Motor Learning of Complex Tasks with Augmented Feedback: Modality-Dependent Effectiveness.

BACKGROUND: This paper aims to evaluate the effectiveness of feedback modalities in the motor learning of complex tasks. METHODS: This study examined sixty-one male university students randomised to three groups: group Verbal (VER) = 20 (body height 178.6 ± 4.3 cm, body mass 81.3 ± 3.7 kg, age 20.3 ± 1.2 years), group Visual (VIS) = 21 (body height 179 ± 4.6 cm, body mass 82 ± 3.4 kg, age 20.3 ± 1.2 years), and group Verbal-Visual (VER&VIS) = 20 (body height 178.6 ± 4.3 cm, body mass 81.3 ± 3.7 kg, age 20.3 ± 1.2 years). The duration of the experiment was 6 months. Training sessions were performed three times per week (on Mondays, Wednesdays, and Fridays). The participants were instructed to perform a vertical jump with an arm swing (with forward and upward motion). During the jump, the participants pulled their knees up to their chests and grabbed their lower legs. The jump was completed with a half-squat landing, with arms positioned sideward. The jumping performance was rated by three gymnastic judges on a scale from 1 to 10. RESULTS: A Tukey post hoc test revealed that in the post-test, a significant difference in the quality of performance was found between the Verbal group concerning errors combined with visual feedback on how to correct them (VER&VIS), the Verbal group concerning errors (VER), and the Visual group with visual feedback on the correctness of task performance (VIS). The ratings observed in the post-test were significantly higher in group VER&VIS than in groups VER and VIS (9%; p < 0.01 and 15%; p < 0.001, respectively). All judges' ratings observed in group VER&VIS and VIS decreased insignificantly, but in group VER the ratings improved insignificantly. CONCLUSION: Providing verbal feedback combined with visual feedback on how to correct errors made in performing vertical jumps proved more effective than the provision of verbal feedback only or visual feedback only.

Analysis of marginal integrity in dentistry composite fillings with flow layer under compression test.

Currently, composite materials dominate among the restorative materials used for direct aesthetic filling. Reinforcement of composites with glass fibers allows for the transfer of greater loads and better durability between the tooth tissue and the filling polymer. New approach to bonding liquid materials with composite with glass fillers is to introduce an additional protective barrier to load a higher force that is, compression test. So, the aim of the study was to analyze the structure of composite fillings, their integrity with tooth tissues and evaluation on the influence of the liquid composite layer on the strength of strength in the compression test. Moreover, the influence of thermal shocks on the bonding with the tooth tissues in the compression test was investigated. According to the results obtained in current research, using the flow composite as a combination with the fiber composite leads to a significant increase in mechanical properties, particularly in the compression test. HIGHLIGHTS: If flow-type composite fluid material are, the greater is strength of composite fillings. Glass fibers composite increase the mechanical strength.

Interrelationships Between Morphometric, Densitometric, and Mechanical Properties of Teeth in 5-Month-Old Polish Merino Sheep.

Interrelationships between morphological, densitometric, and mechanical properties of deciduous mandibular teeth (incisors, canine, second premolar) were investigated. To perform morphometric, densitometric, and mechanical analyses, teeth were obtained from 5-month-old sheep. Measurements of mean volumetric tooth mineral density and total tooth volume were performed using quantitative computed tomography. Microcomputed tomography was used to measure total enamel volume, volumetric enamel mineral density, total dentin volume, and volumetric dentin mineral density. Maximum elastic strength and ultimate force of teeth were determined using 3-point bending and compression tests. Pearson correlation coefficients were determined between all investigated variables. Mutual dependence was observed between morphological and mechanical properties of the investigated teeth. The highest number of positive correlations of the investigated parameters was stated in first incisor indicating its superior predictive value of tooth quality and masticatory organ function in sheep. Positive correlations of the volumetric dentin mineral density in second premolar with final body weight may indicate predictive value of this parameter in relation with growth rate in sheep. Evaluation of deciduous tooth properties may prove helpful for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory organ function, leading to improved performance and economic efficiency of the flock.

