Reducción del error de prescripción y de sus efectos adversos en el área pediátrica de cuidados intensivos / Reduction of prescription error and its adverse effects in the pediatric intensive care area

Resumen Introducción : La prescripción es el nodo del manejo y uso de medicamentos que con mayor frecuencia presen ta errores de medicación, según diversos estudios. Este estudio tiene como objetivo analizar las prescripciones antes y después de la incorporación de una ronda multi disciplinar en el área de cuidados intensivos pediátricos y su implicación en la ocurrencia de eventos adversos por medicamentos. Métodos : Se trata de un estudio antes y después, no controlado. Resultados : Se estudiaron 100 pacientes antes y 100 después, rango 1-17 años, edad media: 6.4 DE: 8.7. El 55.5% (n = 111) eran varones. Se detectó un error de prescripción antes de la intervención del 12% (n = 12) y después de intervención, del 0%, p = 0.001. Se detectó un total de 45 eventos adversos por 100 ingresos y 38 eventos por 100 ingresos, antes y después de la inter vención respectivamente (p > 0.05). Conclusión : La intervención fue útil para disminuir el error de prescripción en esta muestra de pacientes.

Abstract Introduction : Prescription is the node of medication management and use that most frequently presents medication errors, according to various studies. This study aims to analyze prescriptions before and after the incorporation of a multidisciplinary round in the pediatric intensive care area and its implication in the occurrence of adverse drug events. Methods : This is an uncontrolled before and after study. Results : 100 patients were studied before and 100 after, range 1-17 years, mean age: 6.4 SD: 8.7. 55.5% (n = 111) were men. A prescription error was detected before the intervention of 12% (n = 12) and after 0% of the inter vention, 0%, p = 0.001. A total of 45 adverse events were detected, that is, 45 adverse events per 100 admissions and 38, that is, 38 events per 100 admissions, before and after the intervention respectively (p > 0.05). Conclusion : The intervention was useful to reduce prescription error in this sample of patients.

Inmunogenicidad y eventos adversos de vacuna SARS-CoV-2 en trabajadores de salud / Immunogenicity and adverse events of SARS-CoV-2 vac cine in health workers

Resumen Introducción : El objetivo de este estudio fue evaluar los efectos adversos y la respuesta inmune de anticuer pos IgG anti S1 SAEA-CoV-2 en el personal de Salud del Hospital del Milagro de la ciudad de Salta, posterior a recibir dos dosis de vacuna COVID-19. Métodos : Se realizó un estudio prospectivo de co horte desde marzo de 2021 hasta abril 2022. Se reco pilaron datos demográficos, clínicos, eventos adversos supuestamente atribuidos a la vacunación (ESAVI) y se tomaron dos muestras de sangre para medir los niveles de anticuerpos. Resultados : Participaron 408 voluntarios, 401 (98%) fueron vacunados con Sputnik- V. La edad promedio fue de 45.5 años con predominio del sexo femenino (71%). Los ESAVI fueron reportados en 188 (46.1%) y 121 (29.7%) luego de la primera y segunda dosis respectivamente (p<0.001). Estos eventos fueron mayormente de carácter leve y transitorios, más frecuentes luego de la primera dosis. El primer dosaje de anticuerpos fue positivo en 99% con una media de títulos de 9.7 (SD 3.7). El segundo dosaje fue positivo en 88% con una media de títulos de 6.4 (SD 4.4). Los participantes con antecedentes de infección y dosajes previos positivos mostraron títulos significativamente más altos de anticuerpos (p<0.001). Conclusión : Los ESAVI reportados fueron mayorita riamente leves y transitorios. La vacunación masiva y la administración de la dosis recomendada son esenciales para lograr una inmunidad colectiva efectiva. La mayoría de los trabajadores de la salud vacunados desarrollaron anticuerpos y aquellos que cursaron la enfermedad previa a la vacunación presentaron títulos significativos más elevados de anticuerpos.

