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101.
Virginie Treyvaud Amiguet John Thor Arnason Pedro Maquin Victor Cal SÁnchez-Vindas Pablo Poveda Alvarez Luis 《Economic botany》2006,60(1):24-38
A previous study provided a general quantitative analysis of 169 collected medicinal plants used by the Q’eqchi’ Maya healers
of southern Belize. This paper is focused on a statistical analysis of this ethnobotanical information using the method developed
by Moerman (1991). The residual values obtained from the regression analysis of the Q’eqchi’ medicinal plant species versus
the species listed in the checklist of the vascular plants of Belize (Balick, Nee, and Atha, 2001) placed the Piperaceae,
the Rubiaceae, and the Asteraceae in the first three ranks, and the Poaceae, the Cyperaceae, and the Orchidaceae in the last
three ranks. The results were compared with three northern temperate regions (Kashmir, Korea, and North America) and three
southern neotropical regions (Chiapas, Ecuador, and Veracruz). The coefficients of correlation between the checklist of vascular
plants of Belize and the other six floras showed, as expected, high values for regions with similar climatic type. Thus, high
correlations were determined between the tropical vegetation of Belize and those of Chiapas, Ecuador, and Veracruz. The coefficients
were lower with the three temperate floras but still quite high. The same analysis was done with the medicinal plants only
and led to much lower coefficients, but once again, the higher results were obtained for Chiapas and Veracruz. In this case,
the last rank for Ecuador demonstrated that the selection of plants in traditional medicine by the indigenous people is a
complex phenomenon which depends not only on the composition of the flora but also on culture-specific factors.
Analyse par Regression des Plantes Médicinales des Mayas Q’eqchi'’ du Sud du Belize
Résumé Une précédente étude a fourni une analyse quantitative générale de 169 plantes médicinales utilisées par les guérisseurs Maya Q’eqchi’ du sud du Belize. Ce document se concentre sur l’analyse statistique des informations ethnobotaniques selon la méthode développée par Moerman (1991). Les valeurs résiduelles obtenues à partir des analyses de régression des plantes médicinales Q’eqchi’ vis-à-vis des espèces mentionnées dans la liste des plantes vasculaires du Belize (Balick, Nee, et Atha, 2001) ont placé les Piperacées, les Rubiacées et les Asteracées aux trois premières places, et les Poacées, les Cyperacées et les Orchidacées aux trois dernières places. Les résultats ont été comparés avec ceux de trois régions tempérées du nord (Cachemire, Corée, et Amérique du Nord) et de trois régions néotropicales du sud (Chiapas, équateur, et Veracruz). Les coefficients de corrélation entre les plantes listées dans le manuel des plantes vasculaires du Belize et les six autres flores ont montré comme attendu de hautes valeurs pour les régions possédant un type climatique similaire. Ainsi, une haute corrélation a été démontrée entre la végétation tropicale du Belize et celles du Chiapas, de l’équateur, et du Veracruz. Les coefficients étaient plus bas avec les trois régions tempérées mais tout de même passablement élevés. La même analyse a été effectuée avec les plantes médicinales et a mené à des coefficients beaucoup plus bas, mais encore une fois, les résultats les plus élevés ont été obtenus pour le Chiapas et le Veracruz. Dans ce cas, la dernière position de l’équateur a souligné que la sélection des plantes par les indigènes dans la médecine traditionnelle est un phénomène complexe qui dépend non seulement de la composition de la flore mais aussi de facteurs spécifiques à la culture.相似文献
102.
Slack KE Jones CM Ando T Harrison GL Fordyce RE Arnason U Penny D 《Molecular biology and evolution》2006,23(6):1144-1155
Testing models of macroevolution, and especially the sufficiency of microevolutionary processes, requires good collaboration between molecular biologists and paleontologists. We report such a test for events around the Late Cretaceous by describing the earliest penguin fossils, analyzing complete mitochondrial genomes from an albatross, a petrel, and a loon, and describe the gradual decline of pterosaurs at the same time modern birds radiate. The penguin fossils comprise four naturally associated skeletons from the New Zealand Waipara Greensand, a Paleocene (early Tertiary) formation just above a well-known Cretaceous/Tertiary boundary site. The fossils, in a new genus (Waimanu), provide a lower estimate of 61-62 Ma for the divergence between penguins and other birds and thus establish a reliable calibration point for avian evolution. Combining fossil calibration points, DNA sequences, maximum likelihood, and Bayesian analysis, the penguin calibrations imply a radiation of modern (crown group) birds in the Late Cretaceous. This includes a conservative estimate that modern sea and shorebird lineages diverged at least by the Late Cretaceous about 74 +/- 3 Ma (Campanian). It is clear that modern birds from at least the latest Cretaceous lived at the same time as archaic birds including Hesperornis, Ichthyornis, and the diverse Enantiornithiformes. Pterosaurs, which also coexisted with early crown birds, show notable changes through the Late Cretaceous. There was a decrease in taxonomic diversity, and small- to medium-sized species disappeared well before the end of the Cretaceous. A simple reading of the fossil record might suggest competitive interactions with birds, but much more needs to be understood about pterosaur life histories. Additional fossils and molecular data are still required to help understand the role of biotic interactions in the evolution of Late Cretaceous birds and thus to test that the mechanisms of microevolution are sufficient to explain macroevolution. 相似文献
103.
