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(IPNA) Artículos post-print
Mostrando recursos 1 - 20 de 151
On the presence of the endemic skink Chalcides simonyi Steind., 1891 in Lanzarote (Canary Islands) - Nogales, Manuel; De León, Leandro; Gómez, Rafael
The Canarian herpetofauna is characterized by a high number of endemic species (Machado et al., 1985). Reptiles in this archipelago are exclusively represented by tyhree families: Lacertidae, Gekkonidae and Scincidae, Chalcides being the only genus of the family Scincidae in the Canary Islands. This genus includes three endemic species, C. viridanus from Tenerife, La Gomera and El Hierro, C. sexlineatus from Gran Canaria, and C. simonyi up to now only known for the island of Fuerteventura. Therefore, skinks were present in fgive of the seven main islands, except Lanzarote and La Palma (Bischoff, 1985).
Despite Lanzarote being only 10 km away...
A review on the effects of alien rodents in the Balearic (Western Mediterranean Sea) and Canary Islands (Eastern Atlantic Ocean) - Traveset, Anna; Nogales, Manuel; Alcover, Josep Antoni; Delgado, J. D.; López-Darias, Marta; Godoy, D.; Igual, José Manuel; Bover, Pere
Invasions of alien rodents have shown to have devastating effects on insular ecosystems. Here we review the ecological impacts of these species on the biodiversity of the Balearic and the Canary Islands. A total of seven species of introduced rodents (two rats, three mice, one dormouse, and one squirrel) have been recorded (six in the Balearics and four in the Canaries). Some of them can occasionally be important predators of nesting seabirds, contributing to the decline of endangered populations in both archipelagos. Rats are also known to prey upon terrestrial birds, such as the two endemic Canarian pigeons. Furthermore, rats...
Chemical composition and biological effects of essential oils from Artemisia absinthium L. cultivated under different environmental conditions - Bailen, María; Julio, Luis F.; Diaz, Carmen E.; Sanz, Jesús; Martínez-Díaz, Rafael A.; Cabrera, Raimundo; Burillo, Jesús; González-Coloma, Azucena
The objective of this study was the valorization of the essential oils from Spanish Artemisia absinthium domesticated plants from Teruel and Sierra Nevada (Spain). These populations were experimentally cultivated in the field and under controlled conditions. The insect antifeedant properties of their essential oils collected yearly from two locations were tested against Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi. Additionally we studied their phytotoxic, antifungal and antiparasitic effects. The oils from cultivated A. absinthium were characterized by the presence of cis-epoxyocimene, chrysanthenol, and chrysanthenyl acetate. The variations observed in oil composition were mostly quantitative but also qualitative. (Z)-2,6-Dimethyl-5,7-octadien-2,3-diol has been...
Características de los materiales amorfos (SiO2, Fe2O3 y Al2O2) en diferentes tipos de andosoles - Hernández Moreno, J. M.; Cabezas Viaño, O.; Fernández Caldas, E.; Tejedor Salguero, Mª L.
Amorphous materials (Fe2O3. Al2O3. SiO2) are studied in Typic Vitrandepts as well as a comparative study with amorphous materials of Integrades Andosol-Oligotrophic Brown Earth. Dystrandepts and evolutionated vitrandepts of the Canary Islands. This study reveal a differem evolution of these materials according to the type of Andepts, wich depend of the climate and parent material age.
Diet of common ravens on El Hierro, Canary Islands - Nogales, Manuel; Hernández, Elizabeth C.
The Common Raven (Carvus coraxi on El Hierro, an oceanci island in the Canary archipelago, is omnivorous. Although ravens from five regions on El Hierro showed qualitatively similar diets, there were considerable quantitative differences. Diet in wet and dry pastureland was made up principally of animals invertebrates at Jinama (frecuency of occurrence in pellets = 84.8%) and high levels of vertebrates at Bascos (60%). Spring was characterized by the consumption of vertebrates (frecuency in pellets = 48.5%), summer by invertebrates (77.1%), and autumn/winter by a diet of plant material (92.6% and 96.9%, respectively). White diets in many continental environments are...
