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排序方式: 共有211条查询结果,搜索用时 843 毫秒
111.
Oliveira M Nunes SF Carneiro C Bexiga R Bernardo F Vilela CL 《Veterinary microbiology》2007,124(1-2):187-191
Biofilm formation is considered a selective advantage for staphylococci mastitis isolates, facilitating bacterial persistence in the udder. It requires attachment to mammary epithelium, proliferation and accumulation of cells in multilayers and enclosing in a polymeric matrix, being regulated by several loci. As biofilm formation can proceed through different pathways and time ranges, its detection may differ according to the time of observation. This study aimed at evaluating the time course evolution of biofilm production in Staphylococcus aureus (n = 26) and Staphylococcus epidermidis (n = 29) mastitis isolates by Fluorescent In Situ Hybridisation. Biofilm-forming ability increased with incubation time for both species: for S. aureus, 34.6%, 69.2% and 80.8% of the isolates were able to produce biofilm at 24, 48 and 72 h, respectively. For S. epidermidis, 44.8%, 62.1% and 75.9% of the isolates were biofilm-positive at 24, 48 and 72 h, respectively. No significant difference was found between species at each time point (Friedman's test, p > 0.05). For S. aureus, although a significant difference was found between 24 and 48 h (Wilcoxon matched paired test, p < 0.05), no significant difference was found between 24 and 48 h (p > 0.05). For S. epidermidis, significant differences were found between each time point (p < 0.05). Bacterial biofilms may impair eradication of chronic mastitis, rendering antibiotherapy less effective. Detection of biofilm-forming ability in mastitis isolates may provide useful information for the establishment of a more adequate therapeutic regimen, in view of the antimicrobial concentrations required for bacterial control. However, it is essential that biofilm formation time course is taken into consideration. 相似文献
112.
Amita B. Juliano Ma. Elizabeth B. Naredo M.T. Jackson 《Genetic Resources and Crop Evolution》1998,45(3):197-203
This study was carried out to clarify the taxonomic status of the New World diploid wild rice species, Oryza glumaepatula. The morphological variation of 26 diploid rice accessions in the International Rice Genebank at IRRI from South America and Cuba was compared with that of O. rufipogon and O. nivara from Asia. The 28 morphological characters included 16 spikelet and grain, eight leaf and culm, and four panicle characters, and were analyzed using principal component analysis (PCA) and hierarchical agglomerative cluster analysis. The first two principal components accounted for 53.6% of the total variation. The first component was characterized by leaf and sterile lemma characters, 5-panicle dry weight, and grain length, and the second by anther length and its ratio to grain length, grain width, thickness, and 20-hulled grain weight. The characters effectively differentiated the wild rices from Surinam, French Guiana, and the lower Amazon River basin in Brazil, which showed high negative scores along both axes, from other accessions from Venezuela, Colombia, and Cuba, and the Asian species. Most of the accessions from South America are quite distinct from O. rufipogon, with which they have often been grouped as a single species in some taxonomic treatments. Groupings obtained from cluster analysis corresponded closely with the results from PCA. This study supports a distinct taxonomic status of a group of diploid wild rices from South America as O. glumaepatula. 相似文献
113.
Juliano Lauser Coletto Marcelo Peres Pinho Lauro Saint Pastous Madureira 《Fisheries Oceanography》2019,28(1):82-93
Skipjack tuna (Katsuwonus pelamis) ranks third among marine resources that sustain global fisheries. This study delimits the spatiotemporal habitat of the species in the south‐western Atlantic Ocean, based on operational oceanography. We used generalized additive models (GAMs) and catch data from six pole‐and‐line fishing vessels operating during 2014 and 2015 fishing seasons to assess the effect of environmental variables on catch. We also analysed Modis sensor images of sea surface temperature (SST) and surface chlorophyll‐α concentration (SCC) to describe fishing ground characteristics in time and space. Catch was positively related to thermocline depth (24–45 m), SST (22–24.5°C), SCC (0.08–0.14 mg/m³) and salinity (34.9–35.8). Through SST images, we identified that thermal fronts were the main surface feature associated with a higher probability to find skipjack. Also, we state that skipjack fishery is tightly related to shelf break because bottom topography drives the position of fronts in this area. Ocean colour fronts and plankton enrichment were important proxies, accessible through SCC, used to delineate skipjack fishing grounds. Catch per unit effort (CPUE) was higher towards summer (median 14 t/fishing day) due to the oceanographic characteristics of the southern region. High productivity in this sector of the Brazilian coast defines the main skipjack feeding areas and, as a consequence, the greatest abundance and availability for fishing. 相似文献
114.
