Surveillance of Oncomelania hupensis distribution and water levels in Gaoyou sections of the eastern route project of the South-to-North Water Diversion Project following operation of the project / 中国血吸虫病防治杂志

Objective To understand the distribution of Oncomelania hupensis snails and changes of water levels in Gaoyou sections of the Li Canal following the operation of the eastern route project of the South-to-North Water Diversion Project. Methods The Oncomelania snails were monitored in the river banks and water bodies of Gaoyou sections of the Li Canal by means of systematic sampling combined with environmental sampling as well as collection of the floaters from 2014 to 2019, and the water levels were collected in Gaoyou sections of the Li Canal at the typical hydrological year before the operation of the eastern route project of the South-to-North Water Diversion Project and during the period between 2016 and 2019. Results A total area of 235.42 hm2 were investigated and a total of 75.8 kg floaters were collected in Gaoyou sections of the Li Canal from 2014 to 2019; however, no snails were found. The water level in Gaoyou sections of the Li Canal was predominantly high in the flood season and low in the dry season before the operation of the eastern route project of the South-to-North Water Diversion Project, and the water level was elevated in the dry season and relatively low in the flood season after the operation of the project. Conclusion Following the operation of the eastern route project of the South-to-North Water Diversion Project, the original river bank that is characterized by “land in winter and water in summer” has changed in Gaoyou sections of the Li Canal, which is not favorable for snail breeding.

Effect of water conservancy schistosomiasis control projects combined with molluscicide to control Oncomelania hupensis snails in rivers connecting with Yangtze River in Pukou District,Nanjing City / 中国血吸虫病防治杂志

Objective To evaluate the effect of the water conservancy schistosomiasis control projects combined with mollus-cicide to control Oncomelania hupensis snails in the rivers connecting with the Yangtze River. Methods The water conservancy schistosomiasis control projects of Zhujiashan River,Qili River and Gaowang River were chosen as the study objects in Pukou District,Nanjing City. The data review method and field investigation were used to evaluate the effect of the water conservancy schistosomiasis control projects combined with molluscicide to control O. hupensis snails. Results After the projects of the wa-ter level control and concrete slope protection and mollusciciding were implemented,the snails in the project river sections were completely eliminated. The snail diffusion did not happen in the inland irrigation area too. In the outside of the river beach , though the snails still existed,the snail densities plunged below 1.0 snail per 1.0 m2. Conclusion The comprehensive mea-sures of the combination of water level control,concrete slope protection and mollusciciding can effectively control and eliminate the snails,and prevent the snails from spreading.

Water level effect on herbaceous plant assemblages at an artificial reservoir-Lago Azul State Park, Southern Brazil / O efeito do nível hidrométrico sobre a vegetação herbácea de um reservatório artificial no Sul do Brasil

This study presents the effect of water level variation on the assemblages of herbaceous species in Mourão I Reservoir, Lago Azul State Park, Southern Brazil. The structure and distribution of populations was examined in February (dry period) and April (rainy period), 2011, in two transects. These transects started at the forest edge towards the center of the lake. The end of the transect coincided with the end of the plants within the lake. On every two meters along of the transects we sampled a wooden square of 0.25 m2 for species biomass analysis.The macrophyte stand was composed entirely of emergent species. Considering the periods, most species were less frequent in the rainy period (April), but Ipomea ramosissima (Poir.) Choisy, Commelina nudiflora L., Eleocharis acuntagula (Roxb.) Schult. and Verbena litorales (Kunth.) had their frequency increased during this period, probably due to their resistance. The influence of flood as measured by the NMDS point out that both before and after the flood, there are plots with distinct compositions and biomass. The water level variation affects the dynamics of plant composition and structure in marginal areas of the Reservoir.

