423 research outputs found
Reproductive biology of winter-spring spawners of Illex argentinus (Cephalopoda: Ommastrephidae) off Southern Brazil
The reproduction and fecundity of winter-spring spawners of the shortfin squid Illex argentinus off southern Brazil (27°S-34°S) were studied in samples from bottom trawl surveys on the outer shelf and upper slope from 1986 to 1992. The mantle length-total weight relationships were for males: TW = 0.00002456 ML2.974 for females: TW = 0.00004265 ML 2.842 and pooled: TW = 0.00005376 ML 2.809. Males were heavier than females at the same ML. Fully mature squids were found from July to October. Mantle length and total weight of fully mature males ranged from 188 to 296 mm (mean 252.2 mm) and 195.5 to 611 g (mean 382.7 g) and for females from 225 to 356 mm (mean 307.4 mm) and 234 to 772 g (mean 558.4 g). Total weight was maximum at full maturity and decreased in the subsequent stages of both sexes. Mean weight and mean major axis length of ripe oocytes in the oviducts were 0.48 mg (sd= 0.10 mg) and 1.27 mm (sd= 0.08 mm), respectively. Total and oviduct mean fecundities, in thousands of oocytes larger than 0.4 mm, in ten fully mature females (294-336 mm ML) were 177.2 (93.0 to 294.3) and 118.4 (51.5 to 233.9), respectively. Spawning season in this region seems to be more protracted than in higher latitudes. Our results suggest that a northward migration could take place prior to spawning and that in winter and spring, southern Brazil may be a major spawning ground of Illex argentinus that contributes to the local and to the Uruguay and northeastern Argentina recruitment
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Localisation and origin of the bacteriochlorophyll-derived photosensitizer in the retina of the deep-sea dragon fish Malacosteus niger
Most deep-sea fish have a single visual pigment maximally sensitive at short wavelengths, approximately matching the spectrum of both downwelling sunlight and bioluminescence. However, Malcosteus niger produces far-red bioluminescence and its longwave retinal sensitivity is enhanced by red-shifted visual pigments, a longwave reflecting tapetum and, uniquely, a bacteriochlorophyllderived photosensitizer. The origin of the photosensitizer, however, remains unclear. We investigated whether the bacteriochlorophyll was produced by endosymbiotic bacteria within unusual structures adjacent to the photoreceptors that had previously been described in this species. However, microscopy, elemental analysis and SYTOX green staining provided no evidence for such localised retinal bacteria, instead the photosensitizer was shown to be distributed throughout the retina. Furthermore, comparison of mRNA from the retina of Malacosteus to that of the closely related Pachystomias microdon (which does not contain a bacterichlorophyll-derived photosensitzer) revealed no genes of bacterial origin that were specifically up-regulated in Malacosteus. Instead up-regulated Malacosteus genes were associated with photosensitivity and may relate to its unique visual ecology and the chlorophyll-based visual system. We also suggest that the unusual longwave-reflecting, astaxanthin-based, tapetum of Malacosteus may protect the retina from the potential cytotoxicity of such a system
A Combined Pulmonary Function and Emphysema Score Prognostic Index for Staging in Chronic Obstructive Pulmonary Disease
