Distribution of Organochlorine Pesticides in Pine Needles of an Oceanic Island: The Case of Tenerife (Canary Islands,Spain)     

Villa  S.  Finizio  A.  Diaz Diaz  R.  Vighi  M. 《Water, air, and soil pollution》2003,146(1-4):335-349

The distribution of persistent organochlorine pesticides (HCB, HCH, DDT and its metabolites) was studied by analyzing pine needles in the oceanic island of Tenerife (Canary Islands, Spain). Tenerife is a subtropical oceanic island, characterized by the presence of a high mountain (Pico de Teide, 3,718 m a.s.l.) and by a peculiar climatic condition. The southern side is warm and sometimes during the year influenced by dry winds coming from Africa, while the northern side is cool and wet, with an almost persistent cloudiness (called `mar de nubes'), due to winds coming from the northern Atlantic. Furthermore a developed agricultural area is present at sea level. Pine needle samples were collected on both sides of the island, from the sea level up to the upper level of pine distribution (2,100 m a.s.l.). The distribution patterns of organochlorine pesticides seem to be affected mainly by local emissions. Up to the considered altitude layer, the influence of global circulation of persistent organic pollutants seems to play a negligible role. The behavior of chemicals is consistent with their physical-chemical properties, with some influence due to climatic conditions.  相似文献   

Olea europaea L. leaf extract and derivatives: antioxidant properties   总被引：2，自引：0，他引：2  

Briante R  Patumi M  Terenziani S  Bismuto E  Febbraio F  Nucci R 《Journal of agricultural and food chemistry》2002,50(17):4934-4940

This paper reports a very simple and fast method to collect eluates with high amounts of hydroxytyrosol, biotransforming Olea europaea L. leaf extract by a thermophilic beta-glycosidase immobilized on chitosan. Some phenolic compounds in the leaf tissue and in the eluates obtained by biotransformation are identified. To propose the eluates as natural substances from a vegetal source, their antioxidant properties have been compared with those of the leaf extract from which they are originated. The eluates possess a higher concentration of simple phenols, characterized by a stronger antioxidant capacity, than those available in extra virgin olive oils and in many tablets of olive leaf extracts, commercially found as dietetic products and food integrators.  相似文献   

Mutations in the DJ-1 gene associated with autosomal recessive early-onset parkinsonism     

Bonifati V  Rizzu P  van Baren MJ  Schaap O  Breedveld GJ  Krieger E  Dekker MC  Squitieri F  Ibanez P  Joosse M  van Dongen JW  Vanacore N  van Swieten JC  Brice A  Meco G  van Duijn CM  Oostra BA  Heutink P 《Science (New York, N.Y.)》2003,299(5604):256-259

The DJ-1 gene encodes a ubiquitous, highly conserved protein. Here, we show that DJ-1 mutations are associated with PARK7, a monogenic form of human parkinsonism. The function of the DJ-1 protein remains unknown, but evidence suggests its involvement in the oxidative stress response. Our findings indicate that loss of DJ-1 function leads to neurodegeneration. Elucidating the physiological role of DJ-1 protein may promote understanding of the mechanisms of brain neuronal maintenance and pathogenesis of Parkinson's disease.  相似文献   

Astronomy and Solar Physics: X-ray Gas Scintillation Spectrometer Experiment     

Andresen RD  Boella G  Falconi B  Lamb P  Manzo G  Raymont J  Re S  Sims MR  Villa G 《Science (New York, N.Y.)》1984,225(4658):177-179

The payload complement on Spacelab 1 included a spectrometer for observations of the brighter cosmic x-ray sources. The primary scientific objective was to study the detailed spectral features of cosmic x-ray sources and their associated temporal variations over a wide energy range from about 2 to 80 kiloelectron volts. The instrument, based on the gas scintillation proportional counter, had a geometrical area of some 180 square centimeters with an energy resolution of about 9 percent at 7 kiloelectron volts. The results presented here show new results from two galactic binary x-ray sources, Cygnus X-3 and Centaurus X-3, and from the Perseus cluster of galaxies. The excellent energy resolution of the instrument permits line features to be identified in these sources with unprecedented quality.  相似文献   