Resumo Este estudo apresenta o efeito da variação no nível hidrométrico do reservatório Mourão I, no Parque Estadual do Lago Azul, Paraná sobre a assembleia de espécies herbáceas na região de formação do reservatório. O estudo da estrutura e distribuição das populações foi realizado nos meses de fevereiro (seca) e abril (cheia) de 2011, para isto estabeleceu-se em pontos distintos duas transecções. As transecções começavam na bordada floresta em direção ao centro do lago. O fim da coleta na transecção acontecia quando acabavam as plantas dentro do lago. Ao longo das transecções a cada dois metros um quadrado de madeira com área de 0,25 m2 foi utilizado para amostrar as espécies, com coleta de biomassa. A maioria das espécies teve sua frequência reduzida durante a cheia (abril), porém Ipomea ramosissima (Poir.) Choisy, Commelina nudiflora L., Eleocharis acuntagula (Roxb.) Schult. e Verbena litorales (Kunth.) aumentaram sua frequência durante esse período. A influência da cheia medida pelo NMS indica que tanto antes da cheia quanto após a cheia existem parcelas com composições e biomassa típicas. A variação hidrométrica tem influência sobre a dinâmica da composição e estrutural vegetal nas áreas marginais do reservatório.

Water level effect on herbaceous plant assemblages at an artificial reservoir-Lago Azul State Park, Southern Brazil

This study presents the effect of water level variation on the assemblages of herbaceous species in Mourão I Reservoir, Lago Azul State Park, Southern Brazil. The structure and distribution of populations was examined in February (dry period) and April (rainy period), 2011, in two transects. These transects started at the forest edge towards the center of the lake. The end of the transect coincided with the end of the plants within the lake. On every two meters along of the transects we sampled a wooden square of 0.25 m2 for species biomass analysis.The macrophyte stand was composed entirely of emergent species. Considering the periods, most species were less frequent in the rainy period (April), but Ipomea ramosissima (Poir.) Choisy, Commelina nudiflora L., Eleocharis acuntagula (Roxb.) Schult. and Verbena litorales (Kunth.) had their frequency increased during this period, probably due to their resistance. The influence of flood as measured by the NMDS point out that both before and after the flood, there are plots with distinct compositions and biomass. The water level variation affects the dynamics of plant composition and structure in marginal areas of the Reservoir.

Resumo Este estudo apresenta o efeito da variação no nível hidrométrico do reservatório Mourão I, no Parque Estadual do Lago Azul, Paraná sobre a assembleia de espécies herbáceas na região de formação do reservatório. O estudo da estrutura e distribuição das populações foi realizado nos meses de fevereiro (seca) e abril (cheia) de 2011, para isto estabeleceu-se em pontos distintos duas transecções. As transecções começavam na bordada floresta em direção ao centro do lago. O fim da coleta na transecção acontecia quando acabavam as plantas dentro do lago. Ao longo das transecções a cada dois metros um quadrado de madeira com área de 0,25 m2 foi utilizado para amostrar as espécies, com coleta de biomassa. A maioria das espécies teve sua frequência reduzida durante a cheia (abril), porém Ipomea ramosissima (Poir.) Choisy, Commelina nudiflora L., Eleocharis acuntagula (Roxb.) Schult. e Verbena litorales (Kunth.) aumentaram sua frequência durante esse período. A influência da cheia medida pelo NMS indica que tanto antes da cheia quanto após a cheia existem parcelas com composições e biomassa típicas. A variação hidrométrica tem influência sobre a dinâmica da composição e estrutural vegetal nas áreas marginais do reservatório.

Analysis of relationship between natural death of Oncomelania hupensis snails and water level in Eastern Dongting Lake district / 中国血吸虫病防治杂志

Objective To study the reasons of natural death of Oncomelania hupensis snails by comparing the differences of the indicator days covered with water DCW in snail marshland and non?snail marshland around the build of Three Gorges Dam in Eastern Dongting Lake areas. Methods Two marshlands were selected one was a non?snail marshland Qianliang Lake and another was a snail marshland Junshan Park . The measuring points were set through the mechanical sampling. The snails and elevation of the points were surveyed and the data of the water levels from the hydrological station were collected and then DCWs were calculated. Results From 1995 to 2013 DCWs of the marshland of natural death of snails were all more than that of the snail marshland P<0.01 . In Qianliang Lake marshland the difference between DCW before natural death and DCW from natural death until the dam was not significant P=0.23 while DCWs of the two stages both were more than that after the dam P1=0.045 P2=0.002 . Before the build of the dam DCW of the Qianliang Lake marshland of natural death of snails was more than that after the build of the dam P=0.013 and there was the same situation in Junshan Park marshland P=0.005 . The relationship between snail density and DCW was not significant in Junshan Park marshland rs=0.008 P=0.914 and the reference range of DCW of all the measuring points was 76-251 days. Conclusion In the eastern Dongting Lake district the build of Three Gorges Dam and DCW may be not the direct factors affecting the natural death of snails and the latter may change the distribution of snails.

