1,342 research outputs found
On the occurrence of Mesophyllum expansum (Philippi) Cabioch et Mendoza (Melobesioideae, Corallinales, Rhodophyta) in the Mediterranean, the Canary Isles and the Azores.
Copyright © 2010 by Walter de Gruyter.We reviewed literature records, examined herbarium specimens and studied new collections referred to as Mesophyllum lichenoides from the Mediterranean and the North Atlantic, and report for the first time the presence of Mesophyllum expansum in the Canaries and the Azores. Both gametophytes and tetrasporophytes of M. expansum occur in the Canaries, while we found only tetrasporophytes (and sterile thalli) of the species in all other regions. We further consider the presence of M. lichenoides further south than Atlantic France in need of confirmation. A comparative study between these two species points to the number of rosette cells as the most reliable and easily diagnosed character, M. expansum most often having 911 and M. lichenoides 68 cells
Poredbene hematološke i biokemijske analize divovske amazonske kornjače uzgajane pod lošim i normalnim hranidbenim uvjetima
Besides indicating the baseline values of the species, blood parameter assessments of chelonian may also be used as quick tools for diagnosing health status. An investigation was carried out to assess and compare red blood cells parameters, white blood cell (WBC) and total thrombocyte counts and certain blood biochemical parameters for freshwater turtles, Podocnemis expansa Schweigger, 1812 (Pelomedusidae) reared on normal (control group) and poor nutrition (malnourished group). For the malnourished turtles, a signififi cant decrease (P<0.05) in red blood cell counts was found, including hematocrit, plasma glucose, plasma total protein, cholesterol and urea levels, as well as WBC counts, azurophils and heterophils. Malnutrition did not alter the hemostasis, but caused severe normocytic-hypocromic anemia and marked immune depression, which were diagnosed here. This study was the fifi rst to characterize the physiological and immune status of giant turtles from
the Amazon under adverse nutritional conditions.Osim za utvrđivanje osnovnih vrijednosti osebujnih za vrstu, pretraživanje krvnih pokazatelja može u kornjača biti rabljeno za brzo određivanje njihova zdravstvenoga stanja. Istraživanje je poduzeto da se odrede i usporede pokazatelji crvenih krvnih stanica, bijelih krvnih stanica, ukupnog broja trombocita i neki biokemijski pokazatelji za slatkovodne kornjače Podocnemis expansa Schweigger, 1812 (Pelomedusidae) uzgajane u normalnim (kontrolna skupina) i lošim hranidbenim uvjetima (pokusna skupina). U kornjača uzgajanih u lošim uvjetima ustanovljen je značajno smanjen (P<0,05) broj crvenih krvnih stanica kao i smanjene vrijednosti hematokrita, razine glukoze u plazmi, razine ukupnih proteina plazme, kolesterola i mokraćevine te broj bijelih krvnih stanica, azurofila i heterofila. Loša hranidba nije utjecala na hemostazu, ali je prouzročila tešku normocitnu hipokromnu anemiju i znatnu imunodepresiju. Ovo je prvo istraživanje u kojem je prikazan fiziološki i imunološki status divovske kornjače iz Amazone, držane u nepovoljnim hranidbenim uvjetima
Stand dynamics modulate water cycling and mortality risk in droughted tropical forest
Transpiration from the Amazon rainforest generates an essential water source at a global and local scale. However, changes in rainforest function with climate change can disrupt this process, causing significant reductions in precipitation across Amazonia, and potentially at a global scale. We report the only study of forest transpiration following a long-term (>10 year) experimental drought treatment in Amazonian forest. After 15 years of receiving half the normal rainfall, drought-related tree mortality caused total forest transpiration to decrease by 30%. However, the surviving droughted trees maintained or increased transpiration because of reduced competition for water and increased light availability, which is consistent with increased growth rates. Consequently, the amount of water supplied as rainfall reaching the soil and directly recycled as transpiration increased to 100%. This value was 25% greater than for adjacent nondroughted forest. If these drought conditions were accompanied by a modest increase in temperature (e.g., 1.5°C), water demand would exceed supply, making the forest more prone to increased tree mortality.Peer reviewe
Capacitação continuada em pecuária leiteira para técnicos do estado do Mato Grosso: fase I: levantamento de demandas e treinamento básico.
