89 research outputs found

    Quantificação de fibras microplásticas provenientes da lavagem de tecidos

    Get PDF
    Fiber fragments from synthetic textile materials are a subgroup of microplastics, and the presence of this debris in the environment may have its origin from some different sources. In order to investigate the formation of these residues during domestic washing, washings were simulated on samples of textile articles consisting of three different synthetic materials (polyamide, acrylic, and polyester). The effluent generated was collected and filtered, retaining the microplastic fibers shed. Through a gravimetric process, the mass of particles adhered to the filters was determined, and with the use of a fluorescent dye (Nile Red), these particles were quantified under a fluorescence microscope. This study concluded that the different textile compositions shed microplastic fibers during five washing cycles. Acrylic samples shed the highest mass value (40.9 mg) and polyamide samples shed the lowest value (7.5 mg). It has been estimated that an acrylic blouse can shed 726 mg of microplastic fibers in a single washing. Regarding the size of these particles, dimensions ranging from 11µm to 3mm were observed. Visualization in a 1.2μm filter also suggests the existence of particles in nano-dimensions. In general, it was possible to establish that the domestic washing of textile articles highly contributes to the insertion of these pollutants into the water environment. From a national perspective, approximately 13,800 tons of synthetic fibers can be released into water resources annually from washing clothes.Fragmentos de fibras provenientes de materiais têxteis sintéticos são um subgrupo dos microplásticos, e a presença destes detritos no ambiente pode ser dar de algumas fontes. Com o propósito de investigar a formação destes resíduos durante a lavagem doméstica, foram simuladas lavagens em amostras de artigos têxteis com três composições sintéticas distintas (poliamida, acrílico e poliéster). O efluente gerado foi coletado e filtrado, retendo as fibras microplásticas desprendidas. Por um processo de gravimetria, foi determinado a massa de partículas aderidas aos filtros, e com o uso de um corante fluorescente (Nile Red), estas partículas foram quantificadas em microscópio de fluorescência. Este estudo concluiu que as diferentes composições têxteis liberaram fibras microplásticas durante cinco ciclos de lavagem. Amostras de acrílico liberaram o maior valor de massa (40,9 mg), e poliamida o menor valor (7,5 mg). Estimou-se que uma blusa de acrílico possa desprender 726 mg de fibras microplásticas em uma única lavagem. Em relação ao tamanho destas partículas, foram observadas dimensões variando de 11 µm a 3 mm. A visualização em filtro de 1,2 μm sugere ainda a existência de partículas em dimensões nano. De maneira geral, foi possível estabelecer que a lavagem doméstica de artigos têxteis possui elevada contribuição na inserção destes poluentes em meio hídrico. Em uma perspectiva nacional, cerca de 13,8 mil toneladas de fibras sintéticas podem ser liberadas nos recursos hídricos anualmente, a partir da lavagem de roupas

    Uso de Implante Visual Fluorescente de Elastômero (VIFE) na marcação de pequenos peixes de água doce tropicais

    Get PDF
    Algumas técnicas de marcação de peixes são utilizadas para diagnosticar aspectos da dinâmica populacional das espécies, não podendo interferir no comportamento, crescimento e reprodução da população envolvida. O presente estudo visa reportar a utilização do VIFE (Visible Implant Fluorescent Elastomer) na marcação de duas espécies de peixes de pequeno porte em ambiente controlado. O objetivo foi investigar se a mortalidade, a fragmentação e retenção da marca são indicadores da eficiência do implante. Foram marcados 60 peixes, 30 indivíduos do caracídeo Bryconamericus iheringii e 30 indivíduos do loricarídeo Rineloricaria malabarbai. Após 70 dias de experimento, os indivíduos de ambas as espécies não apresentaram crescimento e a taxa de retenção e mortalidade foi baixa. Existiu um grande numero de fragmentações devido à posição onde as marcas foram inseridas no corpo dos peixes. Após 90 dias de experimento todos os peixes morreram devido à contaminação da água. Os resultados de baixa mortalidade e retenção determinam que o uso de VIFE é recomendado

    A case of leucosis in Heptapterus mustelinus (Siluriformes, Heptapteridae) among populations of streams in southern Brazil. Has leucosis in Heptapterus mustelinus an adaptive value in shaded streams?