Fragmentation of carbohydrate anomeric alkoxyl radicals. A new synthesis of chiral β-iodo azides, vinyl azides, and 2H-azirines - Alonso-Cruz, Carmen R.; Kennedy, Alan R.; Rodríguez Morales, María S.; Suárez, Ernesto
The reaction of 3-azido-2,3-dideoxy-hexopyranose compounds from the d-gluco, d-galacto, d-lacto, and l-arabino carbohydrate series, with (diacetoxyiodo)benzene and iodine, generated 2-azido-1,2-dideoxy-1-iodo-alditols with one carbon less than the starting carbohydrate. These β-iodo azides could be transformed by dehydroiodination into vinyl azides, which in turn afforded 3-monosubstituted 2H-azirines under thermal conditions. These β-iodo azides and 2H-azirines may be interesting chiral synthons for the preparation of more complex heterocyclic systems.
Food spectrum of the feral cat (Felis catus L., 1758) in the juniper woodland on El Hierro (Canary Islands) - Nogales, Manuel; Martín, Aurelio; Delgado, Guillermo; Emmerson, Keith
The diet of feral cats inhabiting a juniper woodland on the island of El Hierro (Canary Islands) has been studied by analyzing 248 scats. A total of 1029 prey items have been identified indicating that the introduced mammals (Oryctolagus cuniculus, Mus sp. and Rattus sp.) constitute the basis of the diet appearing in 88.3 % of the samples and representing 85.4 % of the consumed biomass. Mus sp. is the most frequently captured prey but in terms of biomass.Mus sp. is the most frequently captured prey but in terms of biomass, Oryctolagus cuniculus is the fundamental bais of the diet...
Micronutrients in soils and plants from organic farms of Tenerife (Canary Islands) - Piqué, E.; Alvarez, C. E.; Fernández, M.
Soil and plant samples were taken from tropical fruit tree plantations. temperate fruit tree orchards and vegetable gardens grown using organic agricultural methods in Tenerife. Micronutriets Ci, Fe. Mn, and Zn were determined. The micronutrient content of most soils was found to fall within the normal range reported in the literature. Mn was present at low levels in the foliage of many plants, and a negative correlation between foliar Mn and soil organic matter content was observed in avocado and banana plantations. Consequently, maximum levels of soil organic matter content are established for avocado and banana. Cu, Fe, and Zn...
Pineapples cultivated by conventional and organic methods in a soil from banana plantation. A comparative study of soil fertility, plant nutrition and yields - Alvarez, C. E.; Carracedo Torres, A. E.; Iglesias, . E.; Martínez, M. C.
A comparative study on conventional and organically grown pineapples cultivated in a soil from a banana plantation has been carried out in the Canary Islands.
Garden waste compost was used as fertilizer in the organic treatment and current NPK fertilization in the conventional one.
Soil pH, and available Ca and Mg were higher with the compost.
"D" leaf N. K. Ca and Mg levels of plants from the conventional treatment exceeded those from the organic one. but only N seemed to influence yields. Foliar Cu and Zn were higher in plants from the compost treatment. but apparently this did not affect pineapple production.
Soil fertility and mineral Nutrition of a biodynamic avocado plantation in Tenerife - Garcia, Carlos; Alvarez, C. E.; Carracedo Torres, A. E.; Iglesias, E.
The soil fertility of a biodynamic avocado plantation in Tenerife and its relation to mineral nutrition was studied and compared with similar variables investigated previously in conventional plantations. The surface soils of the biodynamic plantation showed pH. organic matter and available P. Ca. Mg and K averages significantly higher than those of the conventional plantations. As regards the foliar nutrient levels, the N, P, K, Mg and Cu averages were similar in both types of plantations, while the average foliar Ca and Mn values were significantly lower in the biodynamic avocados, although they fell within the range considered normal. On...
Soil fertility and mineral nutrition of an organic banana plantation in Tenerife - Alvarez, C. E.; García, C.; Carracedo Torres, A. E.
The soil fertility of an organic banana plantation in Tenerife and its relation to mineral nutrition was studied and compared with the sane variables investigated previously in conventional plantations. The pH of the organic banana plantation soils, as well as the levels of available Mg and Na, were similar to those of the conventional banana plantations. On the other hand, the values of organic matter and available P. Ca and K of the organic plantation soils showed averages significantly higher than those of the conventional plantations. As regards mineral nutrition, while the foliar N, K and Mg levels of the...
