How do leaf wetting events affect gas exchange and leaf lifespan of plants from seasonally dry tropical vegetation?

Foliar uptake of dew is likely an important mechanism of water acquisition for plants from tropical dry environments. However, there is still limited experimental evidence describing the anatomical pathways involved in this process and the effects of this water subsidy on the maintenance of gas exchange and leaf lifespan of species from seasonally dry tropical vegetation such as the Brazilian caatinga. We performed scanning electron, bright-field and confocal microscopic analyses and used apoplastic tracers to examine the foliar water uptake (FWU) routes in four woody species with different foliar phenology and widely distributed in the caatinga. Leaves of plants subjected to water stress were exposed to dew simulation to evaluate the effects of the FWU on leaf water potentials, gas exchange and leaf lifespan. All species absorbed water through their leaf cuticles and/or peltate trichomes but FWU capacity differed among species. Leaf wetting by dew increased leaf lifespan duration up to 36 days compared to plants in the drought treatment. A positive effect on leaf gas exchange and new leaf production was only observed in the anisohydric and evergreen species. We showed that leaf wetting by dew is relevant for the physiology and leaf lifespan of plants from seasonally dry tropical vegetation, especially for evergreen species.

Foliar growth of Eriocnema fulva Naudin (Melastomataceae) in a forest fragment in southeastern Brazil.

Eriocnema fulva Naudin is an endangered herbaceous, perennial, iteroparous, evergreen species geographically restricted to southeastern-center Minas Gerais State, SE Brazil. The individuals occur as patches on rocky riverbanks shaded by seasonal semideciduous Atlantic forest; they are fixed by roots and have a pending stem. Aiming to investigate leaf development and its importance for individual survival, fifteen contiguous plots (1 x 1 m) were set down in Jambreiro Forest (19 degrees 58'-59' S and 43 degrees 52'-55' W, 800-1100 m altitude), in the municipality of Nova Lima. A total of 260 individuals with the largest leaf blade length > or = 1 cm was tagged and measured in 1997, 1998, and 1999. Leaf expansion was recorded each month during 26 months until April 2000. Plant size was measured through leaf blade length, petiole length, stem length, and number of leaves. Significant changes were detected only after two years, thus indicating that plant growth is slow. The proportion of surviving leaves after two years was 60%. Total blade expansion took over 14 months, a slow growth rate when compared to leaves of other tropical forest canopy and understory species. Long leaf lifespans are to be found in plants exhibiting slow growth, and we observed that some leaves lived longer than three years. Petiole growth can help to better position the leaf in the search for light, thus contributing to the growth and survival of the plant. The relationships among size measures were significant, reinforcing the great contribution of leaf size for plant size. The age of the largest individual was estimated as 36 years based on the median annual leaf production rate.

Foliar growth of Eriocnema fulva Naudin (Melastomataceae) in a forest fragment in southeastern Brazil

Eriocnema fulva Naudin is an endangered herbaceous, perennial, iteroparous, evergreen species geographically restricted to southeastern-center Minas Gerais State, SE Brazil. The individuals occur as patches on rocky riverbanks shaded by seasonal semideciduous Atlantic forest; they are fixed by roots and have a pending stem. Aiming to investigate leaf development and its importance for individual survival, fifteen contiguous plots (1 x 1 m) were set down in Jambreiro Forest (19° 58’-59’ S and 43° 52’-55’ W, 800-1100 m altitude), in the municipality of Nova Lima. A total of 260 individuals with the largest leaf blade length > 1 cm was tagged and measured in 1997, 1998, and 1999. Leaf expansion was recorded each month during 26 months until April 2000. Plant size was measured through leaf blade length, petiole length, stem length, and number of leaves. Significant changes were detected only after two years, thus indicating that plant growth is slow. The proportion of surviving leaves after two years was 60 percent. Total blade expansion took over 14 months, a slow growth rate when compared to leaves of other tropical forest canopy and understory species. Long leaf lifespans are to be found in plants exhibiting slow growth, and we observed that some leaves lived longer than three years. Petiole growth can help to better position the leaf in the search for light, thus contributing to the growth and survival of the plant. The relationships among size measures were significant, reinforcing the great contribution of leaf size for plant size. The age of the largest individual was estimated as 36 years based on the median annual leaf production rate.

