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101.
A viable option for increasing nitrogen (N) use efficiency and mitigation of negative impacts of N on the environment is to capitalize on multi-element interactions through implementation of nutrient management programs that provide balanced nutrition. Numerous studies have demonstrated the immediate efficacy of this approach in the developing regions like China and India as well as developed countries in North America. Based on 241 site-years of experiments in these countries, the first-year N recovery efficiency (RE) for the conventional or check treatments averaged 21% while the balanced treatments averaged 54% RE, for an average increase of 33% in RE due to balanced nutrition. Effective policies to promote adoption are most likely those that enable site-specific approaches to nutrient management decisions rather than sweeping, nation-wide incentives supporting one nutrient over another. Local farmers, advisers and officials need to be empowered with tools and information to help them define necessary changes in practices to create more balanced nutrient management. 相似文献
102.
Xiao-Qi Zhang Chengdao Li Amy Tay Reg Lance Daryl Mares Judy Cheong Mehmet Cakir Junhong Ma Rudi Appels 《Molecular breeding : new strategies in plant improvement》2008,22(2):227-236
Pre-harvest sprouting (PHS) is a complex trait controlled by multiple genes with strong interaction between environment and
genotype that makes it difficult to select breeding materials by phenotypic assessment. One of the most important genes for
pre-harvest sprouting resistance is consistently identified on the long arm of chromosome 4A. The 4AL PHS tolerance gene has
therefore been targeted by Australian white-grained wheat breeders. A new robust PCR marker for the PHS QTL on wheat chromosome
4AL based on candidate genes search was developed in this study. The new marker was mapped on 4AL deletion bin 13-0.59-0.66
using 4AL deletion lines derived from Chinese Spring. This marker is located on 4AL between molecular markers Xbarc170 and Xwg622 in the doubled-haploid wheat population Cranbrook × Halberd. It was mapped between molecular markers Xbarc170 and Xgwm269 that have been previously shown to be closely linked to grain dormancy in the doubled haploid wheat population SW95-50213 × Cunningham
and was co-located with Xgwm269 in population Janz × AUS1408. This marker offers an additional efficient tool for marker-assisted selection of dormancy for
white-grained wheat breeding. Comparative analysis indicated that the wheat chromosome 4AL QTL for seed dormancy and PHS resistance
is homologous with the barley QTL on chromosome 5HL controlling seed dormancy and PHS resistance. This marker will facilitate
identification of the gene associated with the 4A QTL that controls a major component of grain dormancy and PHS resistance. 相似文献
103.
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105.
In the golden egg bug, Phyllomorpha laciniata (Heteroptera,Coreidae), both males and females carry eggs on their back.Although females cannot carry their own eggs, males may carryeggs that they have fertilized. If males carry eggs they havefertilized, their behavior may be interpreted as paternal care.In this article, we provide genetic data for paternity assignmentof eggs carried by 40 males collected from the field. The malesand the eggs were typed by using four highly polymorphic microsatelliteDNA markers. Out of the 247 eggs typed, 87% were excluded fromthe father-offspring relationship based on single-locus (leastconservative exclusion) mismatches. Under the more conservative(exclusion by at least two single locus mismatches) method,78% of the eggs were nonpaternal. Relatedness estimates furthersupported our paternity analyses. The average relatedness ofthe eggs to the carrying males was low (bem = -0.052 ±0.024 SE). Within the population, males were unrelated to eachother (bmm = -0.004 ± 0.0002 SE), as were the eggs carriedby individual males (beggs = -0.004 ± 0.0001 SE). Thisfirst genetic study on the breeding system of the golden eggbugs did not find any support for the claim that egg carryingfunctioned as paternal care, nor did it support kin selectionas explanation for conspecific egg carrying. 相似文献
106.
Three columns were differentiated with feeding mixture of H2S and NH3 (MFC), feeding NH3 followed by H2S (NFC), and feeding H2S followed by NH3 (SFC). Removal performance, biodegradation capacity and microbial community structures in the three columns were compared. The results show that NFC has a shorter acclimation period for the removal of NH3 gas and nitrification than MFC. Under the high loading of H2S and NH3 at 164 and 82 g m−3 h−1, respectively, NFC exhibited high removal efficiency of NH3 (>95%) while the removal efficiencies were obtained at 63 and 75% in MFC and SFC, respectively. The removal of NH3 gas in NFC was significantly attributed to nitrification (over 50%), while adsorption and chemical reaction contributed to the removal of NH3 in MFC and SFC. The different biodegradation capacities of NH3 could be due to the dissimilarity in the microbial population presented in each column. 相似文献
107.
