III-V high speed electro-optic laser modulators using slow wave structure technique

Optical communication -- Opto-electronic integrated devices -- Electro-optic modulators -- Theory of electro-optic modulation -- Design of traveling wave electro-optic modulators -- Characterization, fabrication, and measurement techniques

The FIGS (Focused Identification of Germplasm Strategy) approach identifies traits related to drought adaptation in Vicia faba genetic resources : Drought Adaptation and Genetic Resources

Efficient methods to explore plant agro-biodiversity for climate change adaptive traits are urgently required. The focused identification of germplasm strategy (FIGS) is one such approach. FIGS works on the premise that germplasm is likely to reflect the selection pressures of the environment in which it developed. Environmental parameters describing plant germplasm collection sites are used as selection criteria to improve the probability of uncovering useful variation. This study was designed to test the effectiveness of FIGS to search a large faba bean (Vicia faba L.) collection for traits related to drought adaptation. Two sets of faba bean accessions were created, one from moisture-limited environments, and the other from wetter sites. The two sets were grown under well watered conditions and leaf morpho-physiological traits related to plant water use were measured. Machine-learning algorithms split the accessions into two groups based on the evaluation data and the groups created by this process were compared to the original climate-based FIGS sets. The sets defined by trait data were in almost perfect agreement to the FIGS sets, demonstrating that ecotypic differentiation driven by moisture availability has occurred within the faba bean genepool. Leaflet and canopy temperature as well as relative water content contributed more than other traits to the discrimination between sets, indicating that their utility as drought-tolerance selection criteria for faba bean germplasm. This study supports the assertion that FIGS could be an effective tool to enhance the discovery of new genes for abiotic stress adaptation.Peer reviewe

Genetic analysis of photosynthesis-related traits in faba bean (Vicia faba) for crop improvement

Increasing productivity through improvement of photosynthesis in faba bean breeding programmes requires understanding of the genetic control of photosynthesis-related traits. Hence, we investigated the gene action of leaf area, gas exchange traits, canopy temperature, chlorophyll content, chlorophyll fluorescence parameters and biomass. We chose inbred lines derived from cultivars 'Aurora' (Sweden) and 'Melodie' (France) along with an Andean accession, ILB 938, crossed them (Aurora/2 x Melodie/2, ILB 938/2 x Aurora/2 and Melodie/2 x ILB 938/2), and prepared the six standard generations for quantitative analysis (P-1, P-2, F-1, F-2, B-1, and B-2). Gene action was complex for each trait, involving additive and dominance gene actions and interactions. Additive gene action was important for SPAD, photosynthetic rate, stomatal conductance and F-v/F-m. Dominance effect was important for biomass production. It is suggested that breeders selecting for productivity can maximize genetic gain by selecting early generations for canopy temperature, SPAD and F-v/F-m, then later generations for biomass. The information on genetics of various contributing traits of photosynthesis will assist plant breeders in choosing an appropriate breeding strategy for enhancing productivity in faba bean.Peer reviewe

Leptin promotes melanoma tumor growth in mice related to increasing circulating endothelial progenitor cells numbers and plasma NO production

<p>Abstract</p> <p>Background</p> <p>Epidemiological studies propose that obesity increases the risk of several cancers, including melanoma. Obesity increases the expression of leptin, a multifunctional peptide produced predominantly by adipocytes which may promote tumor growth. Several recently experiments have suggested that the tumors growth is in need of endothelial progenitor cell (EPC) dependent generation of new blood vessels.</p> <p>Our objectives in the present study were to examine the effects of leptin on melanoma growth, circulating EPCs number and plasma levels of nitric oxide metabolites (NOx).</p> <p>Methods</p> <p>2 × 10⁶B16F10 melanoma cells were injected to thirty two C57BL6 mice subcutaneously. The mice were randomly divided into 4 groups (n = 8) in 8th day. Two groups were received twice daily intraperitoneal(i.p) injections of either PBS or recombinant murine leptin (1 μg/g initial body weight). Two groups were received i.p. injections of either 9F8 an anti leptin receptor antibody or the control mouse IgG at 50 μg/mouse every 3 consecutive days. By the end of the second week the animals were euthanized and blood samples and tumors were analyzed.</p> <p>Results</p> <p>The tumor weight, EPC numbers and NOx level in leptin, PBS, 9F8, and IgG group were (3.2 ± 0.6, 1.7 ± 0.3, 1.61 ± 0.2,1.7 ± 0.3 g), (222.66 ± 36.5, 133.33 ± 171, 23.33 ± 18, 132.66 ± 27.26/ml of blood), and (22.47 ± 5.5, 12.30 ± 1.5, 6.26 ± 0.84, 15.75 ± 6.3 μmol/L) respectively. Tumors weight and size, circulating EPC numbers and plasma levels of NOx were significantly more in the leptin than 9f8 and both control groups (p < 0.05). The plasma concentration of NOx significantly decreased in 9f8 treated mice compare to control group (p < 0.05).</p> <p>Conclusions</p> <p>In conclusion, our observations indicate that leptin causes melanoma growth likely through increased NO production and circulating EPC numbers and consequently vasculogenesis.</p

