152 research outputs found
Evolução da urbanização em Belo Horizonte (1918-2000) e relações espaciais com os indicadores sóciodemográficos
Este artigo descreve os resultados da análise da correlação espacial entre a evolução da mancha de urbanização em Belo Horizonte e os Ăndices sĂłcio-demográficos. O objetivo principal Ă© identificar em qual fase histĂłrica da evolução da cidade atual localização dos moradores está associada, e correlacioná-la com Ăndices que diferenciam a estrutura etária e a renda dos habitantes. Os dados sociodemográficos foram extraĂdos do Censo demográfico (2000), sendo mapeados em nĂvel de setores censitários. As informações para expansĂŁo urbana foram extraĂdas de fotografias aĂ©reas realizadas em cinco momentos anteriores ao Censo 2000. Essas informações foram interpretadas manualmente pela Secretaria de Planejamento Urbano da Prefeitura de Belo Horizonte atravĂ©s de um SIG, gerando um mapa com a evolução urbana. A Análise de Componentes Principais (ACP) foi utilizada na formulação dos Ăndices de estrutura etária e renda. Foi utilizada a correlação de Pearson na interpretação os Ăndices extraĂdos da ACP e as fases de crescimento urbano de Belo Horizonte. Os resultados mostram que as áreas mais antigas possuem uma população mais idosa. TambĂ©m foi detectado que a renda nĂŁo tem correlação com a evolução do crescimento urbano. Estes resultados mostram que no geral, os moradores envelhecem com seus domicĂlios, e desta maneira, a valorização das áreas mais consolidadas nĂŁo necessariamente indica a presença de uma população de maior rend
Defining quantitative stream disturbance gradients and the additive role of habitat variation to explain macroinvertebrate taxa richness
Most studies dealing with the use of ecological indicators and other applied ecological research rely on some definition or concept of what constitutes least-, intermediate- and most-disturbed condition. Currently, most rigorous methodologies designed to define those conditions are suited to large spatial extents (nations, ecoregions) and many sites (hundreds to thousands). The objective of this study was to describe a methodology to quantitatively define a disturbance gradient for 40 sites in each of two small southeastern Brazil river basins. The assessment of anthropogenic disturbance experienced by each site was based solely on measurements strictly related to the intensity and extent of anthropogenic pressures. We calculated two indices: one concerned site-scale pressures and the other catchment-scale pressures. We combined those two indices into a single integrated disturbance index (IDI) because disturbances operating at both scales affect stream biota. The local- and catchment-scale disturbance indices were weakly correlated in the two basins (r = 0.21 and 0.35) and both significantly (p \u3c 0.05) reduced site EPT (insect orders Ephemeroptera, Plecoptera, Trichoptera) richness. The IDI also performed well in explaining EPT richness in the basin that presented the stronger disturbance gradient (R2 = 0.39, p \u3c 0.001). Natural habitat variability was assessed as a second source of variation in EPT richness. Stream size and microhabitats were the key habitat characteristics not related to disturbances that enhanced the explanation of EPT richness over that attributed to the IDI. In both basins the IDI plus habitat metrics together explained around 50% of EPT richness variation. In the basin with the weaker disturbance gradient, natural habitat explained more variation in EPT richness than did the IDI, a result that has implications for biomonitoring studies. We conclude that quantitatively defined disturbance gradients offer a reliable and comprehensive characterization of anthropogenic pressure that integrates data from different spatial scales
Knockout of insulin-degrading enzyme leads to mice testicular morphological changes and impaired sperm quality
Insulin-degrading enzyme (IDE) is a zinc metalloprotease responsible for degrading and inactivating several bioactive peptides, including insulin. Individuals without this enzyme or with a loss-of-function mutation in the gene that codifies it, present hyperinsulinemia. In addition, impairment of IDE-mediated insulin clearance is associated with the development of metabolic diseases, namely prediabetes. Although insulin regulates male fertility, the role of IDE on male reproductive function remains unknown. We proposed to study the influence of IDE in the reproductive potential of males. As insulin mediates key events for the normal occurrence of spermatogenesis, we hypothesized that IDE functioning might be linked with sperm quality. We used C57BL/6N mice that were divided in three groups according to its genotype: wild type (WT), heterozygous and knockout (KO) male mice for Ide. Spermatozoa were collected from the cauda of epididymis and sperm parameters were evaluated. Testicular tissue morphology was assessed through hematoxylin and eosin stain. Mitochondrial complex protein levels and lipid peroxidation were also evaluated in the testicular tissue. Our results show that KO mice present a 50% decrease in testes weight compared to WT mice as well as a decrease in seminiferous tubules diameter. Moreover, KO mice present impaired sperm quality, namely a decrease in both sperm viability and morphology. These results provide evidence that IDE plays an important role in determining the reproductive potential of males.publishe
Anthropogenic disturbances alter the relationships between environmental heterogeneity and biodiversity of stream insects
Highlights
• EH plays a more important role in biodiversity when anthropogenic disturbance is high.
