Allelic analysis of sheath blight resistance with association mapping in rice

Citation: Jia, Limeng, Wengui Yan, Chengsong Zhu, Hesham A. Agrama, Aaron Jackson, Kathleen Yeater, Xiaobai Li, et al. “Allelic Analysis of Sheath Blight Resistance with Association Mapping in Rice.” PLOS ONE 7, no. 3 (March 12, 2012): e32703. https://doi.org/10.1371/journal.pone.0032703.Sheath blight (ShB) caused by the soil-borne pathogen Rhizoctonia solani is one of the most devastating diseases in rice world-wide. Global attention has focused on examining individual mapping populations for quantitative trait loci (QTLs) for ShB resistance, but to date no study has taken advantage of association mapping to examine hundreds of lines for potentially novel QTLs. Our objective was to identify ShB QTLs via association mapping in rice using 217 sub-core entries from the USDA rice core collection, which were phenotyped with a micro-chamber screening method and genotyped with 155 genome-wide markers. Structure analysis divided the mapping panel into five groups, and model comparison revealed that PCA5 with genomic control was the best model for association mapping of ShB. Ten marker loci on seven chromosomes were significantly associated with response to the ShB pathogen. Among multiple alleles in each identified loci, the allele contributing the greatest effect to ShB resistance was named the putative resistant allele. Among 217 entries, entry GSOR 310389 contained the most putative resistant alleles, eight out of ten. The number of putative resistant alleles presented in an entry was highly and significantly correlated with the decrease of ShB rating (r =20.535) or the increase of ShB resistance. Majority of the resistant entries that contained a large number of the putative resistant alleles belonged to indica, which is consistent with a general observation that most ShB resistant accessions are of indica origin. These findings demonstrate the potential to improve breeding efficiency by using marker-assisted selection to pyramid putative resistant alleles from various loci in a cultivar for enhanced ShB resistance in rice

Long-range ballistic propagation of carriers in methylammonium lead iodide perovskite thin films

© 2019, The Author(s), under exclusive licence to Springer Nature Limited. The performance of semiconductor devices is fundamentally governed by charge-carrier dynamics within the active materials1–6. Although advances have been made towards understanding these dynamics under steady-state conditions, the importance of non-equilibrium phenomena and their effect on device performances remains elusive7,8. In fact, the ballistic propagation of carriers is generally considered to not contribute to the mechanism of photovoltaics (PVs) and light-emitting diodes, as scattering rapidly disrupts such processes after carrier generation via photon absorption or electric injection9. Here we characterize the spatiotemporal dynamics of carriers immediately after photon absorption in methylammonium lead iodide perovskite films using femtosecond transient absorption microscopy (fs-TAM) with a 10 fs temporal resolution and 10 nm spatial precision. We found that non-equilibrium carriers propagate ballistically over 150 nm within 20 fs of photon absorption. Our results suggest that in a typical perovskite PV device operating under standard conditions, a large fraction of carriers can reach the charge collection layers ballistically. The ballistic transport distance appears to be limited by energetic disorder within the materials, probably due to disorder-induced scattering. This provides a direct route towards optimization of the ballistic transport distance via improvements in materials and by minimizing the energetic disorder. Our observations reveal an unexplored regime of carrier transport in perovskites, which could have important consequences for device performance

Long-range ballistic propagation of carriers in methylammonium lead iodide perovskite thin films

© 2019, The Author(s), under exclusive licence to Springer Nature Limited. The performance of semiconductor devices is fundamentally governed by charge-carrier dynamics within the active materials1–6. Although advances have been made towards understanding these dynamics under steady-state conditions, the importance of non-equilibrium phenomena and their effect on device performances remains elusive7,8. In fact, the ballistic propagation of carriers is generally considered to not contribute to the mechanism of photovoltaics (PVs) and light-emitting diodes, as scattering rapidly disrupts such processes after carrier generation via photon absorption or electric injection9. Here we characterize the spatiotemporal dynamics of carriers immediately after photon absorption in methylammonium lead iodide perovskite films using femtosecond transient absorption microscopy (fs-TAM) with a 10 fs temporal resolution and 10 nm spatial precision. We found that non-equilibrium carriers propagate ballistically over 150 nm within 20 fs of photon absorption. Our results suggest that in a typical perovskite PV device operating under standard conditions, a large fraction of carriers can reach the charge collection layers ballistically. The ballistic transport distance appears to be limited by energetic disorder within the materials, probably due to disorder-induced scattering. This provides a direct route towards optimization of the ballistic transport distance via improvements in materials and by minimizing the energetic disorder. Our observations reveal an unexplored regime of carrier transport in perovskites, which could have important consequences for device performance

