Spelling suggestions: "subject:"cavernoso"" "subject:"cavernosum""
1 |
Variação de formas de crescimento de Montastraea cavernosa (Linnaeus, 1767) (Cnidaria, Anthozoa, Scleractinia) : uma abordagem modular / Variation of growth forms of Montastraea cavernosa (Linnaeus, 1767) (Cnidaria, Anthozoa, Scleractinia) : a modular approachBarbeitos , Marcos Soares January 2000 (has links)
Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-01-31T00:18:00Z
No. of bitstreams: 1
414933.pdf: 15896634 bytes, checksum: 6e86128ee7096bec949c9b616f290355 (MD5) / Made available in DSpace on 2018-01-31T00:18:00Z (GMT). No. of bitstreams: 1
414933.pdf: 15896634 bytes, checksum: 6e86128ee7096bec949c9b616f290355 (MD5)
Previous issue date: 2000 / CAPES / Animais clonais crescem por acréscimo de unidades funcionais (zoóides) as quais formam a
colônia. A abordagem modular consiste em descrever a forma das colônias do ponto de vista do
arranjo e tamanho dos módulos. A abordagem modular foi usada aqui para quantificar
variações na forma de crescimento do coral Montastraea cavernosa a partir da mensuração do
arranjo e áreas dos pólipos na face interna do tecido colonial. Foram coletadas 46 amostras no
Parcel das Paredes (BA) e João Pessoa (PB). Os resultados mostraram que área dos pólipos é
parcialmente explicada por fatores ligados ao espaçamento entre eles. Estes fatores variam
com a forma da colônia e com a faixa de tamanho de pólipos considerada. Foi proposto um
modelo conceitual hipotético para a relação entre a forma de crescimento colonial, o tamanho e
a organização dos pólipos. São discutidas possíveis razões evolutivas para o modelo proposto
e implicações deste para estudos morfométricos da espécie. / Clonal animals grow through addition of functional units (zooids), whose assemblage constitutes
a colony. The modular approach consists in describing colony form from the arrangement and
size of modules. The modular approach was used here to access variations in growth forms of
the coral Montastraea cavernosa using the arrangement and the size of polyps in the inner face
of the colonial of 46 samples collected in Parcel das Paredes (BA) and João Pessoa (PB).
Results showed that area of the polyps is partially explained by factors related to the spacing
among them. These factors vary with the form of the colony and with the range of polyp sizes
being analyzed. A hypothetical conceptual model for the relationship among colonial growth
forms, polyp sizes and organization is proposed. Possible evolutionary reasons for such a model
are discussed as well as possible implications to morphometric studies of this species.
|
2 |
"The Effects of Ocean Warming and Sedimentation on the Survival and Growth of Acropora cervicornis" and "Differential Prevalence of Chimerism during Embryogenesis in Corals"De Marchis, Hayley 20 November 2017 (has links)
Part I:
Coral reefs are essential to coastal economies, protecting coastlines from storms, and harboring high biodiversity. However, reefs are declining due to local anthropogenic stressors and ocean warming. Sedimentation, a local stressor, aggravates the impacts of warming on corals and hinders their survival and growth. Therefore, it is important to investigate whether sedimentation and temperature have a synergistic effect on vulnerable coral species, especially during earlier stages of development. To quantify these effects, survival and growth of newly settled Acropora cervicornis corals were measured at two temperatures (29 and 31°C, representing current and predicted for 2050 Summer temperatures) and three sediment concentrations (30, 60 and 120 mg.cm-2, representing a range from natural sedimentation to dredging conditions). The intent of this study was to mix multiple genotypes to test temperature and sedimentation among genotypic unique individuals. However, only 20% of colonies spawned, and spawning was asynchronous by genotype. Therefore, individuals were produced from self-fertilization. The overall high mortality seen in this study suggests that self-fertilization in A. cervicornis does not produce viable juveniles. Although temperature did not have a significant effect on the survival of self-fertilized juveniles, sediment concentration did. The lowest sediment concentration led to the highest juvenile survival in both ambient and heated conditions. The growth of A. cervicornis selfed individuals was not significantly affected by temperature or sedimentation. These results suggest that reducing sedimentation in dredging and coastal construction areas around coral reefs facilitates the survival of Acropora cervicornis juveniles and may help to ensure their persistence in the future. Because self-fertilized larvae were used, these results need to be interpreted with caution, and this research needs to be repeated with outcrossed A. cervicornis. What is clear is that genotypic diversity is needed for A. cervicornis population growth and resilience.
