Diet and trophic structure of the fish fauna in a subtropical ecosystem: impoundment effects

This study examined the diet and trophic structure of the fish fauna, over temporal and spatial scales, as affected by the impoundment of the Iguaçu River in the region of Salto Caxias, Paraná State, Brazil. Sampling was conducted before (March 1997 - February 1998) and after the impoundment (March 1999 - February 2000), at four sampling sites. The stomach contents were analyzed by the volumetric method. The species could be organized in 10 trophic guilds: algivores, carcinophages, detritivores, herbivores, aquatic insectivores, terrestrial insectivores, invertivores, omnivores, piscivores, and planktivores; the first and last guilds were represented only in the post-impoundment period. Similarity patterns and feeding changes were summarized by a non-metric Multi-dimensional Scaling (nMDS) analysis and statistically tested by a Permutational multivariate analysis of variance (PERMANOVA). Most species showed feeding changes, except for the piscivores and detritivores. These changes were related to the temporal factor (impoundment phases), such as reduced intake of benthic organisms and allochthonous food, which were usually replaced by resources from the reservoir itself (algae, microcrustaceans, and fish), simplifying the food spectrum of the fish fauna. A different indicator of food resources (IndVal) corroborated these changes in the feeding of the species. The proportions of the trophic guilds evaluated based on the catch per unit of effort (CPUE) and tested by ANOSIM were significantly different before and after the impoundment. Herbivores and piscivores were the guilds that contributed (SIMPER) to these differences, especially the high increase in biomass of the piscivore guild after the impoundment. Variations in the abundance of trophic guilds were more directly related to changes in the feeding habits of the fish fauna than to increases in the number and biomass of the species that constitute these guilds.

Neste estudo foram avaliadas a dieta e a estrutura trófica da ictiofauna em escala temporal e espacial, sob efeito do represamento do rio Iguaçu, na região de Salto Caxias, Paraná, Brasil. Para tanto, foram realizadas amostragens nas fases pré (março/97 a fevereiro/98) e pós represamento (março/99 a fevereiro/00) em quatro pontos de coleta. Os conteúdos estomacais foram avaliados pelo método volumétrico. As espécies foram organizadas em 10 guildas tróficas: algívora, carcinófaga, detritívora, herbívora, insetívora aquática, insetívora terrestre, invertívora, omnívora, piscívora e planctívora, sendo a primeira e a última representadas apenas após o represamento. Os padrões de similaridade e alterações na dieta foram sintetizados através da ordenação multidimensional não paramétrica (nMDS) e estatisticamente testados pela análise de variância permutacional (PERMANOVA). Foram constatadas alterações na dieta da maioria das espécies, com exceção das piscívoras e detritívoras. Essas alterações foram relacionadas ao fator temporal (fases do represamento), configuradas como redução no consumo de organismos bentônicos e alimentos alóctones, os quais foram geralmente substituídos por recursos provenientes do próprio ambiente (algas, microcrustáceos e peixes), simplificando o espectro alimentar. Diferentes recursos alimentares indicadores (IndVal) corroboram essas alterações na composição alimentar das espécies antes e após o represamento. As proporções na abundância (número e biomassa) das guildas tróficas avaliadas com base na captura por unidade de esforço (CPUE) e testadas pela ANOSIM foram significativamente diferentes antes e após o represamento. As guildas herbívora e piscívora foram as que mais contribuíram (SIMPER) para essas diferenças, especialmente o elevado incremento em biomassa da guilda piscívora após o represamento. As variações na abundância das guildas tróficas foram mais relacionadas às alterações no hábito alimentar da fauna de peixes, do que propriamente aos incrementos em número e em biomassa das espécies que anteriormente compunham tais guildas.

Species composition and richness of avifauna in an urban area of southern Brazil / Composição de especies e riqueza avifauna numa área urbana no sul do Brasil

The urban environment has become an object of study by ornithologists, who seek to understand the relationships between this new habitat and the birds that survive within it. Aiming to investigate the composition and richness of the avifauna present at the State University of Maringá and identify temporal changes in species composition, the obtained results were compared to the study accomplished by Krügel (1998) in this same location. Thus, we performed field samplings from August 2007 to July 2008, using transects, with visual and auditive identification. We recorded 74 species belonging to 27 families from 12 orders, during 72 hours of observation. Most species were constant in the study area. The predominant trophic categories were insectivores (46%) and omnivores (20%). Comparing the analyzed periods, we verified a reduction in the number of species, besides the record of new species for the studied location.

