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Passos L. T. Cruz E. A. da Fischer V. Porciuncula G. C. da Werncke D. Dalto A.G.C Stumpf M. T. Vizzotto E. F. da Silveira I. D. B. 《Tropical animal health and production》2017,49(4):851-856
Tropical Animal Health and Production - Lameness can negatively affect production, but there is still controversy about the perception of pain in dairy cows. This study aimed to verify the effects... 相似文献
63.
AB Verchovsky AV Fisenko LF Semjonova IP Wright MR Lee CT Pillinger 《Science (New York, N.Y.)》1998,281(5380):1165-1168
Nanometer-size presolar diamonds from the Efremovka CV3 chondrite were physically separated into several grain size fractions by ultracentrifugation. The coarsest size fraction is the most enriched in carbon-12; the others have broadly similar carbon isotopic compositions. Measurement of noble gases shows that their concentration decreases with decreasing grain size. This effect is attributed to ion implantation. Such an episode could occur in the envelope of a supernova that produced the diamonds, or in interstellar space; in either case, ions with energies above a certain threshold pass completely through the smaller diamond grains without being captured. Concentrations of nitrogen show only minor variations with grain size, indicating a different mechanism of incorporation into the diamonds. 相似文献
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A. S. Bhering M. G. F. Carmo I. S. Coelho E. S. A. Lima C. F. de Carvalho A. L. R. F. Saraiva S. R. Passos N. M. B. Amaral Sobrinho 《Plant pathology》2020,69(2):302-309
Clubroot, caused by Plasmodiophora brassicae, is a disease limiting the production of Brassica species. Its severity varies according to the density of the pathogen's resting spores and environmental conditions. Although the soil environment (including its physical, chemical and biological characteristics) is determinant in the development of the disease, little is known regarding these characteristics in tropical regions, such as Brazil. The objective of this study was to investigate the relationships between soil attributes, bacterial population composition and clubroot intensity in a tropical mountain agroecosystem. Soil and plant samples were collected from 17 cauliflower-producing localities in Nova Friburgo, Brazil. The physical and chemical attributes, the bacterial population composition, the number of pathogen resting spores in the soil samples, and the clubroot severity were evaluated. Based on bacterial population composition, two distinct groups of soils were identified, which varied in attributes such as organic matter, potential acidity, pH and disease severity. The organic matter level was associated with differences in soil acidity, bacterial population composition and disease intensity, but there was not a cause and effect relationship between bacterial population composition and clubroot severity. Under the conditions of this agroecosystem, soils with increased organic matter presented higher acidity potential (H + Al), which was strongly correlated to clubroot severity. Thus, high acidity potential could be a key factor leading to clubroot development in mountain regions of Brazil. 相似文献
66.
Felipe Cunha Siman Felipe Vaz Andrade Renato Ribeiro Passos 《Communications in Soil Science and Plant Analysis》2020,51(10):1283-1292
ABSTRACT The volatilization of ammonia is the main reaction that decreases the efficiency of nitrogen fertilization and in order to reduce losses. new technologies such as addition of N-n-butyltriamide thiophosphate (NBPT) to the conventional urea granule (UNBPT) or the covering with polymer and sulfur (UPS) have been developed with the aim to optimize nitrogen fertilization. This work aimed to evaluate the volatilization of ammonia (NH3) in conventional urea (CU) and fertilizers with associated technology under: (a) three temperature conditions (b) and three soil moisture management. The fertilizer CU presented the highest losses by volatilization of 25.93 mg dm?3 while fertilizers with associated technology registered 23.93 mg dm?3 and 8.26 mg dm?3 for UNBPT and UPS. respectively. The highest volatilization of NH3 was registered at 45°C for all fertilizers. Fertilizers with associated technology extended the N-release time. delaying the volatilization peak up to the 6th day or even promoted the gradual release of fertilizer in the soil. such as UPS. The UNBPT showed the lowest volatilization values in the 1st water application. while the CU had lower volatilization values at 25°C (14.48 mg dm?3 NH3) and 35°C (16.99 mg dm?3 NH3) when the matric potential was increased from ?100 to ?50 kPa in the 1st application of water. The UPS did not differ from the volatilization values for the three times of water application. 相似文献
67.
Two Methods of Vitrification Followed by In Vitro Culture of the Ovine Ovary: Evaluation of the Follicular Development and Ovarian Extracellular Matrix 下载免费PDF全文
FT Bandeira AA Carvalho SV Castro LF Lima DA Viana JSAM Evangelista MJS Pereira CC Campello JR Figueiredo APR Rodrigues 《Reproduction in domestic animals》2015,50(2):177-185
The aim of this study was to evaluate the influence of two vitrification techniques on the extra cellular matrix (ECM) and ovarian follicular development. The ovarian cortex was fragmented (9 mm3) and divided into six groups, viz. fresh control, cultured control, vitrified by the Ovarian Tissue Cryosystem (OTC) method, conventional solid surface vitrification (SSV) method, OTC/cultured and SSV/cultured. Follicles from all the fragments were analysed for morphology, development and viability. The ECM was evaluated based on the condition of collagen and reticular fibres and the immunolocalization of type I collagen and fibronectin. After 7 days of culture, the tissue vitrified by OTC revealed a higher percentage (p < 0.05) of morphologically normal (30.66%) and viable (60.00%) follicles when compared with those vitrified using the SSV technique (21.33% and 23.00%). In all the fragments cultured, regardless of the vitrification method, a significantly higher percentage of developing follicles was observed when compared with the non‐cultured tissue. Analysis of the type I collagen showed increased immunostaining after the in vitro culture in the vitrified fragments. In conclusion, the OTC is better for preserving the follicular viability and morphology and maintaining the integrity of the extracellular matrix components of the ovine ovary. 相似文献
68.
药食植物玛咖是重要的保健品原料,近年来云南省玛咖产业发展迅速,但由于起步较晚、基础薄弱,种植、加工与国外相比仍有较大的差距。从玛咖生产基地、加工企业、优势区域布局、种植与初加工技术体系、经济效益等方面阐述了云南省玛咖产业发展现状,并对制约其产业发展的主要因素进行分析,最后提出了加强组织领导,抓好宏观调控;加大财政投入,拓宽投融资渠道;加快原料生产加工基地建设;加强现代科技研发工作,建立科技支撑体系;加快培育龙头企业;构建市场营销体系;促进集聚发展,严格质量标准等促进对策。 相似文献
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RJ DOBSON RB BESIER EH BARNES SCJ LOVE A VIZARD K BELL LF Le JAMBRE 《Australian veterinary journal》2001,79(11):756-761
OBJECTIVE: To provide principles for the appropriate use of avermectin/milbemycin or macrocyclic lactone (ML) anthelmintics in sheep, to ensure effective worm control and to minimise selection for ML resistance. STRATEGY: The principles were based on an assessment of the information currently available. The MLs were categorised into three groups (ivermectin [IVM], abamectin [ABA] and moxidectin [MOX]) based on structural differences, persistence and efficacy against ML resistant strains. The reported order of activity or efficacy against ML resistant worm strains was IVM相似文献