Grain cooking and nutrient qualities are the most important components of rice (Oryza sativa L.) quality. A doubled haploid (DH) population from a cross between two japonica cultivars was used to examine the pheno...Grain cooking and nutrient qualities are the most important components of rice (Oryza sativa L.) quality. A doubled haploid (DH) population from a cross between two japonica cultivars was used to examine the phenotypic values and potential QTLs for the quality traits. The cooking and nutrient quality traits, including the amylose content (AC), the gel consistency (CJC), the gelatinization temperature (GT), and the protein content (PC), in rice grown under upland and lowland environments were evaluated. Significant differences for AC, GC, GT, and PC between upland and lowland environments were detected. The phenotypic values of all four traits were higher under upland environment than lowland environment. The value of PC under upland environment was significantly higher (by 37.9%) than that under lowland environment. This suggests that upland cultivation had large effect on both cooking and nutrient qualifies. A total of seven QTLs and twelve pairs of QTLs were detected to have significant additive and epistatic effects for the four traits. Significant Q x E interaction effects of two QTLs and two pairs of QTLs were also discovered. The general contribution of additive QTLs ranged from 1.91% to 19.77%. The Q × E interactions of QTLs QGt3 and QAc6 accounted for 8.99% and 47.86% of the phenotypic variation, respectively, whereas those of the 2 pairs of epistatic QTLs, QAc6-QAcllb and QAc8-QAc9, accounted for 32.54% and 11.82%, respectively. Five QTLs QGt6b, QGt8, QGt11, QGcl, and QPc2, which had relatively high general contribution and no Q x E interactions, were selected to facilitate the upland rice grain quality breeding.展开更多
By means of improved ligand-field theory, the "pure electronic" pressure-induced shift (PS) and the PS due to electron-phonon interaction (EPI) of R-line of MgO:Cr^3+ have been calculated, respectively. The ca...By means of improved ligand-field theory, the "pure electronic" pressure-induced shift (PS) and the PS due to electron-phonon interaction (EPI) of R-line of MgO:Cr^3+ have been calculated, respectively. The calculated results are in very good agreement with the experimental data. The behaviors of the pure electronic PS of R-line of MgO:Cr^3+ and the PS of its R-line due to EPI are different. It is the combined effect of them that gives rise to the total PS of R-line, which has satisfactorily explained the experimental results. The comparison between the feature of R-line PS of MgO:Cr^3+ and that of R1-line PS of ruby has been made.展开更多
Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more e...Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection.We performed a genome-wide association study(GWAS)and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpe?o and non-Tuxpe?o heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms(SNPs).Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses.More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines.Incorporating genotype-by-environment(G×E)interaction increased genomic prediction accuracy.展开更多
Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G. tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately....Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G. tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately. The best growth rate was obtained under the conditions of 32℃, 30 and 240 μmol/(m^2·s) for G. lichenoides, and 24℃, 20 and 200 μmol/(m^2·s) for G. tenuistipitata, respectively. Then a uniform design was used to evaluate the optimal combinations of the three factors. The best conditions for the highest daily specific growth rates (% increase in wet weight) are determined to be 31.30℃, 32.10, and 287.23 lamol/(m^2·s) for G. lichenoides (16.26%/d), and 25.38℃, 21.10, and 229.07 lamol/(m^2·s) for G tenuistipitata (14.83%/d), respectively.展开更多
A theory for shifts of energy spectra due to electron-phonon interaction (EPI) has been developed. Both the temperature-independent contributions and the temperature-dependent ones of acoustic branches and optical bra...A theory for shifts of energy spectra due to electron-phonon interaction (EPI) has been developed. Both the temperature-independent contributions and the temperature-dependent ones of acoustic branches and optical branches have been derived. It is found that the temperature-independent contributions are very important, especially at low temperature. The total pressure-induced shift (PS) of a level (or spectral line or band) is the algebraic sum of its PS without EPI and its PS due to EPI. By means of both the theory for shifts of energy spectra due to EPI and the theory for PS of energy spectra, the total PS of R<SUB>1</SUB> line of tunable laser crystal GSGG:Cr<SUP>3+</SUP> at 70 K as well as the ones of its R<SUB>1</SUB> line, R<SUB>2</SUB> line and U band at 300 K will be successfully calculated and explained in this series of papers.展开更多