Effects of the flood pulse on the isotopic composition (δ13C and δ15N) of the particulate organic carbon (POC) in the upper Paraná floodplain / Efeitos do pulso de inundação sobre a composição isotópica (δ13C e δ15N) do carbono orgânico particulado (COP), na planície de inundação do alto rio Paraná

The particulate organic carbon (POC) is an important energy source present in the food chain of detritivorous fish. Considering its importance, this study aimed to investigate the effect of the flood pulse on the composition of the POC in a neotropical floodplain. For this, we analyzed the seasonal variations of the carbon isotopic composition (δ13C) and nitrogen (δ15N) in two different hydrological periods in the years 2000 and 2009. Sampling of potential sources of primary producers, as well as the POC, was held in different subsystems of the floodplain of the upper Paraná river (subsystems of the rivers Parana, Baía and Ivinheima). In 2000, there were significant differences on isotopic signature (δ13C) of the POC, unlike what was seen in 2009, where the values of δ13C were depleted us three subsystems, and showed significant differences both in the Paraná and Baia rivers. As this isotopic variation was attributed to the presence of flooding in 2009, that may be incorporated into new sources of the ecosystem. This is contrary to what was observed in 2000, when they were filled with recorded values below 3.5 m fluviometric. Thus, it can be concluded that the flood event has an effect on the composition of POC and therefore can directly influence the structure of fish food chains scavengers of the basin.

O carbono orgânico particulado (COP) é uma fonte de energia importante presente na cadeia alimentar de peixes detritívoros. Considerando sua importância, esse estudo teve como objetivo investigar o efeito do pulso de inundação sobre a composição do COP em uma planície de inundação neotropical. Para isso, foi analisado as variações sazonais da composição isotópica de carbono (δ13C) e nitrogênio (δ15N) em dois períodos hidrológicos distintos, verificados para os anos de 2000 e 2009. As amostragens das potenciais fontes de produtores primários, bem como o COP, foram realizadas em diferentes subsistemas da planície de inundação do alto rio Paraná (subsistemas dos rios Paraná, Baía e Ivinheima). Constatou-se que em 2000 não foram registradas diferenças significativas na composição isotópica de carbono (δ13C) do COP, diferentemente do verificado em 2009, em que os valores de δ13C foram deplecionados nos três subsistemas, apresentando diferenças significativas tanto no rio Paraná como Baia. A essa variação isotópica atribuiu-se a presença de cheias em 2009, que pode ter incorporado novas fontes ao ecossistema, ao contrário do que foi verificado em 2000, quando foram registradas cheias com valores fluviométricos inferiores a 3,5 m. Assim, pode-se concluir que o evento de inundação apresenta efeito sobre a composição do COP e que, por conseguinte, pode influenciar a estrutura das cadeias alimentares de peixes detritívoros da bacia.

Water level-dependent morphological plasticity in Sagittaria montevidensis Cham. and Schl. (Alismataceae). / Plasticidade morfológica dependente do nível da água em Sagittaria montevidensis Cham. And Schl. (Alismataceae).

Aquatic plants are able to alter their morphology in response to environmental condition variation, such as water level fluctuations. The aim of this study was to evaluate the effect of water level on Sagittaria montevidensis morphology through measures of vegetative structures formed in drought and flood periods. We hypothesised that the plant height and the biomass of S. montevidensis leaves will increase during flood periods, while the biomass and diameter of petioles, and the basal plant area will increase during dry periods. We sampled a total amount of 270 individuals in nine sediment banks per visit, totalling 1080 plants. In order to compare plant morphology between dry and flood periods, we measured the water level in each bank and took the following variables for each plant: diameter, height and diameter of the biggest petiole. In order to compare biomass allocation between dry and flood periods, we sampled a total amount of 90 individuals in nine sediment banks per visit, totalling 360 plants. Plants were dried and weighed in the laboratory. All measured morphologic traits, as well as the biomass of leaf blades and petioles, were higher during flood periods, indicating that water level highly influences the morphology of S. montevidensis individuals. Our results suggest that these morphological responses allow survival and maintenance of S. montevidensis populations under environmental stress. These results can be linked to the invasive potential of S. montevidensis and sheds light on basic management practices that may be applied in the future.