• Within a stream site, EH does not affect beta diversity of aquatic insects.
• Model selection approach pinpointed the most ecologically meaningful EH metrics.
• Managing EH requires knowledge of how disturbances drive biological indicators.The effects of anthropogenic disturbance on multiple facets of biodiversity are poorly understood. In this study, we worked with the hypothesis that anthropogenic disturbances affect the relationship between environmental heterogeneity (EH) and biodiversity. We used a model selection approach to test three predictions. P1: The greater the level of anthropogenic disturbance, the weaker will be the relationship between EH and both taxonomic and functional alpha diversities. P2: The sign and strength of correlations between EH metrics and both taxonomic and functional alpha diversities will depend on the level of anthropogenic disturbance. P3: Taxonomic and functional beta diversities will not respond to the EH gradient. We sampled 76 stream sites in the Brazilian Neotropical savanna and collected insect of the orders Ephemeroptera, Plecoptera and Trichoptera to measure taxonomic and functional alpha and beta diversities. For P1, we did not find a trend of decreasing strength of this relationship with increasing disturbance. Results confirmed P2. Spatial flow diversity was positively correlated to taxonomic and functional alpha diversities in least-disturbed sites. Bankfull height variation was negatively correlated to taxonomic and functional alpha diversities in moderately-disturbed sites. Thalweg depth variation was positively correlated to taxonomic and functional alpha diversities in most-disturbed sites. Results partially confirmed P3 because taxonomic and functional beta diversities correlated with EH metrics in most-disturbed sites. We conclude that the biodiversity-EH relationship is not the same at all levels of anthropogenic disturbance, a finding that has implications for biomonitoring and ecosystem management
Prosthetic rehabilitation of an edentulous cleft palate using a denture with a palatal obturator: a clinical report
A cleft palate is a genetic disorder that occurs when an oro-nasal communication is present between the palate and
the base of the nose. During pregnancy, the maxillary is not completely merged, and the defect is only seen at birth.
Possible causes are hormonal imbalances, nutritional deficiencies, infections, radiation during pregnancy, alcohol
or cigarette consumption, the ingestion of other teratogenic substances by the mother, and heredity. The resulting
defect requires corrective surgery. In the case of a cleft palate, surgery is postponed until after the first year of life to
avoid disturbing the normal development of speech and the risk of aspiration of food, which causes infections such
as otitis and pneumonia. Ear infections can harm the development of speech in cases where surgery is not possible
or the defect has reappeared. This article describes the prosthetic rehabilitation of a edentulous patient: a woman of
53 years old with a cleft palate who was treated surgically. In a clinical examination, a residual palatal defect was
identified. The prosthetic rehabilitation involved the emplacement of a complete adapted prosthesis, using a palatal
obturator, with a view to sealing the defect and allowing the patient to acquire better speech quality, and improve
her nutrition and well-being
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Is the diet of a typical shredder related to the physical habitat of headwater streams in the Brazilian Cerrado?
