Seasonal Cycle of Leydig Cells in Birds | Chapter 3 | Achievements and Challenges of Medicine and Medical Science Vol. 4

In seasonally breeding birds, an increase in testicular recrudescence mainly involves gamete production, Sertoli cell development and an increased number of Leydig cell production. After successful breeding, a rapid postnuptial testicular regression occurs. An investigation was done to elucidate seasonal histomorphological changes of Leydig cells in Japanese Jungle crows (Corvus macrorhynchos). Histologic data of Leydig cells regarding their locations in the interstitium, appearance and disappearance of lipoidal materials in their cytoplasm, and fibroblasts like precursor cells were studied. The photomicrographs were processed with Adobe Photoshop CS5 for expected size and DPI and saved in JPG format. Finally, the photomicrographs were numbered and placed in the manuscript. In the non-breeding season, in the interstitium, clusters of Leydig cells were found in abundant numbers. They looked foamy, white and easily visible. Their nuclei were found small and are located eccentrically. During recrudescence, the Leydig cell became less foamy and less white. In peak breeding season, the Leydig cells showed bigger in size and the nuclei became prominent. Cytoplasmic lipoidal material was lowest and cytoplasm was found dense pink. At the end of the breeding period, a heavy accumulation of lipid materials occurred in the Leydig cell. The clusters of Leydig cells were visible and looked white and foamy again. During this transition, disintegration of Leydig cells occurred after pycnotic nuclei of Leydig cells were found. During involution, a new generation of fibroblast-like cells appeared in the interstitium. Within the fibroblast-like cells, some of them became lipoidal by accumulating lipid materials. Thus a new generation of Leydig cells appeared in the interstitium. These lipoidal cells are thought to be a new generation of Leydig cells for the next breeding season. This study suggests that in seasonally breeding birds, new generation of Leydig cell is derived from fibroblastlike cells of the interstitium. The study concluded that the beginning of the regeneration phase marks the end of the secretory cycle of the Leydig cells although their ultimate fate seems to be in doubt. During this period a new generation of interstitial cells is derived from fibroblast-like cells. Further studies are needed on how quantitative information on histo-architectures of Leydig cells at the ultrastructural level correlates with serum LH (luteinizing hormone) and testosterone levels during breeding and nonbreeding season in wild birds.

 

Author (s) Details

 

Muhammad Nazrul Islam
Department of Animal Science, Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya, Tochigi 321-8505, Japan and Department of Anatomy and Histology, Faculty of Veterinary and Animal Science, Sylhet Agricultural University, Sylhet-3100, Bangladesh.

 

Masato Aoyama
Department of Animal Science, Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya, Tochigi 321-8505, Japan.

 

Shoei Sugita
Department of Animal Science, Faculty of Agriculture, Utsunomiya University, 350 Minemachi, Utsunomiya, Tochigi 321-8505, Japan.

 

Please see the book here:- https://doi.org/10.9734/bpi/acmms/v4/2672  

Exploring Mechanical Behavior in Pinewood/Polyethylene Composites Under Influence of Moisture, UV Radiation and Coupling Agent | Chapter 4 | Research Advances in Environment, Geography and Earth Science Vol. 6

The present study aims to comprehensively analyze the effects of moisture absorption-desorption (AD) cycles, the amount of coupling agent, and UV radiation (UV) on the absorbed-desorption moisture and the flexural and tensile properties of WPC made from pinewood waste and high-density polyethylene (HDPE). Wood-plastic composites (WPC) incorporate lignocellulosic fillers into plastics to generate advantages in terms of stiffness, mechanical strength, cost-effectiveness and reduced weight. They use lignocellulosic waste to reduce the consumption of natural resources and promote better sustainable practices. First, the effect of UV radiation and the presence of anhydride-grafted polyethylene on the moisture absorption-desorption behavior of the compounds was evaluated, and then its effect on the mechanical properties. Scanning electron microscopy (SEM) was used to analyze the surfaces of the samples subjected to these factors and their subsequent damage in the fracture zones of the samples. A two-stage mechanism was observed in the water absorption-desorption process. The first stage is characterized by notable increases in absorption values over the first five cycles, while the second stage of stabilization starts from the sixth cycle. Initial absorption and delamination, capillary action and polymer-wood interaction, swelling, fiber-matrix interaction, and mechanical damage are all included in the first stage. The second stage involves the balance and stabilization step. Statistically, it was found that the changes in humidity values in the absorption and desorption cycles show that UV radiation has a significant contribution with the effect of increasing the absorption and desorption values, while the presence of polyethylene grafted with anhydride has a minor effect with an effect of decreasing those values. UV rays and moisture cycling had a major impact on the composite's tensile and flexural performances. Tensile and flexural characteristics showed only a modest increase of 5–12% when compared to the sample without anhydride–grafted polyethylene and without treatments; however, treatments with UV radiation and moisture absorption–desorption cycles reduced them by up to 45%. The SEM analysis confirmed the deterioration of the composites in the form of microcracks, delaminations, interfacial voids and mechanical failures in both the wood filler and the polyethylene matrix, especially in the samples exposed to ultraviolet radiation, where this deterioration was lower in the samples containing anhydride-grafted polyethylene. The mechanical properties of the composites are influenced by the interactions between the wood filler and the polymer matrix, where UV radiation and humidity cycles produce damage in the interfacial zone. UV radiation primarily contributes to the damage, while moisture absorption-desorption cycles play a secondary role.

