444 research outputs found
Aplicación de fertilizantes de liberación controlada al establecimiento de Pinus radiata en Valdivia
Thiers, O.; Gerding, V. Universidad Austral de Chile, Instituto de Silvicultura. Casilla 567, Valdivia, Chile.
Leiva, F. Centro Experimental Forestal CEFOR, Universidad Austral de Chile. Casilla 567, Valdivia, Chile.Se evaluó el efecto de fertilizantes de liberación controlada (FLC) (Basacote® Plus 3M, 6M, 9M, y Starter; 10 a 20 g planta-1) en el período de establecimiento de plantaciones de Pinus radiata. Se instaló un ensayo con FLC y una mezcla de fertilizantes hidrosolubles (fertilización tradicional, 87 g planta-1) en tres sitios de la comuna de Valdivia, sobre suelos rojo arcillosos de la serie Los Ulmos (Typic Palehumult). Luego del primer año de evaluación los FLC y la fertilización tradicional permitieron crecimientos mayores (P 90 %) con y sin ellos. Los valores promedio en los mejores tratamientos alcanzaron: 70±16 cm (H), 16±4 mm de diámetro de cuello (DAC) y 194±12 cm3 de factor de producción (F = DAC2xH). La ganancia promedio de los árboles con FLC fue de 12 a 36 % en H y en DAC, y de 68 a 154 % en FP. La proporción de biomasa radicular (18 %) no fue modificada con las fertilizaciones. Los tratamientos con FLC presentaron ventajas operativas y de costos con respecto a la fertilización tradicional.Con aporte de COMPO AGRO Chile y CEFOR-UACh
A convolute diversity of the Auriculariales (Agaricomycetes, Basidiomycota) with sphaeropedunculate basidia
Morphological and DNA data show that effused representatives of the Auriculariales (Basidiomycota) with sphaeropedunculate basidia belong to eleven genera of which seven are dealt with in this study. Among them, Myxarium is the largest genus containing 21 accepted species of which nine are reintroduced below and five are described as new. Protodontia is limited to three species only, P. subgelatinosa (the generic type) and two newly described species from Africa. Protoacia is a new monotypic genus for P. delicata, sp. nov., widely distributed on coniferous hosts in Eurasia. Myxariellum is erected for two new species with smooth hymenophore from northwestern North America while Gelacantha is introduced for G. pura, a new species with hydnoid hymenophore from Caucasus. Our data do not confirm the present synonymy of Sebacina sphaerospora with Tremella glaira, and these species are placed in two separate genera - Hydrophana, gen. nov., and Ofella, gen. nov., respectively. A key to European Myxarium and similar-looking species is included.Peer reviewe
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Comparison of herbarium label data and published medicinal use: herbaria as an underutilized source of ethnobotanical information
The use of herbarium specimens as vouchers to support ethnobotanical surveys is well established. However,
herbaria may be underutilized resources for ethnobotanical research that depends on the analysis of large datasets compiled across multiple sites. Here, we compare two medicinal use datasets, one sourced from
published papers and the other from online herbaria to determine whether herbarium and published data
are comparable and to what extent herbarium specimens add new data and fill gaps in our knowledge of
geographical extent of plant use. Using Brazilian legumes as a case study, we compiled 1400 use reports from
105 publications and 15 Brazilian herbaria. Of the 319 species in 107 genera with cited medicinal uses, 165
(51%) were recorded only in the literature and 55 (17%) only on herbarium labels. Mode of application,
plant part used, or therapeutic use was less often documented by herbarium specimen labels (17% with
information) than publications (70%). However, medicinal use of 21 of the 128 species known from only
one report in the literature was substantiated from independently collected herbarium specimens, and 58
new therapeutic applications, 25 new plant parts, and 16 new modes of application were added for species
known from the literature. Thus, when literature reports are few or information-poor, herbarium data can
both validate and augment these reports. Herbarium data can also provide insights into the history and
geographical extent of use that are not captured in publications
The Core/E1 domain of Hepatitis C virus genotype 4a in Egypt does not contain viral mutations or strains specific for hepatocellular carcinoma
[EN] Background: Hepatitis C virus (HCV) infection is a well-documented etiological factor for hepatocellular carcinoma (HCC). As HCV shows remarkable genetic diversity, an interesting and important issue is whether such a high viral genetic diversity plays a role in the incidence of HCC. Prior data on this subject are conflicting.