Serum Concentration of Macro-, Micro-, and Trace Elements in Silver Fox (Vulpes vulpes) and Their Interrelationships with Morphometric, Densitometric, and Mechanical Properties of the Mandible.

The optimal content of macro-, micro-, and trace elements in tissues ensures proper systemic growth and development and optimal health status in animals and humans. However, very little is known on the elemental content in the plasma compartment in Silver fox. The aim of this study was to determine the content of selected elements in serum obtained from 8-month-old female (N = 8) and male (N = 7) silver foxes. Moreover, relationships of the evaluated elements with the morphological, densitometric, and mechanical parameters of the mandible were determined. Serum content of 12 different elements was measured using inductively coupled plasma-atomic emission spectrometry. The morphometric and densitometric properties of the mandible were determined using quantitative computed tomography method, while mechanical endurance was tested using a three-point bending test. Serum concentration of calcium was significantly higher by 20% in male foxes (P = 0.01), while manganese concentration was significantly lower in males by over 17% (P = 0.03). Positive correlations of serum concentration of calcium, phosphorus, and magnesium with the morphological traits of the mandible such as weight, length, and bone volume were stated (P < 0.05). In the group of elements playing regulatory functions, the positive relationships between serum concentrations of selenium, chromium, manganese, copper, and cobalt were found (P < 0.05). The elaborated experimental model may serve for further studies on foxes, especially focused on nutritional factors affecting elemental homeostasis, whole-body metabolism, and systemic growth and development. Daily diet formulation and precise delivery for farm foxes, together with relatively large animal population maintained at the same environmental conditions, regularly subjected to slaughter procedure, enable economical experimentation with various dietary and pharmacological manipulations.

Interrelationships between Morphological, Densitometric and Mechanical Properties of Eggs in Japanese Quails (Coturnix Japonica).

Eggshell quality in birds results from mineral density and composition determining its mechanical endurance. The aim of the study was to determine interrelationships between morphological, densitometric and mechanical properties of eggs in Japanese quails. Twenty four eggs randomly collected from 17-week-old quails were subjected to morphological, denstiometric and mechanical evaluation using dual-energy X-ray absorptiometry (DEXA), quantitative computed tomography (QCT) and three-point bending test. Weight, height and width of eggs were positively correlated with the densitometric parameters obtained using DEXA (egg mineral density (EMD) and egg mineral content (EMC)) and QCT (total egg volume (TEvol) and total eggshell volume (TESvol)). Positive correlations were stated between TEvol and TESvol (r=0.52; P<0.05) and EMD and EMC r=0.83; P<0.05). Egg mineral density revealed positive correlations with TEvol and mean volumetric eggshell mineral density (MvESMD), while EMC was positively correlated with TEvol, TESvol and MvESMD (all P<0.05). Eggshell breaking strength was positively correlated with MvESMD (r=0.53; P<0.05) and negatively correlated with eggshell thickness (r=-0.50; P<0.05). In conclusion, the results obtained in this study showed numerous interrelationships between morphological, densitometric and mechanical properties of eggs in Japanese quails. Both DEXA and QCT were shown to be valuable tools for evaluation of whole egg and eggshell quality with superior prognostic value of QCT for eggshell mechanical endurance prediction. The elaborated experimental model may serve for further investigations on physiological, pharmacological, environmental, nutritional and toxicological factors influencing egg quality.

Morphometric Parameters of Pyramidal Cells in CA1-CA4 Fields in the Hippocampus of Arctic Fox (Vulpes lagopus).

