scholarly journals THE INFLUENCE OF EXTERNAL AND INTERNAL FACTORS ON THE CHEWING EFFICIENCY OF THE DENTITION

2019 ◽  
Vol 15 (1) ◽  
pp. 109-116
Author(s):  
Сергей Лазарев ◽  
Sergey Lazarev ◽  
Тху Чанг Ле ◽  
Thu Chang Le

Subject. Going upright in human evolution changed the position of the spinal column and head. The position of the spine affects the occlusion through the rotational movements of the first cervical vertebra. The dentofacial system also evolved: the gaps disappeared between the canines and the adjacent teeth; sex differences of teeth were almost erased. As a result, the chewing became more adapted to speech reducing the dominant influence of the canines. Food influenced on the shape of teeth, the occlusion, the lower jaw movement. People use premolars and first molars for chewing soft food, which diminished the chewing efficiency of second molars. The function-dominant chew side also develops dentofacial system. Aim ― research regularities of jaw chewing in stress strain. Methods. Silicone occlusion impressions were obtained from each subject in stress conditions and physical activities. Results. Subjects with a dominant right hand have more amounts of match supracontacts at the right jaw side than at the left one. At opposite side of the spectrum, subjects with a dominant left hand have more amounts of match supracontacts at the left jaw side than at the right one. Ambidextrousnesses have approximately equal amounts at the right and left jaw sides. This is evidence of the force movement at the dominant chewing side. Conclusion. While subjects were falling, the low jaw moved forward resting up against on the canines. In other words, in weightlessness condition the falling subjects were searching for the point of support, which was the occlusion. In the results, it redirected and reduced the kinetic energy of falling bodies and levers of operating forces. The number of supracontact points during lifting is less than in the position of weightlessness. In other words, during the weight lifting the subjects have support points: the lower back and legs. And the occlusion becomes the third point of support only when lifting the extreme physical exertions.

2017 ◽  
Vol 5 (6) ◽  
pp. 196
Author(s):  
Sezer S Yonca ◽  
Çelikel B Engin ◽  
Yücel A Serdar ◽  
Karadağ Mustafa ◽  
Savucu Yüksel

The aim of this research is to evaluate the change in the hand grip strength of the male arm wrestlers before and after a unit of exercise. The participants of the research consist of sportsmen (n=16) of Fırat University arm wrestling team in 18-25 age group.Within the scope of the research, all of the tests and measurements (age, length, body weight, sports age, hand grip strength) were carried out on the experimental group before they started training and the same tests were repeated just after the exercises. A unit of exercise program consisted of warm up, cool down, and 5 sets of weight lifting with 12 repetitions and intensity of 70% that were in that day’s plan and program applied by the trainer.While descriptive statistics were adopted in the statistical analysis, to identify the significance level between the hand grip strength before and after the exercise paired sample t-test analysis was used. The significance level was shown as α = 0.05 in the analyses. While the right hand grip strength of the sportsmen (n=16) was statistically significant at 51.1062 ± 1.69709 before and 49.0437 ± 1.71770 (p=0.000) after the exercise, the left hand grip strength was statistically significant at 46.9000 ± 1.16179 before and 45.8063 ± 1.30078 (p=0.000) after the exercise.In conclusion, it was observed that there is a statistically significant negative decline in the hand grip strength of the arm wrestling sportsmen after a unit of exercise and it can be said that it is because of the exhaustion expected after the exercise.


1946 ◽  
Vol 11 (1) ◽  
pp. 2-2

In the article “Infant Speech Sounds and Intelligence” by Orvis C. Irwin and Han Piao Chen, in the December 1945 issue of the Journal, the paragraph which begins at the bottom of the left hand column on page 295 should have been placed immediately below the first paragraph at the top of the right hand column on page 296. To the authors we express our sincere apologies.


Author(s):  
Marc Ouellet ◽  
Julio Santiago ◽  
Ziv Israeli ◽  
Shai Gabay

Spanish and English speakers tend to conceptualize time as running from left to right along a mental line. Previous research suggests that this representational strategy arises from the participants’ exposure to a left-to-right writing system. However, direct evidence supporting this assertion suffers from several limitations and relies only on the visual modality. This study subjected to a direct test the reading hypothesis using an auditory task. Participants from two groups (Spanish and Hebrew) differing in the directionality of their orthographic system had to discriminate temporal reference (past or future) of verbs and adverbs (referring to either past or future) auditorily presented to either the left or right ear by pressing a left or a right key. Spanish participants were faster responding to past words with the left hand and to future words with the right hand, whereas Hebrew participants showed the opposite pattern. Our results demonstrate that the left-right mapping of time is not restricted to the visual modality and that the direction of reading accounts for the preferred directionality of the mental time line. These results are discussed in the context of a possible mechanism underlying the effects of reading direction on highly abstract conceptual representations.