Abstract Introduction : The aim of this study was to evaluate the adverse effects and immune response associated with IgG anti S1 SAEA-CoV-2 antibodies among health care workers at Señor del Milagro Hospital in Salta city, after receiving two doses of COVID-19 vaccine. Methods : A prospective cohort study was carried out from March 2021 to April 2022. Demographic, clinical data, adverse events supposedly attributed to vaccina tion (AEFIs) were collected and two samples were taken to measure serum antibody levels. Results : 408 volunteers participated, 401 (98%) were vaccinated with Sputnik-V. The average age was 45.5 years with a predominance of the female sex (71%). AEFIs were reported in 188 (46.1%) and 121 (29.7%) after the first and second doses respectively (p<0.001). These events were mostly mild and transient, more frequent after the first dose. The first antibody test was positive in 99% with a mean titer of 9.7 (SD 3.7). The second dosage was positive in 88% with a mean titer of 6.4 (SD 4.4). Participants with a history of infection and previous positive testing showed significantly higher antibody titers (p<0.001). Conclusion : The AEFIs reported were mostly mild and transient. Mass vaccination and administration of the recommended dose are essential to achieve effective herd immunity. The majority of vaccinated healthcare workers developed antibodies and those who had the disease prior to vaccination had significant antibody titers.

Alternativas fitoterápicas no controle da obesidade / Phytotherapy alternatives in obesity control / Alternativas herbales en el control de la obesidad

Nos últimos anos, a obesidade vem aumentando consideravelmente entre adultos e crianças e, segundo a OMS, estima-se que em 2025 o número de obesos ultrapasse a 2,3 milhões em todo o mundo. O indivíduo obeso apresenta maiores riscos de desenvolver doenças crônicas não transmissíveis, como diabetes, doenças cardiovasculares, dislipidemias e ainda alguns tipos de cânceres. O tratamento para a obesidade é variado e inclui mudanças no estilo de vida como: hábitos alimentares e prática de atividade física, tratamento medicamentoso, cirurgia bariátrica e fitoterápicos com o potencial de auxiliar no tratamento. O objetivo deste trabalho foi realizar uma revisão bibliográfica a fim de avaliar os benefícios da utilização de medicamentos fitoterápicos como auxiliar no tratamento da obesidade, seus principais ativos, mecanismos de ação e sua utilização popular. Dentre as plantas pesquisadas e que demonstraram potencial para atuar no tratamento da obesidade encontram-se Camelia sinensis, Citrus aurantium, Hibiscus sabdariffa, Coffea arabica, Ephedra sinica, Zingiber oficinale e Senna alexandrina. Os principais mecanismos de ação envolvidos no potencial anti-obesidade das plantas medicinais são a capacidade de controle do apetite e ingestão de energia, estímulo da termogênese, inibição da lipase pancreática e redução da absorção de gordura, diminuição da lipogênese e aumento da lipólise. Desta forma, conclui-se que as plantas selecionadas neste estudo apresentaram efeitos positivos nos parâmetros bioquímicos e físicos, podendo ser incluídas nos protocolos como coadjuvantes nos tratamentos de emagrecimento.

In recent years, obesity has increased considerably among adults and children and according to the WHO, it is estimated that in 2025 the number of obese people will exceed 2.3 million worldwide. The obese individual is at greater risk of developing non-communicable chronic diseases, such as diabetes, cardiovascular disease, dyslipidemia and even some types of cancer. The treatment for obesity is varied, including changes in lifestyle such as eating habits and physical activity, drug treatment, bariatric surgery and phytotherapy with the potential to aid in the treatment. The objective of this work was to carry out a literature review, evaluating the benefits of using herbal medicines as an aid in the treatment of obesity, their main assets, mechanisms of action and their popular use. Among the plants researched and that have shown potential to act in the treatment of obesity are Camelia sinensis, Citrus aurantium, Hibiscus sabdariffa, Coffea arabica, Ephedra sinica, Zingiber officiale and Senna alexandrina. The main mechanisms of action involved in the antiobesity potential of medicinal plants are the ability to control appetite and energy intake, thermogenesis stimulation, pancreatic lipase inhibition and reduction of fat absorption, lipogenesis decrease and lipolysis increase. Thus, it is concluded that the plants selected in this study showed positive effects on biochemical and physical parameters, and can be included in the protocols as adjuvants in weight loss treatments.

