3D alveolar in vitro model based on epithelialized biomimetically curved culture membranes.

There is increasing evidence that surface curvature at a near-cell-scale influences cell behaviour. Epithelial or endothelial cells lining small acinar or tubular body lumens, as those of the alveoli or blood vessels, experience such highly curved surfaces. In contrast, the most commonly used culture substrates for in vitro modelling of these human tissue barriers, ion track-etched membranes, offer only flat surfaces. Here, we propose a more realistic culture environment for alveolar cells based on biomimetically curved track-etched membranes, preserving the mainly spherical geometry of the cells' native microenvironment. The curved membranes were created by a combination of three-dimensional (3D) micro film (thermo)forming and ion track technology. We could successfully demonstrate the formation, the growth and a first characterization of confluent layers of lung epithelial cell lines and primary alveolar epithelial cells on membranes shaped into an array of hemispherical microwells. Besides their application in submerged culture, we could also demonstrate the compatibility of the bioinspired membranes for air-exposed culture. We observed a distinct cellular response to membrane curvature. Cells (or cell layers) on the curved membranes reveal significant differences compared to cells on flat membranes concerning membrane epithelialization, areal cell density of the formed epithelial layers, their cross-sectional morphology, and proliferation and apoptosis rates, and the same tight barrier function as on the flat membranes. The presented 3D membrane technology might pave the way for more predictive barrier in vitro models in future.

Impact of cigarette smoke and aerobic physical training on histological and molecular markers of prostate health in rats.

Recent evidence suggests that aerobic physical training may attenuate the deleterious effects of cancer risk factors, including smoking. We investigated the effects of cigarette smoke inhalation and aerobic physical training on the expression of steroid receptors and inflammatory and apoptotic proteins in the prostate. Forty male Wistar rats were distributed in four groups: control (CO), exercise (EXE), cigarette smoke exposure (CS), and cigarette smoke exposure with exercise (CS+EXE). For eight weeks, animals were repeatedly exposed to cigarette smoke for 30 min or performed aerobic physical training either with or without the cigarette smoke inhalation protocol. Following these experiments, we analyzed prostate epithelial morphology and prostatic expression of androgen (AR) and glucocorticoid receptors (GR), insulin-like growth factor (IGF-1), B-cell lymphoma-2 (BCL-2), BCL-2-associated X protein (BAX), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and nuclear factor-kappa B (NF-κB) via immunohistochemistry. Cigarette smoke exposure stimulated the expression of AR, IGF-1, BCL-2, and NF-κB while downregulating BAX, IL-6, and TNF-α labeling in the prostate. In contrast, aerobic physical training attenuated cigarette smoke-induced changes in AR, GR, IGF-1, BCL-2, IL-6, TNF-α, and NF-κB. This suggests that cigarette smoke stimulates inflammation and reduces apoptosis, culminating in increased prostatic epithelial and extracellular matrices, whereas physical training promoted beneficial effects towards maintaining normal prostate morphology and protein levels.

Impact of cigarette smoke and aerobic physical training on histological and molecular markers of prostate health in rats

Recent evidence suggests that aerobic physical training may attenuate the deleterious effects of cancer risk factors, including smoking. We investigated the effects of cigarette smoke inhalation and aerobic physical training on the expression of steroid receptors and inflammatory and apoptotic proteins in the prostate. Forty male Wistar rats were distributed in four groups: control (CO), exercise (EXE), cigarette smoke exposure (CS), and cigarette smoke exposure with exercise (CS+EXE). For eight weeks, animals were repeatedly exposed to cigarette smoke for 30 min or performed aerobic physical training either with or without the cigarette smoke inhalation protocol. Following these experiments, we analyzed prostate epithelial morphology and prostatic expression of androgen (AR) and glucocorticoid receptors (GR), insulin-like growth factor (IGF-1), B-cell lymphoma-2 (BCL-2), BCL-2-associated X protein (BAX), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and nuclear factor-kappa B (NF-κB) via immunohistochemistry. Cigarette smoke exposure stimulated the expression of AR, IGF-1, BCL-2, and NF-κB while downregulating BAX, IL-6, and TNF-α labeling in the prostate. In contrast, aerobic physical training attenuated cigarette smoke-induced changes in AR, GR, IGF-1, BCL-2, IL-6, TNF-α, and NF-κB. This suggests that cigarette smoke stimulates inflammation and reduces apoptosis, culminating in increased prostatic epithelial and extracellular matrices, whereas physical training promoted beneficial effects towards maintaining normal prostate morphology and protein levels.