2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Takashi Matsushita ◽  
Tomoyasu Kumano ◽  
Kazuhiko Takehara

Primary cutaneous follicle center lymphoma (PCFCL) accounts for the majority of primary cutaneous B-cell lymphomas. We report a 60-year-old womanwith PCFCL. She had a red nodule (25 × 25 mm) on the right side of the lower jaw. She was diagnosed with PCFCL by skin biopsy. And then, she was treated with radiation therapy (total 30.6 Gy), which completely eliminated the nodule. Our case suggests that radiation therapy may be a first choice for PCFCL patients with a solitary lesion or localized lesions.    


Author(s):  
Emanuela Gualdi-Russo ◽  
Natascia Rinaldo ◽  
Alba Pasini ◽  
Luciana Zaccagni

The aims of this study were to develop and validate an instrument to quantitatively assess the handedness of basketballers in basketball tasks (Basketball Handedness Inventory, BaHI) and to compare it with their handedness in daily activities by the Edinburgh Handedness Inventory (EHI). The participants were 111 basketballers and 40 controls. All subjects completed the EHI and only basketballers filled in the BaHI. To validate the BaHI, a voluntary subsample of basketballers repeated the BaHI. Exploratory and confirmatory factor analyses supported a two-factor model. Our results show that: (i) Handedness score (R) in daily actions did not differ between basketball players (R by EHI = 69.3 ± 44.6) and the control group (R by EHI = 64.5 ± 58.6); (ii) basketballers more frequently favored performing certain sport tasks with the left hand or mixed hands (as highlighted by R by BaHI = 50.1 ± 47.1), although their choice was primarily the right hand in everyday gestures; and (iii) this preference was especially true for athletes at the highest levels of performance (R by BaHI of A1 league = 38.6 ± 58.3) and for those playing in selected roles (point guard’s R = 29.4 ± 67.4). Our findings suggest that professional training induces handedness changes in basketball tasks. The BaHI provides a valid and reliable measure of the skilled hand in basketball. This will allow coaches to assess mastery of the ball according to the hand used by the athlete in the different tasks and roles.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Velarie Ansu ◽  
Stephanie Dickinson ◽  
Alyce Fly

Abstract Objectives To determine which digit and hand have the highest and lowest skin carotenoid scores, to compare inter-and-intra-hand variability of digits, and to determine if results are consistent with another subject. Methods Two subjects’ first(F1), second(F2), third(F3) and fifth(F5) digits on both hands were measured for skin carotenoids with a Veggie Meter, for 3 times on each of 18 days over a 37-day period. Data were subjected to ANOVA in a factorial treatment design to determine main effects for hand (2 levels), digits (4), and days (18) along with interactions. Differences between digits were determined by Tukey's post hoc test. Results There were significant hand x digit, hand x day, digit x day, and hand x digit x day interactions and significant simple main effects for hand, digit, and day (all P < 0.001). Mean square errors were 143.67 and 195.62 for subject A and B, respectively, which were smaller than mean squares for all main effects and interactions. The mean scores ± SD for F1, F2, F3, and F5 digits for the right vs left hands for subject A were F1:357.13 ± 45.97 vs 363.74 ± 46.94, F2:403.17 ± 44.77 vs. 353.20 ± 44.13, F3:406.76 ± 43.10 vs. 357.11 ± 45.13, and F5:374.95 ± 53.00 vs. 377.90 ± 47.38. For subject B, the mean scores ± SD for digits for the right vs left hands were F1:294.72 ± 61.63 vs 280.71 ± 52.48, F2:285.85 ± 66.92 vs 252.67 ± 67.56, F3:268.56 ± 57.03 vs 283.22 ± 45.87, and F5:288.18 ± 34.46 vs 307.54 ± 40.04. The digits on the right hand of both subjects had higher carotenoid scores than those on the left hands, even though subjects had different dominant hands. Subject A had higher skin carotenoid scores on the F3 and F2 digits for the right hand and F5 on the left hand. Subject B had higher skin carotenoid scores on F5 (right) and F1 (left) digits. Conclusions The variability due to hand, digit, and day were all greater than that of the 3 replicates within the digit-day for both volunteers. This indicates that data were not completely random across the readings when remeasuring the same finger. Different fingers displayed higher carotenoid scores for each volunteer. There is a need to conduct a larger study with more subjects and a range of skin tones to determine whether the reliability of measurements among digits of both hands is similar across the population. Funding Sources Indiana University.