En los últimos años, la obesidad ha aumentado considerablemente entre adultos y niños y, según la OMS, se estima que en 2025 el número de obesos superará los 2,3 millones en todo el mundo. Los individuos obesos tienen un mayor riesgo de desarrollar enfermedades crónicas no transmisibles, como la diabetes, las enfermedades cardiovasculares, las dislipidemias e incluso algunos tipos de cáncer. El tratamiento de la obesidad es variado e incluye cambios en el estilo de vida como: hábitos alimenticios y práctica de actividad física, tratamiento farmacológico, cirugía bariátrica y medicamentos a base de hierbas con potencial para ayudar en el tratamiento. El objetivo de este trabajo fue realizar una revisión bibliográfica para evaluar los beneficios del uso de las hierbas medicinales como ayuda en el tratamiento de la obesidad, sus principales activos, mecanismos de acción y su uso popular. Entre las plantas investigadas y que mostraron potencial para actuar en el tratamiento de la obesidad están Camelia sinensis, Citrus aurantium, Hibiscus sabdariffa, Coffea arabica, Ephedra sinica, Zingiber oficinale y Senna alexandrina. Los principales mecanismos de acción implicados en el potencial antiobesidad de las plantas medicinales son la capacidad de controlar el apetito y la ingesta de energía, estimular la termogénesis, inhibir la lipasa pancreática y reducir la absorción de grasas, disminuir la lipogénesis y aumentar la lipólisis. Por lo tanto, se concluye que las plantas seleccionadas en este estudio mostraron efectos positivos sobre los parámetros bioquímicos y físicos, y pueden ser incluidas en los protocolos como coadyuvantes en los tratamientos de pérdida de peso.

Productivity costs associated to voice symptoms, low sleep quality, and stress among college professors during homeworking in times of COVID-19 Pandemic / Costos de productividad asociados a síntomas de voz, baja calidad del sueño y estrés en profesores universitarios durante el trabajo en casa en tiempos de COVID-19

Objective. To estimate the productivity reduction costs associated to self-reported voice symptoms, low sleep quality, and high stress levels among college professors during homeworking in times of COVID-19 pandemic. Methods. This cross-sectional study included fifty-eight college professors who re-ported their reduction in productivity at work due to self-perceived stress levels, sleep quality, and voice symptoms. Results. High stress levels were reported by 24% of the participants, whereas 19% reported voice symptoms, and 3% low sleep quality. Costs associated with the three conditions were calculated for twenty-nine subjects. Productivity costs associated with high stress levels were higher (COP$32.345.925) than those for voice symptoms (COP$1.872.703) and low sleep quality (COP$319.733). Conclusion: Productivity reduction costs were higher for professors who reported high levels of stress followed by participants with self-reported voice symptoms and low sleep quality, which highlight the importance of prioritizing activities to reduce stress levels and voice symptoms in workplace health promotion programs imple-mented in educational settings

Objetivo. Estimar los costos de reducción de productividad asociados con los sínto-mas de voz, la baja calidad del sueño y los altos niveles de estrés entre los profesores universitarios durante el trabajo en casa en tiempos de COVID-19.Métodos. Este estudio transversal incluyó la participación de 58 docentes uni-versitarios, los cuales reportaron la reducción de la productividad en el trabajo relacionada con sus percepciones de los niveles de estrés, la calidad del sueño y los síntomas de voz.Resultados. El 24% de los participantes informó altos niveles de estrés, mientras que el 19% informó síntomas de voz y el 3% mala calidad del sueño. Los costos asociados con las tres condiciones se calcularon para 29 sujetos. Los costos de pro-ductividad asociados a altos niveles de estrés fueron mayores (COP$32.345.925) en comparación con los síntomas de voz (COP$1.872.703) y la mala calidad del sueño (COP$319.733).Conclusiones: Los costos asociados a la reducción en la productividad fueron altos en docentes que reportaron altos niveles de estrés, seguidos de los que reportaron síntomas de voz y baja calidad del sueño. Lo anterior resalta la importancia de prio-rizar actividades dirigidas a reducir los niveles de estrés y los síntomas vocales en los programas de promoción de la salud en los lugares de trabajo que se implementan en las instituciones educativas

