An Account of Larval Budding in the Compound Ascidian, Hypsistozoa fasmeriana

1959 ◽  
Vol s3-100 (52) ◽  
pp. 575-589
Author(s):  
BERYL I. BREWIN

Larval budding in Hypsistozoa fasmeriana is in many ways unique in the sub-family Holozoinae. The stolon, which projects from the left side of the oozooid, is large (235 µ in diameter, 1.8 mm in length) and reaches maximal size before severance of buds occurs. The buds arise one at a time and 9 to 14 are formed. Test forms rapidly between a newly severed bud and the remainder of the stolon. Thus the buds are moved along an arc of a spiral which runs from the left side of the oozooid somewhat anteriorly across the ventral side and posteriorly up the right side. By the end of bud formation the first-formed bud occupies the most posterior position, lying high up on the right side of the oozooid. Each larval bud develops directly into a blastozooid and by the time the tadpole becomes free-swimming there is a considerable degree of organogenesis. The blastozooids together with the oozooid form a ring of zooids tilted slightly away from the vertical. After metamorphosis of the tadpole this ring becomes horizontal, but the tilt is still maintained with the oozooid occupying the most elevated position. Thus in the young colonies the plane of the head is slightly off the horizontal--an arrangement which persists throughout the life of the colony. The development of larval buds in this ascidian is not delayed until after dedifferentiation of the oozooid, as is the case in the other Holozoinae. The blastozooids function simultaneously with the oozooid. They do not, however, become sexually mature, being presumably of sub-maximal size for the species. The newly severed bud differs from that of other Holozoinae in having an extensive epicardial tube and a thick mesenchymal layer of densely granulated cells. The epicardium of the blastozooid is formed from the posterior end of the original epicardial tube. It remains single. The neural tube arises from the left peribranchial sac. H. fasmeriana forms a close link between the sub-family Holozoinae and the sub-family Polyclininae. It resembles the Holozoinae in form of gut, position and mode of origin of the brood pouch, and position of the cardio-pericardium. It shares with the Polyclininae the post-abdominal position of the gonads as well as the structure and organogenesis of the buds.

2017 ◽  
Vol 65 ◽  
pp. 171-175
Author(s):  
Morten Lunde Nielsen ◽  
Arne Thorshøj Nielsen Nielsen

Two pygidia of the trilobite Toxochasmops from the Upper Ordovician (Katian) of the Oslo Region, Norway, display different types of abnormalities. A juvenile pygidium, treated in open nomenclature as Toxochasmops sp. A, has a partially developed axial ring restricted to the right side of the axis which is interpreted as a teratology. The other pygidium, treated in open nomenclature as Toxochasmops sp. B, shows a local fusion of two pleural ribs with a poorly developed furrow crossing the fused area; this may either represent a teratology or regeneration after an injury. In the latter case, it could represent a rare example of metaplasia in trilobites with replacement of a pleural furrow by an interpleural furrow during regeneration. The posterior position of the partially developed axial rings, without corresponding pleural ribs, indicates that the posterior part of the axis possibly represents non-functional somites, and abnormalities in this part probably did not significantly affect the vital organs of the trilobite.


1940 ◽  
Vol s2-82 (326) ◽  
pp. 267-309
Author(s):  
J. B. SMITH

1. The organs associated, either directly or indirectly, with reproduction in the Ophiuroidea are the axial organ and related sinuses (axial organ complex), the genital raehis, the gonads (localized expansions of the raehis), the gonoducts, and the genital bursae. 2. Evidence is presented in favour of the view of Fedotov (1924) that the axial organ of Ophiuroids is made up of two closely associated parts each surrounded by its own sinus from the wall of which it is, during development, proliferated. The left axial sinus (aboral in the adult) is derived from the left anterior coelom of the larva, the right axial sinus (oral in the adult) from the madreporie vesicle which itself is a derivative of the right anterior coelom of the larva. 3. The ampulla of the stone canal is continuous with, and is part of, the left axial sinus. 4. An account is given of the morphology and histology of the genital rachis and sinus. 5. Examination of the gonads of female Ophiothrix indicate that the breeding season extends from about March to October and that, during this time, there is periodic emission of ova, probably at monthly intervals. Males, on the other hand, produce sperm all the year round. 6. The genital bursae number two pairs to each interradial pouch. They serve, primarily, as organs of respiration. Special mechanisms, which are described, are concerned in the intake and expulsion of water. 7. The gonads do not discharge their products directly into the genital bursae nor through temporarily formed pores in the body-wall but through specially developed and permanent gonoducts, one to each of the ten gonads. 8. Young specimens found in the genital bursae have attained their position only after a period of free-swimming larval life. After settling and metamorphosing, some of the young individuals crawl into the bursae. 9. As a consequence of the previous observation it is pointed out that the presence of the young within the genital bursae of the adult is by no means an indication of a viviparous habit.


2020 ◽  
Vol 11 (SPL3) ◽  
pp. 1861-1868
Author(s):  
Bianca Princeton ◽  
Abilasha R ◽  
Preetha S

Oral hygiene is defined as the practice of keeping the mouth clean and healthy, by brushing and flossing to prevent the occurrence of any gum diseases like periodontitis or gingivitis. The main aim of oral health hygiene is to prevent the buildup of plaque, which is defined as a sticky film of bacteria and food formed on the teeth. The coastal guard is an official who is employed to watch the sea near a coast for ships that are in danger or involved with illegal activities. Coastal guards have high possibilities of being affected by mesothelioma or lung cancer due to asbestos exposure. So, a questionnaire consisting of 20 questions was created and circulated among a hundred participants who were coastal guards, through Google forms. The responses were recorded and tabulated in the form of bar graphs. Out of a hundred participants, 52.4% were not aware of the fact that coastal guards have high chances of developing lung cancer and Mesothelioma. 53.7% were aware of the other oral manifestations of lung cancer other than bleeding gums. Majority of the coastal guards feel that they are given enough information about dental hygiene protocols. Hence, to conclude, oral hygiene habits have to be elaborated using various tools in the right manner to ensure better health of teeth and gums.