We have carried out magneto-transport measurements for single crystal SrMnSb2. Clear Shubnikov-de Haas oscil- lations were resolved at relatively low magnetic field around 4 T, revealing a quasi-2D Fermi surface. We o...We have carried out magneto-transport measurements for single crystal SrMnSb2. Clear Shubnikov-de Haas oscil- lations were resolved at relatively low magnetic field around 4 T, revealing a quasi-2D Fermi surface. We observed a development of quantized plateaus in Hall resistance (Rxy) at high pulsed fields up to 60 T. Due to the strong 2D confine- ment and layered properties of the samples, we interpreted the observation as bulk quantum Hall effect that is contributed by the parallel 2D conduction channels. Moreover, the spin degeneracy was lifted leading to Landau level splitting. The presence of anisotropic g factor and the formation of the oscillation beating pattern reveal a strong spin-orbit interaction in the SrMnSb2 system.展开更多
Sorghum [<i><span style="font-family:Verdana;">Sorghum bicolor</span></i><span style="font-family:Verdana;"> (L.) Moench] is a high-yielding, nutrient-use efficient, a...Sorghum [<i><span style="font-family:Verdana;">Sorghum bicolor</span></i><span style="font-family:Verdana;"> (L.) Moench] is a high-yielding, nutrient-use efficient, and drought tolerant crop that can be cultivated on over 80 per cent of the world’s agricultural land. However, a number of biotic and abiotic factors are limiting grain yield increase. Diseases (leaf and grain) are considered as one of the major biotic factors hindering sorghum productivity in the highland and intermediate altitude sorghum growing areas of Ethiopia. In addition, the yield performance of crop varieties is highly influenced by genotype × environment (G × E) interaction which is the major focus of researchers while generating improved varieties. In Ethiopia, high yielding and stable varieties that withstand biotic stress in the highland areas are limited. In line with this, the yield performance of 21 sorghum genotypes and one standard check were evaluated across 14 environments with the objectives of estimating magnitude G </span><span style="font-family:Verdana;">× E interaction for grain yield and to identify high yielder and stable genotypes across environments. The experiment was laid out using Randomized Complete Block Design with three replications in all environments. The combined analysis of variance across environments revealed highly significant differences among environments, genotypes and G × E interactions of grain yield suggesting further analysis of the G × E interaction. The results of the combined AMMI analysis of variance indicated that the total variation in grain yield was attributed to environments effects 71.21%, genotypes effects 4.52% and G × E interactions effects 24.27% indicating the major sources of variation. Genotypes 2006AN7010 and 2006AN7011 were high yielder and they were stable across environments and one variety has been released for commercial production and can be used as parental lines for genetic improvement in the sorghum improvement program. In general, this research study revealed the importance of evaluating sorghum genotypes for their yield and stability across diverse highland areas of Ethiopia before releasing for commercial production.</span>展开更多
By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI o...By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R<SUB>1</SUB> line, R<SUB>2</SUB> line, and U band of GSGG:Cr<SUP>3+</SUP> at 300 K have been calculated, respectively. The calculated results are in good agreement with all the experimental data. Their physical origins have also been explained. It is found that the mixing-degree of and base-wavefunctions in the wavefunctions of R<SUB>1</SUB> level of GSGG:Cr<SUP>3+</SUP> at 300 K is remarkable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role not only for the 'pure electronic' PS of R<SUB>1</SUB> line and R<SUB>2</SUB> line but also the PS of R<SUB>1</SUB> line and R<SUB>2</SUB> line due to EPI. The pressure-dependent behaviors of the 'pure electronic' PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line) and the PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line) due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line). In the range of about 15 kbar ~ 45 kbar, the mergence and/or order-reversal between levels and levels take place, which cause the fluctuation of the rate of PS for with pressure. At 300 K, both the temperature-dependent contribution to R<SUB>1</SUB> line (or R<SUB>2</SUB> line or U band) from EPI and the temperature-independent one are important.展开更多