The importance of demographic niches to tree diversity   总被引：1，自引：0，他引：1  

Condit R  Ashton P  Bunyavejchewin S  Dattaraja HS  Davies S  Esufali S  Ewango C  Foster R  Gunatilleke IA  Gunatilleke CV  Hall P  Harms KE  Hart T  Hernandez C  Hubbell S  Itoh A  Kiratiprayoon S  Lafrankie J  de Lao SL  Makana JR  Noor MN  Kassim AR  Russo S  Sukumar R  Samper C  Suresh HS  Tan S  Thomas S  Valencia R  Vallejo M  Villa G  Zillio T 《Science (New York, N.Y.)》2006,313(5783):98-101

Most ecological hypotheses about species coexistence hinge on species differences, but quantifying trait differences across species in diverse communities is often unfeasible. We examined the variation of demographic traits using a global tropical forest data set covering 4500 species in 10 large-scale tree inventories. With a hierarchical Bayesian approach, we quantified the distribution of mortality and growth rates of all tree species at each site. This allowed us to test the prediction that demographic differences facilitate species richness, as suggested by the theory that a tradeoff between high growth and high survival allows species to coexist. Contrary to the prediction, the most diverse forests had the least demographic variation. Although demographic differences may foster coexistence, they do not explain any of the 16-fold variation in tree species richness observed across the tropics.  相似文献   

Expression and biochemical characteristics of two different aldosterone receptors in both healthy and dilated cardiomyopathy dog heart tissue     

Alejandro R. Reynoso Palomar  Moncerrat Rodriguez Bravo  Abel E. Villa Mancera  Carlos J. Mucha 《Veterinary research communications》2017,41(1):9-14

Recently, replicates of the aldosterone receptor expression have been done in healthy heart dog tissues through immunohistochemistry, showing an apparent heterogeneous distribution in the four chambers. Recent studies have also identified immediate effects of aldosterone, suggesting aldosterone also produces non-genomic effects caused by an unidentified receptor. In order to study the molecular and quantitative expression characteristics of aldosterone binding receptors in the canine heart, we conducted studies, using Western Blot, in the heart from both healthy animals and animals with dilated cardiomyopathy. The results show the presence and distribution of two aldosterone receptors; one of 110/120 kDa molecular weight, suggested as cytosolic/nuclear and the other of undetermined location with a 250 kDa molecular weight.  相似文献   

Large and Fast Deformations Crucial for the Rheology of Proofing Dough     

Peter L. Weegels  Frans Groeneweg  Eddy Esselink  Robert Smit  Rupert Brown  Dudley Ferdinando 《Cereal Chemistry》2003,80(4):424-426

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What controls fish functional diversity patterns in Colombian Andean streams?     

Jose Luis Poveda-Cuellar  Edwin Orlando Lpez Delgado  Pamela Tatiana Zúiga-Upegui  Francisco Antonio Villa Navarro 《Ecology of Freshwater Fish》2022,31(1):87-101

Understanding the mechanisms that structure communities have been a major challenge in ecological theory. Functional trait-based approaches are increasingly used for studying the processes underlying community assembly. However, species-poor systems of Andean streams these processes are largely unknown. Tropical Andean streams are highly variable in space-time and characterised by the harsh or stable environment, resulting in a high taxonomic and ecological diversity. In this study, we tested the influence of environmental variables on the fish functional structure. We proposed that in ecosystems with harsh environments, environmental filtering will structure fish assemblages, and in ecosystems with a more stable environment, limiting similarity will prevail, increasing functional diversity. We analysed fish assemblages using functional diversity indices, fourth-corner RLQ analyses and multiple regression models. Environmental variables such as altitude, stream width, sub-Andean vegetation and pH influenced functional diversity. For instance, high values of functional redundancy were registered at high elevation streams, reflecting fish assemblages composed of highly dominant species with similar functional traits such as species of the genus Astroblepus. However, we found differences between Astroblepus species in the number and distance of gill rakers which might indicate resource partitioning and coexistence. On the other hand, our results show both stochastic dynamics and environmental filtering are structuring fish assemblages in low and high elevation Andean streams respectively.  相似文献