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21.
Silvia Fernández-Lugo Luis Alberto Bermejo Lea de Nascimento Javier Méndez Agustín Naranjo-Cigala José Ramón Arévalo 《Plant Ecology》2013,214(4):641-656
In this study, we inquire into the effects of short-term goat grazing abandonment on plant species and functional composition, bare ground and net primary productivity (NPP) in two traditionally grazed pastures located in the Canarian Network of Natural Protected Areas and the Natura 2000 Network. In addition, we analyse soil chemical properties, biomass tannin content and energetic value to find out how grazing abandonment affects soil fertility and forage quality of these agroecosystems. Grazing exclusion effects on plant species and functional composition, as well as on soil fertility depended on the productivity of the studied pasture. Erect forbs and shrubs (endemic to Macaronesian region and native) were favoured by grazing removal in the most productive pasture, while soil fertility decreased in the driest and least productive site. An increase in NPP after exclusion was consistent among study sites. Although we consider goat grazing as necessary for maintaining traditional agroecosystems, we also suggest controlling it over time, allowing some periods of rest to give endemic shrub species time to recover from near propagule sources. 相似文献
22.
Camila Gewehr Sara Marchesan Oliveira Mateus Fortes Rossato Gabriela Trevisan Gerusa Duarte Dalmolin Flávia Karine Rigo Célio José de Castro Júnior Marta Nascimento Cordeiro Juliano Ferreira Marcus V. Gomez 《PLoS neglected tropical diseases》2013,7(4)
Background
The frequency of accidental spider bites in Brazil is growing, and poisoning due to bites from the spider genus Phoneutria nigriventer is the second most frequent source of such accidents. Intense local pain is the major symptom reported after bites of P. nigriventer, although the mechanisms involved are still poorly understood. Therefore, the aim of this study was to identify the mechanisms involved in nociception triggered by the venom of Phoneutria nigriventer (PNV).Methodology/Principal Findings
Twenty microliters of PNV or PBS was injected into the mouse paw (intraplantar, i.pl.). The time spent licking the injected paw was considered indicative of the level of nociception. I.pl. injection of PNV produced spontaneous nociception, which was reduced by arachnid antivenin (ArAv), local anaesthetics, opioids, acetaminophen and dipyrone, but not indomethacin. Boiling or dialysing the venom reduced the nociception induced by the venom. PNV-induced nociception is not dependent on glutamate or histamine receptors or on mast cell degranulation, but it is mediated by the stimulation of sensory fibres that contain serotonin 4 (5-HT4) and vanilloid receptors (TRPV1). We detected a kallikrein-like kinin-generating enzyme activity in tissue treated with PNV, which also contributes to nociception. Inhibition of enzymatic activity or administration of a receptor antagonist for kinin B2 was able to inhibit the nociception induced by PNV. PNV nociception was also reduced by the blockade of tetrodotoxin-sensitive Na+ channels, acid-sensitive ion channels (ASIC) and TRPV1 receptors.Conclusion/Significance
Results suggest that both low- and high-molecular-weight toxins of PNV produce spontaneous nociception through direct or indirect action of kinin B2, TRPV1, 5-HT4 or ASIC receptors and voltage-dependent sodium channels present in sensory neurons but not in mast cells. Understanding the mechanisms involved in nociception caused by PNV are of interest not only for better treating poisoning by P. nigriventer but also appreciating the diversity of targets triggered by PNV toxins. 相似文献23.
