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941.
Eric Siaw Ntiri Paul-Andre Calatayud Boaz Musyoka Johnnie Van den Berg Bruno Pierre Le Ru 《Phytoparasitica》2018,46(5):607-615
Competitive or facilitative interactions characterise phytophagous insect communities that utilise the same resources. These interactions are often mediated by the host plant. Plant mediation influences the oviposition choices that a community of insects, sharing the same host plant make. In this context, the oviposition choices of females within a community of lepidopteran cereal stemborers namely Busseola fusca, Sesamia calamistis and Chilo partellus were studied in plant choice-experiments under laboratory and field conditions. Gravid females of each species were presented with a choice between maize plants infested by conspecific or heterospecific larvae and uninfested maize plants. The number of eggs and egg batches laid on plants were used to quantify oviposition. Results showed that none of the three stemborer species avoided oviposition on infested maize plants. In some cases a significant preference for infested maize plants were observed. Similarly, data from field trials under natural stemborer infestation, with B. fusca as the only species, showed that the wild ovipositing moths were not avoiding infested plants. Host plant mediation may influence the incidence of multi-species infestations by stemborer species often found in the field. The potential roles of herbivore-induced and egg-deposited-induced plant volatiles in this mechanism are discussed. 相似文献
942.
Effects of drought on weed emergence and growth vary with the seed burial depth and presence of a cover crop
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Stéphane Cordeau Sandra Wayman Carole Reibel Florence Strbik Bruno Chauvel Jean‐Philippe Guillemin 《Weed Biology and Management》2018,18(1):12-25
In conservation agriculture, weed seed germination could decrease with the presence of a cover crop, surface weed seed location and temporal drought in summer just after seed shedding. This study simultaneously examined the effects of a cover crop, burial depth (seed location) and hydric stress on weed emergence and early growth. It was hypothesized that drought would reduce weed emergence and the initial growth of weed seeds and that this effect would be greater when the seeds were on the soil surface and in the presence of a cover crop. Four annual weed species were chosen that are frequently found (Anisantha sterilis, Vulpia myuros, Sonchus asper, Veronica persica) and not frequently found (Alopecurus myosuroides, Poa annua, Cyanus segetum, Capsella bursa‐pastoris) in fields that implement conservation agriculture. The unburied seeds had 26% lower emergence, on average, than the buried seeds (significant for six of the eight species), hydric stress reduced emergence by 20% (for seven of the eight species) and the presence of a cover crop reduced the level of emergence by 17% (for all species). The unburied seeds with hydric stress were emerging under the “most stressful” set of factors, with a 45% decrease in emergence, compared with the seeds emerging under the “least stressful” set of factors (buried seeds without hydric stress). All the weed growth measurements (height, dry matter content and number of leaves) decreased with the presence of a cover crop. The species that are found frequently in the fields that implement conservation agriculture, compared with the species that are not frequently found in conservation agriculture fields, had higher rates of germination and a higher tolerance of hydric stress when their seeds were unburied. 相似文献
943.
Damasceno de Oliveira Laira L. Nunes Bruno Antunes Sara Cristina Campitelli-Ramos Raphael Rocha Odete 《Water, air, and soil pollution》2018,229(4):1-28
Water, Air, & Soil Pollution - Phosphorus (P) is an essential element for all living organisms, and plays a major role in many physiological processes. However, in recent years, excessive... 相似文献
944.
Érica Hasui Vinícius X. Silva Rogério G. T. Cunha Flavio N. Ramos Milton C. Ribeiro Mario Sacramento Marco T. P. Coelho Diego G. S. Pereira Bruno R. Ribeiro 《林业研究》2017,28(5):963-974
Species distribution models are used to aid our understanding of the processes driving the spatial patterns of species’ habitats. This approach has received criticism, however, largely because it neglects landscape metrics. We examined the relative impacts of landscape predictors on the accuracy of habitat models by constructing distribution models at regional scales incorporating environmental variables (climate, topography, vegetation, and soil types) and secondary species occurrence data, and using them to predict the occurrence of 36 species in 15 forest fragments where we conducted rapid surveys. We then selected six landscape predictors at the landscape scale and ran general linear models of species presence/absence with either a single scale predictor (the probabilities of occurrence of the distribution models or landscape variables) or multiple scale predictors (distribution models + one landscape variable). Our results indicated that distribution models alone had poor predictive abilities but were improved when landscape predictors were added; the species responses were not, however, similar to the multiple scale predictors. Our study thus highlights the importance of considering landscape metrics to generate more accurate habitat suitability models. 相似文献
945.
