Jan Długosz University

About: Jan Długosz University is a education organization based out in Częstochowa, Poland. It is known for research contribution in the topics: Crystal structure & Luminescence. The organization has 749 authors who have published 2311 publications receiving 19395 citations. The organization is also known as: Higher Teacher Education School.

Kinematics of taekwon-do front kick

Abstract: Background & Study Aim: Taekwon-do according to the theory of combat sports qualify for category consisting of in hits (strokes). This is of particular importance especially in the case of the traditional version of taekwon-do, in which a single kick might reveal the winner. The aim of the paper is knowledge about the influence of chosen kinematic factors on the front kick technique. Materials & Methods: In the study 6 taekwon-do ITF athletes were examined (age:16.5±1.0 year; body mass: 64.14±10.9 kg; height: 176.5±7.5 cm). According to the criteria commonly used in biomechanical analysis of combat sports athletes were asked to execute the front kick (in taekwon-do terminology referred to as ap chagi). The foot and knee velocities in chosen movement phases were determined in the Cartesian coordinate system and so were the duration of particular phases of movement and the total duration of the complete kick. Results: The maximum average foot velocity obtained was 10.40 ±0.77 m/s. The correlation and dependence values of the determined kinematic parameters and the maximum velocity of the kick denote that the maximum front kick velocity (p<0.05) is affected by the following factors: maximum knee velocity (r = 0.92), total kick duration (r = 0.73), total time of foot takeoff (r = 0.61). Conclusion: The conducted research shows that in order to achieve the maximum foot velocity in the execution of the front kick an athlete needs to increase the velocity of the knee traveling towards the target and to decrease the duration of the foot takeoff.

Complex symbiotic systems of two treehopper species: Centrotus cornutus (Linnaeus, 1758) and Gargara genistae (Fabricius, 1775) (Hemiptera: Cicadomorpha: Membracoidea: Membracidae).

Abstract: The aim of the conducted study was to describe the symbiotic systems (the types of symbionts, distribution in the body of the host insect, the transovarial transmission between generations) of two treehoppers: Centrotus cornutus and Gargara genistae by means of microscopic and molecular techniques. We found that each of them is host to four species of bacteriome-inhabiting symbionts. In C. cornutus, ancestral bacterial symbionts Sulcia and Nasuia are accompanied by an additional symbiont—the bacterium Arsenophonus. In the bacteriomes of G. genistae, apart from Sulcia and Nasuia, bacterium Serratia is present. To our knowledge, this is the first report regarding the occurrence of Serratia as a symbiont in Hemiptera: Auchenorrhyncha. Bacteria Sulcia and Nasuia are harbored in their own bacteriocytes, whereas Arsenophonus and Serratia both inhabit their own bacteriocytes and also co-reside with bacteria Nasuia. We observed that both bacteria Arsenophonus and Serratia undergo autophagic degradation. We found that in both of the species examined, in the cytoplasm and nuclei of all of the cells of the bacteriome, bacteria Rickettsia are present. Our histological and ultrastructural observations revealed that all the bacteriome-associated symbionts of C. cornutus and G. genistae are transovarially transmitted from mother to offspring.

Planthopper (Hemiptera: Flatidae) Parasitized by Larval Erythraeid Mite (Trombidiformes: Erythraeidae)—A Description of Two New Species From Western Madagascar

Abstract: . Descriptions of Dambullaeus adonis Mąkol et Moniuszko sp. nov. (Trombidiformes: Erythraeidae, Callidosomatinae) and Latois nigrolineata Świerczewski et Stroinski sp. nov. (Hemiptera: Fulgoromorpha, Flatidae) from Madagascar are provided. The first host record for ectoparasitic larvae of Dambullaeus Haitlinger, 2001 and the first evidence on host-parasite association between flatid adult and erythraeid larvae are given. Genus Dambullaeus, known exclusively from larvae and now comprising two species of Gondwanan distribution, is critically reappraised.