Tolerância à acidez e alumínio tóxico por isolados de rizóbios de solos no Amazonas, Brasil
Plant traits controlling growth change in response to a drier climate
This is the final version. Available on open access from Wiley via the DOI in this recordPlant traits are increasingly being used to improve prediction of plant function, including plant demography. However, the capability of plant traits to predict demographic rates remains uncertain, particularly in the context of trees experiencing a changing climate. Here we present data combining 17 plant traits associated with plant structure, metabolism and hydraulic status, with measurements of long-term mean, maximum and relative growth rates for 176 trees from the world’s longest running tropical forest drought experiment. We demonstrate that plant traits can predict mean annual tree growth rates with moderate explanatory power. However, only combinations of traits associated more directly with plant functional processes, rather than more commonly employed traits like wood density or leaf mass per area, yield the power to predict growth. Critically, we observe a shift from growth being controlled by traits related to carbon cycling (assimilation and respiration) in well-watered trees, to traits relating to plant hydraulic stress in drought-stressed trees. We also demonstrate that even with a very comprehensive set of plant traits and growth data on large numbers of tropical trees, considerable uncertainty remains in directly interpreting the mechanisms through which traits influence performance in tropical forests.Conselho Nacional de Desenvolvimento Científico e TecnológicoNatural Environment Research Council (NERC)Australian Research Council (ARC)European Union FP7Fundação de Amparo à Pesquisa do Estado de São Paul
Spermatogenesis in goats with and without scrotum bipartition
The objective of the present research was to quantify the seminiferous epithelium cells, spermatogenesis efficiency and characterize the ultrastrucure of Sertoli cells in goats. Eighteen goats were used and divided into three groups: Group I - goats without bipartition of the scrotum; Group II - animals with bipartition of the scrotum in up to 50% of the testicular length; Group III - goats with bipartition of the scrotum in more than 50% of the testicular length. The goat testes in Group III had a greater number of primary spermatocytes (25.37 +/- 4.55 cells per cross sections), spermatids (112 +/- 15.12 cells per cross sections), and Sertoli cells (9.46 +/- 1.74 cells per cross sections) than the animals in Groups land (P <0.05). The spermatogenic mitotic, meiotic, and general efficiency were greater in animals in Group III (1.25 +/- 0.28; 5.12 +/- 1.63; 6.44 +/- 1.96) when compared to those in Groups I and II. Sheet-like processes originated from the Sertoli cell body as simple and smooth structures which involved almost all the surface of germ cells. Slender cord-like processes originated from Sertoli cells and also from the sheet-like processes. The relative frequency of the cycle stages showed differences among the groups of goats studied, and the highest frequency was in Stage 3 (20.68% for goats in Group I, 21.15% for those in Group II, and 16.89% for the animals in Group III). In conclusion, goats with bipartition of the scrotum have a greater number of germ and Sertoli cells per cross section of seminiferous tubule, that indicated a greater sperm production when compared to the other groups, and the ultrastructure of the Sertoli cell process did not present any relationship with bipartition of the scrotum. (C) 2012 Elsevier B.V. All rights reserved.CNPq 620240/2006-
The response of carbon assimilation and storage to long‐term drought in tropical trees is dependent on light availability
Whether tropical trees acclimate to long‐term drought stress remains unclear. This uncertainty is amplified if drought stress is accompanied by changes in other drivers such as the increases in canopy light exposure that might be induced by tree mortality or other disturbances. Photosynthetic capacity, leaf respiration, non‐structural carbohydrate (NSC) storage and stomatal conductance were measured on 162 trees at the world's longest running (15 years) tropical forest drought experiment. We test whether surviving trees have altered strategies for carbon storage and carbon use in the drier and elevated light conditions present following drought‐related tree mortality. Relative to control trees, the surviving trees experiencing the drought treatment showed functional responses including: (a) moderately reduced photosynthetic capacity; (b) increased total leaf NSC; and (c) a switch from starch to soluble sugars as the main store of branch NSC. This contrasts with earlier findings at this experiment of no change in photosynthetic capacity or NSC storage. The changes detected here only occurred in the subset of drought‐stressed trees with canopies exposed to high radiation and were absent in trees with less‐exposed canopies and also in the community average. In contrast to previous results acquired through less intensive species sampling from this experiment, we also observe no species‐average drought‐induced change in leaf respiration. Our results suggest that long‐term responses to drought stress are strongly influenced by a tree's full‐canopy light environment and therefore that disturbance‐induced changes in stand density and dynamics are likely to substantially impact tropical forest responses to climate change. We also demonstrate that, while challenging, intensive sampling is essential in tropical forests to avoid sampling biases caused by limited taxonomic coverage.Publicado online em 29 set. 2020
Propagação e manejo fitossanitário de mudas de maniçoba.