    Get PDF
    Fish populations in environments with a high degree of geographic isolation may be prone to mutations expressed in the phenotypes. These mutations may be related to color pattern, forming leucistic individuals. This work aims to register and to describe possible mechanisms that influence this mutation. Additionally, the study compares other morphometric variations among different populations and leucistic individuals of Heptapterus mustelinus. A total of four leucistic individuals were collected in a small shaded stream, highly segmented by rapids and waterfalls. The biometric analyses showed no significant morphological differences when compared to other populations of the same ecoregion. The selection of leucism may be directly related to the sampled environment, since the leucistic specimens occurred in a shaded stream with dense vegetation cover. Low occurrence of predatory species of fish can be an important point to maintain the characteristic. Consequently, predation may not exert a negative selective pressure on leucistic individuals

    How Far Upstream: A Review of Estuary-Fresh Water Fish Movements in a Large Neotropical Basin

    Get PDF
    The present study comprises the first systematic analysis of the limits of upstream movement by some fish species that use the estuarine area of the Patos Lagoon basin in southern Brazil. The Sinos River sampling program included 86 sites, sampled from 1998 to 2014, covering lowland stretches and headwater streams. The Guaíba sampling program was conducted from February 2011 to March 2013 and comprised 59 independent samples. Six fish species using estuarine areas occur in the upper Patos basin, 250–500 km from the Patos Lagoon outlet to the Atlantic Ocean. Parapimelodus nigribarbis specimens ranged from 11.3 to 18.9 cm (median = 13.3 cm) in length, i.e., were adults (Sinos, n = 459; Guaíba, n = 149). The species was captured almost 500 km from the Patos outlet, as far as 180 km upstream in the Sinos main channel. In Guaíba Lake, the species was captured mainly in autumn, although it was more abundant in winter and spring in the Sinos River. Lycengraulis grossidens was captured in the Sinos Basin, restricted to the lower stretches in spring and summer months (n = 7). In Guaíba Lake (n = 134) the species occurred throughout the lake and year-round, and was ten times more abundant in spring. Most specimens were adult (8.2–26.9 cm, median = 20.0 cm). Most Micropogonias furnieri individuals (n = 63) were juveniles (10.7–33.4 cm, median = 14.2 cm). The species was not captured in the Sinos Basin. In Guaíba Lake M. furnieri occurred predominantly in the southernmost part (downstream) and was more abundant (>10×) in winter. Genidens genidens (n = 27) was captured only in summer in the southern part of Guaíba Lake (closest to the outlet). Most individuals were adults (24.5–34.0 cm, median = 27.8 cm). Genidens barbus (n = 7) was restricted to spring and summer months and was captured only in southern (near-outlet) parts of Guaíba Lake, comprising mainly large juveniles and adults (31.5–68.0 cm, median = 37.9). Mugil liza (n = 13) appeared in spring in relatively low abundances but was widespread throughout Guaíba Lake during the summer. The species was not captured in the Sinos sampling program. The size profile comprised specimens nearing maturity (34.3–45.5 cm, median = 38.9 cm). Finally, we suggest possible biological cycles for these species that combine these new distribution data with published information

    Temporal variability determines phytoplankton structure over spatial organization in a large, shallow, heterogeneous, subtropical lake

    Get PDF
    Spatial heterogeneity is associated with the temporal variability of the habitat and may affect the structural patterns of biological communities. This study evaluated the influence of spatial and temporal heterogeneity on the phytoplankton structure in a large shallow subtropical lake, Lake Mangueira in southern Brazil (Zmax = 6 m; length = 90 km; width = 3–10 km). The lake is continuous warm polymictic, oligo-mesotrophic, under the direct influence of an adjacent wetland on the north, and has extensive aquatic macrophyte beds. Samples for abiotic and biological analyses were taken quarterly for 2 years at 19 points at the water subsurface, comprising the pelagic and littoral zones and the southern, central, and northern areas of the lake. The phytoplankton structure was analyzed with measurements of chlorophyll a, biomass, richness, diversity, and descriptor species. Of the 117 phytoplankton species identified, Cyanobacteria (e.g., Chroococcus limneticus, Aphanocapsa conferta, Aphanothece smithii, and Planktolyngbya contorta) was the major group in all areas and both zones of the lake. Total biomass levels were highest in the northern area, whereas the richness and the descriptor species showed no clear spatial differences. A redundancy analysis (RDA) indicated strong temporal organization of the species according to the abiotic conditions, indicating that the high level of temporal variability due to local hydrodynamics was the main factor structuring the phytoplankton community in Lake Mangueira during the study period