Pre- and postnatal evaluation of offspring rats exposed to Origanum vulgare essential oil during mating, gestation and lactation / Avaliação pré e pós-natal da prole de ratos expostos ao óleo essencial de Origanum vulgare durante acasalamento, gestação e lactação

Despite the increasing use of oregano (Origanum vulgare L.) essential oil for therapeutic purposes, pre- and postnatal development of animals offspring exposed to this oil has not yet been evaluated. In line with previous concerns of genotoxicity, in this study adult rats were exposed to different doses of oregano essential oil (3, 9 and 27% vol/vol) during pre-mating, mating, gestation and lactation. Prenatal screening included fetal development and uterine inspection, where the reproductive rate of females such as breeding, pregnancy, delivery, viability and post-implantation loss rate were measured. Postnatal evaluation of rat offspring included motor development, neuroendocrine and behavioral assessment. Body weight of rat dams and signs of dystocia were evaluated daily. Development of physic characteristics and reflex tests of puppies were also assessed. Additionally, these rats, when adults, were submitted to sexual and open field behavioral tests. The main differences among the groups were observed in the indices of mating, pregnancy and post-implantation loss (P < 0.01). Results demonstrated that the treatment of parental generation with oregano essential oil has the potential to affect the developing fetuses at the highest dose used, but without causing maternal toxicity and changes in general behavior and development of the progeny.

Apesar do aumento do uso do óleo essencial de orégano (Origanum vulgare L.) para fins terapêuticos, o desenvolvimento pré e pós-natal da progênie de animais expostos a este óleo ainda não foi avaliado. Partindo das suspeitas prévias de genotoxicidade desse óleo, neste estudo, ratos Wistar adultos foram expostos a diferentes doses do óleo essencial de orégano (3, 9 e 27% vol/vol) durante o acasalamento, a gestação e a lactação. Para a avaliação pré-natal, o desenvolvimento gestacional foi observado e os úteros inspecionados, assim como os índices reprodutivos das fêmeas, como a taxa de acasalamento, de gestação, parto e perdas pós-implantação. Na avaliação pós-natal, observou-se o desenvolvimento motor, neuroendócrino e comportamental da prole. Observou-se, diariamente, o peso das ratas e sinais de distocia. Após o parto, as características de desenvolvimento e testes de reflexos dos filhotes foram avaliadas, enquanto que, na puberdade, foram realizadas análises histopatológicas e dosagem hormonal. Adicionalmente, na idade adulta, esses ratos foram submetidos ao teste de comportamento em campo aberto e ao comportamento sexual. As principais diferenças entre os grupos foram nos índices de acasalamento, de gestação e de perdas pós-implantação (P < 0,01). Os resultados demonstram que o tratamento da geração parental com óleo essencial de orégano tem potencial para afetar os índices reprodutivos das ratas e o desenvolvimento dos fetos na maior dose utilizada, mas sem causar toxicidade materna e alterações no desenvolvimento geral e comportamental da sua progênie.