Eriocnema fulva é uma espécie herbácea, perene, iteropárica, com distribuição geográfica restrita ao centro-sudeste do Estado de Minas Gerais, Brasil, e ameaçada de extinção. Os indivíduos ocorrem agrupados em paredões rochosos, na beira de riachos sombreados pela Mata Atlântica estacional semidecídua e têm caule que pendem do barranco. Com o objetivo de investigar o desenvolvimento da folha e sua importância para a sobrevivência dos indivíduos, foram instaladas 15 parcelas contíguas de 1 x 1 m na Mata do Jambreiro (19° 58’-59’S, 43° 52’-55’ W, 800-1100 m de altitude), município de Nova Lima. Todos os indivíduos cuja maior folha tivesse comprimento do limbo maior ou igual a 1 cm foram marcados, sendo medidos em 1997, 1998 e 1999. O tempo de expansão da folha foi registrado mensalmente durante 26 meses até abril de 2000. Na área amostrada foram marcados 260 indivíduos cujo limbo foliar tinha comprimento > 1cm. O tamanho das plantas, medido através do comprimento do limbo e do pecíolo e do número de folhas, apresentou mudanças significativas somente após dois anos, indicando que o crescimento é lento. A proporção das folhas sobreviventes após dois anos foi de 60 por cento. O tempo necessário para a expansão da folha foi superior a 14 meses e é lento quando comparado com o de outras espécies do dossel ou do sub-bosque da floresta tropical. Maior longevidade foliar tende a ser encontrada em plantas de crescimento lento. Observamos que algumas folhas tiveram maior longevidade que 3 anos. O crescimento do pecíolo pode ajudar no melhor posicionamento da folha na busca de luz no sub-bosque, contribuindo para o crescimento e sobrevivência da planta. As relações entre a folha e demais medidas de tamanho foram significativas, indicando sua grande importância para o tamanho de cada planta. A idade do indivíduo de maior tamanho foi estimada em 36 anos através da taxa mediana de produção anual de folhas.

Size structure and fertility in an Eriocnema fulva Naudin (Melastomataceae) population in Southeastern Brazil

Eriocnema fulva Naudin is an endangered perennial herbaceous plant, endemic to Minas Gerais state, Brazil. This study was conducted in the Jambreiro Forest (19° 58' -59'S and 43° 52' -55' W, 800-1100 m altitude). In an attempt to describe the population size structure and its association with individual fertility, fifteen 1 x 1 m contiguous plots were set. We tagged, counted, and measured a total of 260 individuals in 1997, 1998 and 1999. Young individuals with leaf lamina lengths < 3.4 cm comprised 33 percent of the total sampled, indicating that the population was reproducing locally. The number of leaves varied significantly, growth differences being detected only after two years of measurements. Stem length was the variable that best showed population size variation. The length of the largest leaf lamina was the best indication of its development phase. Assessing the number of leaves helped to evaluate the alteration in plant size during the study. The probability that individuals with laminas > 10 cm in length did not reproduce was 2.69 percent. The highest survival probability of the large-sized individuals confirmed the strong correlation between size and survival. The data indicated that size is important for the fertility of E. fulva, and it may be one of the relevant aspects to be considered for analyses of survival probability. The intraspecific competition, which was indicated by negative correlation between fruit production per size unit and density, can affect fertility, as larger plants had higher fruit production.