Epoxypukalide induces proliferation and protects against cytokine-mediated apoptosis in primary cultures of pancreatic β-cells - López-Acosta, José Francisco; Moreno-Amador, José Luis; Jiménez-Palomares, Margarita; Díaz-Marrero, Ana R.; Cueto, Mercedes; Perdomo, Germán; Cózar-Castellano, Irene
There is an urgency to find new treatments for the devastating epidemic of diabetes. Pancreatic b-cells viability and function are impaired in the two most common forms of diabetes, type 1 and type 2. Regeneration of pancreatic b-cells has been proposed as a potential therapy for diabetes. In a preliminary study, we screened a collection of marine products for b-cell proliferation. One unique compound (epoxypukalide) showed capability to induce b-cell replication in the cell line INS1 832/ 13 and in primary rat cell cultures. Epoxypukalide was used to study b-cell proliferation by [3H]thymidine incorporation and BrdU incorporation followed by BrdU/insulin...
Nitroamine radicals as intermediates in the functionalization of non-activated carbon atoms - Hernández, Rosendo; Rivera, Augusto; Salazar, José A.; Suárez, Ernesto
Photolysis of N-iodonitroamines generated in situ from the steroidal nitroamines 6β-nitroamino-5α-cholestan-3β-ol acetate, 6β-nitroamino-5α-cholestane-3β,5α-diol diacetate, and 20R-nitroaminopregn-5-en-3-ol acetate removes hydrogen atoms from the Me-18 and Me-19 groups to give 6β-,19-N-nitroepinino-5α-cholestan-3β-ol acetate, 6β,19-N-nitroepinino-5α-cholestane-3β5α-diol diacetate, and 18,20R-N-nitroepiminopregn-5-en-3β-ol acetate.
Aminoselenenylation of alkenes: syntheses of β-phenylseleno carbamates and β-phenylseleno cyanamides - Francisco, Cosme G.; Hernández, Rosendo; León, Elisa I.; Salazar, José A.; Suárez, Ernesto
β-(Phenylseleno)alkylcarbamates and β-(phenylseleno)alkylcyanamides have been synthesized in good yields by reaction of alkenes with carbamates and cyanamide, respectively, in presence of benzeneselenenyl chloride–silver tetrafluoroborate or N-phenylselenophthalimide–H+. The subsequent reductive or oxidative removal of the phenylseleno group affords alkylcarbamates and alkylcyanamides, and allylic carbamates, cyanamides, and cyanimides.
Preparation of gibberellins A9 and A20 from gibberellic acid - Duri, Zvitendo J.; Fraga, Braulio M.; Hanson, James R.
Methyl gibberellate has been converted via the methyl ester of 3-epigibberellin A1 into the 3-chloro- and 3,13-dichloro-derivatives using triphenylphosphine and carbon tetrachloride. Hydrogenolysis of the chlorides with tributyltin hydride afforded gibberellins A20 and A9 as their methyl esters. Gibberellin A9 methyl ester was also prepared from the gibberellin A4/A7 mixture. The stereochemistry of the conjugate reduction of the ring-A-unsaturated ketone is defined.
The reaction of enols with superoxide anion radicals: preparation of tertiary α-ketols - Betancor, Carmen; Francisco, Cosme G.; Freire, Raimundo; Suárez, Ernesto
Pregnan-20-ones (1) and (4), and 3β-hydroxy-5α-cholestan-6-one (7) react with KO2 and 18-crown-6 in benzene solution and under an oxygen atmosphere at 6–7 °C to give the corresponding α-hydroperoxides (2), (5) and (8) which after treatment with Ph3P gives α-ketols (3), (6) and (9) in good yields.
Partial synthesis of a trachylobagibberellin analogue - Arráez, Jacinto D.; Fraga, Braulio M.; González, Antonio G.; Gutiérrez Luis, Javier; Fayos, José; Perales, Áurea
We have synthesized a trachylobagibberellin analogue (14) by rearranging a chloro-enol lactone obtained from trachinodiol (2). Its structure was determined by X-ray analysis. This implies that the stereochemistry previously given to a similar compound (20) obtained from epicandicandiol (19) by the same procedure, should be amended to (21).