On the centers of quantum groups of An-type

Abstract Let g be the finite dimensional simple Lie algebra of type An, and let U = Uq(g, Λ) and U = Uq(g, Q) be the quantum groups defined over the weight lattice and over the root lattice, respectively. In this paper, we find two algebraically independent central elements in U for all n > 2 and give an explicit formula of the Casimir elements for the quantum group U = Uq(g, Λ), which corresponds to the Casimir element of the enveloping algebra U(g). Moreover, for n = 2 we give explicitly the generators of the center subalgebras of the quantum groups U = Uq(g, Λ) and U = Uq(g, Q).This work was supported by National Natural Science Foundation of China (Grant No. 11471282). The authors thank the referees for their careful reading of this article and for valuable comments.center; quantum group; type An; Casimir elemen

Online group pain management for chronic pain: Preliminary results of a novel treatment approach to teletherapy

Objective This pilot study was designed to determine the feasibility, tolerability, safety, and efficacy of group teletherapy for persons with chronic pain. The aim was to present preliminary outcomes of an open trial of group cognitive behavioural therapy (CBT) teletherapy compared with an in-person chronic pain patient group. Methods We recruited 47 chronic pain patients to participate in an 8-session, 2-hour-per-week, online, structured, CBT-oriented pain management group using WebEx and compared them with 46 subjects who participated in a parallel, content-matched, in-person, weekly group. Both groups included goal setting, skills training, relaxation exercises, group discussion, and practice assignments. All subjects completed baseline measures, which were repeated post-treatment. Those in the online group participated in weekly telephone interviews and rated the perceived helpfulness of the remote group. Results The average age of the online group participants was 54.5 ( ± 14.3) years and 70.2% were female, compared with 59.7 ( ± 13.0) years of age and 57.8% females among the in-person group members. On follow-up, both CBT groups showed modest improvements on the outcome measures. Results of this preliminary investigation comparing online teletherapy with in-person CBT suggest similar benefit. Many participants in the online group rated their experience as very helpful (62.5%; 7–10/10) and most would recommend this programme to others (93.7%; 7–10/10). Discussion Preliminary findings suggest that online group CBT may be as effective in improving coping among persons with chronic pain as in-person groups. More rigorous controlled trials are needed to adequately assess the outcome benefit of online teletherapy for chronic pain. </jats:sec

eToxPred: a machine learning-based approach to estimate the toxicity of drug candidates

BACKGROUND: The efficiency of drug development defined as a number of successfully launched new pharmaceuticals normalized by financial investments has significantly declined. Nonetheless, recent advances in high-throughput experimental techniques and computational modeling promise reductions in the costs and development times required to bring new drugs to market. The prediction of toxicity of drug candidates is one of the important components of modern drug discovery. RESULTS: In this work, we describe eToxPred, a new approach to reliably estimate the toxicity and synthetic accessibility of small organic compounds. eToxPred employs machine learning algorithms trained on molecular fingerprints to evaluate drug candidates. The performance is assessed against multiple datasets containing known drugs, potentially hazardous chemicals, natural products, and synthetic bioactive compounds. Encouragingly, eToxPred predicts the synthetic accessibility with the mean square error of only 4% and the toxicity with the accuracy of as high as 72%. CONCLUSIONS: eToxPred can be incorporated into protocols to construct custom libraries for virtual screening in order to filter out those drug candidates that are potentially toxic or would be difficult to synthesize. It is freely available as a stand-alone software at https://github.com/pulimeng/etoxpred

Combination therapy with mTOR kinase inhibitor and dasatinib as a novel therapeutic strategy for vestibular schwannoma

AbstractNeurofibromatosis type 2 (NF2) is an inherited disorder characterized by bilateral vestibular schwannomas (VS) that arise from neoplastic Schwann cells (SCs). NF2-associated VSs are often accompanied by meningioma (MN), and the majority of NF2 patients show loss of the NF2 tumor suppressor. mTORC1 and mTORC2-specific serum/glucocorticoid-regulated kinase 1 (SGK1) are constitutively activated in MN with loss of NF2. In a recent high-throughput kinome screen in NF2-null human arachnoidal and meningioma cells, we showed activation of EPH RTKs, c-KIT, and SFK members independent of mTORC1/2 activation. Subsequently, we demonstrated in vitro and in vivo efficacy of combination therapy with the dual mTORC1/2 inhibitor AZD2014 and the multi-kinase inhibitor dasatinib. For these reasons, we investigated activated mTORC1/2 and EPH receptor-mediated signaling in sporadic and NF2-associated VS. Using primary human VS cells and a mouse allograft model of schwannoma, we evaluated the dual mTORC1/2 inhibitor AZD2014 and the tyrosine kinase inhibitor dasatinib as monotherapies and in combination. Escalating dose-response experiments on primary VS cells grown from 15 human tumors show that combination therapy with AZD2014 and dasatinib is more effective at reducing metabolic activity than either drug alone and exhibits a therapeutic effect at a physiologically reasonable concentration (~0.1 µM). In vivo, while AZD2014 and dasatinib each inhibit tumor growth alone, the effect of combination therapy exceeds that of either drug. Co-targeting the mTOR and EPH receptor pathways with these or similar compounds may constitute a novel therapeutic strategy for VS, a condition for which there is no FDA-approved pharmacotherapy.</jats:p