As plantas aquáticas são capazes de alterar a sua morfologia em resposta a variações nas condições ambientais, tais como mudanças no nível da água. Nosso objetivo foi avaliar o efeito do nível da água na morfologia de Sagittaria montevidensis através de medidas de estruturas vegetativas formadas em períodos de seca e de cheia. Nós hipotetizamos que a altura dos indivíduos e a biomassa das folhas de S. montevidensis aumentarão durante períodos de cheia, enquanto a biomassa e diâmetro dos pecíolos, além da área basal da planta, aumentarão durante períodos de seca. Nós amostramos um total de 270 indivíduos, distribuídos em nove bancos de sedimento, por visita, totalizando 1080 plantas. Para comparar a morfologia das plantas entre os períodos de cheia e seca nós medimos o nível de água em cada banco e tomamos as seguintes medidas para cada planta: diâmetro, altura e diâmetro do maior pecíolo. Para comparar a alocação de biomassa entre os períodos de cheia e seca nós amostramos um total de 90 indivíduos em nove bancos de sedimento por visita, totalizando 360 plantas. As plantas foram secas em estufa e pesadas em laboratório. As plantas foram maiores no período de cheia e também apresentaram maior número e biomassa de folhas, maior diâmetro e biomassa de pecíolos e maiores áreas basais das rosetas. Nós concluímos que o nível da água influencia muito na morfologia de S. montevidensis. Nossos resultados sugerem que essas respostas morfológicas podem permitir a sobrevivência e manutenção de populações de S. montevidensis em estresse ambiental. Esses resultados podem ser ligados ao potencial invasivo de S. montevidensis e lançam luzes sobre práticas de manejo que poderão ser aplicadas no futuro.

Water level-dependent morphological plasticity in Sagittaria montevidensis Cham. and Schl. (Alismataceae)

Aquatic plants are able to alter their morphology in response to environmental condition variation, such as water level fluctuations. The aim of this study was to evaluate the effect of water level on Sagittaria montevidensis morphology through measures of vegetative structures formed in drought and flood periods. We hypothesised that the plant height and the biomass of S. montevidensis leaves will increase during flood periods, while the biomass and diameter of petioles, and the basal plant area will increase during dry periods. We sampled a total amount of 270 individuals in nine sediment banks per visit, totalling 1080 plants. In order to compare plant morphology between dry and flood periods, we measured the water level in each bank and took the following variables for each plant: diameter, height and diameter of the biggest petiole. In order to compare biomass allocation between dry and flood periods, we sampled a total amount of 90 individuals in nine sediment banks per visit, totalling 360 plants. Plants were dried and weighed in the laboratory. All measured morphologic traits, as well as the biomass of leaf blades and petioles, were higher during flood periods, indicating that water level highly influences the morphology of S. montevidensis individuals. Our results suggest that these morphological responses allow survival and maintenance of S. montevidensis populations under environmental stress. These results can be linked to the invasive potential of S. montevidensis and sheds light on basic management practices that may be applied in the future.

As plantas aquáticas são capazes de alterar a sua morfologia em resposta a variações nas condições ambientais, tais como mudanças no nível da água. Nosso objetivo foi avaliar o efeito do nível da água na morfologia de Sagittaria montevidensis através de medidas de estruturas vegetativas formadas em períodos de seca e de cheia. Nós hipotetizamos que a altura dos indivíduos e a biomassa das folhas de S. montevidensis aumentarão durante períodos de cheia, enquanto a biomassa e diâmetro dos pecíolos, além da área basal da planta, aumentarão durante períodos de seca. Nós amostramos um total de 270 indivíduos, distribuídos em nove bancos de sedimento, por visita, totalizando 1080 plantas. Para comparar a morfologia das plantas entre os períodos de cheia e seca nós medimos o nível de água em cada banco e tomamos as seguintes medidas para cada planta: diâmetro, altura e diâmetro do maior pecíolo. Para comparar a alocação de biomassa entre os períodos de cheia e seca nós amostramos um total de 90 indivíduos em nove bancos de sedimento por visita, totalizando 360 plantas. As plantas foram secas em estufa e pesadas em laboratório. As plantas foram maiores no período de cheia e também apresentaram maior número e biomassa de folhas, maior diâmetro e biomassa de pecíolos e maiores áreas basais das rosetas. Nós concluímos que o nível da água influencia muito na morfologia de S. montevidensis. Nossos resultados sugerem que essas respostas morfológicas podem permitir a sobrevivência e manutenção de populações de S. montevidensis em estresse ambiental. Esses resultados podem ser ligados ao potencial invasivo de S. montevidensis e lançam luzes sobre práticas de manejo que poderão ser aplicadas no futuro.