Does a Self-etching Ceramic Primer Improve Bonding to Lithium Disilicate Ceramics? Bond Strengths and FESEM Analyses.

OBJECTIVE:: To compare the effect of hydrofluoric acid (HF) vs self-etching ceramic primer on resin cement microshear bond strength (µSBS) and ultramorphology of lithium disilicate (LD) ceramic. METHODS AND MATERIALS:: LD (IPS e.max CAD, Ivoclar Vivadent) blocks (14×4×2 mm3) were polished to 1200 grit and assigned to nine groups (n=5): CON: control, no LD surface treatment; IVO: 5.0% HF (IPS Ceramic Etching Gel, Ivoclar Vivadent); VIT: 5.0% HF (Vita Ceramics Etch, VITA Zahnfabrik); FGM: 5.0% HF (Condac Porcelana, FGM); ULT: 9.0% HF (Porcelain Etch, Ultradent); PRM: 9.6% HF (Premier Porcelain Etch Gel, Premier); BIS: 9.5% HF (Porcelain Etchant, Bisco Inc); DEN: 10.0% HF (Condicionador de Porcelanas, Dentsply Brazil); and MEP: self-etching ceramic primer (Monobond Etch & Prime, Ivoclar Vivadent). For all HF groups and control, an MDP-containing silane solution (MB+, Monobond Plus, Ivoclar Vivadent) was applied on rinsing the HF gel and air drying. Three transparent matrices for each specimen were filled with light-cured resin cement (Variolink Veneer, Ivoclar Vivadent). After storage in water for 48 hours at 37°C, specimens were tested in shear mode to measure µSBS. Mode of failure was analyzed at 50×. Statistical analysis included one-way analysis of variance and the Duncan post hoc test (α=0.05). Thirty-six additional LD specimens were assigned to the same experimental groups (n=4) and observed under a field-emission scanning electron microscope (FESEM) at magnifications ranging from 10,000× to 100,000×. RESULTS:: IVO resulted in statistically higher mean µSBS than all the other groups. MEP resulted in statistically lower µSBS than all HF groups. The failure mode for MEP was predominantly adhesive. The most frequent failure mode for the HF groups was mixed. CON resulted in 100% pretesting failures. For FESEM, no retentive pattern was observed for CON specimens. MEP resulted in the least pronounced etching pattern, few areas around crystals exhibited a slight increase in retention pattern compared to the control group. All HF gels created microporosities on the LD surface with distinct etching patterns. VIT and DEN resulted in an LD ultramorphology that suggested overetching. CONCLUSIONS:: HF etching followed by a silane solution resulted in higher bond strengths than a self-etching ceramic primer. Some HF gels may cause overetching of the LD intaglio surface.

Frequency of Aedes sp. Linnaeus (Diptera: Culicidae) and Associated Entomofauna in Bromeliads from a Forest Patch within a densely Urbanized Area.

Little is known about the relationship between the presence of Aedes, abiotic factors and the entomofauna existing in phytotelmatas. The aim of this study was to identify biotic and abiotic factors associated with the presence of Aedes in bromeliads sites located in a forest fragment in Rio de Janeiro, Brazil. In the study area, eight bromeliads from the Aechmea genus were chosen and kept in landscape form. Physical and chemical variables were measured. Collected aquatic insects were identified according to the literature. A total of 3102 immature insects were collected. The presence of Aedes aegypti (Linnaeus) (2.29%) was rare. Few specimens were found concentrated in urban-adjacent areas during summer. On the other hand, Aedes albopictus (Skuse) (17.57%) was found throughout the year in 0%-80% of the sites, averaging 1.0 mosq/bromelia. Aedes albopictus was found predominantly in central sites of the forest fragment. The Canonical Correspondence Analysis indicates that most taxa had a moderate association with temperature, dissolved oxygen, and pH. The abiotic variables, such as temperature and dissolved oxygen, affect the distribution of the genus Aedes vectors, while most of the other variables did not.