Macroinvertebrates are important for processing leaf detritus in temperate streams, but studies about their role in tropical streams often present conflicting results. Via digestive tract analyses, we assessed the diets of Phylloicus sp. larvae (Trichoptera: Calamoceratidae), collected from streams of two southeastern Brazil river basins (Araguari, Sao Francisco). We classified gut contents as coarse particulate organic matter (CPOM), fine particulate organic matter (FPOM), algae, animal tissue, vascular plant tissue and mineral material. We hypothesized that the diets of Phylloicus larvae would be related to the physical habitat of the streams (e.g., riparian vegetation, organic matter availability and morphological characteristics), larval size and river basin. Although FPOM content predominated in both basins, we found greater CPOM content in Phylloicus larvae of Upper Sao Francisco sites, and this food item was related to greater riparian vegetation canopy density. The FPOM content was greater in larvae of Upper Araguari sites, and this food item was correlated with greater instream brush cover. Algae, animal tissue, vascular plant tissue and mineral material were very rare in the digestive tracts, and therefore could not be explained. These results indicate the importance of riparian vegetation structure in modulating feeding habitats of macroinvertebrates. We conclude that the Phylloicus larvae had more flexibility in what they eat than we might expect based on their traditional classification as shredders. Therefore, trusting in published classifications, ignoring regional or local differences, may be inaccurate. Instead, regional studies of feeding habits are needed for accurate classifications of invertebrate taxa into trophic guilds
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Importance of environmental factors for the richness and distribution of benthic macroinvertebrates in tropical headwater streams
An understanding of the interactions among local environmental factors (e.g., physical habitat and water quality) and aquatic assemblages is essential to conserve biodiversity in tropical and subtropical headwater streams. We evaluated the relative importance of multiple physical and chemical habitat variables that influence the richness of Ephemeroptera, Plecoptera, and Trichoptera (EPT) assemblages in wadeable Brazilian Cerrado (savanna) streams. We sampled macroinvertebrate assemblages and quantified physical and chemical habitat in 79 randomly selected sites in 2 Cerrado basins in southeastern Brazil. The environmental variables selected by multiple regression models (MLRs) via corrected Akaike Information Criteria (AICc) contributed significantly to variation in EPT taxon richness. The variance explained by physical-habitat variables was slightly greater in the Upper São Francisco Basin (adjusted R² = 0.53) than in the Upper Araguari Basin (adjusted R² = 0.46), and both were greater than the variance explained by a combined basin model (adjusted R² = 0.39). Physical-habitat variables were more important than water-quality variables in structuring EPT genera in streams with catchments dominated by agriculture or pasture land uses. Regional models can be improved by incorporating basin-specific information to refine biological assessments and to provide better understanding of the interactions that maintain biodiversity in stream networks.Keywords: Hydromorphology, Physical habitat, Cerrado headwater streams, EPT assemblages, Macroinvertebrate bioindicators, Stream conservatio
Molecular Characterization of the Schistosoma mansoni Zinc Finger Protein SmZF1 as a Transcription Factor
Schistosomes are parasites that exhibit a complex life cycle during which they progress through many morphological and physiological transformations. These transformations are likely accompanied by alterations in gene expression, making genetic regulation important for parasite development. Here we describe a Schistosoma mansoni protein (SmZF1) that may act as a parasite transcription factor. These factors are key proteins for gene regulation. We have previously demonstrated that SmZF1 is able to bind DNA and that its mRNA is present at different stages during the parasite life cycle. In this study we aimed to define if this protein can function as a transcription factor in S. mansoni. SmZF1 was detected in the nucleus of adult male worms, cercariae and schistosomula cells. It was not, however, observed in female cells, suggesting it to be gender specific. We used mammalian cells expressing recombinant SmZF1 to analyze if SmZF1 protein is able to activate/repress gene transcription and demonstrated that it increased the expression of a reporter gene by two-fold. The results obtained confirm SmZF1 as a S. mansoni transcription factor
Data on metabolic profile of insulin-degrading enzyme knockout mice
Insulin-degrading enzyme (IDE) degrades and inactivates bioactive peptides such as insulin. As insulin is a master regulator of glucose homeostasis, lack of IDE is expected to have a profound impact on both insulin and glucose levels. This article shares data on glucose and insulin homeostasis of control, heterozygous and knockout mice for Ide after 18 weeks of a normal chow diet. This data article is related to a research article entitled “Knockout of insulin-degrading enzyme leads to mice testicular morphological changes and impaired sperm quality” (Meneses et al., 2019).publishersversionpublishe
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