O ambiente urbano vem se tornando objeto de estudo de ornitólogos que buscam entender as relações entre esse novo habitat e as aves que nele sobrevivem. Com o objetivo de determinar a composição e riqueza específica da avifauna presente no Campus sede da Universidade Estadual de Maringá, e de identificar alterações temporais na composição específica dessa comunidade, os resultados obtidos foram comparados com estudos realizados anteriormente por Krügel (1998) na mesma área amostrada. Para tanto, foram realizadas amostragens mensais entre agosto/2007 e julho/2008, utilizando-se o método de transecção, com identificação visual e auditiva. Totalizou-se 72 horas de observação, com o registro de 74 espécies, pertencentes a 27 famílias de 12 ordens. A maioria das espécies foi classificada como constante no local investigado. As categorias tróficas predominantes foram insetívoras (46%) e onívoras (20%). Comparando-se os períodos analisados, constatou-se redução do número de espécies, além do registro de novas ocorrências para o local estudado.

Temporal Changes in Functional Magnetic Resonance Imaging Activation of Heterosexual Couples for Visual Stimuli of Loved Partners

OBJECTIVE: Previous neuroimaging studies on romantic love have focused on determining how the visual stimuli that serve as a representation of loved ones induce the neural activation patterns of romantic love. The purpose of this study was to investigate the temporal changes in romantic love over a period of 6 months and their correlated neurophysiological changes. METHODS: Five heterosexual couples (n=10, mean age 21.1+/-1.97) who started dating not less than 100 days previously were recruited to measure their blood oxygen level dependent (BOLD) signals using functional magnetic resonance imaging (fMRI) while showing them pictures of their loved ones and their previously identified, opposite-sex friends. Subsequently, the subjects were scanned under the same experimental conditions to assess possible changes in their brain activities after 180 days. RESULTS: We found that their Passionate Love Score (PLS) values (M: 118.6+/-9.1, F: 120.2+/-7.0) were significantly reduced after 6 months (M: 110.8+/-4.0, F: 106.2+/-3.0). Furthermore, significantly increased activations were found in the cingulate gyri, inferior frontal gyri, supramarginal gyri, etc., after 6 months, whereas the head and tail of the right caudate nucleus were deactivated, which is indicative of the inhibition of expression and sensory neglect. CONCLUSION: These findings suggest that dynamic neural processes in the cortical-subcortical regions are involved in temporal changes in romantic love.

Temporal changes in caiçara artisanal fishing and alternatives for management: a case study on the southeastern Brazilian coast / Mudanças temporais na pesca artesanal caiçara e alternativas para manejo: um estudo de casa na costa sudeste do Brasil

This paper describes a case study of the changes in fishing that occurred in a Brazilian coastal community after a 10 year interval (1992-2002). There was a decrease in the mean amount of fish caught daily (from 14 kg to 11.32 kg) and annually (from 4.2 t to 3.4 t) and in the richness of species caught (from 21 to 17 species); there was also a low similarity in the species composition of the fish landings (Morisita-Horn index Ch = 0.24). These changes suggested a decline in the locally exploited fish populations, which probably caused the discontinuation of commercial artisanal fishing. However, the diversity of fish caught by hook and line and purse-seine fishing was higher in the second period, whereas there was no significant difference in the diversity of fish caught using gillnets. Despite these changes, the CPUE showed no significant alteration and non-intensive fishing is still practiced by a few (6-35) people in the community. Co-management alternatives (fishing regulations, oysterfarms, ecotourism, etc.) are suggested and may be applicable to other coastal communities after appropriate adaptation for each location.

O uso de recursos por comunidades humanas tem influência direta na conservação da biodiversidade, na medida em que a forma como ele é executada pode implicar em conservação ou sobre-uso dos recursos. Este artigo descreve um estudo de caso sobre as mudanças ocorridas na pesca em uma comunidade da costa brasileira ao longo de 10 anos (1992-2002). Houve um decréscimo das quantidades médias capturadas diariamente (de 14 kg para 11.32 kg) e anualmente (de 4.2 t para 3.4 t) e também na riqueza de espécies (de 21 para 17 espécies). Além disso, a similaridade da composição de espécies presentes nos desembarques pesqueiros entre os dois períodos foi baixa. (Índice de Morisita-Horn Ch = 0.24). Estas mudanças sugerem um declínio das populações de peixes exploradas localmente, o que provavelmente causou o fim da pesca artesanal comercial. No entanto, a diversidade de espécies capturadas com caniço e com o cerco com redes foi maior no segundo período, enquanto não houve diferença significativa na diversidade de peixes capturada com redes de espera. Apesar destas mudanças, não houve alteração significativa na CPUE e a pesca não intensiva é ainda praticada por alguns membros da comunidade (6-35). Algumas medidas de co-manejo, baseadas no que já é de certa forma realizado pela comunidade (controle da pesca, cultivo de ostras, ecoturismo, etc.), são propostas e podem ser aplicadas a outras comunidades costeiras após serem apropriadamente adaptadas às características locais, objetivando a manutenção do uso continuado dos recursos, mas de forma racional.