Eriocnema fulva é endêmica no estado de Minas Gerais e é ameaçada de extinção. Este estudo foi realizado na Mata do Jambreiro (19° 58' -59' S e 43° 52'-55' W, 800-1100 m de altitude) Com o objetivo de descrever a estrutura de tamanho da população e suas relações com a fertilidade dos indivíduos, foram instaladas 15 parcelas contíguas de 1 x 1m. Marcamos, contamos e medimos um total de 260 indivíduos em 1997, 1998 e 1999. Os indivíduos jovens com o comprimento do limbo < 3,4 cm somaram 33 por cento do total amostrado, mostrando que a população estava reproduzindo-se no local. O número de folhas variou significativamente entre os anos, com diferenças de crescimento só detectadas após dois anos de medições. O comprimento do caule foi a variável que melhor mostrou a variação de tamanho na população. O comprimento da lâmina da maior folha foi a melhor expressão da fase de desenvolvimento da planta, e o número de folhas auxiliou na avaliação da alteração do tamanho ao longo do tempo. A probabilidade de indivíduos com limbos foliares > 10 cm não se reproduzirem foi de 2,69 por cento. A maior probabilidade de sobrevivência dos indivíduos de maior tamanho confirmou a forte correlação entre tamanho e sobrevivência. Os dados mostraram que o tamanho é importante para a fertilidade de Eriocnema fulva e pode ser relevante para análises de probabilidade de sobrevivência da espécie. A competição intra-específica, indicada pela correlação negativa entre a produção de frutos por unidade de tamanho e a densidade, pode influir na fertilidade, pois plantas maiores apresentaram maior produção de frutos.

Reproductive system of Eriocnema fulva Naudin (Melastomataceae), an endemic species of Minas Gerais state, SE Brazil.

Eriocnema fulva Naudin is a perennial herb, endemic to Minas Gerais state, SE Brazil, found on humid, shaded rocky riverbanks in montane semideciduous seasonal forests. The species is threatened, but information regarding its biology is still lacking, although such information is fundamental to any management plan. We aimed to evaluate the reproductive system of Eriocnema fulva in the Jambreiro Forest (19 degrees 58'-59' S and 43 degrees 55'-52' W, 800-1100 m altitude), municipality of Nova Lima, by experiments carried out in 1997 and 1998. The flowers are white, and flowering is of the steady state type, occurring once a year from November to December. Anthers are poricidal, and pollen is the only resource for visitors. The chromosome number is n = 17 during meiosis. The species is self-compatible, but does not produce fruits by spontaneous self-pollination or agamospermy; it requires pollen vectors and buzz pollination in order to produce fruits. Cross-pollination is the main reproductive strategy of E. fulva, and is accentuated by the small number of flowers (one or two in each plant) opened per day. Although the population studied was shaded by forest canopy, the seeds needed light to germinate. Germination ratio was lower in germination cabinet on filter paper (14% after 30 days) than in greenhouse on soil brought from the forest (47% after 25 days). Although the fruit is a capsule and the seeds are small, dispersion (anemochory or hydrochory) does not seem to occur at long distance, as it is the case for other Melastomataceae species with similar syndrome.

Reproductive system of Eriocnema fulva Naudin (Melastomataceae), an endemic species of Minas Gerais state, SE Brazil

Eriocnema fulva Naudin is a perennial herb, endemic to Minas Gerais state, SE Brazil, found on humid, shaded rocky riverbanks in montane semideciduous seasonal forests. The species is threatened, but information regarding its biology is still lacking, although such information is fundamental to any management plan. We aimed to evaluate the reproductive system of Eriocnema fulva in the Jambreiro Forest (19° 58'-59' S and 43° 55'-52' W, 800-1100 m altitude), municipality of Nova Lima, by experiments carried out in 1997 and 1998. The flowers are white, and flowering is of the steady state type, occurring once a year from November to December. Anthers are poricidal, and pollen is the only resource for visitors. The chromosome number is n = 17 during meiosis. The species is self-compatible, but does not produce fruits by spontaneous self-pollination or agamospermy; it requires pollen vectors and buzz pollination in order to produce fruits. Cross-pollination is the main reproductive strategy of E. fulva, and is accentuated by the small number of flowers (one or two in each plant) opened per day. Although the population studied was shaded by forest canopy, the seeds needed light to germinate. Germination ratio was lower in germination cabinet on filter paper (14 percent after 30 days) than in greenhouse on soil brought from the forest (47 percent after 25 days). Although the fruit is a capsule and the seeds are small, dispersion (anemochory or hydrochory) does not seem to occur at long distance, as it is the case for other Melastomataceae species with similar syndrome.