    Localization and Characterization of STRO-1+ Cells in the Deer Pedicle and Regenerating Antler

    Get PDF
    The annual regeneration of deer antlers is a unique developmental event in mammals, which as a rule possess only a very limited capacity to regenerate lost appendages. Studying antler regeneration can therefore provide a deeper insight into the mechanisms that prevent limb regeneration in humans and other mammals, and, with regard to medical treatments, may possibly even show ways how to overcome these limitations. Traditionally, antler regeneration has been characterized as a process involving the formation of a blastema from de-differentiated cells. More recently it has, however, been hypothesized that antler regeneration is a stem cell-based process. Thus far, direct evidence for the presence of stem cells in primary or regenerating antlers was lacking. Here we demonstrate the presence of cells positive for the mesenchymal stem cell marker STRO-1 in the chondrogenic growth zone and the perivascular tissue of the cartilaginous zone in primary and regenerating antlers as well as in the pedicle of fallow deer (Dama dama). In addition, cells positive for the stem cell/progenitor cell markers STRO-1, CD133 and CD271 (LNGFR) were isolated from the growth zones of regenerating fallow deer antlers as well as the pedicle periosteum and cultivated for extended periods of time. We found evidence that STRO-1+ cells isolated from the different locations are able to differentiate in vitro along the osteogenic and adipogenic lineages. Our results support the view that the annual process of antler regeneration might depend on the periodic activation of mesenchymal progenitor cells located in the pedicle periosteum. The findings of the present study indicate that not only limited tissue regeneration, but also extensive appendage regeneration in a postnatal mammal can occur as a stem cell-based process

    The German National Registry of Primary Immunodeficiencies (2012-2017)

    Get PDF
    Introduction: The German PID-NET registry was founded in 2009, serving as the first national registry of patients with primary immunodeficiencies (PID) in Germany. It is part of the European Society for Immunodeficiencies (ESID) registry. The primary purpose of the registry is to gather data on the epidemiology, diagnostic delay, diagnosis, and treatment of PIDs. Methods: Clinical and laboratory data was collected from 2,453 patients from 36 German PID centres in an online registry. Data was analysed with the software Stata® and Excel. Results: The minimum prevalence of PID in Germany is 2.72 per 100,000 inhabitants. Among patients aged 1–25, there was a clear predominance of males. The median age of living patients ranged between 7 and 40 years, depending on the respective PID. Predominantly antibody disorders were the most prevalent group with 57% of all 2,453 PID patients (including 728 CVID patients). A gene defect was identified in 36% of patients. Familial cases were observed in 21% of patients. The age of onset for presenting symptoms ranged from birth to late adulthood (range 0–88 years). Presenting symptoms comprised infections (74%) and immune dysregulation (22%). Ninety-three patients were diagnosed without prior clinical symptoms. Regarding the general and clinical diagnostic delay, no PID had undergone a slight decrease within the last decade. However, both, SCID and hyper IgE- syndrome showed a substantial improvement in shortening the time between onset of symptoms and genetic diagnosis. Regarding treatment, 49% of all patients received immunoglobulin G (IgG) substitution (70%—subcutaneous; 29%—intravenous; 1%—unknown). Three-hundred patients underwent at least one hematopoietic stem cell transplantation (HSCT). Five patients had gene therapy. Conclusion: The German PID-NET registry is a precious tool for physicians, researchers, the pharmaceutical industry, politicians, and ultimately the patients, for whom the outcomes will eventually lead to a more timely diagnosis and better treatment
    corecore