Does water level affect benthic macro-invertebrates of a marginal lake in a tropical river-reservoir transition zone? / O nível de água afeta os macro-invertebrados bentônicos de uma lagoa marginal na região de transição rio - represa de zona tropical?

Benthic macro-invertebrates are important components of freshwater ecosystems which are involved in ecological processes such as energy transfer between detritus and consumers and organic matter recycling. The aim of this work was to investigate the variation in organism richness, diversity and density of benthic fauna during the annual cycle in Camargo Lake, a lake marginal to Paranapanema River, southeast Brazil. The correlation of environmental factors with community attributes of the macro-benthic fauna was assessed. Since Camargo Lake is connected to the river, we tested the hypothesis that water level variation is the main regulating factor of environmental variables and of the composition and abundance of benthic macro-invertebrates. The results indicated that lake depth varied with rainfall, being the highest at the end of the rising water period and the lowest at the beginning of this period. The sediment granulometry was more heterogeneous at the bottom of the lake by the end of the high water period. The benthic macro-invertebrate fauna was composed by 15 taxa. The Diptera order was represented by seven taxa and had greater richness in relation to other taxa. This group was responsible for 60% of the total abundance of organisms, followed by Ephemeroptera (22%) and Anellida (16%). Significant differences were observed over time in total richness and, in density of Narapa bonettoi, Chaoborus, Ablabesmyia gr. annulata, Chironomus gigas, Larsia fittkau, and Procladius sp. 2. Total taxa richness correlated negatively with water pH, transparency, conductivity, and bottom water oxygen. Higher positive correlations were found between the densities of some taxa and bottom water oxygen, conductivity and very fine sand, silt + clay of sediment, while negative correlations were recorded with organic matter, and fine, medium and coarse sand, bottom water temperature, mean temperature and rainfall. The significant temporal difference in water level was associated with changes in abiotic factors and macro-invertebrate community attributes.

Os macro-invertebrados são componentes importantes de ecossistemas aquáticas continentais, envolvidos em processos ecológicos como transferência de energia entre detritos e consumidores e, reciclagem de matéria orgânica. O objetivo deste trabalho foi investigar a variação na riqueza de organismos, diversidade e densidade da fauna bentônica durante um ciclo anual na Lagoa do Camargo, marginal ao Rio Paranapanema, sudeste do Brasil. Eventuais relações de fatores ambientais com atributos da comunidade macro-bentônica foram verificadas. Visto que a Lagoa do Camargo é conectada com o rio, nós testamos a hipótese de que a variação do nível de água é o principal fator regulador das variáveis ambientais e da composição e abundância dos macro-invertebrados bênticos. Os resultados indicaram que a profundidade da lagoa variou com a precipitação, sendo mais alta no final do período da enchente e mais baixa no inicio deste período. A granulometria do sedimento foi mais heterogênea no fundo da lagoa no final do período de cheia. A fauna de macro-invertebrados bênticos foi composta de 15 taxa. A ordem Diptera foi representada por sete taxa e tem maior riqueza em relação aos outros taxa. Este grupo foi responsável por 60% da abundância total de organismos, seguido por Ephemeroptera (22%) e Anellida (16%). Diferenças temporais significativas foram observadas na riqueza total e, na densidade de Narapa bonettoi, Chaoborus, Ablabesmyia gr. annulata, Chironomus gigas, Larsia fittkau, and Procladius sp. 2. A riqueza total de taxa correlacionou-se negativamente com pH da água, transparência, condutividade e oxigênio na água do fundo. As mais altas correlações positivas foram encontradas entre as densidades de alguns taxa e oxigênio da água de fundo, condutividade e areia muito fina, silte + argila do sedimento, enquanto que correlações negativas foram obtidas com matéria orgânica, e areia fina, média e grossa, temperatura da água de fundo, temperatura média e precipitação. A diferença temporal significativa do nível de água foi associada a mudanças nos fatores abióticos e nos atributos da comunidade de macro-invertebrados.

