Contribution of exopeptidases to formation of nonprotein nitrogen during ensiling of alfalfa

The experiment was conducted to investigate the exopeptidase classes in alfalfa (Medicago sativa L.) leaves, and to determine their contribution to the formation of nonprotein nitrogen (NPN) components during ensiling. Six classes of inhibitors that included bestatin (aminopeptidase inhibitor), potato carboxypeptidase inhibitor (PCI, carboxypeptidase inhibitor), 1,10-phenanthroline (dipeptidase inhibitor), diprotin A (dipeptidyl-peptidase inhibitor), butabindide (tripeptidyl-peptidase inhibitor), and dipeptide Phe-Arg (peptidyl-dipeptidase inhibitor) were used. To determine the contribution of each exopeptidase to the formation of NPN products, aqueous extracts of fresh alfalfa were fermented to imitate the proteolytic process of ensiled alfalfa and to ensure that each class of exopeptidase inhibitor would have immediate contact with the proteases in the alfalfa extract. Five classes of exopeptidases; namely, aminopeptidase, carboxypeptidase, dipeptidase, dipeptidyl-peptidase, and tripeptidyl-peptidase, were shown to be present in alfalfa leaves, each playing a different role in alfalfa protein degradation. Aminopeptidase, carboxypeptidase, and dipeptidase were the main exopeptidases contributing to the formation of NH3-N. Among the 5 exopeptidases, tripeptidyl-peptidase appeared to be the principal exopeptidase in hydrolyzing forage protein into peptides, whereas carboxypeptidase and dipeptidase appeared to be more important in contributing to the formation of amino acid-N. Dipeptidyl-peptidase and tripeptidyl-peptidase did not play a role in the formation of NH3-N or amino acid-N. Dipeptidase, carboxypeptidase, and tripeptidyl-peptidase were the principal exopeptidases for hydrolyzing forage protein into NPN during ensilage, and treatment with a mixture of the 5 inhibitors reduced the total NPN concentration in the fermented alfalfa extract to about 45% of that in the control after 21 d of fermentation

Constructing a new integrated genetic linkage map and mapping quantitative trait loci for vegetative mycelium growth rate in Lentinula edodes

The most saturated linkage map for Lentinula edodes to date was constructed based on a mono-. karyotic population of 146 single spore isolates (SSIs) using sequence-related amplified polymorphism (SRAP), target region amplification polymorphism (TRAP), insertion deletion (InDel) markers, and the mating-type loci. Five hundred and twenty-four markers were located on 13 linkage groups (LGs). The map spanned a total length of 1006.1 cM, with an average marker spacing of 2.0 cM. Quantitative trait loci (QTLs) mapping was utilized to uncover the loci regulating and controlling the vegetative mycelium growth rate on various synthetic media, and complex medium for commercial cultivation of L. edodes. Two and 13 putative QTLs, identified respectively in the monokaryotic population and two testcross dikaryotic populations, were mapped on seven different LGs. Several vegetative mycelium growth rate-related QTLs uncovered here were clustered on LG4 (Qmgr1, Qdgr1, Qdgr2 and Qdgr9) and LG6 (Qdgr3, Qdgr4 and Qdgr5), implying the presence of main genomic areas responsible for growth rate regulation and control. The QTL hotspot region on LG4 was found to be in close proximity to:the region containing the mating-type A (MAT-A) locus. Moreover, Qdgr2 on LG4 was detected on different media, contributing 8.07%-23.71% of the phenotypic variation. The present study provides essential information for QTL mapping and marker-assisted selection (MAS) in L. edodes. (C) 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.The most saturated linkage map for Lentinula edodes to date was constructed based on a mono-. karyotic population of 146 single spore isolates (SSIs) using sequence-related amplified polymorphism (SRAP), target region amplification polymorphism (TRAP), insertion deletion (InDel) markers, and the mating-type loci. Five hundred and twenty-four markers were located on 13 linkage groups (LGs). The map spanned a total length of 1006.1 cM, with an average marker spacing of 2.0 cM. Quantitative trait loci (QTLs) mapping was utilized to uncover the loci regulating and controlling the vegetative mycelium growth rate on various synthetic media, and complex medium for commercial cultivation of L. edodes. Two and 13 putative QTLs, identified respectively in the monokaryotic population and two testcross dikaryotic populations, were mapped on seven different LGs. Several vegetative mycelium growth rate-related QTLs uncovered here were clustered on LG4 (Qmgr1, Qdgr1, Qdgr2 and Qdgr9) and LG6 (Qdgr3, Qdgr4 and Qdgr5), implying the presence of main genomic areas responsible for growth rate regulation and control. The QTL hotspot region on LG4 was found to be in close proximity to:the region containing the mating-type A (MAT-A) locus. Moreover, Qdgr2 on LG4 was detected on different media, contributing 8.07%-23.71% of the phenotypic variation. The present study provides essential information for QTL mapping and marker-assisted selection (MAS) in L. edodes. (C) 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe

Nautical traffic modelling for safe and efficient ports

Transport & PlanningCivil Engineering and Geoscience

Wind power integration: From individual wind turbine to wind park as a power plant

As power capacities of single wind turbine, single wind park and total wind power installation are continuously increasing, the wind power begins to challenge the safety operation of the power system. This thesis focuses on the grid integration aspects such as the dynamic behaviours of wind power during disturbances, and dynamic behaviours of power system with large wind power integration. The work in this thesis is in a down-up approach, starting with concepts for individual wind turbines, including control and modelling, followed by a conceptual wind park design and control, and finally on the highest level, wind power plant support aimed at improving power system performance.Electrical Power EngineeringElectrical Engineering, Mathematics and Computer Scienc

Online reinforcement learning control for aerospace systems

Reinforcement Learning (RL) methods are relatively new in the field of aerospace guidance, navigation, and control. This dissertation aims to exploit RL methods to improve the autonomy and online learning of aerospace systems with respect to the a priori unknown system and environment, dynamical uncertainties, and partial observability. In the first part of this dissertation, incremental Approximate Dynamic Programming (iADP) methods are proposed. Instead of using nonlinear function approximators to approximate the true cost-to-go, iADP methods use an (extended) incremental model to deal with the nonlinearity of unknown systems and uncertainties of the environment. In the second part, online Adaptive Critic Designs (ACDs) are proposed based on the incremental model. This method replaces the global system model approximator with an incremental model. This approach, therefore, does not need off-line training stages and may accelerate online learning. In the third part, the hybrid Hierarchical Reinforcement Learning (hHRL) method is proposed for guidance and navigation problems. This method consists of several hierarchical levels, where each level uses different methods to optimize the learning with different types of information and objectives. In conclusion, this dissertation contributes with several methods that improve the intelligence and autonomy of aerospace systems. These improvements are mainly from three perspectives: 1) enhancing the adaptability and efficiency of low-level control, 2) improving the intelligence and online learning ability of guidance, navigation, and control, and 3) creating a well-organized hierarchy to ensure coordination between each level. The proposed methods provide novel insights for both the reinforcement learning research community and for developers of aerospace automatic control system.Control & Simulatio

Effect of plastic deformation on residual strength of ship structures after grounding

Ship grounding decreases the strength of ship hull structures once plastic deformation occurs during the event. In practice of ship societies, current method of determining residual strength of ship hull structures after grounding is to totally remove the plastically damaged parts. As plastically deformed part of ship hull structures might still contribute considerable amount of strength, the method of total removal might be overly conservative. The article is oriented to quantify the residual strength of ship hull structures after grounding according to varied levels of plastic deformation. Literature study indicates that most of studies are focused on longitudinal residual strength of damaged ship structures, and transverse residual strength is rarely researched. Hence, it is target to study transverse residual strength after grounding damage, with implementation of a joint study of test and finite element simulation. The experiment gives validation to finite element models, and then an empirical formula can be derived by a series of FE simulations with the verified finite element model.Offshore and Dredging EngineeringMarine & Transport TechnologyMechanical, Maritime and Materials Engineerin

Efficient Online Globalized Dual Heuristic Programming With an Associated Dual Network

Globalized dual heuristic programming (GDHP) is the most comprehensive adaptive critic design, which employs its critic to minimize the error with respect to both the cost-to-go and its derivatives simultaneously. Its implementation, however, confronts a dilemma of either introducing more computational load by explicitly calculating the second partial derivative term or sacrificing the accuracy by loosening the association between the cost-to-go and its derivatives. This article aims at increasing the online learning efficiency of GDHP while retaining its analytical accuracy by introducing a novel GDHP design based on a critic network and an associated dual network. This associated dual network is derived from the critic network explicitly and precisely, and its structure is in the same level of complexity as dual heuristic programming critics. Three simulation experiments are conducted to validate the learning ability, efficiency, and feasibility of the proposed GDHP critic design.Control & Simulatio

Perceived Appropriateness: A Novel View for Remediating Perceived Inappropriate Robot Navigation Behaviors

Robots navigating in social environments inevitably exhibit behavior perceived as inappropriate by people, which they will repeat unless they are aware of them; hindering their social acceptance. This highlights the importance of robots detecting and adapting to the perceived appropriateness of their behavior, in line with what we found in a systematic literature review. Therefore, we have conducted experiments (both outdoor and indoor) to understand the perceived appropriateness of robot social navigation behavior, based on which we collected a dataset and developed a machine learning model for detecting such perceived appropriateness. To investigate the usefulness of such information and inspire robot adaptive navigation behavior design, we will further conduct aWoZ study to understand how trained human operators adapt robot behavior to people's feedback. In all, this work will enable robots to better remediate their inappropriate behavior, thus improving their social acceptance.Internet of ThingsIndustrial Design Engineerin