Part II:
Chimeras occur when two or more genetically unique individuals of the same species fuse together. The presence of chimerism can aid in the survival and evolution of organisms. This study investigated whether the prevalence of chimerism differs between coral species of different reproduction modes and growth rates. To fulfill this goal, the surface area of egg and/or larvae of three coral species, Montastraea cavernosa, Acropora cervicornis, and Porites astreoides, were measured and compared with the respective surface areas of the newly settled juveniles. This comparison suggested that M. cavernosa displayed a greater tendency to form chimeras than A. cervicornis and P. astreoides. Observations during embryogenesis confirmed this prediction. Montastraea cavernosa is a slow grower and has the smallest eggs of all three study species. Chimerism during embryogenesis may increase this species’ tendency to start the sessile stage at a slightly bigger size and thus increases its competitive abilities for reef space. In contrast, A. cervicornis is a broadcast spawner, fast grower and has a relatively larger egg size, possibly explaining the reduced chimeric tendency during embryogenesis. It is possible that P. astreoides formed chimeras during embryogenesis within the polyp, but they did not form them in the swimming planulae stage. The lack of chimerism during P. astreoides planulae development may be attributed to its brooding reproductive mode, directly releasing large competent larvae that have large initial sizes at settlement. Therefore, the ability to form chimeras in an early developmental stage might provide an ecological advantage to M. cavernosa that contributes to its abundance in Broward County: the greater size at settlement caused by chimerism during embryogenesis may provide this species a competitive advantage for reef space.
|
3 |
Gametogenesis and Spawning of Solenastrea bournoni and Stephanocoenia intersepta and the Fecundity of Four Common Transplanted Coral Species Offshore, Southeast Florida.Lueg, Jenna R. 01 August 2011 (has links)
Restoration efforts are being implemented in many of the world’s coral reefs due to damages from anthropogenic sources such as ship groundings and anchor damage. One restoration technique involves attempts to save dislodged and fragmented coral colonies by transplanting them back to damage sites. Research has shown that survivorship and growth of transplanted colonies is comparable to that of natural, control colonies. What remains unknown is to what extent transplantation affects the ecological success and reproduction of dislodged and fragmented coral colonies. The purpose of this study was twofold. Reproduction and spawning information is sparse for S. intersepta and Solenastrea bournoni, so the first purpose was to describe gamete development of these two species and assess correlations between environmental dynamics and spawning of each species. Tissue samples were collected throughout Broward County, Florida and processed for histological examination. Gametes were counted, and development was assessed. For S. intersepta and S. bournoni, late stage oocyte abundance was compared with environmental factors of mean daily water temperatures at depth, lunar phase, semidiurnal tides and solar insolation for correlative evidence to predict future spawning events. Findings indicated that both S. bournoni and S. intersepta are gonochoric broadcast spawners. Solenastrea bournoni spawns annually after the full moon in September when sea temperatures are at a maximum. Stephanocoenia intersepta spawns annually after the full moon of August or September, depending on the timing of the full moon. The second purpose was to determine if previously transplanted Porites astreoides, Montastraea cavernosa, Siderastrea siderea and Stephanocoenia intersepta corals produce gametes and spawn similarly to naturally occurring colonies and to address the issue of transplantation as a suitable resource management tool to aid in reef recovery for future coral generations. Results indicated no significant difference in fecundity between transplants and controls of M. cavernosa, S. siderea or S. intersepta. A significant difference was found in fecundity between P. astreoides transplants and controls, but it is thought that it is due to a difference in depth of collected samples. Overall, this study shows that transplantation of coral colonies after damage and fragmentation events does not have adverse effects on the long-term fecundity of coral colonies.
|
4 |
Species Specific Microcalcification in Reef Building Caribbean Corals in Ocean Acidification ConditionsDungan, Ashley M 13 November 2015 (has links)
Coral reefs are one of the most economically important ecosystems on the planet. Despite their great contribution to the world economy, anthropogenic influence via carbon dioxide emissions is leading to unprecedented changes with concerns about subsequent negative impacts on reefs. Surface ocean pH has dropped 0.1 units in the past century; in spite of this rapid shift in oceanic chemistry, it is unclear if individual species or life stages of Caribbean stony corals will be more sensitive to ocean acidification (OA). Examined is the relationship between CO2-induced seawater acidification, net calcification, photosynthesis, and respiration in three model Caribbean coral species: Orbicella faveolata, Montastraea cavernosa, and Dichocoenia stokesi, under near ambient (465 ± 5.52 ppm), and high (1451 ± 6.51 ppm) CO2 conditions. A species specific response was observed for net calcification; D. stokesi and M. cavernosa displayed a significant reduction in CaCO3 secreted under OA conditions, while O. faveolata fragments showed no significant difference. At the cellular level, transmission electron micrographs verified that all species and treatments were actively calcifying. Skeletal crystals nucleated by O. faveolata in the high CO2 treatments were statistically longer relative to controls. These results suggest that the addition of CO2 may shift the overall energy budget, causing a modification of skeletal aragonite crystal structures, rather than inhibiting skeletal crystal formation. Consequential to this energy shift, Orbicella faveolata belongs in the category of Scleractinian corals that exhibit a lower sensitivity to ocean acidification.
