Ecological civilization: perspectives from landscape ecology and landscape sustainability science     

Frazier  Amy E.  Bryan  Brett A.  Buyantuev  Alexander  Chen  Liding  Echeverria  Cristian  Jia  Peng  Liu  Lumeng  Li  Qin  Ouyang  Zhiyun  Wu  Jianguo  Xiang  Wei-Ning  Yang  Jun  Yang  Lihua  Zhao  Shuqing 《Landscape Ecology》2019,34(1):1-8

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Evaluation of Assouline–Or Adjusted Model to Express Soil Drainage Curve     

Asadi  Z.  Mohammadi  M. H.  Shorafa  M.  Farhbakhsh  M.  Ghezelbash  E. 《Eurasian Soil Science》2020,53(6):749-759

Eurasian Soil Science - The objectives of this research are prediction of soil drainage curve using Assouline and Or (2014) adjusted soil drainage model and comparison of the predicted results with...  相似文献   

Temporal and spatial progress of the diseases caused by the crinivirus tomato chlorosis virus and the begomovirus tomato severe rugose virus in tomatoes in Brazil     

M. A. Macedo  A. K. Inoue-Nagata  T. N. Z. Silva  D. M. S. Freitas  J. A. M. Rezende  J. C. Barbosa  M. Michereff-Filho  A. R. Nascimento  A. L. Lourenção  A. Bergamin Filho 《Plant pathology》2019,68(1):72-84

Efficient management of whitefly-borne diseases remains a challenge due to the lack of a comprehensive understanding of their epidemiology, particularly of the diseases tomato golden mosaic and tomato yellowing. Here, by monitoring 16 plots in four commercial fields, the temporal and spatial distribution of these two diseases were studied in tomato fields in Brazil. In the experimental plots these diseases were caused by tomato severe rugose virus (ToSRV) and tomato chlorosis virus (ToCV), respectively. The incidence of each virus was similar in the plots within a field but varied greatly among fields. Plants with symptoms for both diseases were randomly distributed in three of four spatial analyses. The curves representing the progress of both diseases were similar and contained small fluctuations, indicating that the spread of both viruses was similar under field conditions. In transmission experiments of ToSRV and ToCV by Bemisia tabaci MEAM1 (former biotype B), these viruses had a similar transmission rate in single or mixed infections. It was then shown that primary and secondary spread of ToCV were not efficiently controlled by insecticide applications. Finally, in a typical monomolecular model of disease progress, simulation of the primary dissemination of ToSRV and ToCV showed that infected plants were predominantly randomly distributed. It is concluded that, although the manner of vector transmission differs between ToSRV (persistent) and ToCV (semipersistent), the main dispersal mechanisms are most probably similar for these two diseases: primary spread is the predominant mechanism, and epidemics of these diseases have been caused by several influxes of viruliferous whiteflies.  相似文献   

Assessment of the ideal ratios of digestible essential amino acids for pacu,Piaractus mesopotamicus,juveniles by the amino acid deletion method     

Andr Z. Boaratti  Thiago M. T. Nascimento  Kifayat U. Khan  Cleber F. M. Mansano  Thaís S. Oliveira  Daniel M. A. Queiroz  Rafael S. Romaneli  Andressa T. Rodrigues  Nilva K. Sakomura  Joo B. K. Fernandes 《Journal of the World Aquaculture Society》2021,52(1):88-104

The present study aimed to determine the ideal ratios of digestible essential amino acids (EAAs) for pacu (Piaractus mesopotamicus) juveniles by the amino acid (AA) deletion method. A completely randomized design which consisted of 11 treatments and three replicates each was used. The treatments included a control diet (CD) containing 55% of nonpurified natural ingredients and 45% of purified synthetic amino acids and ingredients, and other ten isonitrogenous and isoenergetic EAA limiting diets (LDs), each being deficient in 44.4 ± 0.02% of the respective EAA. Pacu juveniles with initial average body weight of 6.22 ± 0.09 g were distributed among 33 fiber glass tanks. Fish were fed with semipurified and extruded diets for 113 days two times a day until apparent satiation. The ideal ratio of each dietary EAA was calculated on the basis of the relationship between body N retention and amount of EAA deleted from the respective EAA LD. Based on the AA deletion method, the ideal ratios of digestible EAAs for pacu juveniles, relative to lysine requirement of 100% were estimated as: methionine 14.6%, threonine 35.0%, tryptophan 6.6%, arginine 62.8%, histidine 13.6%, isoleucine 26.3%, leucine 43.7%, phenylalanine 27.2%, and valine 35.8%.  相似文献   

Tritium Distribution in Soil in the Area of “Atomic” Lake near the Semipalatinsk Test Site     

Timonova  L. V.  Lyakhova  O. N.  Lukashenko  S. N.  Aidarkhanov  A. O.  Kabdyrakova  A. M.  Serzhanova  Z. B. 《Eurasian Soil Science》2020,53(3):355-361

Eurasian Soil Science - Data on concentrations and distribution of tritium in soils of the “Atomic” Lake excavation explosion area of Semipalatinsk Nuclear Test Site (Kazakhstan, East...  相似文献   