Eriocnema fulva Naudin é uma planta herbácea, perene, endêmica no estado de Minas Gerais, sendo encontrada em paredões rochosos úmidos, ao longo de riachos sombreados pela Floresta Estacional Semidecídua Montana. A espécie é ameaçada de extinção e não existem informações sobre a sua biologia, embora sejam fundamentais para um plano de manejo. Com o objetivo de avaliar o sistema de reprodução, foram feitos experimentos em 1997 e 1998 em uma população na Mata do Jambreiro (19° 58'-59' S e 43° 55'-52' W, 800-1100 m de altitude), no município de Nova Lima. As flores são brancas e a floração é do tipo steady state, ocorrendo uma vez ao ano durante novembro e dezembro. As anteras são poricidas e o pólen é a única recompensa para os visitantes. O número cromossômico encontrado na meiose foi n = 17. A espécie é autocompatível, não produz frutos por autopolinização espontânea nem por agamospermia, mas requer obrigatoriamente vetores de pólen e polinização vibrátil. A polinização cruzada é a principal estratégia reprodutiva de Eriocnema fulva, sendo acentuada devido ao pequeno número de flores abertas por dia, apenas uma ou duas em cada planta. Embora as populações estejam localizadas em ambientes sombreados e úmidos, as sementes precisam de luz para germinar, sendo fotoblásticas positivas. A taxa de germinação em papel de filtro na câmara de germinação foi menor (14 por cento após 30 dias) que em solo da floresta na casa de vegetação (47 por cento após 25 dias). Embora o fruto seja do tipo cápsula com sementes pequenas, a dispersão (anemocoria ou hidrocoria) parece não ocorrer a distâncias longas, como é observada em outras espécies de Melastomataceae com síndrome de dispersão semelhante.

Size structure and fertility in an Eriocnema fulva Naudin (Melastomataceae) population in Southeastern Brazil.

Eriocnema fulva Naudin is an endangered perennial herbaceous plant, endemic to Minas Gerais state, Brazil. This study was conducted in the Jambreiro Forest (19 degrees 58' -59'S and 43 degrees 52' -55' W, 800-1100 m altitude). In an attempt to describe the population size structure and its association with individual fertility, fifteen 1 x 1 m contiguous plots were set. We tagged, counted, and measured a total of 260 individuals in 1997, 1998 and 1999. Young individuals with leaf lamina lengths < or = 3.4 cm comprised 33% of the total sampled, indicating that the population was reproducing locally. The number of leaves varied significantly, growth differences being detected only after two years of measurements. Stem length was the variable that best showed population size variation. The length of the largest leaf lamina was the best indication of its development phase. Assessing the number of leaves helped to evaluate the alteration in plant size during the study. The probability that individuals with laminas > or = 10 cm in length did not reproduce was 2.69%. The highest survival probability of the large-sized individuals confirmed the strong correlation between size and survival. The data indicated that size is important for the fertility of E. fulva, and it may be one of the relevant aspects to be considered for analyses of survival probability. The intraspecific competition, which was indicated by negative correlation between fruit production per size unit and density, can affect fertility, as larger plants had higher fruit production.

Floristic, frequency, and vegetation life-form spectra of a cerrado site.