Root traits differ between wet- and dry-adapted sets of faba bean accessions selected by FIGS

Grain legumes, such as faba bean (Vicia faba L.), are important sources of protein, particularly for people in developing countries where climate change is expected to result in higher temperatures and changing precipitation patterns. Among grain legumes, faba bean is thought to be relatively sensitive to drought. Faba beans are important legumes in the crop rotations of organic farming. Deeper roots and larger root biomass have been shown to be important contributors to crop performance under drought conditions. Thus root traits could be used as the selection criteria for drought adaptation. During 2010–2011, two sets of faba bean accessions, from ‘wet’ and ‘dry’ regions, each containing 201 accessions, were chosen using the Focused Identification of Germplasm Strategy (FIGS). FIGS uses the environmental data (geographic and agro-climatic information) associated with the collection sites of plant genetic resources to identify sets of accessions ‘most likely’ and, in this case,‘least likely’ to express the trait of interest. The two sets were screened for a variety of morpho-physiological leaf traits related to drought adaptation. The results showed that FIGS successfully differentiated between material selected according to collection site moisture availability. From these results, it was hypothesized that root traits of the two FIGS sets would reflect their different geographic origins. Hence, root traits of six representative accessions from each set (chosen by principal component analysis) were evaluated under well watered conditions and then, under water deficit. Under well watered conditions, the ‘dry’ set had significantly higher root biomass than the ‘wet’ set, but no differences for root length and gas exchange traits. When the plants were exposed to water deficit, root length, root, and shoot biomass decreased significantly more in the ‘wet’ set than in the ‘dry’ one. The ‘dry’ set showed higher gas exchange than the ‘wet’ set under water deficit. These results, together with those on leaf traits, confirm the ability of the FIGS to identify germplasm for breeding for drought resistance in faba bean, and this may be extended to other crops and to other traits related to abiotic stresses and adaptation to climate change

Analysis of Factors Effective on Loyalty of Customers of Websites

Abstract: Today, the issue of keeping and strengthening customer loyalty is considered as a strategic challenge for the companies which are concerned how to retain and develop their competitive position in the market. They bear high costs to understand this concept and to achieve the practical approaches to strengthen it; because as the competition is intensified and the quantitative and qualitative level of the services in the selection area of the customers, it is considered as a vital task to provide the services which would be able to attract their attention and change them into the permanent customers of the services provided by the organization. The present investigation examines the quality system, information quality, interface design quality and their effects on the satisfaction and trust of the customers of websites as well as the effects of such trust and satisfaction on loyalty of customers of websites. Statistical population of this research includes the customers of Center Market website among which a sample of 320 people was selected. The data were analyzed using SPSS and AMOS statistical software and the Structural Equation Modeling (SEM) was used as the statistical method. The results so achieved show that system quality and interface design quality affect significantly on the satisfaction and trust of the customers. Furthermore, the trust and satisfaction are considerably effective on the customer loyalty

Genotypic variation in leaf epicuticular wax quantity in a large faba bean (Vicia faba L.) germplasm collection