2018 ◽  
Vol 4 (1) ◽  
pp. 89-107
Author(s):  
Cheri Bayuni Budjang

Buying and selling is a way to transfer land rights according to the provisions in Article 37 paragraph (1) of Government Regulation Number 24 of 1997 concerning Land Registration which must include the deed of the Land Deed Making Official to register the right of land rights (behind the name) to the Land Office to create legal certainty and minimize the risks that occur in the future. However, in everyday life there is still a lot of buying and selling land that is not based on the laws and regulations that apply, namely only by using receipts and trust in each other. This is certainly very detrimental to both parties in the transfer of rights (behind the name), especially if the other party is not known to exist like the Case in Decision Number 42 / Pdt.G / 2010 / PN.Mtp


2018 ◽  
Author(s):  
Fatima Maria Felisberti

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.


2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Marine Vekua

The main goal of this research is to determine whether the journalism education of the leading media schools inGeorgia is adequate to modern media market’s demands and challenges. The right answer to this main questionwas found after analyzing Georgian media market’s demands, on the one hand, and, on the other hand, differentaspects of journalism education in Georgia: the historical background, development trends, evaluation ofeducational programs and curricula designs, reflection of international standards in teaching methods, studyingand working conditions.


Public Voices ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 7
Author(s):  
Sophie Till

Three years ago Sophie Till started working with pianist Edna Golandsky, the leading exponent of the Taubman Piano Technique, an internationally acclaimed approach that is well known to pianists, on the one hand, for allowing pianists to attain a phenomenal level of virtuosity and on the other, for solving very serious piano-related injuries. Till, a violinist, quickly realized that here was a unique technical approach that could not only identify and itemize the minute movements that underlie a virtuoso technique but could show how these movements interact and go into music making at the highest level. Furthermore, through the work of the Golandsky Institute, she saw a pedagogical approach that had been developed to a remarkable depth and level of clarity. It was an approach that had the power to communicate in a way she had never seen before, despite her own first class violin training from the earliest age. While the geography and “look” on the violin are different from the piano, the laws governing coordinate motion specifically in playing the instrument are the same for pianists and violinists. As a result of Till’s work translating the technique for violin, a new pedagogical approach for violinists of all ages is emerging; the Taubman/Golandsky Approach to the Violin. In reflecting on these new developments, Edna Golandsky wrote, “I have been working with the Taubman Approach for more than 30 years and have worked regularly with other instrumentalists. However, Sophie Till was the first violinist who asked me to teach her with the same depth that I do with pianists. With her conceptual and intellectual agility as well as complete dedication to helping others, she has been the perfect partner to translate this body of knowledge for violinists. Through this collaboration, Sophie is helping develop a new ‘language’ for violinist that will prevent future problems, solve present ones and start beginners on the right road to becoming the best they can be. The implications of this new work for violinists are enormous.”


GEOgraphia ◽  
2010 ◽  
Vol 7 (14) ◽  
Author(s):  
Márcio Piñon de Oliveira

A utopia do direito à cidade,  no  caso específico do Rio de Janeiro, começa, obrigatoriamente, pela  superação da visão dicotômica favela-cidade. Para isso, é preciso que os moradores da favela possam sentir-se tão cidadãos quanto os que têm moradias fora das favelas. A utopia do direito à cidade tem de levar a favela a própria utopia da cidade. Uma cidade que não se fragmente em oposições asfalto-favela, norte-sul, praia-subúrbio e onde todos tenham direito ao(s) seu(s) centro(s). Oposições que expressam muito mais do que diferenças de  localização e que  se apresentam recheadas de  segregação, estereótipos e  ideologias. Por outro  lado, o direito a cidade, como possibilidade histórica, não pode ser pensado exclusivamente a partir da  favela. Mas as populações  que aí habitam guardam uma contribuição inestimável para  a  construção prática  desse direito. Isso porque,  das  experiências vividas, emergem aprendizados e frutificam esperanças e soluções. Para que a favela seja pólo de um desejo que impulsione a busca do direito a cidade, é necessário que ela  se  pense como  parte da história da própria cidade  e sua transformação  em metrópole.Abstract The right  to the city's  utopy  specifically  in Rio de Janeiro, begins by surpassing  the dichotomy approach between favela and the city. For this purpose, it is necessary, for the favela dwellers, the feeling of citizens as well as those with home outside the favelas. The right to the city's utopy must bring to the favela  the utopy to the city in itself- a non-fragmented city in terms of oppositions like "asphalt"-favela, north-south, beach-suburb and where everybody has right to their center(s). These oppositions express much more the differences of location and present  themselves full of segregation, stereotypes and ideologies. On  the other  hand, the right to  the city, as historical possibility, can not be thought  just from the favela. People that live there have a contribution for a practical construction of this right. 


Author(s):  
Tzachi Zamir

Because God is not merely a prescriptive entity but, by virtue of his omnipresence, also a place, Milton implies that knowledge, vitality, and meaningful action depend upon one’s sense of location. For philosophy, one’s understanding (one’s language) determines one’s world; for the religious poet it is the other way round: what one experiences as one’s location, shapes what one knows. A contrast is drawn between the philosopher who begins by denouncing the perceived world, returning to it after a stage of withdrawal into contemplation, and the religious poet who begins with perception of the right kind. Differences between philosophy and religion over the connection between meaningful existence and living an examined life are traced.


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