 

Author (s) Details

Javier Guillen-Mallette
Centro de Investigacion Científica de Yucatan, Calle 43#130 Chuburna de Hidalgo, 97205 Mérida, México.

 

Irma Flores-Ceron
Centro de Investigación Científica de Yucatán, Calle 43#130 Chuburná de Hidalgo, 97205 Mérida, México.

 

Soledad Cecilia Pech-Cohuo
Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, Km 5.5 Carretera Sierra Papacal-Chuburná Puerto, 97302 Mérida, México.

 

Edgar Jose Lopez-Naranjo
Centro Universitario de Ciencias Exactas e Ingenierías, José Guadalupe Zuno 48, 45157 Zapopan, México.

 

Carlos Vidal Cupul-Manzano
Centro de Investigación Científica de Yucatán, Calle 43#130 Chuburná de Hidalgo, 97205 Mérida, México.

 

Alex Valadez-Gonzalez
Centro de Investigación Científica de Yucatán, Calle 43#130 Chuburná de Hidalgo, 97205 Mérida, México.

Ricardo Herbe Cruz-Estrada
Centro de Investigación Científica de Yucatán, Calle 43#130 Chuburná de Hidalgo, 97205 Mérida, México.

 

 

Please see the book here:-  https://doi.org/10.9734/bpi/raeges/v6/12335F

Twin Edge Coloring of Some Path and Cycle Related Graphs: A Recent Study| Chapter 6 | Novel Research Aspects in Mathematical and Computer Science Vol. 4

 A valid edge K-coloring of G with the elements of Zk is a twin edge K-coloring of a graph, therefore the induced vertexK-coloring is a proper vertexK-coloring, in which the colour of a vertex V in G is the sum in Zk of the colours of the edges interacting with v. The twin chromatic index of G is the lowest K for which G has a twin edge K-coloring. The splitting graph of path and cycle, middle graph of path and cycle, and shadow graph of path and cycle all have twin chromatic indexes. The twin chromatic index of Cm X Pn, where X indicates the direct product of Cr and Pr, is also computed. The cycle and the route on each of the r vertices.

Author(s) Details:

J. Naveen,
Department of Mathematics, Government Arts College, Chidambaram, Tamil Nadu, India.

Please see the link here: https://stm.bookpi.org/NRAMCS-V4/article/view/7034

Sub-community Graph Retrieval from a Compressed Community Graph Using Graph Mining: New Perspective | Chapter 2 | Emerging Trends in Engineering Research and Technology Vol. 6

Community detection and retrieval are the most relevant and important topics in graph mining. Hence it is treated as one of the important applications in the field of social network analysis. Community detection plays an important role in a large community graph by enabling and selecting the desired community’s sub-graph. This chapter proposes an algorithm that detects and extracts the desired sub-community graph from a compressed community graph for further analysis purposes. It presents both theoretical and experimental results with three benchmark social networks. 

Author(s) Details

Bapuji Rao
Department of CSEA, Indira Gandhi Institute of Technology, Sarang, Dhenkanal, Dist-Odisha, India

Prof. (Dr.) Sarojananda Mishra
Department of CSEA, Indira Gandhi Institute of Technology, Sarang, Dhenkanal, Dist-Odisha, India.

View Book :- http://bp.bookpi.org/index.php/bpi/catalog/book/200