A mitogenomic study on the phylogenetic position of snakes 总被引:2,自引:0,他引:2
Phylogenetic relationships of squamates (lizards, amphisbaenians and snakes) have received considerable attention, although no consensus has been reached concerning some basal divergences. This paper focuses on the Serpentes (snakes), whose phylogenetic position within the Squamata remains uncertain despite a number of morphological and molecular studies. Some mitogenomic studies have suggested a sister-group relationship between snakes and varanid lizards, while other studies have identified snakes and lizards as sister groups. However, recent studies using nuclear data have presented a different scenario, with snakes being more closely related to anguimorph and iguanian lizards. In this mitogenomic study we have examined the above hypotheses with the inclusion of amphisbaenians, one gekkotan and one acrodont lizard, taxa not represented in previous mitogenomic studies. To this end we have also extended the representation of snakes by sequencing five additional snake genomes: two scolecophidians ( Ramphotyphlops australis and Typhlops mirus ) two henophidians ( Eunectes notaeus and Boa constrictor ) and one caenophidian ( Elaphe guttata ). The phylogenetic analysis recovered snakes and amphisbaenians as sister groups, thereby differing from previous hypotheses. In addition to a discussion on previous morphological and molecular studies in light of the results presented here, the current study also provides some details regarding features of the new snake mitochondrial genomes described. 相似文献
104.
Ammar Saleem Cory S. Harris Muhammad Asim Alain Cuerrier Louis Martineau Pierre S. Haddad John T. Arnason 《Phytochemical analysis : PCA》2010,21(4):328-339
Introduction – Ericaceae medicinal plants are traditionally used by the Eeyou Istchee Cree and other northern peoples of North America to treat type 2 diabetic symptoms. Because of the importance of phenolics as potential cures for degenerative diseases including type 2 diabetes, an analytical method was developed to detect them in the leaf extracts of 14 Ericaceae plants. Objective – To develop an optimised method which is applicable to a relatively large number of Ericaceae plants using their leaf extracts. For this purpose phenolics with a wide range of polarity, including a glucosylated benzoquinone, two phenolic acids, three flavanols, a flavanone, a flavone and five flavonols, were included in this study. Methodology – Characterisation of phytochemicals in extracts was undertaken by automated matching to the UV spectra to those of an in house library of plant secondary metabolites and the authentication of their identity was achieved by reversed phase‐high‐performance chromatography–diode array detection–atmospheric pressure chemical ionisation/mass selective detection. Results – Twenty‐six phenolics were characterised within 26 min of chromatographic separation in 80% ethanol extracts of 14 Ericaceae plants. The calibration curves were linear within 0.5–880 µg/g dry mass of the plant with regression values better than 0.995. The limits of detection ranged from 0.3 for µg/mL for (+)‐catechin to 2.6 µg/mL for chlorogenic acid. This is a first study dealing with relatively large number of Ericaceae extracts and is applicable to other plants of same family. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
105.
Katarina Luptakova Jacalyn Rosenblatt Brett Glotzbecker Heidi Mills Dina Stroopinsky Turner Kufe Baldev Vasir Jon Arnason Dimitri Tzachanis Jeffrey I. Zwicker Robin M. Joyce James D. Levine Kenneth C. Anderson Donald Kufe David Avigan 《Cancer immunology, immunotherapy : CII》2013,62(1):39-49
Lenalidomide is an effective therapeutic agent for multiple myeloma that exhibits immunomodulatory properties including the activation of T and NK cells. The use of lenalidomide to reverse tumor-mediated immune suppression and amplify myeloma-specific immunity is currently being explored. In the present study, we examined the effect of lenalidomide on T-cell activation and its ability to amplify responses to a dendritic cell-based myeloma vaccine. We demonstrate that exposure to lenalidomide in the context of T-cell expansion with direct ligation of CD3/CD28 complex results in polarization toward a Th1 phenotype characterized by increased IFN-γ, but not IL-10 expression. In vitro exposure to lenalidomide resulted in decreased levels of regulatory T cells and a decrease in T-cell expression of the inhibitory marker, PD-1. Lenalidomide also enhanced T-cell proliferative responses to allogeneic DCs. Most significantly, lenalidomide treatment potentiated responses to the dendritic cell/myeloma fusion vaccine, which were characterized by increased production of inflammatory cytokines and increased cytotoxic lymphocyte-mediated lysis of autologous myeloma targets. These findings indicate that lenalidomide enhances the immunologic milieu in patients with myeloma by promoting T-cell proliferation and suppressing inhibitory factors, and thereby augmenting responses to a myeloma-specific tumor vaccine. 相似文献
106.