Nanoscale mapping of carbon oxidation in pyrogenic black carbon from ancient Amazonian anthrosols.

Understanding soil organic matter is necessary for the development of soil amendments, which are important for sustaining agriculture in humid tropical climates. Ancient Amazonian anthrosols are uniquely high in black recalcitrant carbon, making them extremely fertile. In this study, we use high-resolution electron microscopy and spectroscopy to resolve the oxidation process of carbon in the nanoscale crystallites within the black carbon grains of this special soil. Most alkali and acid chemical extraction methods are known to cause chemical modifications in soil organic matter and to give poor or no information about the real spatial structure of soil aggregates. However, here we show that carbon-oxygen functional groups such as phenol, carbonyl, and carboxyl dominate over different spatial regions, with areas varying from over tens to hundreds of nm(2). The chemical maps show that in the nanoscale grain, the surface has a tendency to be less aromatic than the grain core, where higher oxidative-degradation levels are indicated by the presence of carbonyl and carboxyl groups. A deep understanding of these structures could allow artificial reproduction of these natural events.

Development of a benthic multimetric index for the Serra da Bocaina bioregion in Southeast Brazil.

Brazil faces a challenge to develop biomonitoring tools to be used in water quality assessment programs, but few multimetric indices were developed so far. This study is part of an effort to test and implement programs using benthic macroinvertebrates as bioindicators in Rio de Janeiro State. Our aim was first to test the Multimetric Index for Serra dos Órgãos (SOMI) for a different area--Serra da Bocaina (SB)--in the same ecoregion. We sampled 27 streams of different sizes and altitudes in the SB region. Despite the environmental similarities, results indicated biological differences between reference sites of the two regions. Considering these differences, we decided to develop an index specific for the SB region, the Serra da Bocaina Multimetric Index (MISB). We tested twenty-two metrics for sensitivity to impairment and redundancy, and six metrics were considered valid to integrate the MISB: Family Richness, Trichoptera Richness, % Coleoptera, % Diptera, IBE-IOC index, EPT / Chironomidae ratio. A test of the MISB in eleven sites indicated it was more related to land-use and water physico-chemical parameters than with altitude or stream width, being a useful tool for the monitoring and assessment of streams in the bioregion.

The influence of connectivity in forest patches, and riparian vegetation width on stream macroinvertebrate fauna.

We assessed two dimensions of stream connectivity: longitudinal (between forest patches along the stream) and lateral (riparian vegetation), using macroinvertebrate assemblages as bioindicators. Sites representing different land-uses were sampled in a lowland basin that holds a mosaic of protected areas. Land-use analysis, forest successional stages and riparian zone widths were calculated by the GIS analysis. Macroinvertebrate fauna was strongly affected by land-use. We observed a continuous decrease in the number of sensitive species, %Shredders and IBE-IOC biotic index from the upstream protected area to highly deforested sites, increasing again where the stream crosses a Biological Reserve. When analysing buffer strips, we found aquatic fauna responding to land-use alterations beyond the 30 m riparian corridor (60 m and 100 m wide). We discussed the longitudinal connectivity between forest patches and the riparian vegetation buffer strips necessary to hold high macroinvertebrate diversity. We recommend actions for the increase/maintenance of biodiversity in this and other lowland basins.

Influence of agricultural land-use and pesticides on benthic macroinvertebrate assemblages in an agricultural river basin in southeast Brazil.

