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991.
This paper analyses forest fires in the perspective of dynamical systems. Forest fires exhibit complex correlations in size, space and time, revealing features often present in complex systems, such as the absence of a characteristic length-scale, or the emergence of long range correlations and persistent memory. This study addresses a public domain forest fires catalogue, containing information of events for Portugal, during the period from 1980 up to 2012. The data is analysed in an annual basis, modelling the occurrences as sequences of Dirac impulses with amplitude proportional to the burnt area. First, we consider mutual information to correlate annual patterns. We use visualization trees, generated by hierarchical clustering algorithms, in order to compare and to extract relationships among the data. Second, we adopt the Multidimensional Scaling (MDS) visualization tool. MDS generates maps where each object corresponds to a point. Objects that are perceived to be similar to each other are placed on the map forming clusters. The results are analysed in order to extract relationships among the data and to identify forest fire patterns. 相似文献
992.
Viviane Grazielle-Silva Tehseen Fatima Zeb Jason Bolderson Priscila C. Campos Julia B. Miranda Ceres L. Alves Carlos R. Machado Richard McCulloch Santuza M. R. Teixeira 《PLoS neglected tropical diseases》2015,9(6)
BackgroundDNA repair mechanisms are crucial for maintenance of the genome in all organisms, including parasites where successful infection is dependent both on genomic stability and sequence variation. MSH2 is an early acting, central component of the Mismatch Repair (MMR) pathway, which is responsible for the recognition and correction of base mismatches that occur during DNA replication and recombination. In addition, recent evidence suggests that MSH2 might also play an important, but poorly understood, role in responding to oxidative damage in both African and American trypanosomes.Conclusions/SignificanceTaken together, these results indicate MSH2 displays conserved, dual roles in MMR and in the response to oxidative stress. Loss of the latter function results in life cycle dependent differences in phenotypic outcomes in T. brucei MSH2 mutants, most likely because of the greater burden of oxidative stress in the insect stage of the parasite. 相似文献
993.
Borges Aline Chiodi Nishime Thalita Mayumi Castaldelli de Moura Rovetta Sabrina Lima Gabriela de Morais Gouvêa Kostov Konstantin Georgiev Thim Gilmar Patrocínio de Menezes Beatriz Rossi Canuto Machado João Paulo Barros Koga-Ito Cristiane Yumi 《Mycopathologia》2019,184(5):585-595
Mycopathologia - This study aimed to evaluate the effects of cold atmospheric pressure plasma (CAPP) jet on Trichophyton rubrum growth, germination and adherence to nail. The effects of... 相似文献
994.
Juliana A. Fernando Maria Lúcia C. Vieira Silvia R. Machado Beatriz Appezzato-da-Glória 《Plant Cell, Tissue and Organ Culture》2007,91(1):37-44
We present evidences that ultrastructural electron microscope findings are valuable ways to understand the in vitro regeneration
process, in particular in the yellow passion fruit. Shoot-regeneration was induced in hypocotyl and leaf-derived explants
using 4.44 μM BAP, and the entire organogenic process was analyzed using conventional histology, scanning and transmission
electronic microscopy. Both direct and indirect regeneration modes were observed in hypocotyl explants, but only direct regeneration
occurred in leaf-derived cultures. In the direct pathway from both explant types, meristemoids developed into globular structures,
here called protuberances. The peripheral meristematic layers of the protuberances displayed ultrastructural characteristics
indicative of a high metabolic activity, and only these cells originated shoots and leaf primordia, the latter being frequent
when leaf explants were used. Moreover, the peripheral cells of the protuberances derived from leaf explants lost adhesion
during the culture, diminishing the regeneration rates. We recommend the use of hypocotyls as a source of explant to obtain
shoots as well as a genetic transformation system for the yellow passion fruit. However, the direct pathway is preferred because
a type of amitosis occurred in the peripheral cells of hypocotyl-derived calli, which has the potential to result in genetic
instability of the regenerating plants/tissue. 相似文献
995.
The population genetics of polyploids classified at several loci studied in terms of the probabilistic mechanism of crossing over and segregation. The methods of genetic algebra are used. 相似文献
996.
Otto R. Gottlieb Alaíde Braga de Oliveira Terezinha M. Machado Gonçalves Geovane G. de Oliveira Sebastião A. Pereira 《Phytochemistry》1975,14(11):2495-2499
(3R)-Claussequinone (7-hydroxy-4′-methoxyisoflavanquinone is the principal constituent of Cyclolobium clausseni Benth. and C. vecchii A. 相似文献
997.
998.
Porto Bárbara Alves da Silva Thamar Holanda Machado Mariana Resende de Oliveira Fábio Soares Rosa Carlos Augusto Rosa Luiz Henrique 《Extremophiles : life under extreme conditions》2020,24(5):797-807
Extremophiles - We recovered 85 fungal isolates from the acid sulphate soils in chronosequence under para-periglacial conditions in King George Island, Antarctica. Thirty-two taxa belonging to the... 相似文献
999.
The lipoate acetyltransferase (E2p) subunits of the pyruvate dehydrogenase (PDH) complex of Escherichia coli have three tandemly repeated lipoyl domains, although net deletions of one or two has no apparent effect on the activity of the purified complexes. Plasmids containing IPTG-inducible aceEF-lpd operons, which encode PDH complexes bearing from one to nine lipoyl domains per E2p chain (24-216 per complex), were constructed. They were all capable of restoring the nutritional lesion of a strain lacking PDH complex and they all expressed active sedimentable multienzyme complexes having a relatively normal range of subunit stoichiometries. The extra domains are presumed to protrude from the E2p core (24-mer) without significantly affecting the assembly of the E1p and E3 subunits on the respective edges and faces of the cubic core. However, the catalytic activities of the overproduced complexes containing four to nine lipoyl domains per E2p chain were lower than those with fewer lipoyl domains. This could be due to under-lipoylation of the domains participating in catalysis and interference from unlipoylated domains. 相似文献
1000.
Camacho M Machado JD Alvarez J Borges R 《The Journal of biological chemistry》2008,283(33):22383-22389
Secretory vesicles of sympathetic neurons and chromaffin granules maintain a pH gradient toward the cytosol (pH 5.5 versus 7.2) promoted by the V-ATPase activity. This gradient of pH is also responsible for the accumulation of amines and Ca2+ because their transporters use H+ as the counter ion. We have recently shown that alkalinization of secretory vesicles slowed down exocytosis, whereas acidification caused the opposite effect. In this paper, we measure the alkalinization of vesicular pH, caused by the V-ATPase inhibitor bafilomycin A1, by total internal reflection fluorescence microscopy in cells overexpressing the enhanced green fluorescent protein-labeled synaptobrevin (VAMP2-EGFP) protein. The disruption of the vesicular gradient of pH caused the leak of Ca2+, measured with fura-2. Fluorimetric measurements, using the dye Oregon green BAPTA-2, showed that bafilomycin directly released Ca2+ from freshly isolated vesicles. The Ca2+ released from vesicles to the cytosol dramatically increased the granule motion of chromaffin- or PC12-derived granules and triggered exocytosis (measured by amperometry). We conclude that the gradient of pH of secretory vesicles might be involved in the homeostatic regulation of cytosolic Ca2+ and in two of the major functions of secretory cells, vesicle motion and exocytosis. 相似文献