The aim of the study was a quantitative examination of neurons of hippocampal subfields (CA1-CA4) in mature male Arctic fox (Vulpes lagopus; syn. Alopex lagopus). The preparations were dyed using cresyl violet. Histological preparations were used to morphometricaly analyze the neurons of hippocampus. This analysis included the following parameters: average size of cells in µm, periphery of cells in µm, average cell area in µm2, percentage of cells in area and size of the largest and smallest cells in µm in CA1-CA4 fields. Morphometric observations show that the cells involved in hippocampal formation in polar fox in all layers CA1 -CA4 differ in size, shape, cell area and nucleus area. The size of the cell area in CA3 is the largest and fluctuates around 249.4 µm2, whereas in CA2 the cell area is 184.1 µm2. The cells of the CA2 field are densely arranged, pyramidal and contain a small amount of cytoplasm; their size fluctuates. Cells of CA2 and CA4 had the largest diameter of about 23.6 µm, whereas cells of the CA3 field had the smallest diameter of about 8.3 µm.

Morphometric, densitometric and mechanical properties of mandibular deciduous teeth in 5-month-old Polish Merino sheep.

BACKGROUND: Caries, enamel hypoplasia, molar incisor hipomineralization, amylogenesis imperfecta, dentine dysplasia, hypophosphatasia and other dental disorders lead to tooth mineralization disturbances and structural abnormalities, decreasing masticatory organ functions. Dental disorders in sheep can lead to premature slaughter before they have attained final stage of their reproductive life and induce economic loss due to high flock replacement costs. Growth rate, health status and meat quality of sheep depends on tooth properties and quality determining in large extent efficiency of the masticatory apparatus and initial food break up. Considering lack of basic anatomical and physiological data on teeth properties in sheep, the aim of the study was to evaluate morphometric, densitometric and mechanical traits of deciduous mandibular incisor, canine and the second premolar obtained at the slaughter age of 5 months of life. RESULTS: The obtained results have shown the highest values of weight, total tooth volume, enamel volume and dentine volume in second premolar. Morphometric and mechanical parameters of incisors reached the highest values in first incisor and decreased gradually in second and third incisor, and in canine. Densitometric measurements have not revealed significant differences of the volumetric tooth mineral density in hard dental tissues between the investigated teeth. CONCLUSIONS: In conclusion, proposed methodological approach is noninvasive since the deciduous teeth undergo physiological replacement with permanent teeth. Deciduous teeth can be easy collected for analyses from large animal population and may reflect mineral status and metabolism resulting from postnatal growth and development of the whole flock. In individual cases, evaluation of properties of deciduous teeth may serve for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory system functions.

Relationships between biochemical bone metabolism indices and morphometric, densitometric and mechanical properties of mandible in 6-month-old pigs.

INTRODUCTION AND OBJECTIVE: Mandible is used as a bone model for monitoring bone tissue responses to various factors influencing skeletal homeostasis. Considering the lack of experimental data on interrelationships between bone metabolism indices and morphometric, densitometric and mechanical properties of mandible, the aim of this study was to perform such an evaluation in 6-month-old pigs. MATERIALS AND METHODS: Quantitative computed tomography was used to determine bone volume, mean volumetric bone mineral density, cortical bone density and cortical bone area. Using dual-energy X-ray absorptiometry, bone mineral density and bone mineral content were measured for ramus, body and whole jaw. In the three-point bending test, maximum elastic strength and ultimate strength of jaw was determined. Assessment of calcium (Ca), phosphorus (P), magnesium (Mg), parathormone (PTH), growth hormone (GH), insulin-like growth factor-1 (IGF-1), alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BAP), osteocalcin (OC) and C-terminal telopeptide of collagen type-I (CTX) in blood was performed. RESULTS: Statistically significant correlations in relation to the investigated traits of the jaw were found in the case of ALP, OC, CTX, GH and IGF-1. Significant correlations of ALP activity, OC and IGF-1 concentrations with final body weight were stated (p<0.05). CONCLUSIONS: This study shows the highest predictive value of ALP activity determination in relation to assessment of morphological, densitometric and biomechanical properties of mandible. Evaluation of Ca, P, Mg, BAP and PTH has not confirmed its significance for morphological, densitometric and biomechanical properties prediction in the jaw of pigs. ALP activity, OC and IGF-1 concentrations would be prognostic for body weight prediction.