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546,196 artículos
Año:
2017
ISSN:
1561-3194
Puerto Martínez, Marianela
Centro Provincial de Ciencias Médicas de Pinar del Río
Resumen
Introduction: Ehlers-Danlos syndrome is a rare disease which diagnosis is in many cases underestimated. It is an inherited disease, caused by chromosomal mutations, which may have autosomal dominant, recessive or X-linked behavior. Objective: it is classified into 6 subtypes, being the most frequent type I and III, and the most serious of all, is the vascular subtype. It is important to make an appropriate clinical diagnosis. Development: this disease is characterized mainly by defects in the production of collagen, and as a result of the present damage in the enzymes responsible for its synthesis. The variety with which it is presented causes it to be considered heterogeneous; it is why there are great types of this disease, each with similar signs and symptoms, but with different progression and evolution, presenting joint hyperlaxity, hyperelasticity of the skin and hyper- ecchymoses due to fragility of the blood vessels. At present there is no specific treatment for it. Conclusion: genetic and biochemical studies are needed to help to identify the coexisting defects. Some forms of the syndrome are common, while others are very rare. It is important to perform the complete physical examination and look for the specific characteristics of each subtype to identify it with the highest possible precision.
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Año:
2017
ISSN:
2215-2075, 0034-7744
Sonnenholzner, Jorge; Alcivar, Gema; Marquez, Adrián; Lodeiros, César
Universidad de Costa Rica
Resumen
The sea urchins Arbacia incisa and Eucidaris thouarsii (Echinodermata) as fouling biocontrol agents in culture cages of Crassostrea gigas (Mollusca: Ostreidae).Fouling clogs cultivation cages of bivalves afecting their growth. We tested biocontrol with sea urchins in the suspended culture of C. gigas during one month. The experimental design included: 1) oysters without sea urchins, 2) oysters with the black sea urchin Arbacia incisa (50.5 ± 0.43 mm of diameter testa-DT), 3) oysters with the pencil sea urchin E. thouarsii (34. 2 ± 2.13 mm DT) and 4) oysters without sea urchins with a pearl net protective bag (to avoid predation). The dry mass of the pearl nets and the oyster soft tissues were determined at the beginning and end of the experiment. There was similar fouling in cages without urchins (55.3 ± 5.80 g) and with A. incisa (46.1 ± 2.84 g). These amounts were significantly higher than those found in cages with E. thouarsii (39.1 ± 1.9 g) and with protective sacs without urchins (35.6 ± 5.17 g). The growth of C. gigas with E. thouarsii was significantly higher (0.49 ± 0.089 g). We recommend E. thouarsii as a fouling biocontrol agent for C. gigas. Rev. Biol. Trop. 65(Suppl. 1): S35-S41. Epub 2017 November 01.
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Año:
2017
ISSN:
2215-2075, 0034-7744
Hernández, José Carlos
Universidad de Costa Rica
Resumen
Echinoids play an important role in marine ecosystems structuring. Often, their population density experience markedly fluctuations that promote a state shift in the ecosystems they inhabit. Population increments of some sea urchins may cause catastrophic changes in temperate areas of the planet by decimating the erect macroalgae cover. These population increments results in unproductive and very stable assemblages, known as “blanquizales” (ericeras/moradales), or sea urchin barren ground. Macroalgae are the main ecosystem engineers in temperate areas and generate a suitable nursery and feeding habitat for fishes. These algae stands are also important zones for biofiltration of coastal waters and CO2 uptake. The main consequence of vegetated biomass lost is a trophic disequilibrium that generates important economic losses for artisanal fisheries and tourism. In tropical areas, sea urchin’s outbreaks can cause bioerosion in coral reefs. However, the most important event to highlight was the mass mortality occurred in the Caribbean during the 80’s. This event favored the development of algae communities that suffocated the coral reef ecosystem. Therefore, both in temperate and tropical areas of the planet, these boom-bust echinoids generate undesired ecosystems states. Very recently, various global scale collaborative papers have highlighted a clear anthropogenic cue. Human activity though overfishing or favoring global warming, weakens marine ecosystem resilience and promote these catastrophic ecosystem shifts. To mitigate the effects of these population changes different management strategies have been used. For instance, in temperate areas, sea urchin reduction actions (manually or by using quick lime), sea urchin harvesting or the implementation of marine reserves have been used, with contrasting results. In Caribbean coral reefs affected by urchin mass mortality, some sea urchin juvenile’s reintroduction plans have been used but with very low effectiveness. The more feasible ecosystem scale strategy due to its preventive nature, seems to be the implementation of protected areas. However, the impact of global warming will exceed our capacity to manage marine ecosystems locally and will required more efficient global actions to prevent undesired sea urchin fluctuations. Rev. Biol. Trop. 65(Suppl. 1): S23-S34. Epub 2017 November 01.