Nutrient levels, soil moisture and soil organic matter were monitored monthly during a three year period in a site cleared
for shifting agriculture (milpa) and in adjacement undisturbed high bush forest soils in Belize. Throughout the study there
was no evidence of a decline in available nutrient levels in the cleared site. Sharp changes in P and Mn were considered indicative
of wetting and drying periods.
Corn yields for the rainy season crop in the first two years were average for the region ca 2500 kg ha−1 dry wt, but declined dramatically in the third year. Total weed biomass for the rainy season crop conversely increased every
year and reduced grain yield probably through competition for nutrients (especially N), light and water. Substantial amounts
of nutrients were also immobilized in the weed biomass, which served the agroecological purpose of preventing nutrient loss
by leaching. 相似文献
107.
M K Nicholas J P Antel K Stefansson B G Arnason 《Journal of immunology (Baltimore, Md. : 1950)》1987,139(7):2275-2283
In order to examine questions concerning immunologic privilege of the central nervous system, we placed neocortical transplants into cerebral ventricles of mice. We compared the fates of transplants between fully H-2 compatible (isografts) and H-2 incompatible (allografts) animals. Histologic evaluation comparing animals from iso- and allograft groups revealed significant differences in the number of inflammatory cells and in the degree of necrosis within the grafts. Response to allografted tissue within the brain mimics that seen in several immune-mediated diseases of the nervous system in that neurons appear to be selectively spared. Only upon subsequent stimulation of the host's immune system with an orthotopic skin graft bearing the major histocompatibility complex antigens of the neural graft are neurons destroyed. Immunohistochemical evaluation revealed that the inflammatory cell infiltrates in and around the allografts were composed of Lyt-2+, L3T4+, and Mac-1+ cells. In addition, Ia+ endothelial cells as well as Ia+ parenchymal CNS cells were found in both donor and host tissue of allografted animals. Hence, H-2 incompatible neural tissue transplanted to the CNS is recognized and rejected by the immune system of the recipient animal. The cellular infiltrates seen within the first weeks to months following transplantation of allogeneic CNS tissue resemble those seen in other allografts undergoing rejection. We conclude that the CNS is not unconditionally privileged as either a transplant site or as a source of transplanted tissue. 相似文献
108.
109.
Plant lifeform composition and levels of nutrients accumulated by fallows aged 1, 2 and 3 years under shifting (milpa) cultivation in Belize were measured. Levels of N, P and K allocated to leaves rapidly reached a plateau in 1 year old fallows with little increase in 2 and 3 year old sites. In stem material, K was accumulated rapidly, with little increase after the first year of fallow growth, while N and P accumulation proceeded at steady rates during three years of fallow development. Total biomass in 3 year old fallows averaged 2070 g m–2 with 10.3 g m–2 N, 0.73 g m–2P and 13.2 g m–2K. Nutrient concentrations in early successional species were higher than in species of later successional status, suggesting different strategies for nutrient utilization.Woody lifeforms dominated the fallow vegetation, accounting for 80% of total biomass in first year fallows and eliminating herbaceous species after 2 and 3 years of fallow growth. The importance of rapid recovery of woody species is discussed as it relates to fallow management and weed control. 相似文献
110.
Leaf, fruit, stem, bark and root of Zanthoxylum americanum were investigated for antifungal activity with 11 strains of fungi representing diverse opportunistic and systemic pathogens, including Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. All extracts demonstrated a broad spectrum of antifungal activity and inhibited at least eight fungal species in a disk diffusion assay (600 microg/disk). Antifungal activity was light-dependent, with fruit and leaf extracts most active in general. The presence of light-mediated compounds, such as psoralen, 8-methoxypsoralen and imperatorin in extracts of different organs was confirmed by RP-HPLC. A high furanocoumarin content was detected in fruit and leaf and low furanocoumarin levels were found in bark and wood. A high positive correlation was observed between total furanocoumarin content and fungal inhibition zones (r2=0.902, p<0.001). The results provide a phytochemical basis for the very widespread use of Z. americanum in indigenous North American ethnomedical tradition for conditions that may be related to fungal infections. 相似文献