Land-use alterations and pesticide run-offs are among the main causes for impairment in agricultural areas. We evaluated the influence of different land-uses (forest, pasture and intensive agriculture) on the water quality and on benthic macroinvertebrate assemblages on three occasions: in the dry season, wet season and at the end of the wet season. Macroinvertebrates responded to this gradient of impairment: agricultural sites had significantly lower richness numbers than forested and pasture sites, and all major invertebrate groups were significantly affected. Most taxa found in forested sites were found in pasture sites, but often with lower densities. In this case, the loss of habitats due to sedimentation and the lower complexity of substrates seem to be the disruptive force for the macroinvertebrate fauna.

Decolorization of different textile dyes by Penicillium simplicissimum and toxicity evaluation after fungal treatment

The objective of this study was to investigate the capacity of decolorization and detoxification of the textile dyes Reactive Red 198 (RR198), Reactive Blue 214 (RB214), Reactive Blue 21 (RB21) and the mixture of the three dyes (MXD) by Penicillium simplicissimum INCQS 40211. The dye RB21, a phthalocyanine, was totally decolorized in 2 days, and the others, the monoazo RR198, the diazo RB214 and MXD were decolorized after 7 days by P. simplicissimum. Initially the dye decolorization involved dye adsorption by the biomass followed by degradation. The acute toxicity after fungal treatment was monitored with the microcrustacean Daphnia pulex and measured through Effective Concentration 50 percent (EC50). P. simplicissimum reduced efficiently the toxicity of RB21 from moderately acutely toxic to minor acutely toxic and it also reduced the toxicity of RB214 and MXD, which remained minor acutely toxic. Nevertheless, the fungus increased the toxicity of RR198 despite of the reduction of MXD toxicity, which included this dye. Thus, P. simplicissimum INCQS 40211 was efficient to decolorize different textile dyes and the mixture of them with a significant reduction of their toxicity. In addition this investigation also demonstrated the need of toxicological assays associated to decolorization experiments.

[Ultrasound in the diagnosis of fetal head engagement. A preliminary French prospective study]. / Diagnostic échographique d'engagement de la présentation foetale. A propos d'une série prospective préliminaire française.

OBJECTIVE: The subjectivity and inter- and intra-observer variability of transvaginal (TV) digital examination in the diagnosis of fetal head engagement set a real problem in the strategic choice of the mode of delivery. We conducted a preliminary study on the feasibility of using ultrasound in the diagnosis of fetal head engagement during labour. MATERIAL AND METHOD: From 3rd January to 20th February 2007, a prospective monocentered study was set up by comparing the fetal head position in the pelvic cavity obtained by TV digital examination with the ultrasound measurement of the perineum-fetal head distance. Sixty-five measurements were obtained from 45 patients (single pregnancies, cephalic presentations), during labour and/or at complete cervical dilatation, by a single operator. RESULTS: Whenever the perineum-fetal head distance was greater than 60 mm, the fetal head was not engaged in the pelvic cavity, with a specificity of 89% and a negative predictive value of 94.1%. However, if the distance is less or equal to 60 mm, the fetal head was engaged with a sensitivity of 97.8% and a positive predictive value of 95.6%. It was even possible to define the fetal head station in the cavity as the distances are now known: high cavity : 50 mm, mid cavity : 38 mm, low cavity : 20 mm. CONCLUSION: This technique based on a single distance measurement is not difficult and the reference point is easily localized. An abdominal probe is sufficient, making the diffusion of this method quite easy. With its excellent negative predictive value, transperineal ultrasound would allow obstetricians avoid difficult vaginal extractions, localize correctly the fetal position in the cavity and obtain the exact fetal head orientation, even in case of scalp blood humps. The feasibility and relevance of this technique must be confirmed by larger studies.

Decolorization of different textile dyes by Penicillium simplicissimum and toxicity evaluation after fungal treatment.