Objectives: Potential association between HCV genetic mutations or strain variability and HCC incidence has been examined through a comparative genetic analysis merely focused on a single HCV subtype (genotype 4a) in a single country (Egypt).
Study design: The study focused on three HCV sequence datasets with explicit sampling dates and disease patterns. An overlapping HCV Core/E1 domain from three datasets was used as the target for comparative analysis through genetic and phylogenetic approaches.
Results: Based on partial Core/E1 domain (387 bp), genetic and phylogenetic analysis did not identify any HCC-specific viral mutations and strains, respectively.
Conclusions: The Core/E1 domain of HCV genotype 4a in Egypt does not contain HCC-specific mutations or strains. Additionally, sequence errors resulting from the polymerase chain reaction, together with a strong evolutionary pressure on HCV in patients with end-stage liver disease, have significant potential to bias data generation and interpretation. (C) 2011 Elsevier B.V. All rights reserved.This work was supported by NIH grants R01 DK80711 (Dr. Xiaofeng Fan), R21 AI076834 (Dr. Adrian M. Di Bisceglie) and USA and Egypt Science and Technology Joint Fund BIO6-002-004 (Dr. Adrian M. Di Bisceglie).Zhang, X.; Ryu, SH.; Xu, Y.; Elbaz, T.; Zekri, AN.; Abdelaziz, AO.; Abdel-Hamid, M.... (2011). The Core/E1 domain of Hepatitis C virus genotype 4a in Egypt does not contain viral mutations or strains specific for hepatocellular carcinoma. Journal of Clinical Virology. 52(4):333-338. https://doi.org/10.1016/j.jcv.2011.08.022S33333852
Biogeographical analyses to facilitate targeted conservation of orchid diversity hotspots in Costa Rica
Aim: We conduct a biogeographical assessment of orchids in a global biodiversity
hotspot to explore their distribution and occurrences of local hotspots while identifying geographic attributes underpinning diversity patterns. We evaluate habitat
characteristics associated with orchid diversity hotspots and make comparisons to
other centres of orchid diversity to test for global trends. The ultimate goal was to
identify an overall set of parameters that effectively characterize critical habitats to
target in local and global orchid conservation efforts.
Location: Costa Rica; Mesoamerica.
Taxon: Orchidaceae.
Methods: Data from an extensive set of herbarium records were used to map orchid
distributions and to identify diversity hotspots. Hotspot data were combined with
geographic attribute data, including environmental and geopolitical variables, and a
random forest regression model was utilized to assess the importance of each variable for explaining the distribution of orchid hotspots. A likelihood model was created based on variable importance to identify locations where suitable habitats and
unidentified orchid hotspots might occur.
Results: Orchids were widely distributed and hotspots occurred primarily in mountainous regions, but occasionally at lower elevations. Precipitation and vegetation
cover were the most important predictive variables associated with orchid hotspots.
Variable values underpinning Costa Rican orchid hotspots were similar to those reported at other sites worldwide. Models also identified suitable habitats for sustaining orchid diversity that occurred outside of known hotspots and protected areas.
Main conclusions: Several orchid diversity hotspots and potentially suitable habitats
occur outside of known distributions and/or protected areas. Recognition of these
sites and their associated geographic attributes provides clear targets for optimizing
orchid conservation efforts in Costa Rica, although certain caveats warrant consideration. Habitats linked with orchid hotspots in Costa Rica were similar to those documented elsewhere, suggesting the existence of a common biogeographical trend
regarding critical habitats for orchid conservation in disparate tropical regions.Universidad de Puerto Rico/[]/UPR/Puerto RicoUniversidad de Costa Rica/[]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL
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