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61.
62.
Craig Daniels Manuel Espinosa‐Urgel José‐Luis Niqui‐Arroyo Carmen Michán Juan L. Ramos 《Microbial biotechnology》2010,3(1):10-14
In the following highlight we refer to a number of new advances in the field of Biotechnology that address issues relating to the synthesis of new antibiotics, new biocatalysts and matrices in biofilms. 相似文献
63.
C. de Julián Fernández C. Sangregorio C. Innocenti G. Mattei P. Mazzoldi 《Inorganica chimica acta》2008,361(14-15):4138-4142
The magnetic properties of Co–Ni alloys nanoparticles with composition Co80Ni20 and Co50Ni50 and dispersed in a silica matrix are investigated. The effective magnetic anisotropies are evaluated from the analysis of the temperature dependence of the zero-field-cooling magnetizations and from the hysteresis loops at 3 K considering the coherent rotation model. The results show that, on the contrary of what expected, Co80Ni20 nanoparticles have smaller anisotropy than the Co50Ni50 one showing that the magnetic properties of the system can be tuned from soft to hard by simply adjusting the alloy composition. This behaviour can be explained on the basis of the different size and composition of the two systems. Moreover we found that the evaluation of the anisotropy constant depends on the experimental method adopted due to the modifications by interparticle dipolar interactions of the reversal process. 相似文献
64.
Independent component analysis (ICA) is an emerging technique for multidimensional signal processing. In recent years, these techniques have been proposed for solving a large number of biomedical applications. This work reviews current knowledge on ICA in electrocardiographic (ECG) analysis. The benefits that ICA can bring to clinical practice are illustrated with four relevant clinical applications: foetal ECG extraction from maternal ECG recordings, analysis of atrial fibrillation, ECG denoising and removal of pacemaker artefacts. 相似文献
65.
66.
Acorn dispersal estimated by radio-tracking 总被引:2,自引:0,他引:2
Bird-dispersed seeds are difficult to track, especially in the case of long-distance dispersal events. To estimate the oak
dispersal distance and the seed shadow generated by the European jay (Garrulus glandarius), we inserted radio-transmitters in 239 acorns, placed them in bird-feeders and then located them by radio-tracking. Using
this methodology we located the exact caching site of 94 Quercus ilex and 54 Q. suber acorns and determined the caching habitat characteristics (vegetation type, distance, spatial distribution). The results
show that: (1) there is no differences in the dispersal distance distribution between the different acorn species or sizes,
(2) dispersal distances range from approximately 3 m up to approximately 550 m (mean = 68.6 m; median = 49.2 m), (3) recently
abandoned fields and forest tracks were the sites preferred by jays to cache acorns, whereas fields and shrublands were avoided
and (4) seed shadows showed acorn aggregation zones (i.e. clusters of caches) close to the feeder as well as isolated caches
at longer distances. The results also suggest that radio-transmitters are a cheap and reliable way to determine seed shadows
and quantify both seed dispersal and post-dispersal seed predation for medium to large seeds. 相似文献
67.
Marcelo R. de Carvalho Flávio A. Bockmann Dalton S. Amorim Carlos Roberto F. Brandão Mário de Vivo José L. de Figueiredo Heraldo A. Britski Mário C. C. de Pinna Naércio A. Menezes Fernando P. L. Marques Nelson Papavero Eliana M. Cancello Jorge V. Crisci John D. McEachran Robert C. Schelly John G. Lundberg Anthony C. Gill Ralf Britz Quentin D. Wheeler Melanie L. J. Stiassny Lynne R. Parenti Larry M. Page Ward C. Wheeler Julián Faivovich Richard P. Vari Lance Grande Chris J. Humphries Rob DeSalle Malte C. Ebach Gareth J. Nelson 《Evolutionary biology》2007,34(3-4):140-143
68.