We used Raunkiaer's system to classify in life-forms the vascular plants present in 12 random 25 m2 quadrats of a cerrado site. The study area is covered by cerrado sensu stricto and is located in the Valério fragment, at about 22 degrees 13'S and 47 degrees 51'W, 760 m above sea level, in the Itirapina Ecological and Experimental Station, São Paulo State, southeastern Brazil. The floristic spectrum considers the life-form of each species, while in the frequency spectrum, each species is weighted by its frequency. The vegetation spectrum does not consider the species at all, but only the individuals in each life-form class. In the floristic spectrum, the most represented life-forms were the phanerophytes and the hemicryptophytes, as in other cerrado sites. This spectrum differed significantly from Raunkiaer's normal spectrum, mainly due to under-representation of therophytes and over-representation of phanerophytes. The floristic and frequency spectra were similar, but both differed from the vegetation spectrum. We recommend the floristic spectrum when working at larger scales and a description of the phytoclimate is wanted. The vegetation spectrum is preferable when working at smaller scales and wanting a quantitative description of the physiognomy. The frequency spectrum is not recommended at all.

Floristic, frequency, and vegetation life-form spectra of a cerrado site

Usamos o sistema de Raunkiaer para classificar, em formas de vida, as plantas vasculares presentes em 12 parcelas aleatórias de 25 m2 de cerrado. A área de estudo é coberta por cerrado sensu stricto e se localiza no fragmento do Valério, aproximadamente a 22§13'S e 47§51'W, a 760 m de altitude, na Estação Ecológica e Experimental de Itirapina, Estado de São Paulo. O espectro florístico considera a forma de vida de cada espécie; no espectro de freqüência, cada espécie é ponderada por sua freqüência e o espectro vegetacional não considera as espécies, mas sim os indivíduos em cada classe. No espectro florístico, as forma de vida mais bem representadas foram as dos fanerófitos e dos hemicriptófitos, como em outros cerrados. Esse espectro diferiu significativamente do espectro normal de Raunkiaer devido, principalmente, à sub-representação dos terófitos e à super-representação dos fanerófitos. Os espectros florísticos e de freqüência foram similares, mas ambos diferiram do espectro vegetacional. Recomendamos o espectro florístico para os trabalhos em escalas maiores e para descrição do fitoclima e o espectro vegetacional para os trabalhos em escalas menores e para descrição quantitativa da fisionomia. O espectro de freqüência não é recomendado em nenhuma situação.

[Inhalation of nitric oxide - dependence: case report] / Dependência do óxido nítrico inalatório: relato de caso.

OBJECTIVE: Describe the hemodynamic response with rebound of pulmonary hypertension after withdrawal of inhaled nitric oxide (NO) in a pediatric patient with acute respiratory distress syndrome (ARDS). METHODS: Case report of a child with ARDS and pulmonary hypertension evaluated through ecocardiografic with dopller, receiving inhaled NO for a period of 21 days. RESULTS: There was a decrease of the pulmonary artery pressure (PAP) from 52 mmHg to 44 mmHg after the initial titulation of NO inhalation dose. After the withdrawal of inhaled NO an elevation of PAP was observed (55 mmHg). It was necessary to reinstall the inhaled NO to obtain a more appropriate value (34 mmHg). A new attempt of interruption of the inhaled NO after prolonged inhalation (20 days) resulted in a new clinic worsening and increase of PAP, with the indication to reinstall the inhaled NO. In the 24th day of permanence in the intensive care unit the patient died due to multiple organ dysfunction. CONCLUSIONS: The possibility of pulmonary hypertension rebound after withdrawal of inhaled NO is a complication that may have important clinical implications for patients who need a prolonged treatment with NO. This case report emphasizes these implications.

[Variations of structure and of flora of the "carrasco" vegetation of the Ibiapaba plateau, state of Cearsá, Brazil]. / Variações estruturais e florísticas do carrasco no planalto da ibiapaba, estado do Ceará.