Creatine kinase levels in patients with bipolar disorder: depressive, manic, and euthymic phases / Comparação das fases de depressão, mania e eutimia sobre os níveis de creatina quinase em pacientes bipolares

OBJECTIVE: Bipolar disorder is a severe, recurrent, and often chronic psychiatric illness associated with significant functional impairment, morbidity, and mortality. Creatine kinase is an important enzyme, particularly for cells with high and fluctuating energy requirements, such as neurons, and is a potential marker of brain injury. The aim of the present study was to compare serum creatine kinase levels between bipolar disorder patients, in the various phases (depressive, manic, and euthymic), and healthy volunteers. METHOD: Forty-eight bipolar patients were recruited: 18 in the euthymic phase; 17 in the manic phase; and 13 in the depressive phase. The control group comprised 41 healthy volunteers. The phases of bipolar disorder were defined as follows: euthymic-not meeting the DSM-IV criteria for a mood episode and scoring < 8 on the Hamilton Depression Rating Scale (HDRS) and Young Mania Rating Scale (YMRS); manic-scoring < 7 on the HDRS and > 7 on the YMRS; depressive-scoring > 7 on the HDRS and < 7 on the YMRS. Patients in mixed phases were excluded. Blood samples were collected from all participants. RESULTS: Creatine kinase levels were higher in the manic patients than in the controls. However, we observed no significant difference between euthymic and depressive patients in terms of the creatine kinase level. CONCLUSION: Our results suggest that the clinical differences among the depressive, manic, and euthymic phases of bipolar disorder are paralleled by contrasting levels of creatine kinase. However, further studies are needed in order to understand the state-dependent differences observed in serum creatine kinase activity.

OBJETIVO: O transtorno do humor bipolar é uma doença psiquiátrica grave, recorrente e crônica associada a significativo prejuízo funcional, morbidade e mortalidade. A creatina quinase tem sido proposta como um marcador de dano cerebral. A creatina quinase é uma enzima importante principalmente para células que necessitam de uma grande quantidade de energia, como os neurônios. O objetivo do presente estudo foi comparar os níveis de creatina quinase entre as fases depressiva, maníaca e eutímica de pacientes com transtorno do humor bipolar. MÉTODO: Para avaliação dos níveis de creatina quinase no soro, 48 pacientes bipolares foram recrutados; 18 estavam eutímicos, 17 estavam em mania e 13 em episódio depressivo. Foi feita também uma comparação com um grupo controle que incluiu 41 voluntários saudáveis. Grupo eutimia: foram incluídos os pacientes que não cumpriam os critérios do DSM-IV para episódios de humor e deveriam ter a pontuação inferior a oito nas escalas de avaliação de mania (YMRS) e depressão (HDRS); grupo mania: foram incluídos os pacientes que apresentavam YMRS > 7 e HDRS < 7; grupo depressão: foram incluídos os pacientes que apresentavam HDRS > 7 e YMRS < 7. Os pacientes em episódios mistos não foram incluídos no estudo. Amostras de sangue foram coletadas de todos os participantes. RESULTADOS: Durante a mania, os níveis de creatina quinase foram aumentados em comparação com voluntários saudáveis. Entretanto, não houve diferença significativa nos níveis de creatina quinase em pacientes eutímicos e depressivos, quando comparados com o grupo controle. CONCLUSÃO: Nossos resultados sugerem que as fases maníaca, depressiva e eutímica do transtorno do humor bipolar, além de apresentarem sintomatologia distinta, também podem ser diferenciadas pelo nível de creatina quinase presente no sangue do paciente. Entretanto, mais estudos são necessários para entender as diferenças observadas na atividade da creatina quinase durante as fases do transtorno do humor bipolar.