Neste trabalho são apresentadas as principais recomendações para alcançar sucesso na propagação de mudas de maniçoba por meio de sementes ou por meio de estaquia em condições de viveiro, bem como o manejo fitossanitário, com o objetivo de direcionar de forma adequada as práticas adotadas por viveiristas e agricultores na condução desta etapa inicial do desenvolvimento das plantas.O principal fator para quebra de dormência em sementes de maniçoba é o tempo de armazenamento de no mínimo 1 ano. Se utilizado em conjunto com a escarificação mecânica com lixa e imersão em água, por 2 horas, não haverá grandes dificuldades para a produção de mudas por este método. Para fixação das qualidades genéticas de boas matrizes de maniçoba (produção de clones), a propagação de mudas por estaquia é a escolha correta. No caso da maniçoba, este método é mais rápido e fácil para a produção por pequenos produtores. Neste caso, a escolha da matriz é o principal fator a ser observado na produção de mudas de maniçoba.bitstream/item/219143/1/COMUNICADO-TECNICO-179.pd
DETECCIÓN, CARACTERIZACIÓN SEROLÓGICA Y ANTIBIOGRAMAS DEEscherichia coli AISLADAS DE CARNE DE TERNERA (BABILLA) ENTERA Y PICADA
Los brotes de Enfermedades Transmisibles por Alimentos (ETA) representan una preocupación para las industrias alimentarias y los organismos de salud pública. Las cepas patógenas de Escherichia coli están comúnmente presentes en el trato intestinal de los animales, lo que favorece la contaminación durante el sacrificio o durante un procesamiento inadecuado de la canal. La importancia que la carne tiene en la alimentación humana junto con la necesidad de ofrecer un alimento inocuo e incapaz de transmitir enfermedades, incitaron el desarrollo de este estudio, que tiene por objetivos, detectar, caracterizar los serogrupos y realizar los antibiogramas de E. coli. aisladas de 30 muestras de carne de ternera (babilla) comercializadas en mercados y carnicerías de Río de Janeiro, Brasil. Se emplearon 15 muestras de carne entera y 15 de carne picada (en el propio establecimiento). Se utilizaron diferentes metodologías para la confirmación bioquímica y serológicamente de las colonias aisladas. Una vez identificados los serogrupos, se testó su susceptibilidad a diferentes antibióticos. De las muestras analizadas, el 100% resultaron contaminadas con coliformes totales y en cinco (16,7%) de ellas, no se detectaron coliformes fecales. En carne entera, los recuentos de coliformes totales oscilaron de 4,0x103 a 1,1x106 y E.coli de 0 a 2,4x103 mientras que en carne picada oscilaron de 4,4x103 a 2,5x107 y 0 a 3,0x105, respectivamente. Con relación a la metodología empleada,el segundo método demostró ser más eficiente que el tercer método, ya que presentó un mayornúmero de colonias confirmadas. Utilizando el segundo método, se aislaron 52 cepas de E. colienteropatogénica (EPEC), ocho cepas de E. coli enteroinvasiva (EIEC) y una cepa de E. coli enterohemorrágica (EHEC). Las cepas de E. coli aisladas y tipificadas como patógenas presentaron un gran espectro de resistencia a los antibióticos testados, principalmente a ampicilina (11,32%), cefalotina (11,11%) y amicacina (10,06%). La presencia de serogrupos de E. coli en las muestras confirman la necesidad de implantar los programas de Buenas Practicas de Fabricac ión (BPF), Procedimientos Patrón de Higiene Operacional (PPHO) y Análisis de Peligros y Puntos Críticos de Control (APPCC), lo que diminuiría el riesgo para el consumidor.Palabras clave: Escherichia coli, carne de ternera entera y picada, antibiograma.Escherichia coli, whole and ground beef, antibiogram
- …