Lucas de Castro Moreira da Silva Junior Cesar Avanzi Devison Souza Peixoto Marina Neves Merlo Emerson Borghi lvaro Vilela de Resende Salvador Francisco Acua-Guzman Bruno Montoani Silva 《国际水土保持研究(英文)》2021,9(4):591-604
Water scarcity threatens global food security and agricultural systems are challenged to achieve high yields while optimizing water usage. Water deficit can be accentuated by soil physical degradation, which also triggers water losses through runoff and consequently soil erosion. Although soil health in cropping systems within the Brazilian Cerrado biome have been surveyed throughout the years, information about soil erosion impacts and its mitigation are still not well understood; especially concerning the role of cropping system diversification and its effects on crop yield. Thus, the aim of this study was to assess whether ecological intensification of cropping systems –inclusion of a consorted perennial grass and crop rotation– could promote soil coverage and consequently decrease water erosion and soil, water, and nutrient losses. This work studied the effects of crop rotation and consorted Brachiaria, along with different levels of investment in fertilization on soil physical quality and on soil, water, and nutrient losses, and crop yields. Results proved that soybean monoculture (SS) is a system of low sustainability even under no-till in the Brazilian Cerrado conditions. It exhibited high susceptibility to soil, water, and nutrient losses, causing low crop yields. Our results showed that water losses in SS cropping system were approximately 10% of the total annual rainfall, and total K losses would require an additional 35% of K application. Conversely, ecological intensification of cropping systems resulted in enhanced soil environmental and agronomic functions, increased grain yield, and promoted soil and water conservation: high soil cover rate, and low soil, water and nutrient losses. Ecological intensification proved to be an adequate practice to boost crop resilience to water deficit in the Brazilian Cerrado. 相似文献
115.
Daniele M. Nascimento Letícia R. Oliveira Luana L. Melo João C. Silva José M. Soman Karine T. Girotto Renan P. Eburneo Marcos R. Ribeiro-Junior Maria M. P. Sartori Tadeu A. F. Silva Júnior Antonio C. Maringoni 《Plant pathology》2020,69(7):1357-1367
Weeds are important alternative hosts of pathogens, responsible for the survival and spread of phytopathogenic bacteria. Our study evaluated the potential of weeds as hosts of Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), causal agent of bacterial wilt, one of the main diseases of common beans. Cff survival was evaluated in the phyllosphere and in the rhizosphere of 21 weeds, in four experiments under field conditions, during the years 2018 and 2019. The aerial part of the plant was inoculated by spraying bacterial suspension (107 cfu/ml) of Cff, while the soil of the growing pots was infested with the same suspension. Cff survival was evaluated every 7 days, for 70 days. The identity of the bacterium was confirmed by PCR with the specific primers CffFOR2 and CffREV4, from strains recovered from all samples. Principal component analysis (PCA) showed that high temperatures and rainfall reduced Cff survival in the phyllosphere, while high temperatures reduced the survival of the bacterium in the rhizosphere. Our results demonstrated that Amaranthus viridis (family Amaranthaceae), Conyza bonariensis, Emilia fosbergii, Galinsoga parviflora, Gnaphalium purpureum (Asteraceae), Raphanus sativus, Lepidium virginicum (Brassicaceae), Commelina benghalensis (Commelinaceae), Ipomoea triloba (Convolvulaceae), Cyperus rotundus (Cyperaceae), Senna obtusifolia (Fabaceae), Digitaria insularis (Poaceae), Nicandra physalodes, and Solanum americanum (Solanaceae) are potential hosts for Cff. Their eradication in common bean fields is recommended, especially in fields with a history of bacterial wilt occurrence. 相似文献
116.
