direction change
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2021 ◽  
Vol 40 (2) ◽  
pp. 66-72
Author(s):  
Deise Ponzoni ◽  
Edela Puricelli

The correlation between TMJ's growing, structure and function is consensual in the specialized literature. Until the moment, the little knowledge about post-birth changes are studied by observation of condylar growth and disc reestructuration. In an experimental model in rabbits (Oryctolagus cuniculus 1.), it was observed tecidual alterations of the TMJ's components — mandibular condyle, articular disc and temporal bone, face to a direction change of mandibular power axis, which has the incidence upon these structures. Twentyfour rabbit were divided in four groups. Two of each group formed a control group. Four experimental periods were established 15, 30, 60 and 90 days. The animals from the experimental group were submitted to surgical procedure involving the mandible right side, changing the direction of mandibular power axis, which has incidence in the TMJ. Histological observations of TMJ in the control group, at different times, the growth and development of this structure were showed, compatible to the normality. At experimental group, the change of mandibular power axis caused alteration of the mandibular condyle and the discal structure. Significative responses at temporal bone were observed too, as a process of osseous modelation, suggestive of growth of this cranial structure.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yeongjae Choi ◽  
Cheolheon Park ◽  
Amos C. Lee ◽  
Junghyun Bae ◽  
Hyeli Kim ◽  
...  

AbstractWe introduce highly programmable microscale swimmers driven by the Marangoni effect (Marangoni microswimmers) that can self-propel on the surface of water. Previous studies on Marangoni swimmers have shown the advantage of self-propulsion without external energy source or mechanical systems, by taking advantage of direct conversion from power source materials to mechanical energy. However, current developments on Marangoni microswimmers have limitations in their fabrication, thereby hindering their programmability and precise mass production. By introducing a photopatterning method, we generated Marangoni microswimmers with multiple functional parts with distinct material properties in high throughput. Furthermore, various motions such as time-dependent direction change and disassembly of swimmers without external stimuli are programmed into the Marangoni microswimmers.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254551
Author(s):  
Mariia Dvoriashyna ◽  
Eric Lauga

The bacterium Escherichia coli (E. coli) swims in viscous fluids by rotating several helical flagellar filaments, which are gathered in a bundle behind the cell during ‘runs’ wherein the cell moves steadily forward. In between runs, the cell undergoes quick ‘tumble’ events, during which at least one flagellum reverses its rotation direction and separates from the bundle, resulting in erratic motion in place and a random reorientation of the cell. Alternating between runs and tumbles allows cells to sample space by stochastically changing their propulsion direction after each tumble. The change of direction during a tumble is not uniformly distributed but is skewed towards smaller angles with an average of about 62°–68°, as first measured by Berg and Brown (1972). Here we develop a theoretical approach to model the angular distribution of swimming E. coli cells during tumbles. We first use past experimental imaging results to construct a kinematic description of the dynamics of the flagellar filaments during a tumble. We then employ low-Reynolds number hydrodynamics to compute the consequences of the kinematic model on the force and torque balance of the cell and to deduce the overall change in orientation. The results of our model are in good agreement with experimental observations. We find that the main change of direction occurs during the ‘bundling’ part of the process wherein, at the end of a tumble, the dispersed flagellar filaments are brought back together in the helical bundle, which we confirm using a simplified forced-sphere model.


Author(s):  
Nikola AKSOVIĆ ◽  
Bojan BJELICA ◽  
Filip MİLANOVİĆ ◽  
Nemanja JOVANOVİĆ ◽  
Milan ZELENOVİĆ

Author(s):  
А.Г. Шоберг ◽  
С.В. Сай

Рассмотрен ряд вопросов инвариантности дискретных блочных преобразований. Показано, что смена направления обработки при выполнении обратимых преобразований приводит к изменению, получаемых частотных составляющих. Предложены математические модели блочных дискретных преобразований на основе матричного представления. Предлагается рассматривать дискретные преобразования в зависимости от количества блоков и направления обработки. Приводятся результаты моделирования на основе дискретного преобразования Фурье. Some questions of invariance of a discrete block transforms are considered. It is shown a processing direction change in a reversible transforms performing leads to a frequency components change. Mathematical models are proposed for block discrete transforms based on a matrix representation. The discrete transforms are proposed depending on a blocks number and direction of processing. Modeling results on the discrete Fourier transform are presented.


2021 ◽  
Author(s):  
Petar Gabrić

Recent discoveries of semantic compositionality in Japanese tits have enlivened the discussions on the presence of this phenomenon in animal communication. However, data on semantic compositionality in primates are lacking. In this paper, I revisit the study by Boesch [1991 (Hum Evol 6:81-89] who investigated drumming sequences by an alpha male in a chimpanzee (Pan troglodytes) community in the Taï National Park, Côte d'Ivoire. A reanalysis of the data reveals that, similar to the Japanese tits, the alpha male produced conjunctively (“additively”) combined messages of travel direction change and resting period initiation. Unlike the Japanese tits, the elements of the conjunctive message were not simply juxtaposed but displayed structural reduction reminiscent of fusion in human languages. Also unlike the Japanese tits, the elements of the conjunctive message did not pass the movement test for syntactic constituents. Additionally, limited data possibly point to processes similar to reduplication in human languages.


Abstract. In recent years, the number of single elderly people has been increasing, and the needs of residents have been diversifying. Towards these backgrounds, we propose the concept of "Biofiled bulding". The aim of Biofied Building is to create living spaces where residents can live safely, securely and comfortably. Small robots are used as an interface between residents and living space in Biofied Building. The aim of using robots is to sense the position and movement of residents in real time and providing feedback to them. However,he present control systems of the robot do not have enough functions to estimate the risk of accidents such as falls and choose the pathways which do not disturb residents. Therefore, the purpose of this research is to recognize and predict human behavior in a living space by using a robot to realize Biofied Building. In particular, we focus on the direction change motion, which is an important behavior in a living space, and extract the prediction parameters. In particular, it is reported that the direction change motion account for about 20% of gait during the daily life. Therefore, our research group decided to focus on direction change motion. In this study, we focused on the center of the head to extract parameters for prediction of the direction change motion. There are features in the velocity change of the center of the head compared with straight-line gait. There was a velocity amplification of the opposite direction of the direction change before the start of the motion. It is assumed that the shift of the center of mass make it to easier to step out to the direction of the turn.


Author(s):  
Gökhan Kerse

The aim of this chapter is to make it easier to understand the concept of change and offer some suggestions on how the change should be managed. In this direction, change, change management, and its importance have been dealt with, and a conceptual framework has been established through examples. Then, the types of change are discussed by explaining what environmental factors bring about the change. The process of managing change is reviewed; the resistance to change and the sources that reveal this resistance are examined, as well as how to overcome the resistance. Finally, the role of the leader in change management and creating change culture has been discussed.


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