2021 ◽  
Vol 13 (3) ◽  
pp. 420
Author(s):  
Jingru Sun ◽  
Gabriel Vecchi ◽  
Brian Soden

Multi-year records of satellite remote sensing of sea surface salinity (SSS) provide an opportunity to investigate the climatological characteristics of the SSS response to tropical cyclones (TCs). In this study, the influence of TC winds, rainfall and preexisting ocean stratification on SSS evolution is examined with multiple satellite-based and in-situ data. Global storm-centered composites indicate that TCs act to initially freshen the ocean surface (due to precipitation), and subsequently salinify the surface, largely through vertical ocean processes (mixing and upwelling), although regional hydrography can lead to local departure from this behavior. On average, on the day a TC passes, a strong SSS decrease is observed. The fresh anomaly is subsequently replaced by a net surface salinification, which persists for weeks. This salinification is larger on the right (left)-hand side of the storm motion in the Northern (Southern) Hemisphere, consistent with the location of stronger turbulent mixing. The influence of TC intensity and translation speed on the ocean response is also examined. Despite having greater precipitation, stronger TCs tend to produce longer-lasting, stronger and deeper salinification especially on the right-hand side of the storm motion. Faster moving TCs are found to have slightly weaker freshening with larger area coverage during the passage, but comparable salinification after the passage. The ocean haline response in four basins with different climatological salinity stratification reveals a significant impact of vertical stratification on the salinity response during and after the passage of TCs.


Author(s):  
Peter S. Hagedorn ◽  
Bernhard Hirt ◽  
Thomas Shiozawa ◽  
Peter H. Neckel

AbstractMuscular variants of the forearm are common and frequently cause neurovascular compression syndromes, especially when interfering with the compact topography of the carpal tunnel or the Canalis ulnaris. Here, we report on a male body donor with multiple muscular normal variations on both forearms. The two main findings are (1) an accessory variant muscle (AVM) on the right forearm originating from the M. brachioradialis, the distal radius, and the M. flexor pollicis longus. It spanned the wrist beneath the Fascia antebrachia and inserted at the proximal phalanx of the digitus minimus. (2) Moreover, we found a three-headed palmaris longus variant on the left arm with proximal origin tendon and a distal, trifurcated muscle belly, with separated insertions at the palmar aponeurosis, the flexor retinaculum, and, in analogy to the accessory muscle on the contralateral arm, at the base of the proximal phalanx of the digitus minimus. We found a considerable thickening of the left-hand median nerve right before entering the carpal tunnel indicative of a possible chronic compression syndrome adding clinical relevance to this anatomical case. We also discuss the notion that both, the AVM and the contralateral three-headed palmaris variant are developmental descendants of the M. palmaris longus. Additionally, we found a previously not recorded variant of the M. palmaris brevis on the left hand.


Südosteuropa ◽  
2019 ◽  
Vol 67 (2) ◽  
pp. 175-195
Author(s):  
Petru Negură

Abstract The Centre for the Homeless in Chișinău embodies on a small scale the recent evolution of state policies towards the homeless in Moldova (a post-Soviet state). This institution applies the binary approach of the state, namely the ‘left hand’ and the ‘right hand’, towards marginalised people. On the one hand, the institution provides accommodation, food, and primary social, legal assistance and medical care. On the other hand, the Shelter personnel impose a series of disciplinary constraints over the users. The Shelter also operates a differentiation of the users according to two categories: the ‘recoverable’ and those deemed ‘irrecoverable’ (persons with severe disabilities, people with addictions). The personnel representing the ‘left hand’ (or ‘soft-line’) regularly negotiate with the employees representing the ‘right hand’ (‘hard-line’) of the institution to promote a milder and a more humanistic approach towards the users. This article relies on multi-method research including descriptive statistical analysis with biographical records of 810 subjects, a thematic analysis of in-depth interviews with homeless people (N = 65), people at risk of homelessness (N = 5), professionals (N = 20) and one ethnography of the Shelter.


1966 ◽  
Vol 44 (2) ◽  
pp. 287-293 ◽  
Author(s):  
Jacques LeBlanc ◽  
Pierre Potvin

It was possible to produce habituation to cold in a group of human subjects by immersing the left hand in cold water for [Formula: see text] minutes twice a day for 19 days. The right hand did not adapt. Another group of subjects was exposed similarly with the difference that an anxiety test (mental arithmetic test) was always given simultaneously with the cold-water test. In this second group the original blood pressure response, i.e. for the first day, was greater than in the first group because of the cumulative effects of the two tests. After 19 days definite evidence was obtained for adaptation to these two tests administered together. However, when these tests were given separately to the second group, no adaptation was evident; adaptation occurred only to both tests given simultaneously. These results indicate that no adaptation develops to cold per se if the subjects are distracted from cold discomfort. It was also found that adaptation of one hand to cold water not only failed to induce adaptation in the opposite hand but even reinforced responses of the unadapted hand. These findings suggest a participation of the central nervous system in adaptation to cold pain, and tend to minimize the importance of local peripheral changes.


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