The objective of this study was to investigate the capacity of decolorization and detoxification of the textile dyes Reactive Red 198 (RR198), Reactive Blue 214 (RB214), Reactive Blue 21 (RB21) and the mixture of the three dyes (MXD) by Penicillium simplicissimum INCQS 40211. The dye RB21, a phthalocyanine, was totally decolorized in 2 days, and the others, the monoazo RR198, the diazo RB214 and MXD were decolorized after 7 days by P. simplicissimum. Initially the dye decolorization involved dye adsorption by the biomass followed by degradation. The acute toxicity after fungal treatment was monitored with the microcrustacean Daphnia pulex and measured through Effective Concentration 50% (EC50). P. simplicissimum reduced efficiently the toxicity of RB21 from moderately acutely toxic to minor acutely toxic and it also reduced the toxicity of RB214 and MXD, which remained minor acutely toxic. Nevertheless, the fungus increased the toxicity of RR198 despite of the reduction of MXD toxicity, which included this dye. Thus, P. simplicissimum INCQS 40211 was efficient to decolorize different textile dyes and the mixture of them with a significant reduction of their toxicity. In addition this investigation also demonstrated the need of toxicological assays associated to decolorization experiments.

[Assisted vaginal delivery using the vacuum extractor in frank breech presentation]. / Extraction par ventouse obstétricale sur présentation du siège décomplété

OBJECTIVES: When all the breech conditions for the acceptance of a vaginal breech birth are present, we occasionally practise a total breech extraction for non frank breech presentations. Similarly, for frank breech presentations, instead of using the fetal leg as tractor, we sometimes apply the vacuum extractor on the breech presentation in order to perform the first step of the total breech extraction. The vacuum extractor is not traumatic for the fetus and enable a quick extraction. This study was conducted to describe the technique we use in our ward. PATIENTS AND METHODS: A retrospective study including every singleton delivery with a breech presentation and a tried and assisted vaginal delivery using the vacuum extractor in our maternity ward from 1994 to 2004. A descriptive analysis of maternal, fetal and obstetrical elements has been carried out. RESULTS: Twenty-eight deliveries were indexed. In each case, a vaginal delivery was performed. Neonatal outcomes were satisfactory with a five minutes Apgar score always higher than 7. In all 96.5% of the extractions were realized under pelvic level +2. The main indication of extraction (78.5%) was a second stage of labour which was too long. CONCLUSION: Obstetricians should know several techniques to accept and to manage breech deliveries. Indications for assisted vaginal delivery using the vacuum extractor in frank breech presentation are unusual, concerning delay in the second stage with an engaged foetus. This technique may avoid some cesarean sections. Nevertheless vaginal breech delivery try should be happening with great caution and with a strict patient's eligibility.

[Instrumental extractions using Thierry's spatulas: evaluation of the risk of perineal laceration according to occiput position in operative deliveries]. / Extraction instrumentale par spatules de Thierry: évaluation du risque périnéal en fonction du dégagement.

OBJECTIVE: Risk factors for severe perineal lacerations are nowadays well-known and they include operative vaginal deliveries and extractions in occiput posterior (OP) positions. The aim of this study was to assess whether OP position increases the risk for anal sphincter injury when compared with occiput anterior (OA) positions in operative deliveries using Thierry's spatulas. METHODS: Retrospective study of 163 extractions with Thierry's spatulas over a five-year period (January 2000 to December 2005) performed in a general hospital. Singleton cephalic pregnancies at term were studied and the incidence of severe perineal lacerations was noted in deliveries in OP and OA positions. RESULTS: In these 163 cases, the varieties of presentation obtained by vaginal examination were 129 in anterior and 34 in posterior positions. Eleven posterior positions rotated anteriorly on delivery and 23 remained in a posterior position. The OA group (n=140) and the OP group (n=23) were constituted. Anal sphincter injury occurred significantly more often in the OP group compared with the OA group (17.4% versus 2.9%, p=0.014) with an odds ratio of 7.1 (95% CI 1.6-31). Only one fourth-degree laceration was noted. Within the OP group, the incidence of vaginal lacerations was increased compared to the OA group, but without any significant difference (43.5% versus 27.9%, p=0.20). In a logistic regression model, the OP position was 6.4 times (95% CI 1.3-31.5) more likely to be associated with anal sphincter injury than OA position. The incidence of OP position was 14.1% within the whole population studied and Thierry's spatulas permit anterior rotations of occipito posterior presentation in only 32.4% of cases. CONCLUSION: The efficiency of Thierry's spatulas is proven. As with forceps and vacuum extractors, extraction with Thierry's spatulas is a risk factor for perineal laceration compared to a spontaneous delivery. In deliveries with spatulas, OP head positions further increase this perineal risk against OA positions. OP positions before fetal extractions do not seem to be an ideal situation for using spatulas, even if an anterior rotation is achieved in one-third of cases.