Iracema Andrade Nascimento Sheyla Santa Izabel Marques Iago Teles Dominguez Cabanelas Solange Andrade Pereira Janice Isabel Druzian Carolina Oliveira de Souza Daniele Vital Vich Gilson Correia de Carvalho Maurício Andrade Nascimento 《Bioenergy Research》2013,6(1):1-13
The viability of algae-based biodiesel industry depends on the selection of adequate strains in regard to profitable yields and oil quality. This work aimed to bioprospecting and screening 12 microalgae strains by applying, as selective criteria, the volumetric lipid productivity and the fatty acid profiles, used for estimating the biodiesel fuel properties. Volumetric lipid productivity varied among strains from 22.61 to 204.91 mg l?1 day?1. The highest lipid yields were observed for Chlorella (204.91 mg l?1 day1) and Botryococcus strains (112.43 and 98.00 mg l?1 day?1 for Botryococcus braunii and Botryococcus terribilis, respectively). Cluster and principal components analysis analysis applied to fatty acid methyl esters (FAME) profiles discriminated three different microalgae groups according to their potential for biodiesel production. Kirchneriella lunaris, Ankistrodesmus fusiformis, Chlamydocapsa bacillus, and Ankistrodesmus falcatus showed the highest levels of polyunsaturated FAME, which incurs in the production of biodiesels with the lowest (42.47–50.52) cetane number (CN), the highest (101.33–136.97) iodine values (IV), and the lowest oxidation stability. The higher levels of saturated FAME in the oils of Chlamydomonas sp. and Scenedesmus obliquus indicated them as source of biodiesel with higher oxidation stability, higher CN (63.63–64.94), and lower IV (27.34–35.28). The third group, except for the Trebouxyophyceae strains that appeared in isolation, are composed by microalgae that generate biodiesel of intermediate values for CN, IV, and oxidation stability, related to their levels of saturated and monosaturated lipids. Thus, in this research, FAME profiling suggested that the best approach for generating a microalgae-biodiesel of top quality is by mixing the oils of distinct cell cultures. 相似文献
24.
Raquel Montero Manuela Grazina Ester López-Gallardo Julio Montoya Paz Briones Aleix Navarro-Sastre John M. Land Iain P. Hargreaves Rafael Artuch Maria del Mar O'Callaghan Cristina Jou Cecilia Jimenez Nuria Buján Mercè Pineda Angels García-Cazorla Andrés Nascimento Plácido Navas 《Mitochondrion》2013,13(4):337-341
We evaluated coenzyme Q10 (CoQ) levels in patients studied under suspicion of mitochondrial DNA depletion syndromes (MDS) (n = 39). CoQ levels were quantified by HPLC, and the percentage of mtDNA depletion by quantitative real-time PCR. A high percentage of MDS patients presented with CoQ deficiency as compared to other mitochondrial patients (Mann–Whitney-U test: p = 0.001). Our findings suggest that MDS are frequently associated with CoQ deficiency, as a possible secondary consequence of disease pathophysiology. Assessment of muscle CoQ status seems advisable in MDS patients since the possibility of CoQ supplementation may then be considered as a candidate therapy. 相似文献
25.
Fabrícia F. Nascimento Ana Lazar Albert N. Menezes Andressa da Matta Durans Janio C. Moreira Jorge Salazar-Bravo Paulo S. D′Andrea Cibele R. Bonvicino 《PloS one》2013,8(4)
The Neotropics harbors a high diversity of species and several hypotheses have been proposed to account for this pattern. However, while species of forested domains are frequently studied, less is known of species from open vegetation formations occupying, altogether, a larger area than the Amazon Forest. Here we evaluate the role of historical barriers and the riverine hypothesis in the speciation patterns of small mammals by analyzing an ancient rodent lineage (Thrichomys, Hystricomorpha). Phylogenetic and biogeographic analyses were carried out with mitochondrial and nuclear DNA markers to analyze the evolutionary relationships between Thrichomys lineages occurring in dry domains along both banks of the Rio São Francisco. This river is one of the longest of South America whose course and water flow have been modified by inland tectonic activities and climate changes. Molecular data showed a higher number of lineages than previously described. The T. inermis species complex with 2n = 26, FN = 48 was observed in both banks of the river showing a paraphyletic arrangement, suggesting that river crossing had occurred, from east to west. A similar pattern was also observed for the T. apereoides complex. Thrichomys speciation occurred in Late Miocene when the river followed a different course. The current geographic distribution of Thrichomys species and their phylogenetic relationships suggested the existence of frequent past connections between both banks in the middle section of the Rio São Francisco. The extensive palaeodune region found in this area has been identified as a centre of endemism of several vertebrate species and is likely to be a center of Thrichomys diversification. 相似文献
26.