By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI o...By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R<SUB>1</SUB> line of GSGG:Cr<SUP>3+</SUP> at 70 K have been calculated, respectively. Their physical origins have been revealed. It is found that the admixture of and base-wavefunctions in the wavefunctions of R<SUB>1</SUB> level of GSGG:Cr<SUP>3+</SUP> at 70 K is remarkable under the normal pressure, and the degree of the admixture rapidly decreases with increasing pressure. The change of the degree of the admixture with the pressure plays a key role for not only the pure electronic PS of R<SUB>1</SUB> line but also the PS of R<SUB>1</SUB> line due to EPI. The detailed calculations and analyses show that the pressure-dependent behaviors of the pure electronic PS of R<SUB>1</SUB> line and the PS of R<SUB>1</SUB> line due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R<SUB>1</SUB> line, which has satisfactorily explained the experimental data (including a reversal of PS of R<SUB>1</SUB> line). In contributions to PS of R<SUB>1</SUB> line due to EPI at 70 K, the temperature-independent contribution is much larger than the temperature-dependent contribution. The former results from the interaction between the zero-point vibration of the lattice and localized electronic state.展开更多
Elucidation of the relationships between genetic polymorphisms and environmental exposures can provide insights into the pathways and mechanisms underlying complex traits. A new approach was used to detect G×E (...Elucidation of the relationships between genetic polymorphisms and environmental exposures can provide insights into the pathways and mechanisms underlying complex traits. A new approach was used to detect G×E (gene-environment) interactions involved in human skin pigmentation variation to better understand the adaptive evolution of skin pigmentation. Specifically, we used genetic engineering, remote UVR (ultraviolet radiation) sensing and GIS (geographic information systems) to integrate the analysis of genetic and environmental factors into a coherent biological framework. Since we expected to generate large datasets for this multidimensional analysis, we used PCA (principal components analysis) as a spatial statistical analysis technique for analyzing the G×E interactions. The results suggest that skin pigmentation may be affected by mutations induced by UVR and support the hypothesis that global variation in skin pigmentation may be the result of localized adaptation to different UVR conditions via natural selection. Analyzing the relationships between heterozygous frequencies for SNP (single nucleotide polymorphism) loci and seasonal UVR levels as the environment changes will help elucidate the selective mechanisms involved in the UVR-induced evolution of skin pigmentation. Skin pigmentation fulfills the criteria for a successful evolutionary G×E interactions model.展开更多
Multifunctional hybrid polymer composites were projected as novel solutions to meet the demands in various industrial applications ranging from automotive to aerospace. This investigation focuses on processing, flexur...Multifunctional hybrid polymer composites were projected as novel solutions to meet the demands in various industrial applications ranging from automotive to aerospace. This investigation focuses on processing, flexural strength and fracture toughness characterization of the glass fabric reinforced epoxy (G-E) composites and graphite/fly ash cenosphere (FAC) modified interface between the epoxy matrix and glass fabric. Hand lay-up followed by compression moulding method was used to fabricate the laminates. Flexural and fracture toughness tests at room temperature, elevated temperature and cryogenic temperature were conducted to assess the flexural strength (FS) and mode-I plane-strain fracture toughness (K<sub>IC</sub>). The experimental and characterization efforts suggest that both graphite and FAC fillers improve bonding at the interface. The study showed that the graphite is more favorable for enhancing FS and KIC of G-E composites. Graphite filled G-E hybrid composites with significant FS and KIC to that of unfilled and FA filled G-E were successfully achieved by incorporating 10 wt% graphite. The incorporation of fillers resulted in improvement of FS, which increased by 43% and 37.7% for 10Gr+G-E and 10FAC+G-E hybrid composites respectively. All composites show a 26% improvement in KIC at cryogenic temperature and a decrease of 12.5% at elevated temperature. According to the SEM observations, fiber debonding from the matrix is suppressed due to the presence and uniform distribution of graphite. In addition, micro-pores, matrix shearing, active toughening mechanisms induced by graphite, such as crack deflection, layer breakage and delamination of graphite layers contributed to the enhanced KIC of hybrid G-E composites.展开更多
Sixteen faba bean genotypes were evaluated in 13 environments in Ethiopia during the main cropping season for three years(2009–2011). The objectives of the study were to evaluate the yield stability of the genotypes ...Sixteen faba bean genotypes were evaluated in 13 environments in Ethiopia during the main cropping season for three years(2009–2011). The objectives of the study were to evaluate the yield stability of the genotypes and the relative importance of different stability parameters for improving selection in faba bean. The study was conducted using a randomized complete block design with four replications. G × E interaction and yield stability were estimated using 17 different stability parameters. Pooled analysis of variance for grain yield showed that the main effects of both genotypes and environments, and the interaction effect, were highly significant(P ≤ 0.001) and(P ≤ 0.01), respectively. The environment main effect accounted for 89.27% of the total yield variation, whereas genotype and G × E interaction effects accounted for 2.12% and 3.31%, respectively.Genotypic superiority index(Pi) and FT3 were found to be very informative for selecting both high-yielding and stable faba bean genotypes. Twelve of the 17 stability parameters,including CVi, RS, α, λ, S2 di, bi, S(2)i, Wi, σ2i, EV, P59, and ASV, were influenced simultaneously by both yield and stability. They should accordingly be used as complementary criteria to select genotypes with high yield and stability. Although none of the varieties showed consistently superior performance across all environments, the genotype EK 01024-1-2ranked in the top third of the test entries in 61.5% of the test environments and was identified as the most stable genotype, with type I stability. EK 01024-1-2 also showed a17.0% seed size advantage over the standard varieties and was released as a new variety in2013 for wide production and named "Gora". Different stability parameters explained genotypic performance differently, irrespective of yield performance. It was accordingly concluded that assessment of G × E interaction and yield stability should not be based on a single or a few stability parameters but rather on a combination of stability parameters.展开更多
Microarray has become a popular biotechnology in biological and medical research. However, systematic and stochastic variabilities in microarray data are expected and unavoidable, resulting in the problem that the raw...Microarray has become a popular biotechnology in biological and medical research. However, systematic and stochastic variabilities in microarray data are expected and unavoidable, resulting in the problem that the raw measurements have inherent “noise” within microarray experiments. Currently, logarithmic ratios are usually analyzed by various clustering methods directly, which may introduce bias interpretation in identifying groups of genes or samples. In this paper, a statistical method based on mixed model approaches was proposed for microarray data cluster analysis. The underlying rationale of this method is to partition the observed total gene expression level into various variations caused by different factors using an ANOVA model, and to predict the differential effects of GV (gene by variety) interaction using the adjusted unbiased prediction (AUP) method. The predicted GV interaction effects can then be used as the inputs of cluster analysis. We illustrated the application of our method with a gene expression dataset and elucidated the utility of our approach using an external validation.展开更多
基金This work was supported by the State Key Basic Research and Development Plan of China (973)the Hi-Tech Research and De-velopment Program of China (863) National Natural Science Foundation of China.
文摘Grain cooking and nutrient qualities are the most important components of rice (Oryza sativa L.) quality. A doubled haploid (DH) population from a cross between two japonica cultivars was used to examine the phenotypic values and potential QTLs for the quality traits. The cooking and nutrient quality traits, including the amylose content (AC), the gel consistency (CJC), the gelatinization temperature (GT), and the protein content (PC), in rice grown under upland and lowland environments were evaluated. Significant differences for AC, GC, GT, and PC between upland and lowland environments were detected. The phenotypic values of all four traits were higher under upland environment than lowland environment. The value of PC under upland environment was significantly higher (by 37.9%) than that under lowland environment. This suggests that upland cultivation had large effect on both cooking and nutrient qualifies. A total of seven QTLs and twelve pairs of QTLs were detected to have significant additive and epistatic effects for the four traits. Significant Q x E interaction effects of two QTLs and two pairs of QTLs were also discovered. The general contribution of additive QTLs ranged from 1.91% to 19.77%. The Q × E interactions of QTLs QGt3 and QAc6 accounted for 8.99% and 47.86% of the phenotypic variation, respectively, whereas those of the 2 pairs of epistatic QTLs, QAc6-QAcllb and QAc8-QAc9, accounted for 32.54% and 11.82%, respectively. Five QTLs QGt6b, QGt8, QGt11, QGcl, and QPc2, which had relatively high general contribution and no Q x E interactions, were selected to facilitate the upland rice grain quality breeding.
文摘By means of improved ligand-field theory, the "pure electronic" pressure-induced shift (PS) and the PS due to electron-phonon interaction (EPI) of R-line of MgO:Cr^3+ have been calculated, respectively. The calculated results are in very good agreement with the experimental data. The behaviors of the pure electronic PS of R-line of MgO:Cr^3+ and the PS of its R-line due to EPI are different. It is the combined effect of them that gives rise to the total PS of R-line, which has satisfactorily explained the experimental results. The comparison between the feature of R-line PS of MgO:Cr^3+ and that of R1-line PS of ruby has been made.