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Año:
2017
ISSN:
2215-2075, 0034-7744
Rubilar, Tamara; Crespi-Abril, Augusto
Universidad de Costa Rica
Resumen
Traditional ethics reflection centers the discussion in conflicts that affect humans. According to epistemology-based ethics, facts are needed to include other living beings as object of ethical consideration. In this sense, huge efforts have been made to demonstrate that animal suffering is real. However, the ethical reflection only reaches large vertebrates and some species of small ones, excluding invertebrates. However, a different approach (ethic-based epistemology) is equally valid and questions the assumptions of traditional ethics. This new insight does not demand facts to demonstrate that living beings should be considered ethically, since ethics should be first than epistemology (facts). Thus, all living beings should be treated with respect and a relationship based on empathy should be established. In this context, we discuss all the advances made in echinoderm research in the last 3000 years and the different uses humans made of these organisms. Finally we emphasize that, when studying echinoderms, a reflection about our behavior as researchers is necessary, and we encourage the use of ethically responsible research. Rev. Biol. Trop. 65(Suppl. 1): S11-S22. Epub 2017 November 01.
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Año:
2017
ISSN:
2215-2075, 0034-7744
Hogue, Charles L.
Universidad de Costa Rica
Resumen
From the author's field observations and literature records, neotropical "Lantern Bugs" (Fulgora spp.) are now known to use tree species of 5 families as resting, and presumably, feeding hosts: Simaroubaceae-Simarouba amara Aublet; Simaba versicolor St. Hilaire; Fabaceae Hymenaea oblongifolia (var. palustris (Ducke) Lee & Langenheim, Hymenaea coubaril Linnaeus; Myroxylon balsamum (Linnaeus); Rutaceae-Zanthoxylum sp.; Lecythidaceae-Lecythis sp,; Vochysiaceae- Vochysia tucanorum Martius. Most of these are producers of resins or noxious chemicals which may be sequestered by the bugs.These trees are also frequented by various arboreal lizards which are good candidates for models for mimicry by the bugs because of the reptilian-like appearance of the latter's large head protuberance and other structural and color features. The resemblance of Fulgora laternaria Linnaeus to Plica plica (Linnaeus) in the Iquitos area of Peru is especially close and this is postulated as the model in that area.
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Año:
2017
ISSN:
2215-2075, 0034-7744
Conand, Chantal
Universidad de Costa Rica
Resumen
The sea cucumber fisheries have expanded during the past two decades, at a faster rate than the management capacity. The exploitation is now qualified as ‘serial’ and ‘contagious’. I present the most recent trends from the last six years of the FAO capture data. Hong Kong remains the most important market for the imports and re-exports of the processed products, mainly the dry “trepang” (or bêche-de-mer), but also other product forms, which raised difficulties for the analysis. The catches still increase. with new countries developing export fisheries, species targeted change and new products are traded. Rev. Biol. Trop. 65(Suppl. 1): S1-S10. Epub 2017 November 01.
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Año:
2017
ISSN:
2215-2075, 0034-7744
Fraysse, Cintia; Malanga, Gabriela; Pérez, Analía F.
Universidad de Costa Rica
Resumen
The organoleptic characteristics of sea urchins gonads (size and color, among others) can be improved by artificial diets. Loxechinus albus is considered one of the most economically significant resources from the littoral-benthic systems in the South Pacific Ocean from Peru to Chile. The objective was to determine artificial diets effects on the organoleptic traits of gonads, reproductive condition, body growth and survival of Loxechinus albus. Two types of diets were administrated (low carotene content diet (LC): balanced food with 0.02% β-carotene and high carotene content diet (HC): balanced food with 0.045% β-carotene) for 16 weeks. As a measurement of growth rate, test diameter of sea urchins fed with artificial diets was measured at the beginning and at the end of the experiment. At both times, size (GI) and color (CI) of the gonads were recorded in ten individuals from each treatment and ten from the natural population (NP). Energy density (ED), energy content (EC) and total carotenes (TCC) were determined by calorimetry and spectrophotometry, respectively. Histological sections were examined microscopically and the sex was identified. Each female was assigned to a gametogenic stage (reproductive condition) and determined: number and diameter of the oocytes, gonadal area occupied by oocytes, and relative frequencies of reproductive stages. At the end of the experiment in relation to the NP, it was possible to achieve higher GI values for both artificial diets. The NP showed higher gonadal area occupied by oocytes and larger oocyte diameter at 16 weeks (P<0.01). In addition, individuals fed with both artificial diets, presented “growth” and “advanced growth” gonad stages (both times), while the NP individuals, presented stages of “prematurity”, “maturity” and “partial spawning” at week 16. The data shows the highest CI value for the HC diet at eight weeks (P<0.01). Moreover, TCC values for the NP were significantly higher at week 16 (P<0.01). Loxechinus albus is an appropriate species to be kept in captivity, as their mortality is very low, facilitating the achievement of long-term experiences of gonadal improvement. According to our data the optimal time to improve the organoleptic characteristics is eight weeks with a high carotene artificial diet, since optimal gonad coloration was reached, and GI values did not differ significantly from the ones achieved at the end of the experiment for both diets, or the ones shown in the NP. This is translated into a lower cost by a reduced cultivation time. Rev. Biol. Trop. 65(Suppl. 1): S207-S220. Epub 2017 November 01.