Chronic Obstructive Pulmonary Disease (COPD) is characterized by high morbidity and mortality. Lung computed tomography parameters, individually or as part of a composite index, may provide more prognostic information than pulmonary function tests alone.To investigate the prognostic value of emphysema score and pulmonary artery measurements compared with lung function parameters in COPD and construct a prognostic index using a contingent staging approach.Predictors of mortality were assessed in COPD outpatients whose lung computed tomography, spirometry, lung volumes and gas transfer data were collected prospectively in a clinical database. Univariate and multivariate Cox proportional hazard analysis models with bootstrap techniques were used.169 patients were included (59.8% male, 61.1 years old; Forced Expiratory Volume in 1 second % predicted: 40.5±19.2). 20.1% died; mean survival was 115.4 months. Age (HR = 1.098, 95% Cl = 1.04-1.252) and emphysema score (HR = 1.034, 95% CI = 1.007-1.07) were the only independent predictors of mortality. Pulmonary artery dimensions were not associated with survival. An emphysema score of 55% was chosen as the optimal threshold and 30% and 65% as suboptimals. Where emphysema score was between 30% and 65% (intermediate risk) the optimal lung volume threshold, a functional residual capacity of 210% predicted, was applied. This contingent staging approach separated patients with an intermediate risk based on emphysema score alone into high risk (Functional Residual Capacity ≥210% predicted) or low risk (Functional Residual Capacity <210% predicted). This approach was more discriminatory for survival (HR = 3.123; 95% CI = 1.094-10.412) than either individual component alone.Although to an extent limited by the small sample size, this preliminary study indicates that the composite Emphysema score-Functional Residual Capacity index might provide a better separation of high and low risk patients with COPD, than other individual predictors alone
Lista anotada e ilustrada de cefalópodos (Mollusca) registrados en aguas brasileñas con una clave de identificación de especies
An annotated list of cephalopods from the Brazilian Economic Exclusive Zone is presented. Species are briefly described, mainly based on external characters with information on their habitat and distribution, and images of freshly caught or preserved specimens are given. This list updates the nomenclature and geographical distribution given in previous lists, and it includes some recently described species, as well as unpublished records identified to genera. A key for the identification of families, genera and species, and images of live specimens are included. A total of 93 species are recorded, belonging to the orders Spirulida (1), Sepioidea (6), Myopsida (6), Oegopsida (46), Bathyteuhida (2), Vampyromorpha (1) and Octopoda, suborders Cirrata (4) and Incirrata (27), all in the Subclass Coloidea. Almost half of the species are benthic from the continental shelf or slope, and the remainder are water-column species, mostly from the slope and adjacent oceanic waters. Only 17 species are considered endemic to the southwest Atlantic, including two that are currently known to occur only in Brazil.Se presenta una lista anotada de cefalópodos de la Zona Económica Exclusiva de Brasil. Las especies se describen brevemente, basándose principalmente en caracteres externos con información sobre su hábitat y distribución, y se ofrecen imágenes de ejemplares recién capturados o conservados. Esta lista actualiza la nomenclatura y la distribución geográfica indicadas en listas anteriores, e incluye algunas especies descritas recientemente, así como registros inéditos identificados hasta géneros. Se incluye una clave para la identificación de familias, géneros y especies, así como imágenes de ejemplares vivos. Se registra un total de 93 especies, pertenecientes a los órdenes Spirulida (1), Sepioidea (6), Myopsida (6), Oegopsida (46), Bathyteuhida (2), Vampyromorpha (1) y Octopoda, subórdenes Cirrata (4) e Incirrata (27), todos en la Subclase Coloidea. Casi la mitad de las especies son bentónicas de la plataforma continental o del talud, y el resto son especies de la columna de agua, en su mayoría del talud y de aguas oceánicas adyacentes. Solo 15 especies se consideran endémicas del Atlántico Sudoccidental, incluyendo dos cuya ocurrencia se restringe a aguas brasileras
Generation of human vascular smooth muscle subtypes provides insight into embryological origin-dependent disease susceptibility.
