defensive survival.
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BFBNIB, DOBA, FSPLJ, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
•We tested whether motor imagery of rising on tiptoes modulates the EMG–COP association.•Kinesthetic imagery promotes large COP sway without changes in EMG amplitude.•Remarkably, kinesthetic imagery ...led to higher EMG–COP association.•Subliminal fringe may account for motor imagery effects on postural muscle activity.
Motor imagery (MI) performed in an upright stance promotes increases in postural sway without changes in usual amplitude measures of calf muscle EMG. However, postural muscle activity can also be determined from the temporal association between EMG and center of pressure (COP) displacements. In this study we investigated whether the MI modulation of postural sway is accompanied by changes in EMG–COP association. Surface EMG from the lateral gastrocnemius (LG) muscle and COP coordinates were collected from 12 subjects while they imagined themselves performing a rising on tiptoes movement via kinesthetic or visual imagery. As a control condition subjects were requested to imagine singing a song. The standard deviation of the forward–backward COP sway and the coefficient of variation of the EMG were calculated and compared across tasks. The degree of association between COP sways and LG activity was evaluated through a cross-correlation function. Kinesthetic imagery promoted a larger COP displacement than both visual and control imagery (p<0.02). No difference in EMG amplitude was observed across imagery tasks (p=0.08). Crucially, we found a stronger EMG–COP association during kinesthetic imagery compared to control imagery (p=0.02), whereas the EMG–COP association in visual imagery was not different from that observed during kinesthetic or control imagery (p>0.19). In conclusion, kinesthetic imagery resulted in a higher EMG–COP temporal association. Subliminal fringe mechanisms may account for the imagery effects on muscle activity and postural sway during upright stance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Neuromuscular adaptations are well-reported in stroke survivors. The death of motor neurons and the reinnervation of residual muscle fibers by surviving motor neurons, for example, seem to explain ...the increased density of muscle units after stroke. It is, however, unknown whether reinnervation takes place locally or extensively within the muscle. Here we combine intramuscular and surface electromyograms (EMGs) to address this issue for medial gastrocnemius (MG); a key postural muscle. While seven stroke survivors stood upright, two intramuscular and 15 surface EMGs were recorded from the paretic and non-paretic gastrocnemius. Surface EMGs were triggered with the firing instants of motor units identified through the decomposition of both intramuscular and surface EMGs. The standard deviation of Gaussian curves fitting the root mean square amplitude distribution of surface potentials was considered to assess differences in the spatial distribution of motor unit action potentials and, thus, in the distribution of muscle units between limbs. The median number of motor units identified per subject in the paretic and non-paretic sides was, respectively, 2 (range: 1-3) and 3 (1-4). Action potentials in the paretic gastrocnemius were represented at a 33% wider skin region when compared to the non-paretic muscle (Mann-Whitney;
= 0.014). Side differences in the representation of motor unit were not associated with differences in subcutaneous thickness (skipped-Spearman
= -0.53; confidence interval for
: -1.00 to 0.63). Current results suggest stroke may lead to the enlargement of the gastrocnemius muscle units recruited during standing. The enlargement of muscle units, as assessed from the skin surface, may constitute a new marker of neuromuscular plasticity following stroke.
► Refining of vegetable oils. ► Deacidification of babassu oil by liquid–liquid extraction using ethanol as solvent. ► Distribution coefficient values of lauric acid and neutral oil were evaluated. ► ...The carbon chain length of the molecules influenced the solubility of the system.