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Año:
2017
ISSN:
2215-2075, 0034-7744
Pañola-Madrigal, Abigail; Calderon-Aguilera, Luis E.; Aguilar-Cruz, Carlos A.; Reyes-Bonilla, Héctor; Herrero-Pérezrul, María Dinorah
Universidad de Costa Rica
Resumen
The brown sea cucumber Isostichopus fuscus is highly prized and intensively fished, yet no studies of its reproductive cycle at its northernmost distribution site exist. To characterize its reproductive cycle, monthly surveys (Oct 2014-Dec 2016) that included gonad collection were conducted in 118 sites along the eastern coast of Baja California, including islands from Bahía San Luis Gonzaga (29o 49’ 14.18” N, 114 o 3’56.17” W) to the 28th parallel north. A total of 2 808 sea cucumber specimens were measured (mean length ± SD = 21.4 ± 6 cm) and weighed (375.6 ± 249 g). Seven hundred and seventeen organisms were dissected but only 553 gonads were suitable for processing through histological analysis to identify sex and developmental stage. Of these individuals, 224 were female, 162 were male, 157 were undifferentiated and 10 were hermaphrodites, resulting in a sex ratio that was significantly different from 1:1 (χ2 = 36.63, P = 0.03, df = 23). There was no statistical difference (p > 0.05) of either size or weight between males and females, but females were larger than males. The length-weight relationship observed was W = 0.18L2.4, r2 = 0.82, p <0.05 while the size-at-first-maturity was 16 cm. Five gonad stages were identified: 28% undifferentiated, 9% gametogenesis, 15% mature, 19% expulsion and 29% post-expulsion. The Oocyte Theoretical Diameter (OTD) was estimated by measuring the area of 10 291 oocytes, finding 2 307 individuals in oogenesis (mean ± SD of 65.3 ± 19.7 µm), 3 630 in maturity (66.0 ± 17.8 µm), 3 756 in spawning (73.8 ± 14.6 µm) and 868 in post-spawning (49.18 ± 20.7 µm). Modal progression analysis shows that oocytes increase 23% in size from oogenesis to maturity, and decrease 9%in size from maturity to spawning and, on average, oocytes are 72% smaller post-spawning that during spawning. Rev. Biol. Trop. 65(Suppl. 1): S180-S196. Epub 2017 November 01.
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Año:
2017
ISSN:
2215-2075, 0034-7744
Pérez, Analía F.; Fraysse, Cintia; Boy, Claudia C.; Epherra, Lucia; Javier, Calcagno
Universidad de Costa Rica
Resumen
The brooding sea star Anasterias antarctica is distributed from the coast of Patagonia to the northern Peninsula of Antarctica. In the Beagle Channel, the females of A. antarctica brood their eggs for seven months and do not feed during this period. The endoparasite Dendrogaster argentinensis (Crustacea: Ascothoracica) causes castration in several species of Anasterias. We randomly collected four samplings of adults in May, August and October (brooding period) and January (non-brooding period). The gonad (GI) and pyloric caeca index (PCI) were calculated as organ wet weight (g) x 100/total wet weight (g). Each individual was sexed by microscopic examination of the gonads. Sex ratio, brooding females/non-brooding females and mature females/non-mature females ratios was 1:1. The male GI reached maximum values in January, when most individuals were sexually mature. The GI of non-brooding females reached its maximum during October when it was significantly higher than those from brooding females. The PCI was minimum in October, being lower in brooding females (August and October). During the non-brooding period, mature females had a significantly higher GI than non-mature females. The PCI did not vary neither between males, nor between mature and non mature females. By the end of the brooding period, non-brooding females showed a higher GI than the brooding females. This is explained by proliferation and increase of the oocytes size of non-brooding females. Mature females showed an incremented GI with presence of mature oocytes, while non-mature females exhibited more abundance of previtelogenic oocytes. Males showed synchronicity in reproductive condition. The females that have not brooded presented a process of active gametogenesis, reaching the summer with a high GI, therefore becoming mature females. Females that had brooded were probably lacking energy for new gonadal maturation. The pyloric caeca would be performing the role of a reserve organ in the brooding females, decreasing its size during the brooding period. Prevalence of D. argentinensis in A. antarctica was 11.06%. As this parasite was recorded in sea stars lacking gonads, these infected hosts could have been castrated. Rev. Biol. Trop. 65(Suppl. 1): S221-S232. Epub 2017 November 01.
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