Trophic interactions among sympatric zooplanktivorous fish species in volume change conditions in a large, shallow, tropical lake

Significant reductions in the water volume of shallow lakes impose a restriction on species segregation promoting more interactions in the trophic relationships. The diets of three closely related zooplanktivorous silversides belonging to the Atherinopsidae species flock of lake Chapala, Mexico, were analyzed at two sites (Chirostoma jordani, C. labarcae, andC. consocium). Diets were described in critical shallow (August 2000) and volume recovery conditions (August 2005). Diets included mainly cladocerans (Bosmina, Ceriodaphnia, and Daphnia) and copepods (Cyclops). A significant difference in diets was detected when comparing years (MRPP analysis, A = 0.22, p < 0.0001) and sites at different years (MRPP analysis, A = 0.17, p = 0.004). According to niche breadth mean values, species were classified as specialized and intermediate feeders. In shallow conditions, the small range of niche breadth (1.72 to 3.64) and high diet overlap values (D = 0.64, L = 8.62) indicated a high potential for interspecific exploitative interaction. When the lake volume recovered, an increase in the niche breadth range (1.04 to 4.96) and low niche overlap values (D = 0.53, L = 2.32) indicated a reduction of the species interaction. The Mann- Whitney U-test supported this pattern by showing a significant difference between years for niche overlap (p = 0.006). The increased interaction during the low volume suggests alternative segregation in life-history variations and other niche dimensions such as spatial or temporal distribution.

La reducción significativa en el volumen de agua de los lagos someros impone una restricción en la segregación de las especies y promueve una mayor interacción en las relaciones tróficas. Se analizó la dieta de tres especies cercanamente emparentadas de zooplanctívoros pertenecientes al flock de Aterinópsidos del lago de Chapala en dos sitios (Chirostoma jordani, C. labarcae y C. consocium). Las dieta fue descrita en una condición somera crítica (Agosto 2000) y en una condición de recuperación del lago (Agosto 2005). En la dieta se incluyen principalmente cladóceros (Bosmina, Ceriodaphnia y Daphnia) y copépodos (Cyclops). Se detectó una diferencia significativa en la dieta cuando se comparan los años (análisis MRPP, A = 0.22, p < 0.0001) y los sitios en los diferentes años (análisis MRPP, A = 0.17, p = 0.004). De acuerdo a los valores promedio de amplitud de nicho, las especies fueron clasificadas como especialistas y consumidores intermediarios. En condiciones someras, el pequeño intervalo de la amplitud de nicho (1.72 a 3.64) y los altos valores del traslape de nicho (D = 0.64, L = 8.62) indicaron un alto potencial para una interacción explotativa inter-específica. Cuando el lago se recupera en su volumen, un incremento en el intervalo de amplitud de nicho (1.04 a 4.96) y los bajos valores del traslape de nicho (D = 0.53, L = 2.32) indicaron una reducción en la interacción de las especies. La prueba U de Mann-Whitney refuerza este patrón al mostrar una diferencia significativa entre los años para el traslape de nicho (p = 0.006). El incremento en la interacción de las especies durante condiciones de volumen bajo, sugiere una segregación alternativa con variaciones en la historia de vida y en otras dimensiones del nicho como en el caso de la distribución espacial y temporal.

Impact of the changing water level on the variance of Oncomelania hupensis populations in Lake Area with general additive model / 中华流行病学杂志

Objective To explore the impact and regularity of snail population after changing of water level and to develop effective control and prediction programs. Methods A typical snail habitat closed to Changjiang county in Yueyang city, Hunan province was selected as the survey field.Data on water level and the changing trend of snail population during 2001-2009 including the average water level, maximum and minimum water levels, snail and infected snail densities,proportion of sampling frames with living and infected snails etc. were collected. The distribution of water level and snail indexes were described and a general additive model(GAM)for the relationships between these indexes were also fitted. Results Impacts of the average water level and the watered-out days in current year in the surveyed field on the snail density were statistically significant(P＜0.01), showing a quadratic curve association. The snail density remained at the lowest level when the average water level was at 25.0 m and the surveyed field watered-out days was 120. The average water level in current year and the field watered-out days in the past year showed statistically significant impacts on the infected snail density(P＜0.001), the proportion of sampling frames with infected snails(P＜0.05)and living snails(P value neared 0.05), presented a quadratic curve, a cubic curve or even a more complicated piecewise curve association. Both the infected snail density and the proportion of sampling frames with infected snails remained at the lowest level when the average water level was at 25.0 m and the watered-out days in the past year was 110, while the proportion of sampling frames with living snails kept the lowest level when the average water level was at 25.0 m and the watered-out days in the past year was 160. Conclusion The water level and the field watered-out days affected the development of snail population directly. The changing water level had an impact on snail population change, which mainly presented as nonlinear smooth function relation. Impact of the field watered out days on the infected snail density and the proportion of sampling frames with living snails and infected snails showed a hysteresis effect. The snail density was predicted to be retaining a high level when the water level was 24.0 m and the field watered-out days was 3 months. It had obvious advantages to fit the relationship of the changing water level and the snail indexes with a GAM which could get closer to the reality as well as easier to find and explain the potential associations and regulations.