"Carrasco" is a closed, tall-shrubby, xerophilous vegetation on Quartz Sand soils between altitudes of 700 and 900 m on Ibiapaba and Araripe plateaus in the Brazilian semi-arid domain. As it is still very poorly known, this paper aims to describe the structure and composition of the woody community and its spatial variation in relation to the soil. One-hundred 10 x 10 m plots were located by pairs of random numbers in a coordinate system at the locality of Jaburuna (3 degrees 54'34"S, 40 degrees 59'24"W, about 830 m altitude), municipality of Ubajara, north Ibiapaba. All woody plants with a minimum stem diameter of 3 cm at ground level had their vertical height (not for climbers) and stem perimeter recorded. A soil extract from 0-50 cm depth was taken at the centre of each plot. Published surveys of other carrasco areas on the south Ibiapaba were considered for comparison. The community structure showed great dominance concentration, the most abundant species (Acacia langsdorffii, Piptadenia moniliformis, Thiloa glaucocarpa) varied between surveys. At Jaburuna 81% of all sampled plants were shrubs, 14% trees (the most with less than 10 cm of trunk diameter and 6 m height), and 5% climbers. Canberra distances and Jaccard's Indices were calculated from a primary matrix of 87 species (with 5 or more individuals) and 175 plots. Several methods of cluster analysis were employed, all showed great floristic variation from place to place. A matrix of soil physical and chemical variates per plot was constructed, and the canonical correspondence analysis was applied to both primary and soil matrices. Lower pH and higher sum of bases (e. g. Brunfelsia cuneifolia, Neojeobertia candoleana), higher content of gross sand (e. g. Acacia glomerosa, Aspidosperma subincanumn) and higher content of fine sand (e. g. Aspidosperma discolor, Hymenaea velutina) were the main variates separating species. The floristic richness at Jaburuna was of 74 species, and the surveys showed no difference in Shannon's diversity, which varied from 2.87 to 3.16 nats/individual.

[3-Hydroxy-3-methyl-glutaryl-CoA-lyase deficiency as coma etiology in the neonatal period: case report]. / Deficiência da 3-OH-3-metil-glutaril-CoA-liase como causa de coma no período neonatal. Relato de caso.

We report a patient that presented two episodes of coma in the neonatal period, with severe metabolic acidosis and hypoglycemia, without ketosis. The urinary organic acid analysis showed increased amounts of 3-hydroxy-3-methyl-glutaric, 3-methylglutaconic, 3-methylglutaric and 3-hydroxyisovaleric acid. The deficiency of 3-hydroxy-3-methylglutaryl-CoA lyase was diagnosed by the clinical and metabolic features. This disease shows autosomal recessive inheritance and the treatment is done by a diet with restriction of protein (mainly leucine) and lipids, high in carbohydrate content, and the avoidance of fasting and carnitine supplementation.

Severe and fatal mass attacks by 'killer' bees (Africanized honey bees--Apis mellifera scutellata) in Brazil: clinicopathological studies with measurement of serum venom concentrations.

In São Paulo State, Brazil, five males, aged between 8 and 64 years, were attacked by 'Africanized' honey bees (Apis mellifera scutellata). The estimated number of stings received by each patient ranged from > 200 to > 1000. All five were transferred to intensive care units in São Paulo City. Clinical features included intravascular haemolysis, respiratory distress with ARDS, hepatic dysfunction, rhabdomyolysis (with myoglobinaemia and myoglobinuria), hypertension and myocardial damage (perhaps explained by release of endogenous catecholamines by venom phospholipase A2 and mellitin), shock, coma, acute renal failure and bleeding. Laboratory findings included gross neutrophil leucocytosis, elevated serum enzymes [AST, ALT, LDH, CPK (predominantly CPK-MM)] and creatinine. Clotting times were slightly prolonged. Despite treatment with antihistamines, corticosteroids, bronchodilators, vasodilators, bicarbonate, mannitol and mechanical ventilation, three of the patients died between 22 and 71 h after the attacks, with histopathological features of ARDS, hepatocellular necrosis, acute tubular necrosis, focal subendocardial necrosis and disseminated intravascular coagulation. Whole bee venom and phospholipase A2 (PLA2) antigen concentrations were measured in serum and urine for the first time, using enzyme immunoassay. High venom and PLA2 concentrations were detected in serum and urine for more than 50 h after the stings in two fatal cases, in one of which the total circulating unbound whole venom was estimated at 27 mg, one hour after the attack. An antivenom should be developed to treat the increasing numbers of victims of mass attacks by Africanized 'killer' bees in USA, Middle and South America.