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101.
Potential antagonists were isolated from the epiphytic flora associated with oranges and pome fruit. A total of 1465 microorganisms were tested in a preliminary screening against blue and green moulds on pome and citrus fruit, respectively. Among them, approximately 3% reduced incidence and severity by more than 50% and 4 microorganisms fulfilled the selection criteria of reduction in severity and incidence by 75%. The most effective was a yeast identified as Metschnikowia andauensis, strain NCYC 3728 (PBC-2), isolated from the surface of ‘Bravo de Esmolfe’ apple fruit cultivated in North Portugal. The biocontrol activity of M. andauensis PBC-2 was dependent on its applied concentration. At 5 × 106 cfu/mL incidence (% of infected wounds) and severity (lesion diameter) were reduced by 62 and 70%, respectively and at 1 × 107 cfu/mL, the greatest reduction was achieved, 90% of incidence and 95% of severity. The broad spectrum of action of M. andauensis PBC-2 was evaluated with effective control being achieved against Rhizopus stolonifer, Penicillium expansum and Botritys cinerea, on ‘Rocha’ pears and on different apple cultivars and against Penicillium digitatum and Penicillium italicum on mandarins and oranges. In semi-commercial trials in cold storage, the reduction of blue mould was 90%. Rapid colonization of fresh apple fruit wounds was observed during the first 24 h of cold storage, followed by a significant population increase during the first 15 days of storage and then the population remained stable until the end of storage. 相似文献
102.
The Penman–Monteith equation for reference evapotranspiration (ETo) estimation cannot be applied in many situations, because climatic records are totally or partially not available or reliable.
In these cases, empirical equations that rely on few climatic variables are necessary. Nevertheless, the uncertainty associated
with empirical model estimations is often high. Thus, the improvement of methods relying on few climatic inputs as well as
the development of emergency estimation tools that demand no local climatic records turns into a task of great relevance.
The present study describes different approaches based on multiple linear regression, simple regression and artificial neural
networks (ANNs) to deal with ETo estimation exclusively from exogenous records from secondary stations. This cross-station approach is based on a continental
characterization of the study region, which enables the selection and hierarchization of the most suitable ancillary data
supplier stations. This procedure is compared with different traditional and cross-station approaches, including methodologies
that also consider local temperature inputs. The proposed methods are also evaluated as gap infilling procedures and compared
with a simple methodology, the window averaging. The artificial neural network and the multiple linear regression approaches
present very similar performance accuracies, considerably higher than simple regression and traditional temperature-based
approaches. The proposed input combinations allow similar performance accuracies as ANN models relying on exogenous ETo records and local temperature measurements. The cross-station multiple linear regression procedure is recommended due to
its higher simplicity. 相似文献
103.
Samanta A Costa MH Nunes EL Vieira SA Xu L Myneni RB 《Science (New York, N.Y.)》2011,333(6046):1093; author reply 1093
Zhao and Running (Reports, 20 August 2010, p. 940) reported a reduction in global terrestrial net primary production (NPP) from 2000 through 2009. We argue that the small trends, regional patterns, and interannual variations that they describe are artifacts of their NPP model. Satellite observations of vegetation activity show no statistically significant changes in more than 85% of the vegetated lands south of 70°N during the same 2000 to 2009 period. 相似文献
104.
105.
Jadzinsky PD Calero G Ackerson CJ Bushnell DA Kornberg RD 《Science (New York, N.Y.)》2007,318(5849):430-433
Structural information on nanometer-sized gold particles has been limited, due in part to the problem of preparing homogeneous material. Here we report the crystallization and x-ray structure determination of a p-mercaptobenzoic acid (p-MBA)-protected gold nanoparticle, which comprises 102 gold atoms and 44 p-MBAs. The central gold atoms are packed in a Marks decahedron, surrounded by additional layers of gold atoms in unanticipated geometries. The p-MBAs interact not only with the gold but also with one another, forming a rigid surface layer. The particles are chiral, with the two enantiomers alternating in the crystal lattice. The discrete nature of the particle may be explained by the closing of a 58-electron shell. 相似文献
106.
Ferguson SM Brasnjo G Hayashi M Wölfel M Collesi C Giovedi S Raimondi A Gong LW Ariel P Paradise S O'toole E Flavell R Cremona O Miesenböck G Ryan TA De Camilli P 《Science (New York, N.Y.)》2007,316(5824):570-574
Dynamin 1 is a neuron-specific guanosine triphosphatase thought to be critically required for the fission reaction of synaptic vesicle endocytosis. Unexpectedly, mice lacking dynamin 1 were able to form functional synapses, even though their postnatal viability was limited. However, during spontaneous network activity, branched, tubular plasma membrane invaginations accumulated, capped by clathrin-coated pits, in synapses of dynamin 1-knockout mice. Synaptic vesicle endocytosis was severely impaired during strong exogenous stimulation but resumed efficiently when the stimulus was terminated. Thus, dynamin 1-independent mechanisms can support limited synaptic vesicle endocytosis, but dynamin 1 is needed during high levels of neuronal activity. 相似文献
107.