|
5 |
Coral Persistence to Ocean Warming via Developmental AcclimationSchaneen, Heather L 29 July 2016 (has links)
Scleractinian corals are the ‘engineers’ of tropical coral reef ecosystems. Their three-dimensional structure provides habitat for thousands of fish and invertebrate species. The persistence of corals is threatened by climate change. In this study I investigated if corals may be able to increase tolerance to ocean warming through developmental acclimation, i.e. if corals that experience warmer temperatures during embryonic and larval development are better able to cope with higher temperatures later in life. Larvae of the broadcast spawning coral Montastraea cavernosa were raised at ambient (29°C) and future projected ocean warming temperatures (+2°C, 31°C). After larval settlement, coral juveniles from each treatment were split and reared for two months at either current or +2°C conditions. Larvae reared at the warmer temperature had lower survival and displayed a smaller size at settlement. Juveniles that were in the warmer conditions had faster growth rates. Individuals raised during larval and juvenile stages at 31°C had faster growth rates than individuals only in the elevated temperature treatment after settlement, thus indicating that developmental acclimation may have occurred. However, the highest mortality also occurred in this treatment, therefore the growth results could also be explained by positive selection of the most thermally tolerant individuals. My results suggest that acclimation and/or directed selection may help corals withstand future rises in ocean temperature.
|
6 |
Artères et nerfs du pénis humain adulte : étude par dissection anatomique assistée par ordinateur (DAAO) / Arteries and nerves of penis : a computer-assisted anatomic dissection study (CAAD)Diallo, Djibril 11 October 2013 (has links)
Introduction : l’innervation et la vascularisation des corps caverneux du pénis sont très difficilement explorables par les techniques de dissection anatomiques classiques. De ce fait, elles demeurent pas très bien connues. La dissection anatomique assistée par ordinateur (CAAD), combinant méthodes immuno-histochimiques et reconstruction tridimensionnelle représente un outil original permettant l’analyse microscopique des artères et des nerfs au sein des corps caverneux. Les objectifs de ce travail étaient donc d’étudier l’innervation et la vascularisation microscopique des corps caverneux par dissection anatomique assistée par ordinateur (CAAD).Matériel et méthodes : Des coupes histologiques sériées de pénis ont été réalisées chez huit cadavres adultes masculins et sur des pièces issues de pénnectomie pour cancer à l’hôpital du kremlin-Bicêtre. Les coupes ont été traitées par des méthodes histologiques (Hématoxyline-Eosine et trichrome de Masson) et immuno-histochimiques pour détecter les fibres nerveuses (anti-S100), les fibres somatiques (anti-PMP22), les fibres adrénergiques (anti-TH), cholinergiques (anti-VAChT) et nitrergiques (anti-nNOS). Les lames ont ensuite été numérisées par un scanner de haute résolution optique et les images bidimensionnelles ont été reconstruites en trois dimensions grâce au logiciel WinSurf. Résultats: La reconstruction tridimensionnelle des coupes histologiques immuno-marquées a permis de décrire l’innervation et la vascularisation des corps caverneux du pénis. Les artères et les nerfs du pénis sont très largement anastomosés entre eux.Les anastomoses entre les artères caverneuses et les artères urétrales se font en dehors de l’albuginée du corps spongieux d’où le terme de « shunts caverno-urétraux » utilisé dans ce travail pour qualifier ces vaisseaux anastomotiques.La vascularisation et l’innervation permettent de distinguer deux compartiments anatomiques distincts au niveau du pénis : une partie proximale (les 2/3 du pénis) autonome dont les artères et les nerfs proviennent du plexus hypogastrique inférieur (supra-lévatorien), et le tiers distal somatique dont les artères et les nerfs proviennent des artères et nerfs dorsaux du pénis (infra-lévatorien).Les communications entre les systèmes autonomes et somatiques (entre le plexus hypogastrique inférieur supra-lévatorien et le nerf pudendal infra-lévatorien) existent donc à quatre niveaux : proximal, intermédiaire, à la racine du pénis et intracaverneuses. Les communications intracaverneuses sont responsables des marquages autonomes observés dans les nerfs dorsaux du pénis. Elles confèrent également aux corps caverneux une sensibilité à peu près semblable à celui du gland au cours de l’acte sexuel.Conclusion: Nos résultats montrent de très nombreuses anastomoses vasculaires et nerveuses dans les corps caverneux entre les systèmes supra et infra-lévatoriens avec 2 régions anatomiques distinctes : les 2/3 proximaux érectiles et le 1/3 distal sensitif. Ces anastomoses permettent d’espérer une certaine plasticité dans la vascularisation et l’innervation du pénis en cas de dysérection. / Introduction: The innervation and the vascularization of