Plant phenology is in great measure driven by air temperature. To forecast harvest time for ‘Algerie’ loquat accurately, the
growing degree days (GDD) needed from bloom to ripening were determined using data from nine seasons. The methods proposed
by Zalom et al. (Zalom FG, Goodell PB, Wilson LT, Barnett WW, Bentley W, Degree-days: the calculation and use of heat units
in pest management, leaflet no 21373, Division Agriculture and Natural Resources, University of California 10 pp, 1983) were compared as regards their ability to estimate heat summation based on hourly records. All the methods gave remarkably
similar results for our cultivation area, although the double-sine method showed higher performance when temperatures were
low. A base temperature of 3°C is proposed for ‘Algerie’ loquat because it provides a coefficient of variation in GDD among
seasons of below 5%, and because of its compatibility with loquat growth. Based on these determinations, ‘Algerie’ loquat
requires 1,715 GDD from bloom to harvest; under our conditions this heat is accumulated over an average of 159 days. Our procedure
permits the ‘Algerie’ harvest date to be estimated with a mean error of 4.4 days (<3% for the bloom-harvest period). GDD summation
did not prove superior to the use of the number of calendar days for predicting ‘Algerie’ harvest under non-limiting growing
conditions. However, GDD reflects the developmental rate in water-stressed trees better than calendar days. Trees under deficit
irrigation during flower development required more time and more heat to ripen their fruits. 相似文献
69.
Background and Aims Many plants produce extrafloral nectar (EFN), and increase production following above-ground herbivory, presumably to attract natural enemies of the herbivores. Below-ground herbivores, alone or in combination with those above ground, may also alter EFN production depending on the specificity of this defence response and the interactions among herbivores mediated through plant defences. To date, however, a lack of manipulative experiments investigating EFN production induced by above- and below-ground herbivory has limited our understanding of how below-ground herbivory mediates indirect plant defences to affect above-ground herbivores and their natural enemies.Methods In a greenhouse experiment, seedlings of tallow tree (Triadica sebifera) were subjected to herbivory by a specialist flea beetle (Bikasha collaris) that naturally co-occurs as foliage-feeding adults and root-feeding larvae. Seedlings were subjected to above-ground adults and/or below-ground larvae herbivory, and EFN production was monitored.Key Results Above- and/or below-ground herbivory significantly increased the percentage of leaves with active nectaries, the volume of EFN and the mass of soluble solids within the nectar. Simultaneous above- and below-ground herbivory induced a higher volume of EFN and mass of soluble solids than below-ground herbivory alone, but highest EFN production was induced by above-ground herbivory when below-ground herbivores were absent.Conclusions The induction of EFN production by below-ground damage suggests that systemic induction underlies some of the EFN response. The strong induction by above-ground herbivory in the absence of below-ground herbivory points to specific induction based on above- and below-ground signals that may be adaptive for this above-ground indirect defence. 相似文献
70.
Non‐territorial Macaques Can Range Like Territorial Gibbons When Partially Provisioned With Food
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Juan Manuel José‐Domínguez Marie‐Claude Huynen Carmen J. García Aurélie Albert‐Daviaud Norberto Asensio 《Biotropica》2015,47(6):733-744
Human food supplementation can affect components of animal socioecology by altering the abundance and distribution of available food. We studied the effect of food supplementation by comparing the ranging patterns and intergroup interactions of two groups of northern pigtailed macaques (Macaca leonina), a non‐territorial primate species. One group was partially reliant on food provisioning, whereas the other group foraged wild food. We also compared the macaques’ movement with that of a group of white‐handed gibbons (Hylobates lar), a territorial species inhabiting the same site. Home range, core area, and daily path lengths were significantly smaller for the semi‐provisioned group than for the wild‐feeding group. In contrast to wild‐feeding macaques, supplemented macaques showed higher fidelity to home range, core area, and particularly to the region where human food was most accessible and abundant. The relationship of daily path length and home range indicated a low defendability index for wild‐feeding macaques; the higher index for the semi‐provisioned group was consistent with the territorial pattern found in gibbons. Semi‐provisioned macaques showed further traits of territoriality with aggression during intergroup encounters. These findings indicate that human modification of food availability can significantly affect movement patterns and intergroup competition in macaques. The observed ranging dynamics related to food provisioning may decrease the efficiency of macaques as seed dispersers and increase predation on their home range, and thus have important consequences for plant regeneration and animal diversity. 相似文献