基金funded by the CGIAR Research Program(CRP)on MAIZEthe USAID through the Accelerating Genetic Gains Supplemental Project(Amend.No.9 MTO 069033),and the One CGIAR Initiative on Accelerated Breeding+1 种基金funding from the governments of Australia,Belgium,Canada,China,France,India,Japan,the Republic of Korea,Mexico,the Netherlands,New Zealand,Norway,Sweden,Switzerland,the United Kingdom,the United States,and the World Banksupported by the China Scholarship Council。
文摘Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection.We performed a genome-wide association study(GWAS)and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpe?o and non-Tuxpe?o heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms(SNPs).Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses.More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines.Incorporating genotype-by-environment(G×E)interaction increased genomic prediction accuracy.
基金Supported by the 908 Special Program (908-02-04-07)the National Basic Research Program of China (973 Program, No. 2006CB400608)K. C. Wong Magna Fund in Ningbo University
文摘Effects of temperature, salinity and light intensity on growth rates of Gracilaria lichenoides and G. tenuistipitata var. liui Zhang et Xia were tested. Eight to ten levels of each factor were first tested separately. The best growth rate was obtained under the conditions of 32℃, 30 and 240 μmol/(m^2·s) for G. lichenoides, and 24℃, 20 and 200 μmol/(m^2·s) for G. tenuistipitata, respectively. Then a uniform design was used to evaluate the optimal combinations of the three factors. The best conditions for the highest daily specific growth rates (% increase in wet weight) are determined to be 31.30℃, 32.10, and 287.23 lamol/(m^2·s) for G. lichenoides (16.26%/d), and 25.38℃, 21.10, and 229.07 lamol/(m^2·s) for G tenuistipitata (14.83%/d), respectively.
文摘A theory for shifts of energy spectra due to electron-phonon interaction (EPI) has been developed. Both the temperature-independent contributions and the temperature-dependent ones of acoustic branches and optical branches have been derived. It is found that the temperature-independent contributions are very important, especially at low temperature. The total pressure-induced shift (PS) of a level (or spectral line or band) is the algebraic sum of its PS without EPI and its PS due to EPI. By means of both the theory for shifts of energy spectra due to EPI and the theory for PS of energy spectra, the total PS of R<SUB>1</SUB> line of tunable laser crystal GSGG:Cr<SUP>3+</SUP> at 70 K as well as the ones of its R<SUB>1</SUB> line, R<SUB>2</SUB> line and U band at 300 K will be successfully calculated and explained in this series of papers.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0303302)the National Natural Science Foundation of China(Grant Nos.61322407,11474058,and 61674040)
文摘We have carried out magneto-transport measurements for single crystal SrMnSb2. Clear Shubnikov-de Haas oscil- lations were resolved at relatively low magnetic field around 4 T, revealing a quasi-2D Fermi surface. We observed a development of quantized plateaus in Hall resistance (Rxy) at high pulsed fields up to 60 T. Due to the strong 2D confine- ment and layered properties of the samples, we interpreted the observation as bulk quantum Hall effect that is contributed by the parallel 2D conduction channels. Moreover, the spin degeneracy was lifted leading to Landau level splitting. The presence of anisotropic g factor and the formation of the oscillation beating pattern reveal a strong spin-orbit interaction in the SrMnSb2 system.