the corpora cavernosa of the penis are very difficult searchable by the classical anatomic dissections. Therefore, they remain not very well known. The computer-assisted anatomic dissection (CAAD), combining immunohistochemical methods and three-dimensional reconstruction is a unique tool for the microscopic analysis of the arteries and nerves in the corpora cavernosa.The objectives of this study were therefore to investigate the microscopic innervation and vascularization of the corpora cavernosa by the CAAD.Materials and methods: Serial histological sections of penis were performed in eight adult male cadavers and one piece after penectomy for cancer in the hospital of Kremlin Bicetre. The sections were processed by histological methods (hematoxylin-eosin and Masson trichrome) and immunohistochemistry to detect nerve fibers (anti-S100), somatic fibers (anti-PMP22), adrenergic fibers (anti-TH), cholinergic fibers (anti-VAChT) and nitrergic fibers (anti-nNOS). The slides were then scanned by a high resolution scanner and two-dimensional images were reconstructed in three dimensions using WinSurf software.Results: Three-dimensional reconstruction of immunolabeled histological sections allowed describing the innervation and vascularization of the corpora cavernosa of the penis. The arteries and nerves of the penis are widely anastomosed.The anastomoses between the cavernous arteries and urethral arteries are outside the tunica albuginea of the corpus spongiosum hence the term "cavernous urethral shunts".The innervation of the penis distinguishs two distinct anatomical portions: a proximal portion (2/3 of the penis) is autonomic whose arteries and nerves come from the inferior hypogastric plexus (supralevator), and the third including somatic distal nerves from the dorsal nerves of the penis (infralevator).The communications between autonomic and somatic systems (between the inferior hypogastric plexus and the pudendal nerve) exist in four levels: proximal, middle, crura of penis and intra-cavernous. The intra-cavernous communications are responsible for autonomic fibers observed in the dorsal nerves of the penis.Conclusion: Our results show a large number of vascular and nerve anastomoses in the corpora cavernosa between supra and infralevator sustems with two distinct anatomical regions: the 2/3 proximal erectile portion and 1/3 distal sensorial portion. These anastomoses provide a hope for the plasticity in the vascularization and innervation of the penis in cases of erectile dysfunction.
|
7 |
Coral Propagation: A Growth and Survival Comparison among Six Scleractinian Boulder Corals Employing In Situ and Ex Situ Nursery TechniquesCrossett, Daniel James 25 January 2013 (has links)
Knowledge of effective reef restoration techniques are necessary in this age of worldwide coral reef decline. Coral transplantation is a restoration technique employed after natural (i.e. hurricanes) and anthropogenic (i.e. vessel groundings) physical disturbance events. The study was conducted to compare the efficacy of propagating small colony fragments in laboratory and field conditions in terms of survival and growth. Fragment growth and survival were assessed for six scleractinian boulder corals common to Florida and Caribbean reefs: Montastraea annularis, M. cavernosa, Diploria clivosa, Siderastrea siderea, S. radians and Dichocoenia stokesii. Broken coral colonies were salvaged from vessel grounding sites and marine debris, fragmented into pucks and secured to travertine tiles. One hundred and fifty-three coral colony fragments were cultivated in an ex situ laboratory nursery and 133 coral colony fragments were cultivated in an in situ field nursery and monitored for 13 months. Survival of all colonies was 94%, with 98% survival in the laboratory treatment and 89% survival in the field treatment. Complete colony mortality was documented in three S. radians colonies, all in the laboratory treatment. All colony loss in the field treatment was due to colony pucks being detached from the tiles. Overall mean percent change in colony tissue area from initial to final monitoring events was calculated to determine growth. Across species, growth was greater in the laboratory treatment (76 ± 4 % SEM) in comparison to the field treatment (27 ± 5 % SEM). Positive growth was observed in D. clivosa, D. stokesii, M. annularis, M. cavernosa and S. siderea in the laboratory treatment. In the field treatment, D. clivosa, M. annularis and M. cavernosa were the only species that exhibited positive growth. Negative growth was observed in both the laboratory and field treatments for S. radians. In conclusion, colonies propagated in the ex situ nursery (laboratory treatment) had higher growth and survival than colonies propagated in the in situ nursery (field treatment). A critical acclimation period accomplished through the use of stable laboratory conditions will produce healthier, more secure coral colonies that may be used to repopulate disturbed reef sites.
|
Page generated in 0.0478 seconds