A Puri R Sethi B Singh SK Dwivedi VS Narain RK Saran VK Puri 《Indian pacing and electrophysiology journal》2009,9(3):186-189
A 25-year-old previously asymptomatic pregnant woman at 36 weeks'' gestation was noticed to have repetitive monomorphic ventricular tachycardia. A dilated left ventricle with moderately reduced systolic function was found on echocardiographic examination. This is a very rare presentation of peripartum cardiomyopathy (PPCMP) presenting with repetitive monomorphic ventricular tachycardia. 相似文献
108.
He-Long Jiang Abdul Majid Maszenan Zhi-Wei Zhao Joo-Hwa Tay 《Journal of industrial microbiology & biotechnology》2010,37(3):253-262
The physical structure and activity of aerobic granules, and the succession of bacterial community within aerobic granules
under constant operational conditions and shock loading were investigated in one sequencing batch reactor over ten months.
While the maturation phase of the granulation process began on day 30, the structure of microbial community changed markedly
until after three months of reactor operation under constant conditions with a loading rate of 1.5 g phenol L−1 day−1. A shock loading of 6.0 g phenol L−1 day−1 from days 182–192 led to divergence of bacterial community, an inhibition of the biomass activity, and a decrease in phenol
removal rate in the reactor. However, phenol was still completely removed under this disturbance. After the shock loading,
the mean sizes of aerobic granules increased, and the activity of the microbial population within the granules decreased,
although there appeared highly resilient for the dominant bacterial community of aerobic granules which mainly included β-Proteobacteria.
Correlation analysis suggested that biomass concentration and biomass loading were significantly related to the community
composition of aerobic granules during the whole operational period. The development of a relatively stable bacterial community
in aerobic granules implied that those distinct dominant microbes in aerobic granules were favorably selected and proliferated
under the operational conditions. 相似文献
109.
Background
In early vertebrate development, embryonic tissues modulate cell adhesiveness and acto-myosin contractility to correctly orchestrate the complex processes of gastrulation. E-cadherin (E-cadh) is the earliest expressed cadherin and is needed in the mesendodermal progenitors for efficient migration [1], [2]. Regulatory mechanisms involving directed E-cadh trafficking have been invoked downstream of Wnt11/5 signaling [3]. This non-canonical Wnt pathway regulates RhoA-ROK/DAAM1 to control the acto-myosin network. However, in this context nothing is known of the intracellular signals that participate in the correct localization of E-cadh, other than a need for Rab5c signaling [3].Methodology/Principal Findings
By studying loss of Chp induced by morpholino-oligonucleotide injection in zebrafish, we find that the vertebrate atypical Rho-GTPase Chp is essential for the proper disposition of cells in the early embryo. The underlying defect is not leading edge F-actin assembly (prominent in the cells of the envelope layer), but rather the failure to localize E-cadh and β-catenin at the adherens junctions. Loss of Chp results in delayed epiboly that can be rescued by mRNA co-injection, and phenocopies zebrafish E-cadh mutants [4], [5]. This new signaling pathway involves activation of an effector kinase PAK, and involvement of the adaptor PAK-interacting exchange factor PIX. Loss of signaling by any of the three components results in similar underlying defects, which is most prominent in the epithelial-like envelope layer.Conclusions/Significance
Our current study uncovers a developmental pathway involving Chp/PAK/PIX signaling, which helps co-ordinate E-cadh disposition to promote proper cell adhesiveness, and coordinate movements of the three major cell layers in epiboly. Our data shows that without Chp signaling, E-cadh shifts to intracellular vesicles rather than the adhesive contacts needed for directed cell movement. These events may mirror the requirement for PAK2 signaling essential for the proper formation of the blood-brain barrier [6], [7]. 相似文献110.
Shi Yang Li Wei Yu Yao Yong Jin Yuan Wen Shu Tay Nian-Lin Reena Han Rehena Sultana Pryseley N. Assam Alex Tiong-Heng Sia Ban Leong Sng 《BMC anesthesiology》2017,17(1):169