Heterogeneity of embryological origins is a hallmark of vascular smooth muscle cells (SMCs) and may influence the development of vascular disease. Differentiation of human pluripotent stem cells (hPSCs) into developmental origin-specific SMC subtypes remains elusive. Here we describe a chemically defined protocol in which hPSCs were initially induced to form neuroectoderm, lateral plate mesoderm or paraxial mesoderm. These intermediate populations were further differentiated toward SMCs (>80% MYH11(+) and ACTA2(+)), which displayed contractile ability in response to vasoconstrictors and invested perivascular regions in vivo. Derived SMC subtypes recapitulated the unique proliferative and secretory responses to cytokines previously documented in studies using aortic SMCs of distinct origins. Notably, this system predicted increased extracellular matrix degradation by SMCs derived from lateral plate mesoderm, which was confirmed using rat aortic SMCs from corresponding origins. This differentiation approach will have broad applications in modeling origin-dependent disease susceptibility and in developing bioengineered vascular grafts for regenerative medicine
Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats
Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV
The role of neutralizing antibodies in prevention of HIV-1 infection: what can we learn from the mother-to-child transmission context?
International audienceIn most viral infections, protection through existing vaccines is linked to the presence of vaccine-induced neutralizing antibodies (NAbs). However, more than 30 years after the identification of AIDS, the design of an immunogen able to induce antibodies that would neutralize the highly diverse HIV-1 variants remains one of the most puzzling challenges of the human microbiology. The role of antibodies in protection against HIV-1 can be studied in a natural situation that is the mother-to-child transmission (MTCT) context. Indeed, at least at the end of pregnancy, maternal antibodies of the IgG class are passively transferred to the fetus protecting the neonate from new infections during the first weeks or months of life. During the last few years, strong data, presented in this review, have suggested that some NAbs might confer protection toward neonatal HIV-1 infection. In cases of transmission, it has been shown that the viral population that is transmitted from the mother to the infant is usually homogeneous, genetically restricted and resistant to the maternal HIV-1-specific antibodies. Although the breath of neutralization was not associated with protection, it has not been excluded that NAbs toward specific HIV-1 strains might be associated with a lower rate of MTCT. A better identification of the antibody specificities that could mediate protection toward MTCT of HIV-1 would provide important insights into the antibody responses that would be useful for vaccine development. The most convincing data suggesting that NAbs migh confer protection against HIV-1 infection have been obtained by experiments of passive immunization of newborn macaques with the first generation of human monoclonal broadly neutralizing antibodies (HuMoNAbs). However, these studies, which included only a few selected subtype B challenge viruses, provide data limited to protection against a very restricted number of isolates and therefore have limitations in addressing the hypervariability of HIV-1. The recent identification of highly potent second-generation cross-clade HuMoNAbs provides a new opportunity to evaluate the efficacy of passive immunization to prevent MTCT of HIV-1
Atlas de otolitos de peces marinos presentes en el Atlántico Sudoccidental a lo largo del sur de Brasil (28° S-34° S)
Otoliths are acellular apposition structures composed of approximately 90% of calcium carbonate and other inorganic salts, which develop over a protein matrix located in the inner ear of bony fishes playing an essential role in the senses of balance and hearing. These structures grow throughout a fish’s lifetime. Owing to their species-specific shape, otoliths are an important tool for the identification of fish species in the diet of predators when collected from stomachs and, due to their low water content, are helpful for archaeological, paleontological and anthropological studies for its presence in fossilized remains. This atlas is aimed at the identification of abundant or frequent bony fishes otoliths in the diet of predators and in fossilized remains from the continental shelf and upper continental slope of southern Brazil between Santa Marta Grande cape (28° S) and Chuí (34° S) on the border with Uruguay. It includes the otolith description of 136 bony fishes species, including most of the abundant and frequent species in the region. Easy to use graphics are provided to infer fish size based on otolith measurements. Vouchers of different sizes of otolith of all