Sewage input effects on the macroinvertebrate community associated to Typha domingensis Pers in a coastal lagoon in southeastern Brazil.

This study was carried out at Imboassica Lagoon, located in an urban zone in the municipality of Macaé, Rio de Janeiro state, Brazil. This lagoon has been subject to anthropogenic impacts due to the increasing city population, such as the input of sewage. Areas of variable degree of anthropogenic influence in the lagoon were compared regarding the structure of the macroinvertebrate community associated to Typha domingensis leaves. For sampling, we used 35 x 20 cm net plastic bags, with 6.8 mm mesh containing T. domingensis leaves for colonization. Two different sampling stations were selected: station A, under direct input of sewage; and station B with lesser sewage influence. The bags were removed after 20, 40 and 75 days of colonization. For each sample the Shannon-Wiever Diversity, Pielou Evenness, Jaccard Similarity Indices, Correspondence Analysis and taxonomic richness were calculated. A total of 31,874 individuals were sampled, belonging to 34 taxa. The main taxonomical groups were: Oligochaeta (41%), Chironomidae (40%), Ancylidae (4.6%), Polymitarcyidae (4%) and Thiaridae (3%). At station A, the taxonomic richness, the Evenness and Diversity values were lower than in station B. On the other hand, the total density was three times higher in station A than in B. It was already possible to discriminate the community structure of each sampling station in the first sampling. Trichoptera and Ephemeroptera were the main exclusive groups of station B and are considered good water quality indicators due to their high sensibility to contamination. The major contribution to discriminate between the macroinvertebrate communities of the two sample stations came from Chironomidae, Oligochaeta and Ephemeroptera.

[Prevention of shoulder dystocia by an ultrasound selection at the beginning of labour of foetuses with large abdominal circumference]. / Prévention de la dystocie des épaules par la sélection échographique en début de travail des foetus à fort périmètre abdominal.

OBJECTIVE: Prevent shoulder dystocia occuring with macrosomic foetuses, by an ultrasound screening, at the beginning of labour, made by a member of obstetrics staff. MATERIAL AND METHOD: A prospective study in the maternity hospital, la Mère et l'Enfant of University Teaching Hospital, Besançon, about 170 patients. We have measured only one parameter: the foetal abdominal circumference (AC). RESULTS: An AC>or=350 mm had a sensitivity of 100% to detect newborns of birth weight>or=4250 g. CONCLUSION: An AC>or=350 mm measured during labour by a member of obstetrics staff allow to alert and to make the staff sensitive to a risk of macrosomia and shoulder dystocia.

Sewage input effects on the macroinvertebrate community associated to Typha domingensis Pers in a coastal lagoon in southeastern Brazil

