Tiling mechanisms of the compound eye through geometrical tessellation

Tilling patterns are observed in many biological structures. Hexagonal tilling, commonly observed in the compound eyes of wild-type Drosophila, is dominant in nature; this dominance can probably be attributed to physical restrictions such as structural robustness, minimal boundary length, and space filling efficiency. Surprisingly, tetragonal tiling patterns are also observed in some Drosophila small eye mutants and aquatic crustaceans. Herein, geometrical tessellation is shown to determine the ommatidial tiling patterns. In small eye mutants, the hexagonal pattern is transformed into a tetragonal pattern as the relative positions of neighboring ommatidia are stretched along the dorsal-ventral axis. Hence, the regular distribution of ommatidia and their uniform growth collectively play an essential role in the establishment of tetragonal and hexagonal tiling patterns in compound eyes.

Quantitative modeling of regular retinal microglia distribution

Microglia are resident immune cells in the central nervous system, showing a regular distribution. Advancing microscopy and image processing techniques have contributed to elucidating microglia’s morphology, dynamics, and distribution. However, the mechanism underlying the regular distribution of microglia remains to be elucidated. First, we quantitatively confirmed the regularity of the distribution pattern of microglial soma in the retina. Second, we formulated a mathematical model that includes factors that may influence regular distribution. Next, we experimentally quantified the model parameters (cell movement, process formation, and ATP dynamics). The resulting model simulation from the measured parameters showed that direct cell–cell contact is most important in generating regular cell spacing. Finally, we tried to specify the molecular pathway responsible for the repulsion between neighboring microglia.

Quantitative modeling of regular retinal microglia distribution

Microglia are resident immune cells in the central nervous system (CNS), showing a regular distribution. Advancing microscopy and image processing techniques have contributed to elucidating microglia’s morphology, dynamics, and distribution. However, the mechanism underlying the regular distribution of microglia remains to be elucidated. First, we quantitatively confirmed the regularity of the distribution pattern of microglial soma. Second, we formulated a mathematical model that includes factors that may influence regular distribution. Next, we experimentally quantified the model parameters (cell movement, process formation, and ATP dynamics). The resulting model simulation from the measured parameters showed that direct cell-cell contact is most important in generating regular cell spacing. Finally, we tried to specify the molecular pathway responsible for the repulsion between neighboring microglia.

On Singular Distributions With Statistical Structure

In this paper, we extend our previous study regarding a Riemannian manifold endowed with a singular (or regular) distribution, generalizing Bochner’s technique and a statistical structure. Following the construction of an almost Lie algebroid, we define the central concept of the paper: The Weitzenböck type curvature operator on tensors, prove the Bochner–Weitzenböck type formula and obtain some vanishing results about the null space of the Hodge type Laplacian on a distribution.

Serendipita sacchari sp. nov. from a sugarcane rhizosphere in southern China

We isolated a new species, proposed here as Serendipita sacchari, from a sugarcane rhizosphere in Guangxi Province, China. This species is characterized by its unstable nucleus numbers (1–15) in its chlamydospores versus their regular distribution in hyphal cells. ITS rDNA and combined LSU+ TEF1-α sequence analyses also support the uniqueness of this new plant symbiont.

SHRUB FUEL CHARACTERISTICS IN THE PRIVATE NATURAL HERITAGE RESERVE CAMINHO DAS TROPAS, PARANÁ – BRAZIL

This research was carried out in the Private Natural Heritage Reserve (PNHR) “Caminho das Tropas”, located in Palmeira, Paraná state - Brazil, in an area dominated by natural fields. The objective was to characterize the shrub fuel of the grassy-woody steppe in the area. For the sampling, an area of 25 hectares was fenced and 100 plots sized 50 x 50 m (0.25 ha) were allocated. The plots were grouped into two treatments: one containing over 50% density and the other less than 50% density and regular distribution of shrub vegetation. The average load of fuel obtained for the first category was 1.2886 Mg.ha-1, being 0.9667 Mg.ha-1of living material and 0.3219 Mg.ha-1 of dead material. For the second category, the load was 0.9328 Mg.ha-1 , with 0.6516 and 0.2812 Mg.ha-1of live and dead fuel respectively. The average moisture content of the fuel in the first treatment was 87.90% and in the second, 81.49%. The characteristics found in the shrub fuel of the study area are compatible with the results found in the literature for Brazilian natural grasslands vegetation.