Pre- and postnatal evaluation of offspring rats exposed to Origanum vulgare essential oil during mating, gestation and lactation / Avaliação pré e pós-natal da prole de ratos expostos ao óleo essencial de Origanum vulgare durante acasalamento, gestação e lactação

Despite the increasing use of oregano (Origanum vulgare L.) essential oil for therapeutic purposes, pre- and postnatal development of animals offspring exposed to this oil has not yet been evaluated. In line with previous concerns of genotoxicity, in this study adult rats were exposed to different doses of oregano essential oil (3, 9 and 27% vol/vol) during pre-mating, mating, gestation and lactation. Prenatal screening included fetal development and uterine inspection, where the reproductive rate of females such as breeding, pregnancy, delivery, viability and post-implantation loss rate were measured. Postnatal evaluation of rat offspring included motor development, neuroendocrine and behavioral assessment. Body weight of rat dams and signs of dystocia were evaluated daily. Development of physic characteristics and reflex tests of puppies were also assessed. Additionally, these rats, when adults, were submitted to sexual and open field behavioral tests. The main differences among the groups were observed in the indices of mating, pregnancy and post-implantation loss (P < 0.01). Results demonstrated that the treatment of parental generation with oregano essential oil has the potential to affect the developing fetuses at the highest dose used, but without causing maternal toxicity and changes in general behavior and development of the progeny.(AU)

Apesar do aumento do uso do óleo essencial de orégano (Origanum vulgare L.) para fins terapêuticos, o desenvolvimento pré e pós-natal da progênie de animais expostos a este óleo ainda não foi avaliado. Partindo das suspeitas prévias de genotoxicidade desse óleo, neste estudo, ratos Wistar adultos foram expostos a diferentes doses do óleo essencial de orégano (3, 9 e 27% vol/vol) durante o acasalamento, a gestação e a lactação. Para a avaliação pré-natal, o desenvolvimento gestacional foi observado e os úteros inspecionados, assim como os índices reprodutivos das fêmeas, como a taxa de acasalamento, de gestação, parto e perdas pós-implantação. Na avaliação pós-natal, observou-se o desenvolvimento motor, neuroendócrino e comportamental da prole. Observou-se, diariamente, o peso das ratas e sinais de distocia. Após o parto, as características de desenvolvimento e testes de reflexos dos filhotes foram avaliadas, enquanto que, na puberdade, foram realizadas análises histopatológicas e dosagem hormonal. Adicionalmente, na idade adulta, esses ratos foram submetidos ao teste de comportamento em campo aberto e ao comportamento sexual. As principais diferenças entre os grupos foram nos índices de acasalamento, de gestação e de perdas pós-implantação (P < 0,01). Os resultados demonstram que o tratamento da geração parental com óleo essencial de orégano tem potencial para afetar os índices reprodutivos das ratas e o desenvolvimento dos fetos na maior dose utilizada, mas sem causar toxicidade materna e alterações no desenvolvimento geral e comportamental da sua progênie.(AU)

Spatial prediction of soil penetration resistance using functional geostatistics

Knowledge of agricultural soils is a relevant factor for the sustainable development of farming activities. Studies on agricultural soils usually begin with the analysis of data obtained from sampling a finite number of sites in a particular region of interest. The variables measured at each site can be scalar (chemical properties) or functional (infiltration water or penetration resistance). The use of functional geostatistics (FG) allows to perform spatial curve interpolation to generate prediction curves (instead of single variables) at sites that lack information. This study analyzed soil penetration resistance (PR) data measured between 0 and 35 cm depth at 75 sites within a 37 ha plot dedicated to livestock. The data from each site were converted to curves using non-parametric smoothing techniques. In this study, a B-splines basis of 18 functions was used to estimate PR curves for each of the 75 sites. The applicability of FG as a spatial prediction tool for PR curves was then evaluated using cross-validation, and the results were compared with classical spatial prediction methods (univariate geostatistics) that are generally used for studying this type of information. We concluded that FG is a reliable tool for analyzing PR because a high correlation was obtained between the observed and predicted curves (R2 = 94 %). In addition, the results from descriptive analyses calculated from field data and FG models were similar for the observed and predicted values.(AU)