Paulo Ricardo Porfírio do Nascimento Daniella Regina Arantes Martins Glória Regina Góis Monteiro Paula Vivianne Queiroz Francisco Paulo Freire-Neto José Wilton Queiroz ádila Lorena Morais Lima Selma Maria Bezerra Jeronimo 《PloS one》2013,8(10)
Leishmania infantum infection in humans and dogs can evolve with a wide range of clinical presentations, varying from asymptomatic infections to visceral leishmaniasis. We hypothesized that the immune response elicited by L. infantum infection could modulate whether the host will remain asymptomatic or progress to disease. A total of 44 dogs naturally infected with L. infantum were studied. Leishmania burden was estimated in the blood and spleen by qPCR. The expression of IFN-γ, TNF-α, IL-10 and Iron Regulatory Protein 2 (IRP2) were determined in the spleen by quantitative PCR. Sera cytokines were evaluated by ELISA. Dogs were grouped in quartiles according parasite burden. Increased expression of IFN-γ and TNF-α was associated with reduced Leishmania burden, whereas increased IL-10 and IRP2 expressions were associated with higher Leishmania load. Increased plasma albumin and IFN-γ expression explained 22.8% of the decrease in parasite burden in the spleen. These data confirm that lower IFN-γ response and higher IL-10 correlated with increased parasite load and severity of the visceral leishmaniasis in dogs. The balance between the branches of immune response and the intracellular iron availability could determine, in part, the course of Leishmania infection. 相似文献
27.
Paulo Roque Obreli-Neto Leonardo Régis Leira Pereira Camilo Molino Guidoni André de Oliveira Baldoni Srecko Marusic Divaldo Pereira de Lyra-Júnior Kelsen Luis de Almeida Ana Claudia Montolezi Pazete Janaina Dutra do Nascimento Mitja Kos Edmarlon Girotto Roberto Kenji Nakamura Cuman 《PloS one》2013,8(12)
28.
do Nascimento Jessica Catarine Frutuoso Beltrão Eduardo Isidoro Carneiro Rocha Cíntia Renata Costa 《Glycoconjugate journal》2020,37(2):263-275
Glycoconjugate Journal - The complex enzyme network responsible for glycan synthesis suffers significant changes during the first steps of tumor development, leading to the early formation of... 相似文献
29.
Maíra S. A. Rocha Robson C. Silva José C. E. Santos Marianne Schorer Maria P. Nascimento Marcelo M. Pedreira 《Journal of fish biology》2020,96(1):49-58
The aim of the present study was to perform comparative histological analyses of the ontogenetic development of two fish species endemic to the São Francisco River in Brazil: Prochilodus argenteus and Lophiosilurus alexandri. Histological analyses were performed every 24 h from the moment of hatching until 14 days post-hatching (dph) for the observation of larval development and until 39 dph for the observation of gonadal development. Whole larvae were fixed in Bouin's solution and the histological slides were stained with haematoxylin–eosin. Lophiosilurus alexandri larvae had a larger body size compared with P. argenteus larvae since hatching. Lophiosilurus alexandri larvae had mouth opening and pigmentation of the eyes upon hatching, whereas these events were observed at 1 dph in P. argenteus larvae. The visualisation and the inflation of the swim bladder occurred at 1 and 3 dph, respectively, in the P. argenteus, whereas these events occurred at 2 and 8 dph, respectively, in L. alexandri. Yolk granules were absorbed at 4 dph in P. argenteus and the 10 dph in L. alexandri. At 7 dph, the digestive tube was more differentiated in L. alexandri than P. argenteus and at 14 dph, the digestive system of both species had features of their eating habits: broad stomach and short intestine in L. alexandri, typical of carnivorous habits; stomach with a mechanical function and long intestine in P. argenteus, typical of detritivorous habits. The epithelial lining tissue, formed by a single layer of cells in the newly hatched larvae (0 dph), differentiated throughout the study, exhibiting scales in P. argenteus and numerous club cells in the middle epithelial region of L. alexandri at 39 dph. Undifferentiated gonads with somatic cells and primordial germ cells were observed at 39 dph, with caudal-cranial migration since 1 dph in both species. The anatomic changes during the ontogeny of P. argenteus and L. alexandri larvae are directly associated with the evolutionary history of each species, which explains their feeding habits, behaviour and distribution in the environment: Prochilodus argenteus is detritivorous and actively swims in the water column, whereas L. alexandri is carnivorous and inhabits bottom regions. At 39 dph neither species exhibited sexual differentiation. 相似文献
30.
Severo Juliana Soares Morais Jennifer Beatriz Silva Beserra Jessica Batista dos Santos Loanne Rocha de Sousa Melo Stéfany Rodrigues de Sousa Gustavo Santos de Matos Neto Emídio Marques Henriques Gilberto Simeone do Nascimento Marreiro Dilina 《Biological trace element research》2020,193(1):81-88
Biological Trace Element Research - Excessive adipose tissue promotes the manifestation of endocrine disorders such as reduction of the secretion of zinc-α2-glycoprotein (ZAG), an adipokine... 相似文献