Occurrence of prophage and historical perspectives associated with the dissemination of huanglongbing in mainland China     

S. Fu  Z. Bai  H. Su  J. Liu  J. S. Hartung  C. Zhou  X. Wang 《Plant pathology》2020,69(1):132-138

Huanglongbing (HLB), associated with a non-culturable bacterium ‘Candidatus Liberibacter asiaticus’ (CLas), is a highly destructive citrus disease with a long but poorly documented history in China. No effective treatment for HLB is available. The identification of new prophages in abundant CLas genomic sequence data provides new insights into both the diversity of CLas strains and HLB management. In this study, CLas populations from nine provinces were surveyed for the presence of prophage. Two major prophage typing groups (PTGs) were discovered to be associated with two different altitude regions: strains of CLas in PTG1 from high altitude regions (HAR) mainly contained prophage Type 1 only or Types 1 and 3, whereas strains of CLas in PTG2 from low altitude regions (LAR) mainly contained prophage Type 2. The discovery of these CLas population patterns provides evidence for independent origins of HLB in HAR and LAR. Guangdong province is the generally recognized domestic region of origin for HLB and is primarily responsible for the dissemination of HLB in LAR through transport of seedlings. Both Yunnan and Sichuan provinces are the probable regions of origin for HLB in HAR. PTG2 was further divided into two subgroups: PTG2-1, found in Guangdong, Fujian and Guangxi and PTG2-2, found in Jiangxi, Zhejiang and Hunan. These regions and prophage types are correlated with early and late introductions of HLB in LAR. These molecular analyses were supported by studying the history of the dissemination of HLB in historical documents.  相似文献   

混合盐胁迫对马蔺幼苗根系构型及生长量的影响     

袁泽斌  牟昌红  欧阳秀琴  王波  孙向丽 《中国农学通报》2020,36(16):55-60

为探讨不同种类盐胁迫对马蔺幼苗生长状况的影响,采用室内培养的方法,研究总质量浓度为0.3%的NaCl、NaHCO₃单盐溶液及其不同配比的混合盐溶液胁迫对马蔺(Iris lactea var. chinensis)幼苗生长量、地上部干鲜重比值、地下部干鲜重比值以及根系构型的影响。结果表明,随着胁迫时间的延长,0.3%NaCl溶液对叶数和株高增长量的影响最小,其次为3种混合盐溶液,各处理在第14天时株高增幅达到最大。经0.3%NaHCO₃处理后的幼苗地上部干鲜重的比值为空白对照的2.17倍,地下部干鲜重则为空白对照的56.61%,随着混合溶液中NaHCO₃浓度的上升,地上部干鲜重比值表现出上升的趋势,地下部干鲜重比值则表现出下降的趋势。经35天处理后,0.3%NaHCO₃胁迫的马蔺幼苗根系总长、根系表面积较对照均显著下降,降幅分别为39.73%、26.08%,而各处理间的根系体积却无显著差异。研究结果显示,0.3%NaHCO₃溶液对马蔺幼苗的胁迫作用最强,2种单盐对根系的胁迫作用强于混合盐胁迫,而0.3%NaCl溶液对生长量的胁迫作用最弱。  相似文献   

浅析奖励机制在科研成果产出中的导向作用 ——以北京市农林科学院为例   总被引：1，自引：1，他引：0  

王彦珍  张越萍  欧阳伸明  张峻峰 《农业科技管理》2020,39(2):47-49,62

科研成果产出反映了科技创新能力的强弱,成果产出离不开杰出的科研人才和团队.为了提升科技创新能力,有效激发科研人员的主动性和积极性,不断提升科研成果质量,国家、地方、科研单位和高校都制定并出台了相应的科研成果奖励办法.文章以北京市农林科学院为例,对该院科技创新成果奖励的执行情况进行分析,以期总结出科技创新奖励对成果产出的导向作用.  相似文献   

A case of verminous mastitis in a mare     

Z. Gratwick  J. Frean  D. du Plessis  M. Hewetson  V. Schwan 《Equine Veterinary Education》2021,33(8):e248-e252

This report describes bilateral mammary gland infection with a previously unidentified Cephalobus species of nematode. Only one previous case of verminous mastitis due to a Cephalobus species has been reported, pre-dating the widespread use of molecular diagnostics. This report describes the case presentation and management, as well as the morphological and molecular methods of nematode identification.  相似文献   

An updated review: Laboratory investigation of equine renal disease     

Z. Gratwick 《Equine Veterinary Education》2021,33(10):546-555

A variety of laboratory tests are available to assist the clinician in the assessment of kidney health and function. The majority of widely used tests are indicative of altered renal function, not becoming abnormal until function is significantly compromised. These include serum urea and creatinine concentrations, serum electrolyte concentrations, urine specific gravity (USG), fractional electrolyte excretion ratios and symmetric dimethylarginine (SDMA) concentrations. Some of these parameters may also be affected by nonrenal disease. The results of a further group of tests can indicate renal damage, but do not reflect renal function. These include urine tubular enzyme concentrations, urine protein concentrations, urine neutrophil gelatinase-associated lipocalin (NGAL) concentrations and cytological abnormalities.  相似文献