Spatial prediction of soil penetration resistance using functional geostatistics

Knowledge of agricultural soils is a relevant factor for the sustainable development of farming activities. Studies on agricultural soils usually begin with the analysis of data obtained from sampling a finite number of sites in a particular region of interest. The variables measured at each site can be scalar (chemical properties) or functional (infiltration water or penetration resistance). The use of functional geostatistics (FG) allows to perform spatial curve interpolation to generate prediction curves (instead of single variables) at sites that lack information. This study analyzed soil penetration resistance (PR) data measured between 0 and 35 cm depth at 75 sites within a 37 ha plot dedicated to livestock. The data from each site were converted to curves using non-parametric smoothing techniques. In this study, a B-splines basis of 18 functions was used to estimate PR curves for each of the 75 sites. The applicability of FG as a spatial prediction tool for PR curves was then evaluated using cross-validation, and the results were compared with classical spatial prediction methods (univariate geostatistics) that are generally used for studying this type of information. We concluded that FG is a reliable tool for analyzing PR because a high correlation was obtained between the observed and predicted curves (R2 = 94 %). In addition, the results from descriptive analyses calculated from field data and FG models were similar for the observed and predicted values.

Plantas taniníferas e o controle de nematóides gastrintestinais de pequenos ruminantes

The gastrointestinal nematodes are responsible for a marked reduction in the productivity of sheep and goats. In an attempt to control these parasites, different synthetic anthelmintics are used, but development of resistance has become this control little effective. In the search for alternatives to control these nematodes, the use of tanniferous plants has attracted attention from researchers in different regions of the world. This review aims to address the various aspects related to the administration of these plants to sheep and goats, and the main results obtained from studies using tannins to control nematodes in small ruminants.

Os nematóides gastrintestinais são responsáveis por acentuada redução na produtividade de ovinos e caprinos. Na tentativa de controlar esses parasitos, são utilizados diversos anti-helmínticos sintéticos, mas o desenvolvimento da resistência tem tornado esse controle pouco eficaz. Na busca por alternativas de controle dos nematóides gastrintestinais, a utilização de plantas taniníferas tem despertado interesse de pesquisadores em várias regiões do mundo. Essa revisão visa a abordar os diversos aspectos relacionados ao fornecimento dessas plantas a ovinos e caprinos, bem como os principais resultados obtidos em pesquisas utilizando taninos para o controle de nematóides de pequenos ruminantes.

Plantas taniníferas e o controle de nematóides gastrintestinais de pequenos ruminantes

The gastrointestinal nematodes are responsible for a marked reduction in the productivity of sheep and goats. In an attempt to control these parasites, different synthetic anthelmintics are used, but development of resistance has become this control little effective. In the search for alternatives to control these nematodes, the use of tanniferous plants has attracted attention from researchers in different regions of the world. This review aims to address the various aspects related to the administration of these plants to sheep and goats, and the main results obtained from studies using tannins to control nematodes in small ruminants.

Os nematóides gastrintestinais são responsáveis por acentuada redução na produtividade de ovinos e caprinos. Na tentativa de controlar esses parasitos, são utilizados diversos anti-helmínticos sintéticos, mas o desenvolvimento da resistência tem tornado esse controle pouco eficaz. Na busca por alternativas de controle dos nematóides gastrintestinais, a utilização de plantas taniníferas tem despertado interesse de pesquisadores em várias regiões do mundo. Essa revisão visa a abordar os diversos aspectos relacionados ao fornecimento dessas plantas a ovinos e caprinos, bem como os principais resultados obtidos em pesquisas utilizando taninos para o controle de nematóides de pequenos ruminantes.

Leaf traits and gas exchange in saplings of native tree species in the Central Amazon

Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV) at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA), leaf thickness (LT), and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season) and August (dry season) of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax) and stomatal conductance (g s), and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]). Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot) and leaf anatomy (leaf thickness).

