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41.
Muñoz J Felicísimo AM Cabezas F Burgaz AR Martínez I 《Science (New York, N.Y.)》2004,304(5674):1144-1147
Anisotropic (direction-dependent) long-distance dispersal (LDD) by wind has been invoked to explain the strong floristic affinities shared among landmasses in the Southern Hemisphere. Its contribution has not yet been systematically tested because of the previous lack of global data on winds. We used global winds coverage from the National Aeronautics and Space Administration SeaWinds scatterometer to test whether floristic similarities of Southern Hemisphere moss, liverwort, lichen, and pteridophyte floras conform better with (i) the anisotropic LDD hypothesis, which predicts that connection by "wind highways" increases floristic similarities, or (ii) a direction-independent LDD hypothesis, which predicts that floristic similarities among sites increase with geographic proximity. We found a stronger correlation of floristic similarities with wind connectivity than with geographic proximities, which supports the idea that wind is a dispersal vehicle for many organisms in the Southern Hemisphere. 相似文献
42.
Two types of consolidated memory have been described in Drosophila, anesthesia-resistant memory (ARM), a shorter-lived form, and stabilized long-term memory (LTM). Until now, it has been thought that ARM and LTM coexist. On the contrary, we show that LTM formation leads to the extinction of ARM. Flies devoid of mushroom body vertical lobes cannot form LTM, but spaced conditioning can still erase their ARM, resulting in a remarkable situation: The more these flies are trained, the less they remember. We propose that ARM acts as a gating mechanism that ensures that LTM is formed only after repetitive and spaced training. 相似文献
43.
G protein signalling involved in host recognition and mycoparasitismrelated chitinase expression in Trichoderma atroviride
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Susanne Zeilinger Barbara Reithner Kurt Brunner Valeria Scala Isabel Peiβl Matteo Lorito Robert L Mach 《浙江大学学报(农业与生命科学版)》2004,30(4):448-448
Mycoparasitic species of Trichoderma are commercially applied as biological control agents against various fungal pathogens. The mycoparasitic interaction is host specific and includes recognition, attack and subsequent penetration and killing of the host. Investigations on the underlying events revealed that Trichoderma responds to multiple signals from the host (e.g. lectins or other ligands such as low molecular weight components released from the host's cell wall) and host attack is ac… 相似文献
44.
45.
Lara Vilar del Hoyo M. Pilar Martín Isabel F. Javier Martínez Vega 《European Journal of Forest Research》2011,130(6):983-996
About 90% of the wildland fires occurred in Southern Europe are caused by human activities. In spite of these figures, the
human factor hardly ever appears in the definition of operational fire risk systems due to the difficulty of characterising
it. This paper describes two spatially explicit models that predict the probability of fire occurrence due to human causes
for their integration into a comprehensive fire risk–mapping methodology. A logistic regression technique at 1 × 1 km grid
resolution has been used to obtain these models in the region of Madrid, a highly populated area in the centre of Spain. Socio-economic
data were used as predictive variables to spatially represent anthropogenic factors related to fire risk. Historical fire
occurrence from 2000 to 2005 was used as the response variable. In order to analyse the effects of the spatial accuracy of
the response variable on the model performance (significant variables and classification accuracy), two different models were
defined. In the first model, fire ignition points (x, y coordinates) were used as response variable. This model was compared with another one (Kernel model) where the response variable
was the density of ignition points and was obtained through a kernel density interpolation technique from fire ignition points
randomly located within a 10 × 10 km grid, which is the standard spatial reference unit established by the Spanish Ministry
of Environment, Rural and Marine Affairs to report fire location in the national official statistics. Validation of both models
was accomplished using an independent set of fire ignition points (years 2006–2007). For the validation, we used the area
under the curve (AUC) obtained by a receiver-operating system. The first model performs slightly better with a value of AUC
of 0.70 as opposed to 0.67 for the Kernel model. Wildland–urban interface was selected by both models with high relative importance. 相似文献
46.