This study was carried out at Imboassica Lagoon, located in an urban zone in the municipality of Macaé, Rio de Janeiro state, Brazil. This lagoon has been subject to anthropogenic impacts due to the increasing city population, such as the input of sewage. Areas of variable degree of anthropogenic influence in the lagoon were compared regarding the structure of the macroinvertebrate community associated to Typha domingensis leaves. For sampling, we used 35 x 20 cm net plastic bags, with 6.8 mm mesh containing T. domingensis leaves for colonization. Two different sampling stations were selected: station A, under direct input of sewage; and station B with lesser sewage influence. The bags were removed after 20, 40 and 75 days of colonization. For each sample the Shannon-Wiever Diversity, Pielou Evenness, Jaccard Similarity Indices, Correspondence Analysis and taxonomic richness were calculated. A total of 31,874 individuals were sampled, belonging to 34 taxa. The main taxonomical groups were: Oligochaeta (41 percent), Chironomidae (40 percent), Ancylidae (4.6 percent), Polymitarcyidae (4 percent) and Thiaridae (3 percent). At station A, the taxonomic richness, the Evenness and Diversity values were lower than in station B. On the other hand, the total density was three times higher in station A than in B. It was already possible to discriminate the community structure of each sampling station in the first sampling. Trichoptera and Ephemeroptera were the main exclusive groups of station B and are considered good water quality indicators due to their high sensibility to contamination. The major contribution to discriminate between the macroinvertebrate communities of the two sample stations came from Chironomidae, Oligochaeta and Ephemeroptera.

O presente estudo foi realizado na Lagoa Imboassica, localizada no perímetro urbano da cidade de Macaé, RJ, Brasil. Esta lagoa vem sofrendo impactos antrópicos com o aumento da cidade, como o aporte de esgotos sem tratamento. Areas com diferentes graus de influência antrópica na lagoa foram comparadas quanto à estrutura da fauna de macroinvertebrados associada a folhas de Typha domingensis. A amostragem da fauna foi realizada por meio de cestos de tela plástica de 35 x 20 cm e malha de 6,8 mm, com folhas de T. domingensis para colonização. Dois pontos amostrais foram selecionados: ponto A, sujeito a aporte direto de esgotos; e ponto B, sob menor influência de esgotos. Os cestos foram retirados após 20, 40 e 75 dias de colonização. Foram aplicados em cada amostra os índices de diversidade de Shannon-Wiever, equitabilidade de Pielou e similaridade de Jaccard, riqueza taxonômica e Análise de Correspondência. Foram encontrados 31.874 indivíduos, distribuídos em 34 táxons. Os principais grupos foram: Oligochaeta (41 por cento); Chironomidae (40 por cento); Ancylidae (4,6 por cento); Polimitarcyidae (4 por cento); e Thyaridae (3 por cento). No ponto A, os valores de riqueza taxonômica, equitabilidade e diversidade foram inferiores aos do ponto B. Por outro lado, a densidade total foi três vezes maior no ponto A. A estrutura da comunidade foi diferente nos dois pontos amostrais para todos os testes utilizados, desde a primeira retirada. Trichoptera e Ephemeroptera foram os principais grupos exclusivos do ponto B, sendo considerados indicadores da qualidade da água devido à sua sensibilidade. Chironomidae, Oligochaeta e Ephemeroptera foram os principais grupos a contribuir com as diferenças nas comunidades de macroinvertebrados entre os pontos amostrais.

Spatial and temporal distribution of benthic macroinvertebrates in a Southeastern Brazilian river.

Benthic macroinvertebrate assemblages are structured according to physical and chemical parameters that define microhabitats, including food supply, shelter to escape predators, and other biological parameters that influence reproductive success. The aim of this study is to investigate spatial and temporal distribution of macroinvertebrate assemblages at the Macaé river basin, in Rio de Janeiro state, Southeastern Brazil. According to the "Habitat Assessment Field Data Sheet--High Gradient Streams" (Barbour et al., 1999), the five sampling sites are considered as a reference condition. Despite the differences in hydrological parameters (mean width, depth and discharge) among sites, the physicochemical parameters and functional feeding groups' general structure were similar, except for the less impacted area, which showed more shredders. According to the Detrended Correspondence Analysis based on substrates, there is a clear distinction between pool and riffle assemblages. In fact, the riffle litter substrate had higher taxa in terms of richness and abundance, but the pool litter substrate had the greatest number of exclusive taxa. A Cluster Analysis based on sampling sites data showed that temporal variation was the main factor in structuring macroinvertebrate assemblages in the studied habitats.