Tadeu O. Xavier Mariana Michelato Luiz V. O. Vidal Valria R. B. Furuya Wilson M. Furuya 《Journal of the World Aquaculture Society》2014,45(4):439-446
Meat and bone meal (MBM) is an excellent source of amino acids (AAs) for fish but its proximate composition varies according to its origin and processing. Apparent digestibility coefficients (ADC) of dry matter, crude protein, and gross energy, and apparent availability coefficients (AAC) of essential and nonessential AAs (EAA and NEAA, respectively) in MBM containing various levels of crude protein (MBM‐340, 370, 400, 430, and 460 g/kg) were determined for juvenile Nile tilapia (Oreochromis niloticus, 32.7 ± 4.5 g). A reference diet containing 351.9 g/kg crude protein and 4541.1 kcal/kg of gross energy and test diets containing a 70:30 mixture of the reference diet and MBM were used with 5 g/kg Cr2O3 as an external indicator. ADC of dry matter, gross energy, and crude protein in MBM samples were 42.9–76.2%, 71.6–89.1%, and 49.4–86.9%, respectively. MBM‐400, 430, and 460 showed higher dry matter, gross energy, and crude protein ADC than that by MBM‐340 and 370. All AAs in MBM‐460 showed AAC of EAA > 90%, while the value for MBM‐430 was >85%, except arginine (82.1%) and lysine (84.8%). High ADC of energy, crude protein, and AAC in MBM‐430 and 460 indicate good potential as quantitative AA sources. Besides the low AA quality of MBM‐340, 370, and 400, their utilization is limited by low digestible energy and high ash, which should be considered in the production of least‐cost, well‐balanced, and sustainable diets for tilapia. 相似文献
117.
Rosas Jorge Tadeu Fim de Assis Silva Samuel de Almeida Samira Luns Hatum Medauar Caique Carvalho Moraes Willian Bucker de Souza Lima Julião Soares 《European journal of plant pathology / European Foundation for Plant Pathology》2021,161(3):677-692
European Journal of Plant Pathology - Coffee rust has been one of the main factors responsible for reducing crop yield. The management of this disease corresponds to one of the main costs in the... 相似文献
118.
Corazon P. Villareal Bienvenido O. Juliano 《Plant foods for human nutrition (Dordrecht, Netherlands)》1989,39(3):287-297
Among 30 IR varieties, variety had greater effect on thiamine content of brown rice than season. Both season and variety affected riboflavin content. Purple- and red-pericarped Philippines rices had higher riboflavin and crude protein contents than IR rices. Crude oil contents of brown rice and bran-polish of 19 IR rices were significantly affected by variety, but only brown rice oil content was significantly affected by season. Bran-polish of waxy rice IR29 had the highest oil content. Silicon content of hull of 16 IR rices showed significant variation due to variety and season and tended to be higher in the dry season crop. Variety rankings in nutrient composition were not consistent for the two crops. The levels of nutrients of IR rices were within the range of values reported for other rices. 相似文献
119.
Salgado JM Rodrigues BS Donado-Pestana CM dos Santos Dias CT Morzelle MC 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(4):384-390
Cupuassu (Theobroma grandiflorum) is a fruit tree native to the Brazilian Amazon. Cupuassu beans are extensively used in the Brazilian food industry. Fat
from cupuassu beans, which are a rich source of triacylglycerols and fatty acids, is used extensively in the production of
candies and confectionery in the northern and northeastern regions of Brazil. The potential use of the agro-industrial by-products
of cupuassu has only slightly been addressed by the scientific community. Often, such by-products are sources of bioactive
compounds with functional properties. Thus, the aims of this study were to characterize the use of cupuassu peel flour (CPF)
and to examine the potential of CPF as a partial replacement in the preparation of breads through various means: chemical
analyses, determination of protein digestibility, tannins, phytic acid and phenolic contents, pH, color, volume, and acceptance
tests. The results show that CPF is a potential source of dietary fiber (79.81%), mainly insoluble fiber (78.29%), and breads
made with added CPF present high dietary fiber content (5.40 and 6.15 g/100 g for inclusions with 6 and 9% CPF, respectively)
and phytochemical values. The use of this by-product did not produce substantial changes in the physical, chemical or rheological
characteristics of breads. Therefore, breads enhanced with CPF may be a convenient functional food, offering a good source
of dietary fiber and phytochemicals. Breads prepared with 6% added CPF presented an acceptable overall quality to consumers. 相似文献
120.
Santos-Cividanes Terezinha M. Cividanes Francisco J. Garcia Jlio C. Vilela Michelle Moraes Jair C. Barbosa Jos Carlos 《Journal of pest science》2022,95(2):783-795
Journal of Pest Science - The sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae) is a major pest of sugarcane (Saccharum sp.) (Glumiflorae: Poaceae) in Brazil and has been... 相似文献