文摘Sorghum [<i><span style="font-family:Verdana;">Sorghum bicolor</span></i><span style="font-family:Verdana;"> (L.) Moench] is a high-yielding, nutrient-use efficient, and drought tolerant crop that can be cultivated on over 80 per cent of the world’s agricultural land. However, a number of biotic and abiotic factors are limiting grain yield increase. Diseases (leaf and grain) are considered as one of the major biotic factors hindering sorghum productivity in the highland and intermediate altitude sorghum growing areas of Ethiopia. In addition, the yield performance of crop varieties is highly influenced by genotype × environment (G × E) interaction which is the major focus of researchers while generating improved varieties. In Ethiopia, high yielding and stable varieties that withstand biotic stress in the highland areas are limited. In line with this, the yield performance of 21 sorghum genotypes and one standard check were evaluated across 14 environments with the objectives of estimating magnitude G </span><span style="font-family:Verdana;">× E interaction for grain yield and to identify high yielder and stable genotypes across environments. The experiment was laid out using Randomized Complete Block Design with three replications in all environments. The combined analysis of variance across environments revealed highly significant differences among environments, genotypes and G × E interactions of grain yield suggesting further analysis of the G × E interaction. The results of the combined AMMI analysis of variance indicated that the total variation in grain yield was attributed to environments effects 71.21%, genotypes effects 4.52% and G × E interactions effects 24.27% indicating the major sources of variation. Genotypes 2006AN7010 and 2006AN7011 were high yielder and they were stable across environments and one variety has been released for commercial production and can be used as parental lines for genetic improvement in the sorghum improvement program. In general, this research study revealed the importance of evaluating sorghum genotypes for their yield and stability across diverse highland areas of Ethiopia before releasing for commercial production.</span>
文摘By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R<SUB>1</SUB> line, R<SUB>2</SUB> line, and U band of GSGG:Cr<SUP>3+</SUP> at 300 K have been calculated, respectively. The calculated results are in good agreement with all the experimental data. Their physical origins have also been explained. It is found that the mixing-degree of and base-wavefunctions in the wavefunctions of R<SUB>1</SUB> level of GSGG:Cr<SUP>3+</SUP> at 300 K is remarkable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role not only for the 'pure electronic' PS of R<SUB>1</SUB> line and R<SUB>2</SUB> line but also the PS of R<SUB>1</SUB> line and R<SUB>2</SUB> line due to EPI. The pressure-dependent behaviors of the 'pure electronic' PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line) and the PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line) due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R<SUB>1</SUB> line (or R<SUB>2</SUB> line). In the range of about 15 kbar ~ 45 kbar, the mergence and/or order-reversal between levels and levels take place, which cause the fluctuation of the rate of PS for with pressure. At 300 K, both the temperature-dependent contribution to R<SUB>1</SUB> line (or R<SUB>2</SUB> line or U band) from EPI and the temperature-independent one are important.
文摘By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R<SUB>1</SUB> line of GSGG:Cr<SUP>3+</SUP> at 70 K have been calculated, respectively. Their physical origins have been revealed. It is found that the admixture of and base-wavefunctions in the wavefunctions of R<SUB>1</SUB> level of GSGG:Cr<SUP>3+</SUP> at 70 K is remarkable under the normal pressure, and the degree of the admixture rapidly decreases with increasing pressure. The change of the degree of the admixture with the pressure plays a key role for not only the pure electronic PS of R<SUB>1</SUB> line but also the PS of R<SUB>1</SUB> line due to EPI. The detailed calculations and analyses show that the pressure-dependent behaviors of the pure electronic PS of R<SUB>1</SUB> line and the PS of R<SUB>1</SUB> line due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R<SUB>1</SUB> line, which has satisfactorily explained the experimental data (including a reversal of PS of R<SUB>1</SUB> line). In contributions to PS of R<SUB>1</SUB> line due to EPI at 70 K, the temperature-independent contribution is much larger than the temperature-dependent contribution. The former results from the interaction between the zero-point vibration of the lattice and localized electronic state.
文摘Elucidation of the relationships between genetic polymorphisms and environmental exposures can provide insights into the pathways and mechanisms underlying complex traits. A new approach was used to detect G×E (gene-environment) interactions involved in human skin pigmentation variation to better understand the adaptive evolution of skin pigmentation. Specifically, we used genetic engineering, remote UVR (ultraviolet radiation) sensing and GIS (geographic information systems) to integrate the analysis of genetic and environmental factors into a coherent biological framework. Since we expected to generate large datasets for this multidimensional analysis, we used PCA (principal components analysis) as a spatial statistical analysis technique for analyzing the G×E interactions. The results suggest that skin pigmentation may be affected by mutations induced by UVR and support the hypothesis that global variation in skin pigmentation may be the result of localized adaptation to different UVR conditions via natural selection. Analyzing the relationships between heterozygous frequencies for SNP (single nucleotide polymorphism) loci and seasonal UVR levels as the environment changes will help elucidate the selective mechanisms involved in the UVR-induced evolution of skin pigmentation. Skin pigmentation fulfills the criteria for a successful evolutionary G×E interactions model.