Temporal Changes of Myocardial Capillary Flow after Attempted Reperfusion in Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: As lack of myocardial perfusion was demonstrated Microvascular function after reperfusion of infarct related artery (IRA) can be changed in convalescent stage for several possible mechanisms such as hyperemia and microvascular stunning. Therefore, myocardial contrast echocardiography (MCE) performed early stage after reperfusion of IRA may cause over or underestimation of the extent of myocardial necrosis. The aims of the study were to demonstrate the temporal changes of myocardial perfusion after revascularization of IRA and to explore the association of late changes of myocardial capillary flow with contractile recovery. METHODS: MCE was performed 5-7days after the attack of acute myocardial infarction (AMI) in 21 patients (M:F=17:4, age: 58+/-12yrs) who underwent successful reperfusion of IRA. MCE was graded by semiquantitative score (0: no opacification, 0.5: partial opacification, 1: homogenous opacification) by 16 segment model. Every patient underwent 1-2months follow up 2D echocardiography and MCE. Improvement of wall motion score more than 1 at follow up was considered to have contractile recovery. RESULTS: Thirty-one of 71 initially akinetic segments were scored as 1, 30 segments as 0.5 and 10 segments as 0 after attempted reperfusion. Twelve of 30 segments with score of 0.5 and 5 of 10 segments with score of 0 showed late improvement of MCE score to 1 and 0.5. Only 1 of 30 segments with score of 0.5 got worse to score of 0. Every segment with late improvement from 0.5 to 1 showed contractile recovery, whereas none of 5 segments with late improvement from 0 to 0.5 showed contractile recovery. There was no significant difference of predictive value between early and late MCE (p=ns). CONCLUSION: Temporal changes of myocardial perfusion from 1week to 2 months in AMI were mainly progressive improvement caused by recovery of microvascular function from stunning rather than progressive microvascular damage or reactive hyperemia. However, it may not significantly affect the validity of MCE in predicting contractile recovery.

Temporal Changes of Myocardial Capillary Flow after Attempted Reperfusion in Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: As lack of myocardial perfusion was demonstrated Microvascular function after reperfusion of infarct related artery (IRA) can be changed in convalescent stage for several possible mechanisms such as hyperemia and microvascular stunning. Therefore, myocardial contrast echocardiography (MCE) performed early stage after reperfusion of IRA may cause over or underestimation of the extent of myocardial necrosis. The aims of the study were to demonstrate the temporal changes of myocardial perfusion after revascularization of IRA and to explore the association of late changes of myocardial capillary flow with contractile recovery. METHODS: MCE was performed 5-7days after the attack of acute myocardial infarction (AMI) in 21 patients (M:F=17:4, age: 58+/-12yrs) who underwent successful reperfusion of IRA. MCE was graded by semiquantitative score (0: no opacification, 0.5: partial opacification, 1: homogenous opacification) by 16 segment model. Every patient underwent 1-2months follow up 2D echocardiography and MCE. Improvement of wall motion score more than 1 at follow up was considered to have contractile recovery. RESULTS: Thirty-one of 71 initially akinetic segments were scored as 1, 30 segments as 0.5 and 10 segments as 0 after attempted reperfusion. Twelve of 30 segments with score of 0.5 and 5 of 10 segments with score of 0 showed late improvement of MCE score to 1 and 0.5. Only 1 of 30 segments with score of 0.5 got worse to score of 0. Every segment with late improvement from 0.5 to 1 showed contractile recovery, whereas none of 5 segments with late improvement from 0 to 0.5 showed contractile recovery. There was no significant difference of predictive value between early and late MCE (p=ns). CONCLUSION: Temporal changes of myocardial perfusion from 1week to 2 months in AMI were mainly progressive improvement caused by recovery of microvascular function from stunning rather than progressive microvascular damage or reactive hyperemia. However, it may not significantly affect the validity of MCE in predicting contractile recovery.