Spatial and temporal distribution of benthic macroinvertebrates in a Southeastern Brazilian river

A fauna de macroinvertebrados bentônicos é estruturada por fatores físicos e químicos que determinam os microhábitats, incluindo a disponibilidade de alimento, a existência de refúgios contra predadores e tempestades, o sucesso reprodutivo e outros parâmetros biológicos. O objetivo deste estudo foi investigar a distribuição espaço-temporal da comunidade de macroinvertebrados bentônicos na bacia do rio Macaé, Estado do Rio de Janeiro, Brasil. De acordo com o Habitat Assessment Field Data Sheet – High Gradient Streams (Barbour et al., 1999), os cinco locais coletados são considerados como referência para propósito de biomonitoramento. Apesar das diferenças em parâmetros hidrográficos (largura, profundidade e vazão médias), os parâmetros físico-químicos e a composição dos grupos de alimentação funcional foram similares entre os locais, com exceção da área mais preservada, onde a porcentagem de organismos cortadores foi maior. De acordo com a Análise de Correspondência, há uma clara distinção entre áreas de remanso e de correnteza. De fato, o substrato folhiço de correnteza apresentou a fauna mais rica e abundante, enquanto o substrato folhiço de fundo apresentou o maior número de táxons exclusivos. A Análise de Agrupamento considerando os dados dos locais de coleta indicou que a variação temporal foi o fator mais importante na estruturação das comunidades nos hábitats estudados.

Spatial and temporal distribution of benthic macroinvertebrates in a Southeastern Brazilian river

Benthic macroinvertebrate assemblages are structured according to physical and chemical parameters that define microhabitats, including food supply, shelter to escape predators, and other biological parameters that influence reproductive success. The aim of this study is to investigate spatial and temporal distribution of macroinvertebrate assemblages at the Macaé river basin, in Rio de Janeiro state, Southeastern Brazil. According to the "Habitat Assessment Field Data Sheet - High Gradient Streams" (Barbour et al., 1999), the five sampling sites are considered as a reference condition. Despite the differences in hydrological parameters (mean width, depth and discharge) among sites, the physicochemical parameters and functional feeding groups' general structure were similar, except for the less impacted area, which showed more shredders. According to the Detrended Correspondence Analysis based on substrates, there is a clear distinction between pool and riffle assemblages. In fact, the riffle litter substrate had higher taxa in terms of richness and abundance, but the pool litter substrate had the greatest number of exclusive taxa. A Cluster Analysis based on sampling sites data showed that temporal variation was the main factor in structuring macroinvertebrate assemblages in the studied habitats.

A fauna de macroinvertebrados bentônicos é estruturada por fatores físicos e químicos que determinam os microhábitats, incluindo a disponibilidade de alimento, a existência de refúgios contra predadores e tempestades, o sucesso reprodutivo e outros parâmetros biológicos. O objetivo deste estudo foi investigar a distribuição espaço-temporal da comunidade de macroinvertebrados bentônicos na bacia do rio Macaé, Estado do Rio de Janeiro, Brasil. De acordo com o Habitat Assessment Field Data Sheet - High Gradient Streams (Barbour et al., 1999), os cinco locais coletados são considerados como referência para propósito de biomonitoramento. Apesar das diferenças em parâmetros hidrográficos (largura, profundidade e vazão médias), os parâmetros físico-químicos e a composição dos grupos de alimentação funcional foram similares entre os locais, com exceção da área mais preservada, onde a porcentagem de organismos cortadores foi maior. De acordo com a Análise de Correspondência, há uma clara distinção entre áreas de remanso e de correnteza. De fato, o substrato folhiço de correnteza apresentou a fauna mais rica e abundante, enquanto o substrato folhiço de fundo apresentou o maior número de táxons exclusivos. A Análise de Agrupamento considerando os dados dos locais de coleta indicou que a variação temporal foi o fator mais importante na estruturação das comunidades nos hábitats estudados.