Núbia Rosa da Silva Maaike De Ridder Jan M. Baetens Jan Van den Bulcke Mélissa Rousseau Odemir Martinez Bruno Hans Beeckman Joris Van Acker Bernard De Baets 《Annals of Forest Science》2017,74(2):30
?Key message
Pattern recognition has become an important tool to aid in the identification and classification of timber species. In this context, the focus of this work is the classification of wood species using texture characteristics of transverse cross-section images obtained by microscopy. The results show that this approach is robust and promising.?Context
Considering the lack of automated methods for wood species classification, machine vision based on pattern recognition might offer a feasible and attractive solution because it is less dependent on expert knowledge, while existing databases containing high-quality microscopy images can be exploited.?Aims
This work focuses on the automated classification of 1221 micro-images originating from 77 commercial timber species from the Democratic Republic of Congo.?Methods
Microscopic images of transverse cross-sections of all wood species are taken in a standardized way using a magnification of 25 ×. The images are represented as texture feature vectors extracted using local phase quantization or local binary patterns and classified by a nearest neighbor classifier according to a triplet of labels (species, genus, family).?Results
The classification combining both local phase quantization and linear discriminant analysis results in an average success rate of approximately 88% at species level, 89% at genus level and 90% at family level. The success rate of the classification method is remarkably high. More than 50% of the species are never misclassified or only once. The success rate is increasing from the species, over the genus to the family level. Quite often, pattern recognition results can be explained anatomically. Species with a high success rate show diagnostic features in the images used, whereas species with a low success rate often have distinctive anatomical features at other microscopic magnifications or orientations than those used in our approach.?Conclusion
This work demonstrates the potential of a semi-automated classification by resorting to pattern recognition. Semi-automated systems like this could become valuable tools complementing conventional wood identification.946.
Farinacci M Colitti M Sgorlon S Stefanon B 《Veterinary immunology and immunopathology》2008,126(1-2):54-63
Neutrophils play an essential role in host defense and inflammation. Plants have long been used to improve the immune function, but for most of them specific investigations on animal health are lacking. In the present study, water and hydroethanolic extracts from 11 plant wastes have been screened on immune responses of ovine neutrophils. Eight sheep clinically healthy, not lactating, non-pregnant were selected and used for the experiment. Freshly isolated neutrophils were incubated with the extracts of the residues at increasing doses, and then they were tested for adhesion and superoxide production induced with PMA. The residues of Larix decidua, Thymus vulgaris, Salix alba, Sinupret, Helianthus annuus, Mangifera indica modulated the neutrophil immune functions, moreover, Larix decidua, Thymus vulgaris and Salix alba presented the highest anti-inflammatory activity. 相似文献
947.
Andreas Redl Marie Hlne Morel Joëlle Bonicel Bruno Vergnes Stephane Guilbert 《Cereal Chemistry》1999,76(3):361-370
Gluten-glycerol dough was extruded under a variety of processing conditions using a corotating self-wiping twin-screw extruder. Influence of feed rate, screw speed, and barrel temperature on processing parameters (die pressure, product temperature, residence time, specific energy) were examined. Use of flow modeling was successful for describing the evolution of the main flow parameters during processing. Rheological properties of extruded samples exhibited network-like behavior and were characterized and modeled by Cole-Cole distributions. Changes in molecular sizes of proteins during extrusion were measured by chromatography and appeared to be correlated to molecular size between network strands, as derived from the rheological properties of the materials obtained. Depending on operating conditions, extrudates presented very different surface aspects, ranging from very smooth-surfaced extrudates with high swell to completely broken extrudates. The results indicated that extrudate breakup was caused by increasing network density, and some gliadins may have acted as cross-linking agents. Increasing network density resulted in decreasing mobility of polymeric chains, and “protein melt” may no longer have been able to support the strain experienced during extrusion through the die. Increasing network density was reflected in increased plateau modulus and molecular size of protein aggregates. Increasing network structure appeared to be induced by the severity of the thermomechanical treatment, as indicated by specific mechanical energy input and maximum temperature reached. 相似文献
948.
María Noelia Jimnez Emilia Fernndez‐Ondoo María ngeles Ripoll Juan Castro‐Rodríguez Lynn Huntsinger Francisco Bruno Navarro 《Land Degradation \u0026amp; Development》2016,27(2):357-365
This work studies the influence of two mulching treatments on soil properties and the field performance of afforested holm‐oak seedlings (Quercus ilex L. subsp. ballota (Desf.) Samp.) nine years after outplanting. Mulching treatments composed of stones, forest debris, and an untreated control were randomly applied to 180 seedlings (n = 60) in January 2001 at the bed level (1 × 1 m) in an abandoned agricultural field in SE Spain. Survival, growth measured by means of leaf area, and nutrient concentrations in leaves and soil were measured. Both mulches provided higher survival and greater leaf‐area growth than the control, but did not differ in leaf‐nutrient concentration. Most of the analysed soil variables were not affected by the mulching treatments at the end of the study period, and, therefore, the soil properties changes by mulching might be slower than expected under semi‐arid conditions. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献