文摘Multifunctional hybrid polymer composites were projected as novel solutions to meet the demands in various industrial applications ranging from automotive to aerospace. This investigation focuses on processing, flexural strength and fracture toughness characterization of the glass fabric reinforced epoxy (G-E) composites and graphite/fly ash cenosphere (FAC) modified interface between the epoxy matrix and glass fabric. Hand lay-up followed by compression moulding method was used to fabricate the laminates. Flexural and fracture toughness tests at room temperature, elevated temperature and cryogenic temperature were conducted to assess the flexural strength (FS) and mode-I plane-strain fracture toughness (K<sub>IC</sub>). The experimental and characterization efforts suggest that both graphite and FAC fillers improve bonding at the interface. The study showed that the graphite is more favorable for enhancing FS and KIC of G-E composites. Graphite filled G-E hybrid composites with significant FS and KIC to that of unfilled and FA filled G-E were successfully achieved by incorporating 10 wt% graphite. The incorporation of fillers resulted in improvement of FS, which increased by 43% and 37.7% for 10Gr+G-E and 10FAC+G-E hybrid composites respectively. All composites show a 26% improvement in KIC at cryogenic temperature and a decrease of 12.5% at elevated temperature. According to the SEM observations, fiber debonding from the matrix is suppressed due to the presence and uniform distribution of graphite. In addition, micro-pores, matrix shearing, active toughening mechanisms induced by graphite, such as crack deflection, layer breakage and delamination of graphite layers contributed to the enhanced KIC of hybrid G-E composites.
基金supported by the Ethiopian Institute of Agricultural Research
文摘Sixteen faba bean genotypes were evaluated in 13 environments in Ethiopia during the main cropping season for three years(2009–2011). The objectives of the study were to evaluate the yield stability of the genotypes and the relative importance of different stability parameters for improving selection in faba bean. The study was conducted using a randomized complete block design with four replications. G × E interaction and yield stability were estimated using 17 different stability parameters. Pooled analysis of variance for grain yield showed that the main effects of both genotypes and environments, and the interaction effect, were highly significant(P ≤ 0.001) and(P ≤ 0.01), respectively. The environment main effect accounted for 89.27% of the total yield variation, whereas genotype and G × E interaction effects accounted for 2.12% and 3.31%, respectively.Genotypic superiority index(Pi) and FT3 were found to be very informative for selecting both high-yielding and stable faba bean genotypes. Twelve of the 17 stability parameters,including CVi, RS, α, λ, S2 di, bi, S(2)i, Wi, σ2i, EV, P59, and ASV, were influenced simultaneously by both yield and stability. They should accordingly be used as complementary criteria to select genotypes with high yield and stability. Although none of the varieties showed consistently superior performance across all environments, the genotype EK 01024-1-2ranked in the top third of the test entries in 61.5% of the test environments and was identified as the most stable genotype, with type I stability. EK 01024-1-2 also showed a17.0% seed size advantage over the standard varieties and was released as a new variety in2013 for wide production and named "Gora". Different stability parameters explained genotypic performance differently, irrespective of yield performance. It was accordingly concluded that assessment of G × E interaction and yield stability should not be based on a single or a few stability parameters but rather on a combination of stability parameters.
基金This research was partially supported by the National Natural Science Foundation of China(No.30470916).
文摘Microarray has become a popular biotechnology in biological and medical research. However, systematic and stochastic variabilities in microarray data are expected and unavoidable, resulting in the problem that the raw measurements have inherent “noise” within microarray experiments. Currently, logarithmic ratios are usually analyzed by various clustering methods directly, which may introduce bias interpretation in identifying groups of genes or samples. In this paper, a statistical method based on mixed model approaches was proposed for microarray data cluster analysis. The underlying rationale of this method is to partition the observed total gene expression level into various variations caused by different factors using an ANOVA model, and to predict the differential effects of GV (gene by variety) interaction using the adjusted unbiased prediction (AUP) method. The predicted GV interaction effects can then be used as the inputs of cluster analysis. We illustrated the application of our method with a gene expression dataset and elucidated the utility of our approach using an external validation.