Among grain legumes, faba bean is reputed to be relatively sensitive to drought stress. Epicuticular wax (ECW) quantity is considered as an important drought adaptation strategy in plant species. This study aimed to define variation in leaf ECW concentration as a drought-adaptive trait in 197 faba bean accessions under well-watered conditions. The relationship between ECW and stomatal characteristics was also investigated. Highly significant differences were found in the ECW concentration, which ranged from 0.680 to 2.104 mg/dm(2). No relationships were found between ECW and any measure of stomatal morphology and function. This study provides evidence of the wide variation in ECW in faba bean germplasm, which is independent of stomatal characteristics and leaf water content. This variation may allow the genetic improvement of ECW as a drought-adaptive character in faba bean breeding programs aiming at the economical use of water.Peer reviewe

Physiological and Biochemical Basis of Faba Bean Breeding for Drought Adaptation —A Review

Grain legumes are commonly used for food and feed all over the world and are the main source of protein for over a billion people worldwide, but their production is at risk from climate change. Water deficit and heat stress both significantly reduce the yield of grain legumes, and the faba bean is considered particularly susceptible. The genetic improvement of faba bean for drought adaptation (water deficit tolerance) by conventional methods and molecular breeding is time-consuming and laborious, since it depends mainly on selection and adaptation in multiple sites. The lack of high-throughput screening methodology and low heritability of advantageous traits under environmental stress challenge breeding progress. Alternatively, selection based on secondary characters in a controlled environment followed by field trials is successful in some crops, including faba beans. In general, measured features related to drought adaptation are shoot and root morphology, stomatal characteristics, osmotic adjustment and the efficiency of water use. Here, we focus on the current knowledge of biochemical and physiological markers for legume improvement that can be incorporated into faba bean breeding programs for drought adaptation.Peer reviewe

Genomic regions associated with chocolate spot (Botrytis fabae Sard.) resistance in faba bean (Vicia faba L.)

Chocolate spot (CS), caused by Botrytis fabae Sard., is an important threat to global faba bean production. Growing resistant faba bean cultivars is, therefore, paramount to preventing yield loss. To date, there have been no reported quantitative trait loci (QTL) associated with CS resistance in faba bean. The objective of this study was to identify genomic regions associated with CS resistance using a recombinant inbred line (RIL) population derived from resistant accession ILB 938. A total of 165 RILs from the cross Melodie/2 x ILB 938/2 were genotyped and evaluated for CS reactions under replicated controlled climate conditions. The RIL population showed significant variation in response to CS resistance. QTL analysis identified five loci contributing to CS resistance on faba bean chromosomes 1 and 6, accounting for 28.4% and 12.5%, respectively, of the total phenotypic variance. The results of this study not only provide insight into disease-resistance QTL, but also can be used as potential targets for marker-assisted breeding in faba bean genetic improvement for CS resistance.Peer reviewe

A multi-parent faba bean (Vicia faba L.) population for future genomic studies

Faba bean (Viciafaba L.) is a valuable grain legume and a staple protein crop in many countries. Its large and complex genome requires novel approaches for its genetic dissection. Here we introduce a multi-parent population developed from four founders (ILB 938/2, Disco/2, IG 114476 and IG 132238). The selection of parental lines was based on geographic (Colombia, France, Bangladesh and China), genetic and phenotypic diversity. The parental lines were inbred and then genotyped using 875 single nucleotide polymorphism (SNP) markers. Based on molecular data, the parents had high homozygosity and high genetic distance among them. The population segregates for several important traits such as seed morphology, seed chemistry, phenology, plant architecture, drought response, yield and its components, and resistance to Botrytis fabae. The population was checked for unbiased segregation in each generation by observing simply inherited Mendelian traits such as stipule spot pigmentation (SSP) and flower colour at different generations. All 1200 four-way cross Fl plants had pigmented flowers and stipule spots. The segregation ratios for white flower colour (single gene, zt2) fit 7:1, 13:3 and 25:7 at F2, F3 and F4 generations, respectively, and the segregation ratio of SSP (two recessive unlinked genes, ssp1 and ssp2) fit 49:15 and 169:87 at the F2 and F3 generations, respectively, demonstrating unbiased generation advance. We will subject the F5 generation of this population to a high-throughput SNP array and make it available for further phenotyping and genotyping.Peer reviewe