Ediane Batista da Silva Bruna Daniella de Souza Silva Jerônimo Rafael Ruiz Leon André Kipnis Isabel K.F. de Miranda Santos Ana Paula Junqueira-Kipnis 《Veterinary journal (London, England : 1997)》2011,187(2):276-278
This study evaluated the Mycobacterium tuberculosis protein antigen MPT-51, the trimeric antigen 85 (Ag85) complex, and Bacillus Calmette-Guérin (BCG) in an indirect ELISA to diagnose bovine tuberculosis (TB) from serum samples. Serum was collected from 208 intra-dermal tuberculin test (ITT)-positive and 54 ITT-negative animals from a region where bovine TB is endemic. Using the Ag85 and BCG antigens, the indirect ELISA was able to discriminate ITT-positive from ITT-negative animals. This level of discrimination was not achieved when using the MPT-51 antigen. The highest sensitivity (Se) and specificity (Sp) of the test was found when BCG was used (Se, 82%; Sp, 91%). Further work in different epidemiological settings and with larger numbers of animals will be required to validate these findings. 相似文献
47.
Aurelia Bonet Nieves Diaz-Caneja Isabel Gutierrez Antonio Martínez Eugenio Villar 《Water, air, and soil pollution》1988,38(1-2):181-188
A study was carried out on the pH values obtained from bulk (wet and dry) precipitation samples collected simultaneously in two cities in Cantabria (Spain), Santander and Torrelavega over a period of a year. It was observed that the annual weighted average values for the pH of precipitation, 4.42 and 4.21, respectively, differ significantly although the difference is less than that existing between their pollution levels. The difference is greater when total annual H+ depositions are compared. The study also demonstrated the strong influence of long-range transport effect on acidity and to a lesser degree the effect of mid-range transport. 相似文献
48.
Gallardo-Guerrero L Hornero-Méndez D Mínguez-Mosquera MI 《Journal of agricultural and food chemistry》2002,50(23):6746-6751
The pectic and pigment compositions and Ca and Cu contents of the alcohol-insoluble solid (AIS) residues were determined in cv. Gordal olives treated with NaOH solution and kept at different constant pH values (3.5-6.5). The same controls were made in table olives presenting green staining alteration. The ratio between the various pectin fractions of the more acid pH experiment samples remained similar in fruits not showing green staining. In altered fruits, the protopectin fraction was lower, and the calcium pectate or EDTA soluble pectins were higher. Regarding the presence of Ca and Cu in the AIS, it was observed that, whereas Ca levels fell at the most acid pH values, those of Cu increased. The concentration of Ca was higher in the AIS of altered olives than in nonaltered ones. The same trend was seen for the zone with or without green staining of an altered fruit. In the case of Cu, the relationship was the opposite: a decrease in the levels of AIS Cu in fruits and zones of fruits with green staining. This result was correlated with the highest concentration of Cu-chlorophyll complexes found in such samples and suggested that pectins might act as a reservoir of Cu involved in the alteration. 相似文献
49.
Nogueira I Lobo-da-Cunha A Afonso A Rivera S Azevedo J Monteiro R Cervantes R Gago-Martinez A Vasconcelos V 《Marine drugs》2010,8(10):2721-2732
Neurotoxicity induced in fish by domoic acid (DA) was assessed with respect to occurrence of neurotoxic signs, lethality, and histopathology by light microscopy. Sparus aurata were exposed to a single dose of DA by intraperitoneal (i.p.) injection of 0, 0.45, 0.9, and 9.0 mg DA kg(-1) bw. Mortality (66.67 ± 16.67%) was only observed in dose of 9.0 mg kg(-1) bw. Signs of neurological toxicity were detected for the doses of 0.9 and 9.0 mg DA kg(-1) bw. Furthermore, the mean concentrations (±SD) of DA detected by HPLC-UV in extracts of brain after exposure to 9.0 mg DA kg(-1) bw were 0.61 ± 0.01, 0.96 ± 0.00, and 0.36 ± 0.01 mg DA kg(-1) tissue at 1, 2, and 4 hours. The lack of major permanent brain damage in S. aurata, and reversibility of neurotoxic signs, suggest that lower susceptibility to DA or neuronal recovery occurs in affected individuals. 相似文献
50.
Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico
and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria
(Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite
amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation.
Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured
as transpiration and diffusive resistance, when these trees were cultivated without water restrictions. 相似文献