Treetop shelter of a neotropical river otter cub (Lontra longicaudis - Carnivora: Mustelidae) in an Amazonian flooded forest

The finding of a Neotropical river otter (Lontra longicaudis) cub occupying a shelter in a hollowed treetop is reported. The observation was made in a seasonally flooded forest in Central Amazonia, during the high water peak of the annual inundation cycle. A literature review indicates that this is the first description of a shelter of the species, both in a hollowed tree and in Amazonia. This observation can indicate a strong relationship between the species' breeding cycle with the annual dynamics of Amazonian rivers. We discuss potential advantages and disadvantages of breeding when water level is high.

É relatada a observação de um filhote de lontra (Lontra longicaudis) ocupando um abrigo em uma cavidade na copa de uma árvore. A observação foi feita em uma floresta inundada na Amazônia Central, no pico de cheia do ciclo anual de inundação. A revisão da literatura revela que esta é a primeira descrição de um abrigo desta espécie em uma cavidade de árvore na natureza e na Amazônia. Tal observação pode indicar uma forte relação entre o ciclo reprodutivo da espécie e a dinâmica anual dos rios amazônicos. Discutimos vantagens e desvantagens potenciais da reprodução na época da cheia.

The effects of water Immersion on dynamic and static pulmonary function at both neck and diaphragm levels in normal subjects / 体力科学

A study was conducted to clarify the influence of water immersion at different levels on pulmonary response. The subjects, ten healthy men (mean age, 26.2±7.9 years), subjected to measurement of static lung volumes and maximum expiratory flow-volume curves while sitting immersed in water at the level of both the neck and diaphragm. TLC, VC, ERV and FRC for water immersion at the diaphragm level were significantly decreased in comparison with those measured in air. These lung volumes were further decreased upon water immersion to neck level. However, RV did not change significantly upon immersion at either water level. Significant decreases of FEV<SUB>1⋅0</SUB>, FEV<SUB>1⋅0</SUB>%, V<SUB>50</SUB> and V<SUB>25</SUB> were observed upon water immersion at the diaphragm level as compared with those obtained in air. Water immersion to neck level produced further decreases in pulmonary functional parameters. Although peak flow and V<SUB>75</SUB> did not change significantly upon water immersion at either level, V<SUB>50</SUB> and V<SUB>25</SUB> were decreased markedly in comparison with the values obtained in air. A tendency for a marked decrease in pulmonary function parameters was observed upon water immersion to neck level. The changes observed upon water immersion to diaphragm level may have resulted from compression of small airways induced by both an increase of blood volume in the thorax and hydrostatic pressure against the abdomen. The changes induced by water immersion to neck level may have been exacerbated by the two mechanisms described above, in addition to hydrostatic pressure on the chest wall. The present results suggest that the significant reduction of pulmonary functional parameters caused by water immersion may be due to compression of small airways induced by an increase of blood volume in the thorax and hydrostatic pressure on the chest wall and abdomen.

Impact of precipitation and water level on acute schistosomiasis in Dongting Lake area / 中国血吸虫病防治杂志

Objective To study the impact of precipitation and water level on acute schistosomiasis for providing reference to control acute schistosomiasis in advance. Methods The historical data on precipitation and water level as well as acute schistosomiasis from 2003 to 2007 in Eastern, Southern and Western Dongting Lake regions were collected and analysed for the correlation between acute schistosomiasis and precipitation and water level in local areas. Results Acute schistosomiasis gradually decreased year by year from 2003 to 2007. Compared with 2003, the number of acute schistosomiasis in 2007 reduced by 95.37%. There was no outbreak of acute schistosomiasis from 2005 to 2007.In the period of peak acute schistosomiasis, the average monthly rainfall reduced from year to year for the successive 5 years. There was a significantly correlation between acute schistosomiasis and monthly average water level. Conclusions The acute schistosomiasis is directly affected by nature factors and has a close correlation with the rainfall and water level in Dongting Lake regions.