Two Algorithms For Static Polygon Shape Formation Control

This paper provides a two algorithms for designing robust formation control of multiple robots called Leader- Neighbor algorithm and Neighbor-Leader algorithm in unknown environment. The main function of the robot group is to use the RP lidar sensor attached to each robot to form a static geometric polygon. The algorithms consist of two phases implemented to investigate the formation of polygon shape. In the leading- neighbor algorithm, the first stage is the leader alignment and the adjacent alignment is the second stage. The first step uses the information gathered by the main RP Lidar sensor to determine and compute the direction of each adjacent robot. The adjacent RP Lidar sensors are used to align the adjacent robots of the leader by transferring these adjacent robots to the leader. By performing this stage, the neighboring robots will be far from the leader. The second stage uses the information gathered by adjacent RP sensors to reposition the robots so that the distance between them is equal. On the other hand, in the neighbor-leader algorithm, the adjacent robots are rearranged in a regular distribution by moving in a circular path around the leader, with equal angles between each of the two neighbor robots. A new distribution will be generated in this paper by using one leader and four adjacent robots to approve the suggested leader neighbor algorithm and neighbor-leader algorithm.

A FOTOPOLIMERIZAÇÃO DE COMPÓSITOS ODONTOLÓGICOS ALÉM DA POTÊNCIA LUMINOSA

O objetivo deste estudo foi mostrar que a potência da luz das unidades de fotopolimerização (LED) não é a única ou a propriedade mais importante para uma polimerização satisfatória de compósitos dentários. A distribuição regular e o ângulo de incidência dos raios de luz também são igualmente responsáveis por uma polimerização mais completa e profunda. Esta revisão de literatura mostra que avançamos o suficiente na potência da luz emitida pelos LEDs, mas no que diz respeito à regularidade e ângulo dos raios emitidos, ainda temos muito a avançar. Novos compósitos com cargas reflexivas e preocupações com a diferença de índice de refração entre as cargas e a matriz são importantes para melhorar essa polimerização, mas os LEDs com vários comprimentos de onda podem complicar ainda mais a distribuição regular dos raios de luz emitidos. Dispositivos com diferentes LEDs emitindo raios de luz com diferentes comprimentos de onda não distribuem essas ondas no modo regular. Portanto, parte da restauração pode estar sub polimerizada, tornando-se menos resistente aos esforços mastigatórios e à infiltração. O estudo também relembra propostas de avaliação científica dessa distribuição regular e conclui que os LEDs modernos emitem raios de luz com grande potência e irradiância, mas ainda são irregulares na distribuição dos raios de luz emitidos.Palavras-chave: fotopolimerização, conprimento de onda, irradiância, resina composta.PHOTOPOLIMERIZATION OF DENTAL COMPOSITES BEYOND THE LIGHT POWER EMITED BY LED LIGHT CURING UNITSABSTRACT: The objective of this study was to show that light power of light curing units (LCU) is not the only or the most important property for a satisfactory polymerization of dental composites. Regular distribution and angle of incidence of the light rays are also equally responsible for a fuller and deeper polymerization. This literature review shows that we advanced enough in the power of light emitted by LCUs, but as regards the regularity and angle of the emitted rays, we still have much to advance. New composites with reflective fillers and concerns about the difference of refractive index between the fillers and the matrixare important help to improve this polymerization, but LCUs with several wavelengths can further complicate the regular distribution of emitted light rays. Devices with different LEDs emitting light rays with different wavelengths does not distribute these waves in a regular mode. Therefore, part of the restoration can be under polymerized, becoming less resistant to masticatory efforts and infiltration as well. The study also recalls proposals for scientific evaluation of this regular distribution and concludes that modern LCUs emit light rays with great power and irradiance, but are still irregular in the distribution of emitted light rays.Keywords: photopolymerization, wavelength, Irradiance, composite.

Effect of Orientation and Pre-Tension on Stresses Distribution on V-Die Bending Processes by Finite Element Method

Simulation of metal forming processes using the Finite Element Method (FEM) is a well-established procedure, being nowadays possible to develop alternative approaches, such as inverse methodologies, in solving complex problems. This study investigated the effect of orientation and pre-tension on stresses distribution numerically by software ANSYS 19 using the finite element method. The pre-tension is 55% from total strained in each rolling direction. The results show that the orientation has a significant effect on stresses distribution and stress value before and after pre-tension 55%. Although there is a regular distribution of stresses in three direction, but there is significant difference in the values of stresses in each of (0, 45, 90) degrees. The highest value of the stress is in the 0̊ to rolling direction, while the least value of the stress recorded in 45̊ to rolling direction. The pre-tension has a greater impact on stresses distribution and stress value. Although, there is a regular distribution of stresses in blank before and after pre-tension, but there is significant difference in the values. Where in 0 degree on rolling direction the stresses increased by 31.7% from their values before pre-tension, while in 45 degrees on rolling direction the stresses increased by 35.6% and in 90 degrees on rolling direction the stresses increased by 23.6% from their values before pre-tension.