Os modelos climáticos globais prevêem mudanças na extensão da época seca na Amazônia, o que pode afetar a fisiologia das árvores. Os objetivos deste trabalho foram determinar o efeito da sazonalidade da precipitação e fração de céu visível (FSV) no sub-bosque da floresta nas características foliares e trocas gasosas de 10 espécies florestais da Amazônia Central. Também examinou-se a relação entre área foliar específica (SLA), espessura da folha (LT) e nitrogênio foliar em parâmetros fotossintéticos. Os resultados foram coletados nos meses de janeiro (época chuvosa) e agosto (época seca) de 2008. Observou-se um padrão de variação diurna na fotossíntese saturada por luz (Amax) e na condutância estomática (g s). Independente da espécie, Amax foi menor na época seca. No entanto, não houve efeito da sazonalidade das chuvas em g s nem na capacidade fotossintética (Apot medida em [CO2] saturante). Apot e a espessura da folha (LT) aumentaram com FSV, o contrário foi observado para a relação FSV-SLA. Também, observou-se uma relação positiva entre Apot por unidade de área e conteúdo de nitrogênio foliar, e entre Apot, por unidade de massa e SLA. Embora o regime das chuvas apenas levemente influenciou a umidade do solo, características fotossintéticas parecem responderem a fatores relacionados com as chuvas, o que repercute em Amax. Finalmente, relata-se que pequenas variações em FSV parecem afetar a fisiologia da folha (Apot) e a anatomia foliar (espessura da folha).

Leaf traits and gas exchange in saplings of native tree species in the Central Amazon

Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV) at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA), leaf thickness (LT), and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season) and August (dry season) of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax) and stomatal conductance (g s), and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]). Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot) and leaf anatomy (leaf thickness).

Os modelos climáticos globais prevêem mudanças na extensão da época seca na Amazônia, o que pode afetar a fisiologia das árvores. Os objetivos deste trabalho foram determinar o efeito da sazonalidade da precipitação e fração de céu visível (FSV) no sub-bosque da floresta nas características foliares e trocas gasosas de 10 espécies florestais da Amazônia Central. Também examinou-se a relação entre área foliar específica (SLA), espessura da folha (LT) e nitrogênio foliar em parâmetros fotossintéticos. Os resultados foram coletados nos meses de janeiro (época chuvosa) e agosto (época seca) de 2008. Observou-se um padrão de variação diurna na fotossíntese saturada por luz (Amax) e na condutância estomática (g s). Independente da espécie, Amax foi menor na época seca. No entanto, não houve efeito da sazonalidade das chuvas em g s nem na capacidade fotossintética (Apot medida em [CO2] saturante). Apot e a espessura da folha (LT) aumentaram com FSV, o contrário foi observado para a relação FSV-SLA. Também, observou-se uma relação positiva entre Apot por unidade de área e conteúdo de nitrogênio foliar, e entre Apot, por unidade de massa e SLA. Embora o regime das chuvas apenas levemente influenciou a umidade do solo, características fotossintéticas parecem responderem a fatores relacionados com as chuvas, o que repercute em Amax. Finalmente, relata-se que pequenas variações em FSV parecem afetar a fisiologia da folha (Apot) e a anatomia foliar (espessura da folha).

Effects of hydrological regime and connectivity on the interannual variation in taxonomic similarity of periphytic algae

The aim of this study was to analyze the effects of flood pulses (intensity) on the richness and composition of periphytic algae in lentic environments of the Upper Paraná River floodplain, over a six-year period. Other factors, such as connectivity of the environments with the main channel of the river and the availability of substrate for the periphyton, were also evaluated. For qualitative analyses, periphyton community was sampled from adult petioles of Eichhornia azurea Kunth taken from the littoral regions of the lakes studied. A total of 457 taxa of periphytic algae, distributed within 141 genera and 10 classes, were registered in the four environments. The greatest richness of periphytic algae was observed in connected floodplain lakes, especially in 2007 and during high water periods. In both connected and disconnected lakes, richness correlated positively with water levels of the Paraná River. Richness was also positively correlated with the number of taxa of aquatic macrophytes. The specific composition of periphytic algae differed between high and low water periods, and between connected and disconnected lakes. Therefore, among the considered variables, it is evident that flood pulse constitutes the principal force acting on periphytic algae communities of the floodplain, followed by the degree of connectivity and the presence of aquatic macrophytes.