Deacidification of vegetable oils can be performed using liquid–liquid extraction as an alternative method to the classical chemical and physical refining processes. This paper reports experimental data for systems containing refined babassu oil, lauric acid, ethanol, and water at 303.2
K with different water mass fractions in the alcoholic solvent (0, 0.0557, 0.1045, 0.2029, and 0.2972). The dilution of solvent with water reduced the distribution coefficient values, which indicates a reduction in the loss of neutral oil. The experimental data were used to adjust the NRTL equation parameters. The global deviation between the observed and the estimated compositions was 0.0085, indicating that the model can accurately predict the behavior of the compounds at different levels of solvent hydration.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Meat obtained under commercial conditions shows considerable variability, mostly due to genetic background and production system. In this study, meat physicochemical properties and fatty acid ...profiles were analysed to investigate the feasibility of using them as tools to discriminate between meats produced by different genetic groups and finishing systems. Samples of the Longissimus thoracis were collected from 160 commercial bulls of the B. taurus (n = 75) and B. indicus (n = 85) groups, finished either on pasture (n = 46) or with grain supplementation (n = 114) and analysed by standard procedures. Data were analysed by discriminant analysis using a stepwise procedure, to select the meat characteristics that better contribute to discriminate the various groups. Our results indicate that fatty acid profiles of meat had better discriminating ability than physicochemical properties, especially to identify meat from animals finished on grain or pasture. The overall discrimination of meat from different genetic groups was achieved with a slightly lower reliability. Nonetheless, our results show that reliability of allocation to genetic group can be improved if prior information on finishing system is considered. These results are of high importance because they can be incorporated as tools to assess the authenticity of beef, particularly in meat certification programs.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Conversion of non-edible oils through heterogeneous catalysis and their kinetic aspects are essential in order to produce economically viable biodiesel. Especially for oils containing high Free Fatty ...Acids (FFA) content since those cannot be viably converted through homogenous catalysis. Herein, the heterogeneous catalytic esterification kinetics of macauba pulp acid oil was exploited. The reaction tests were conducted in a stirred batch reactor with ethanol, and a cation exchange resin (Purolite® CT275)as a catalyst. The reaction kinetics was modeled based on a pseudo-homogeneous (PH) model of second order, showing good agreement with the experimental data acquired under different reaction conditions. The reaction progress was monitored by validated HPLC and GC methods. The internal and external mass transfer resistances were evaluated, and show that the rate limiting step is the surface reaction. To assess the catalyst stability, scanning electron microscopy was performed on both fresh and spent (after 10 reaction cycles) catalysts; reuse of catalyst was conducted without further treatment. The catalyst recycling demonstrates good performance where 85% of its performance was retained, and the SEM images show that the materials were structurally stable. Because the Pseudo-Homogeneous model properly described the kinetic aspects of the esterification process it was possible to estimate thermodynamic parameters by using the Arrhenius plot. The activation energy of the forward reaction was determined as 44.0 kJ/mol, while for the reverse reaction was 11.7 kJ/mol. Therefore, the kinetic and thermodynamic descriptions along with the catalyst stability upon several cycles without any further treatment reflect the viability of these resins for industrial application in the energy sector. Furthermore, combining these features with the low cost of macauba pulp acid oil, we conclude that the process is suitable for scaling up studies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•Beneficial effect of Ethylicum 6cH in acute murine infection by T. cruzi.•Ethylicum 6cH presented pronounced Th2 response.•Ethylicum 6cH decreased inflammation in heart and increased ...host's survival.•Ethylicum 30cH exhibited pronounced Th1 response.
To evaluate the effects of dynamized ethyl alcohol (Ethylicum)6cH and 30cH in mice infected with T. cruzi.
In a blind, randomized and controlled assay, 63 eight-week-old, Swiss, male mice, infected with IP (1400 trypomastigotes, T. cruzi-Y-strain), were allocated into groups: CNI-non-infected (n=12), CI-infected and non-treated (n=17), Et6cH-infected, treated with Ethylicum 6cH (dilution 1:1012) (n=17), Et30cH-infected, treated with Ethylicum 30cH (dilution 1:1060) (n=17).
Treatment was administered 48h before and after infection, followed by 56h/56h periods, until the 9th day after infection (a.i), for 16 h. Survival and mortality were assessed until the 82nd day after infection (a.i.). TNF-α, IL-6, IL-10, IL-5 and IL-17A cytokines were assessed in serum (3–4 animals/group), at time T0 (before infection), T8 and T12 (8th and 12th a.i), using the Mouse Cytokine 20-Plex Panel Magnetic Kit (Invitrogen, USA). Inflammation was determined in heart sections (eosin-hematoxylin staining) and behavior was analyzed with ANY-maze® software. The study was approved by the Animal Ethics Committee/UEM. Statistica 8.0 and R 3.0.2 software were used for statistical analyses.
The greater survival observed in the Et6cH group was related to decreased inflammation in heart tissue and increased IL-5 at T0 (p<0.05) and IL-10 at T8 (p<0.05), characterizing the Th2 response. It was also related to shorter periods of immobility, observed on day 12 a.i. The higher mortality in the Et30cH group was related to increased inflammation in the heart and a higher concentration of IL-6 and TNF-α cytokines, characterizing the Th1 response.
The results demonstrate the beneficial effect of Ethylicum 6cH in acute murine infection by T. cruzi.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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