More than 1000 genotypes are required to derive robust relationships between yield, yield stability and physiological parameters: a computational study on wheat crop

Identifying target traits for breeding stable and high-yielded cultivars simultaneously is difficult due to limited knowledge of physiological mechanisms behind yield stability. Besides, there is no consensus about the adequacy of a stability index (SI) and the minimal number of environments and genotypes required for evaluating yield stability. We studied this question using the crop model APSIM-Wheat to simulate 9100 virtual genotypes grown under 9000 environments. By analysing the simulated data, we showed that the shape of phenotype distributions affected the correlation between SI and mean yield and the genotypic superiority measure (Pi) was least affected among 11 SI. Pi was used as index to demonstrate that more than 150 environments were required to estimate yield stability of a genotype convincingly and more than 1000 genotypes were necessary to evaluate the contribution of a physiological parameter to yield stability. Network analyses suggested that a physiological parameter contributed preferentially to yield or Pi. For example, soil water absorption efficiency and potential grain filling rate explained better the variations in yield than in Pi; while light extinction coefficient and radiation use efficiency were more correlated with Pi than with yield. The high number of genotypes and environments required for studying Pi highlight the necessity and potential of in silico experiments to better understand the mechanisms behind yield stability

More than 1000 genotypes are required to derive robust relationships between yield, yield stability and physiological parameters: a computational study on wheat crop

Identifying target traits for breeding stable and high-yielded cultivars simultaneously is difficult due to limited knowledge of physiological mechanisms behind yield stability. Besides, there is no consensus about the adequacy of a stability index (SI) and the minimal number of environments and genotypes required for evaluating yield stability. We studied this question using the crop model APSIM-Wheat to simulate 9100 virtual genotypes grown under 9000 environments. By analysing the simulated data, we showed that the shape of phenotype distributions affected the correlation between SI and mean yield and the genotypic superiority measure (Pi) was least affected among 11 SI. Pi was used as index to demonstrate that more than 150 environments were required to estimate yield stability of a genotype convincingly and more than 1000 genotypes were necessary to evaluate the contribution of a physiological parameter to yield stability. Network analyses suggested that a physiological parameter contributed preferentially to yield or Pi. For example, soil water absorption efficiency and potential grain filling rate explained better the variations in yield than in Pi; while light extinction coefficient and radiation use efficiency were more correlated with Pi than with yield. The high number of genotypes and environments required for studying Pi highlight the necessity and potential of in silico experiments to better understand the mechanisms behind yield stability.Peer Reviewe

SH2B1β regulates N-cadherin levels, cell-cell adhesion and nerve growth factor-induced neurite initiation

[[abstract]]Little is known regarding the role of inter-cellular interaction during neuronal differentiation. Homophilic N-cadherin engagement between cells contributes to neuronal migration. However, its function in neurite initiation is not clear. In this study, we provide the first evidence that the adaptor protein SH2B1β regulated N-cadherin levels and neurite initiation. Overexpression of SH2B1β reduces N-cadherin levels and increased phosphotyrosine 654 β-catenin, leading to increased nerve growth factor-induced neurite initiation in PC12 cells, an established model for neuronal differentiation. In contrast, overexpression of the dominant-negative mutant SH2B1β(R555E) increases N-cadherin expression, cell-cell aggregation, and reduces neurite initiation. Moreover, SH2B1β binds directly or indirectly to N-cadherin indicative of its involvement in regulating the levels of N-cadherin. Taken together, these findings provide significant new insights into how N-cadherin-mediated inter-cellular interactions may influence neurite initiation and how SH2B1β may regulate these processes.[[fileno]]2050132010021[[department]]生命科學

The Adaptor Protein SH2B3 (Lnk) Negatively Regulates Neurite Outgrowth of PC12 Cells and Cortical Neurons

[[abstract]]SH2B adaptor protein family members (SH2B1-3) regulate various physiological responses through affecting signaling, gene expression, and cell adhesion. SH2B1 and SH2B2 were reported to enhance nerve growth factor (NGF)-induced neuronal differentiation in PC12 cells, a well-established neuronal model system. In contrast, SH2B3 was reported to inhibit cell proliferation during the development of immune system. No study so far addresses the role of SH2B3 in the nervous system. In this study, we provide evidence suggesting that SH2B3 is expressed in the cortex of embryonic rat brain. Overexpression of SH2B3 not only inhibits NGF-induced differentiation of PC12 cells but also reduces neurite outgrowth of primary cortical neurons. SH2B3 does so by repressing NGF-induced activation of PLCγ, MEK-ERK1/2 and PI3K-AKT pathways and the expression of Egr-1. SH2B3 is capable of binding to phosphorylated NGF receptor, TrkA, as well as SH2B1β. Our data further demonstrate that overexpression of SH2B3 reduces the interaction between SH2B1β and TrkA. Consistent with this finding, overexpressing the SH2 domain of SH2B3 is sufficient to inhibit NGF-induced neurite outgrowth. Together, our data demonstrate that SH2B3, unlike the other two family members, inhibits neuronal differentiation of PC12 cells and primary cortical neurons. Its inhibitory mechanism is likely through the competition of TrkA binding with the positive-acting SH2B1 and SH2B2[[fileno]]2050132010019[[department]]生命科學

The analysis of BOT strategies based on game theory – case study on Taiwan's high speed railway project