Este trabalho visou analisar o efeito do pulso de inundação (intensidade) sobre a riqueza e composição de algas perifíticas, ao longo de seis anos, em ambientes lênticos da planície de inundação do Alto Rio Paraná. A influência da conectividade dos ambientes com a calha principal do rio e disponibilidade de substratos para a comunidade de algas perifíticas também foi avaliada. Para análise, a comunidade perifítica foi amostrada de pecíolos adultos de Eichhornia azurea Kunth, retirados da região litorânea das lagoas estudadas. Considerando os quatro ambientes, foram registrados 457 táxons de algas, distribuídos em 141 gêneros e 10 classes. A maior riqueza de algas perifíticas foi observada em lagoas conectadas, com destaque para o ano de 2007 e para o período de águas altas. A riqueza apresentou correlação positiva, nas lagoas conectadas e não conectadas, com nível hidrométrico do Rio Paraná. Também esteve correlacionada positivamente com o número de táxons de macrófitas aquáticas. A composição de algas perifíticas diferiu entre os períodos de águas altas e águas baixas e entre lagoas conectadas e não conectadas. Ficou evidente que, dentre as variáveis consideradas, o pulso de inundação constitui a principal função de força atuando sobre a comunidade de algas perifíticas na planície, seguido pelo grau de conectividade e presença de macrófitas aquáticas.

Effects of hydrological regime and connectivity on the interannual variation in taxonomic similarity of periphytic algae

The aim of this study was to analyze the effects of flood pulses (intensity) on the richness and composition of periphytic algae in lentic environments of the Upper Paraná River floodplain, over a six-year period. Other factors, such as connectivity of the environments with the main channel of the river and the availability of substrate for the periphyton, were also evaluated. For qualitative analyses, periphyton community was sampled from adult petioles of Eichhornia azurea Kunth taken from the littoral regions of the lakes studied. A total of 457 taxa of periphytic algae, distributed within 141 genera and 10 classes, were registered in the four environments. The greatest richness of periphytic algae was observed in connected floodplain lakes, especially in 2007 and during high water periods. In both connected and disconnected lakes, richness correlated positively with water levels of the Paraná River. Richness was also positively correlated with the number of taxa of aquatic macrophytes. The specific composition of periphytic algae differed between high and low water periods, and between connected and disconnected lakes. Therefore, among the considered variables, it is evident that flood pulse constitutes the principal force acting on periphytic algae communities of the floodplain, followed by the degree of connectivity and the presence of aquatic macrophytes.

Este trabalho visou analisar o efeito do pulso de inundação (intensidade) sobre a riqueza e composição de algas perifíticas, ao longo de seis anos, em ambientes lênticos da planície de inundação do Alto Rio Paraná. A influência da conectividade dos ambientes com a calha principal do rio e disponibilidade de substratos para a comunidade de algas perifíticas também foi avaliada. Para análise, a comunidade perifítica foi amostrada de pecíolos adultos de Eichhornia azurea Kunth, retirados da região litorânea das lagoas estudadas. Considerando os quatro ambientes, foram registrados 457 táxons de algas, distribuídos em 141 gêneros e 10 classes. A maior riqueza de algas perifíticas foi observada em lagoas conectadas, com destaque para o ano de 2007 e para o período de águas altas. A riqueza apresentou correlação positiva, nas lagoas conectadas e não conectadas, com nível hidrométrico do Rio Paraná. Também esteve correlacionada positivamente com o número de táxons de macrófitas aquáticas. A composição de algas perifíticas diferiu entre os períodos de águas altas e águas baixas e entre lagoas conectadas e não conectadas. Ficou evidente que, dentre as variáveis consideradas, o pulso de inundação constitui a principal função de força atuando sobre a comunidade de algas perifíticas na planície, seguido pelo grau de conectividade e presença de macrófitas aquáticas.