species included in this atlas are deposited and available for consultation at the Demersal Fisheries Resources and Cephalopods Laboratory (IO-FURG).Los otolitos son estructuras de aposición acelular compuestas por alrededor de un 90% de carbonato de calcio y otras sales inorgánicas, que se desarrollan sobre una matriz proteica ubicada en el oído interno de los peces óseos y que desempeña un papel fundamental en los sentidos del equilibrio y la audición. Estas estructuras crecen a lo largo de la vida de un pez. Debido a su forma especie-específica, los otolitos son una herramienta importante para la identificación de las especies de peces en la dieta de los depredadores cuando se recolectan de estómagos y, debido a su bajo contenido de agua, son útiles para estudios arqueológicos, paleontológicos y antropológicos debido a su presencia en los restos fosilizados. Este atlas tiene como objetivo la identificación de otolitos de peces óseos abundantes o frecuentes en la dieta de los depredadores y restos fosilizados de la plataforma continental y talud continental superior del sur de Brasil entre el Cabo Santa Marta Grande (28° S) y Chuí (34° S) en la frontera con Uruguay. Incluye la descripción de otolitos de 136 especies de peces óseos, incluyendo la mayoría de las especies abundantes y frecuentes en la región. Se proporcionan gráficos fáciles de usar para inferir el tamaño del pez en función a las medidas de los otolitos. Los otolitos se encuentran depositados y disponibles para consulta en el Laboratorio de Recursos Pesqueros Demersales y Cefalópodos (IO-FURG) comprobantes de diferentes tamaños de otolitos de todas las especies incluidas en este atlas
Pogonias courbina
This demersal species inhabits and forms seasonal spawning aggregations in shallow coastal waters and estuaries from southeastern Brazil to Argentina. It is a relatively long-lived, large-bodied species that canattain over 140 cm in length and 40 kg in weight and reach over 50 years in age. The estimated generation length is 28 years. It is targeted by commercial, artisanal and recreational fisheries throughout its range. Fisheries targeted spawning migrations in the Patos Lagoon estuary in southern Brazil at a high level from the 1940s to early 1980s, and landings have declined by 88% since 1982, orover the past 37 years. After these four decades of exploitation, only juveniles and small-sized adults are currently captured in the fishery. In Uruguay and Argentina, fishing effort primarily targets spawning aggregations in the La Plata River estuary. Landings in this fishery increased by 260% since 2000, or overthe past 19 years, as compared to landings in the period from 1975-1999. The current absence of large individuals in the La Plata River commercial catch and anecdotal observations of declines by Argentines portfishers, strongly implies that a truncation in age structure and a significant decline in abundance occurred.This species has intrinsic characteristics, including large body size, long longevity and high vulnerability to capture during predictable spawning/feeding migrations or aggregations, that cause it to be susceptible to large population declines under exploitation. However, its high fecundity and early age at© The IUCN Red List of Threatened Species: Pogonias courbina , published in 2020.https://dx.doi.org/10.2305/IUCN.UK.2020-2.RLTS.T159145751A159145756.en1maturity (5-10% of the longevity) favours its resilience to exploitation under adequate fisheries management. The large decline in the southern Brazil fishery that targets this species was caused by years of intense fishing pressure, and that stock has not recovered. This is a clear warning that the fishery operating in La Plata estuary will follow the same path of decline unless urgent and drastic management measures are not implemented in the near future. Based on fisheries data and catch observations over time, it is inferred this species has undergone global-level declines of at least 30-40%over the past one and half generation lengths (about 42 years), and due to insufficient conservation measures, this decline is expected to continue over the next one and half generation lengths. Therefore,it is listed as Vulnerable A2bd+4bd with a strong recommendation to improve fisheries monitoring and management.Fil: Haimovici, M. Universidade Federal Do Rio Grande.; BrasilFil: Chao, L.. National Museum Of Marine Biology And Aquarium In Taiwa; República de ChinaFil: Vieira, J.P.. Universidade Federal Do Rio Grande.; BrasilFil: Buratti, C.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Díaz de Astarloa, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Irigoyen, A.. No especifíca;Fil: Riestra, C.. Instituto Nacional de Investigaciones y Desarrollo Pesquero; ArgentinaFil: Landaeta, M.. Universidad de Valparaíso; ChileFil: Hüne, M.. Universidad Austral de Chile; Chil
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