Uncertainty in a contract for some BOT (Build-Operate-Transfer) projects may allow an opportunistic developer to take advantage of information asymmetrical factors, long-term external changes, and agency dilemma to request renegotiation and to alter the contact after it has been awarded. Such requests often entrap the government in hold-up problems and result in improper payments to the developers and may even create general public dissatisfaction with a project. In this paper, the Game Theory model is used to analyze the Taiwan High Speed Railroad project to examine how developers implement different strategies at the various stages of a project to alter the contract's conditions in order to continually creating competitive advantage after they have been awarded the contract. This project developer is now facing serious financial difficulties. In this study, the financial information on the Taiwan High Speed Railroad operations was used as the foundation for conducting a simulation to calculate the project's value after this project began operation. The results will serve as reference to the best decision-making strategy for renegotiating costs in competition and cooperation so that a developer can select the optimum project offering the maximum reward. Also, the result will be offered to industries involved in market competition or act as an approach to establish future BOT policies on renegotiation

Antioxidant activity and growth inhibition of human colon cancer cells by crude and purified fucoidan preparations extracted from Sargassum cristaefolium

AbstractFucose-containing sulfated polysaccharides, also termed “fucoidans”, which are known to possess antioxidant, anticoagulant, anticancer, antiviral, and immunomodulating properties, are normally isolated from brown algae via various extraction techniques. In the present study, two methods (SC1 and SC2) for isolation of fucoidan from Sargassum cristaefolium were compared, with regard to the extraction yields, antioxidant activity, and inhibition of growth of human colon cancer cells exhibited by the respective extracts. SC1 and SC2 differ in the number of extraction steps and concentration of ethanol used, as well as the obtained sulfated polysaccharide extracts, namely, crude fucoidan preparation (CFP) and purified fucoidan preparation (PFP), respectively. Thin layer chromatography, Fourier transform infrared analysis, and measurements of fucose and sulfate contents revealed that the extracts were fucoidan. There was a higher extraction yield for CFP, which contained less fucose and sulfate but more uronic acid, and had weaker antioxidant activity and inhibition of growth in human colon cancer cells. In contrast, there was a lower extraction yield for PFP, which contained more fucose and sulfate but less uronic acid, and had stronger antioxidant activity and inhibition of growth in human colon cancer cells. Thus, since the difference in bioactive activities between CFP and PFP was not remarkable, the high extraction yield of SC1 might be favored as a method in industrial usage for extracting fucoidan

The Adaptor Protein SH2B3 (Lnk) Negatively Regulates Neurite Outgrowth of PC12 Cells and Cortical Neurons

SH2B adaptor protein family members (SH2B1-3) regulate various physiological responses through affecting signaling, gene expression, and cell adhesion. SH2B1 and SH2B2 were reported to enhance nerve growth factor (NGF)-induced neuronal differentiation in PC12 cells, a well-established neuronal model system. In contrast, SH2B3 was reported to inhibit cell proliferation during the development of immune system. No study so far addresses the role of SH2B3 in the nervous system. In this study, we provide evidence suggesting that SH2B3 is expressed in the cortex of embryonic rat brain. Overexpression of SH2B3 not only inhibits NGF-induced differentiation of PC12 cells but also reduces neurite outgrowth of primary cortical neurons. SH2B3 does so by repressing NGF-induced activation of PLCγ, MEK-ERK1/2 and PI3K-AKT pathways and the expression of Egr-1. SH2B3 is capable of binding to phosphorylated NGF receptor, TrkA, as well as SH2B1β. Our data further demonstrate that overexpression of SH2B3 reduces the interaction between SH2B1β and TrkA. Consistent with this finding, overexpressing the SH2 domain of SH2B3 is sufficient to inhibit NGF-induced neurite outgrowth. Together, our data demonstrate that SH2B3, unlike the other two family members, inhibits neuronal differentiation of PC12 cells and primary cortical neurons. Its inhibitory mechanism is likely through the competition of TrkA binding with the positive-acting SH2B1 and SH2B2

Clinical characteristics and outcomes of Mycobacterium tuberculosis disease in adult patients with hematological malignancies

BACKGROUND: Diseases caused by Mycobacterium tuberculosis (TB) among adult patients with hematological malignancies have rarely been investigated. METHODS: Adult patients with hematological malignancies at National Taiwan University Hospital between 1996 and 2009 were retrospectively reviewed. Patients with positive serology for HIV were excluded. TB disease is diagnosed by positive culture(s) in the presence of compatible symptoms and signs. The demographics, laboratory and, microbiological features, were analyzed in the context of clinical outcomes. RESULTS: Fifty-three of 2984 patients (1.78%) were diagnosed with TB disease. The estimated incidence was 120 per 100,000 adult patients with hematological malignancies. Patients with acute myeloid leukemia had a significantly higher incidence of TB disease than other subtypes of hematological malignancies (2.87% vs. 1.21%, p = 0.002, odds ratio, 2.40; 95% confidence interval, 1.39-4.41). Thirty-eight patients (72%) with non-disseminated pulmonary TB disease presented typically with mediastinal lymphadenopathy (53%), pleural effusion (47%) and fibrocalcific lesions (43%) on chest imaging. The 15 (28%) patients with extra-pulmonary disease had lower rates of defervescence within 72 h of empirical antimicrobial therapy (13% vs 45%, p = 0.03) and a higher 30-day in-hospital mortality (20% vs. 0%, p = 0.004) compared to those with disease confined to the lungs. CONCLUSIONS: TB disease is not uncommon among patients with hematological malignancies in Taiwan. Patients who received a diagnosis of extra-pulmonary TB suffered higher mortality than those with pulmonary TB alone. Clinicians should consider TB in the differential diagnoses of prolonged fever in patients with hematological malignancies, particularly in regions of high endemicity