Luís?Borda-de-águaEmail author Laetitia?Navarro Catarina?Gavinhos Henrique?M.?Pereira 《Landscape Ecology》2011,26(2):253-265
Roads can have drastic impacts on wildlife populations. Although there is wide recognition of the negative impacts caused
by roads and a wealth of practical studies, there is a lack of theoretical work that can be used to predict the impact of
road networks or to implement mitigation measures. Here, using Skellam’s diffusion model, we develop analytic and numerical
approaches to analyze the impact of road networks on the survival of populations. Our models show that the viability of a
population is determined not only by road density but also by the size and shape of patches. Accordingly, we studied the minimum
size of a patch to sustain a population with given diffusion and growth parameters. We provide simple formulas to estimate
the minimum patch size, and illustrate the importance of shape with square and rectangular patches. Our models also allow
the estimation of time to extinction after road construction for a population in a patch smaller than that of the minimum
size. Finally, using numerical computations we illustrate how the spatial arrangement of fences strongly affects both the
equilibrium density and the spatial distribution of populations, and that not all fence layouts are equally effective. We
anticipate that our methods provide a tool to assess the impact of geometrical features of road networks on wildlife and that
they can be used to design mitigation measures to prevent the decline and extinction of populations in an anthropogenically
disturbed landscape. 相似文献
108.
Paula Aguilera Fernando Borie Alex Seguel Pablo Cornejo 《Soil biology & biochemistry》2011,43(12):2427-2431
Arbuscular mycorrhizal spores and glomalin-related soil protein (GRSP) isolated from acid soils were analyzed using confocal laser scanning microscopy (CLSM) for Al detection. Mycorrhizal structures of Glomus intraradices produced under in vitro conditions as well as spores and GRSP from neutral and Cu-polluted soils were used as contrasting criteria. Spores and GRSP from soils with 7 and 70% Al saturation showed autofluorescence which increased especially at the highest soil Al level and when Al3+ solution was added. G.intraradices spores showed fluorescence only when exogenous Al3+ was added. On the contrary, spores and GRSP from neutral and Cu-polluted soils showed little or no significant fluorescence. This fluorescence shown by fungal structures and GRSP when subjected to high Al (of endogenous or exogenous origin) suggest a high capacity for Al immobilization, which could be an effective way to reduce Al activity and phytotoxicity in acid soils. 相似文献
109.
Piper L. Nelson Andreas Beck Henrique Cheng 《Veterinary journal (London, England : 1997)》2011,187(2):153-164
The transient receptor potential proteins (TRPs) make up a very important family of ion channels responsible for a wide array of cellular functions. Originally identified in the visual system of Drosophila melanogaster, these channels are ubiquitously distributed throughout the mammalian system. The TRP family is divided into seven subfamilies in two groups: the first group comprises TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPN (Drosophila NOMPC) and TRPA (ankyrin). The second group contains TRPML (mucolipin) and TRPP (polycystin).The biophysical characterization of TRPs has revealed significantly different activation mechanisms and selectivity between channels. Functional studies have demonstrated that TRPs are necessary for a number of physiological processes, including sensation (such as taste, smell and temperature), hormone secretion and development. TRPs mediate these effects mainly by controlling the intracellular Ca2+ concentration, which acts as a second messenger. Recent research has linked TRPs to different diseases. This review considers the impact of TRPs on cell physiology and the abnormalities observed with channel dysfunction. 相似文献
110.
Adrien Gallou Hernán Patricio Lucero Mosquera Sylvie Cranenbrouck Juan Pablo Suárez Stéphane Declerck 《Physiological and Molecular Plant Pathology》2011,76(1):20-26
Biological control of soil-borne pathogens by arbuscular mycorrhizal (AM) fungi has been repeatedly demonstrated. However, their role in the control of above-ground hemibiotrophic pathogens is less conclusive. Here, we investigated in vitro the impact of an AM fungus on Phytophthora infestans in potato plants. The leaf infection index was decreased in mycorrhizal potato plants. Real-Time Quantitative PCR revealed the induction of two pathogenesis related genes (PR1 and PR2) in the leaves of mycorrhizal plants shortly after infection with P. infestans. These results suggested a systemic resistance in mycorrhizal plants, related to the priming of the two PR genes in potato. 相似文献