52 research outputs found

    Evolution of kinematic transformation from the Altyn Tagh fault to the Qilian Shan in the northern Tibetan Plateau: from early Cenozoic initiation to mid-Miocene extrusion

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    The Altyn Tagh fault has been a crucial tectonic boundary of the Tibetan Plateau during the Cenozoic India-Eurasia collision. However, issues have not been addressed regarding the Cenozoic evolution of the kinematic transformation from the eastern Altyn Tagh fault to the Qilian Shan. Here we focus on the kinematics at a crucial point, the Subei triple junction, along the Altyn Tagh fault, which was recorded by faulting in the Suganhu basin to the south of the junction. We reconstructed the structural pattern of faults and thickness distribution of the Cenozoic strata in the Suganhu basin by integrating seismic profiles, well logging, and topographic data. We inferred that only crustal shortening and thickening in the Danghenan Shan, a prominent topographic high, absorbed the strike-slip displacement along the Altyn Tagh fault during the early Cenozoic. Since the mid-Miocene, strike-slip fault belts within the Suganhu basin were initiated, based on the fault geometry and uneven thickness distribution across the fault belts. We thus proposed a mid-Miocene kinematic transformation realized by blocks extruding southeastward, as well as the crustal shortening and thickening in the entire Qilian Shan. Those blocks are bounded by preexisting weaknesses with lateral movements, and lithospheric heterogeneity played an essential role in the block-scale extrusion

    Chromosome-level genome assembly of the yellow boxfish (Ostracion cubicus) provides insights into the evolution of bone plates and ostracitoxin secretion

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    The Ostracion cubicus, commonly known as the yellow boxfish, is a remarkable species with a body encased in a bone plate and the ability to produce an ostracitoxin from their skin when under stress. However, the genetic basis of those effective defense traits is still largely unknown due to the lack of genomic resources. Here, we assembled the first chromosome-level genome of O. cubicus with 867.50 Mb in genome size and 34.86 Mb N50 scaffold length by HiFi and Hi-C sequencing. Twenty-five pseudo-chromosomes, numbered according to size, covered 94.13% of the total assembled sequences. A total of 23,224 protein-coding genes were predicted, with a BUSCO completeness of 98.6%. Positive selection or rapid evolution was observed in genes related to scale and bone development (acsl4a, casr, keap1a, tbx1), and up-regulation of transcription was found in the skin of boxfish (bmp1, bmp2k, bmp4, bmp7, smad5, suco, prelp, mitf), likely associated with the bone plates evolution in the yellow boxfish. An expansion of the solute carrier family 22, a cluster of genes in solute carrier (SLCs) family, transmembrane protein family (TMEMs), vesicle trafficking (SECs), ATP-binding cassette (ABCs) and apolipoproteins (APOs) were identified under positive selection, rapid evolution, or up-regulated in the skin of boxfish, likely associated with the ostracitoxin secretion in the yellow boxfish. Our study not only presents a high-quality boxfish genome but also provides insights into bone plates evolution and ostracitoxin secretion of O. cubicus

    Edible bio-based nanostructures: delivery, absorption and potential toxicity

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    The development of bio-based nanostructures as nanocarriers of bioactive compounds to specific body sites has been presented as a hot topic in food, pharmaceutical and nanotechnology fields. Food and pharmaceutical industries seek to explore the huge potential of these nanostructures, once they can be entirely composed of biocompatible and non-toxic materials. At the same time, they allow the incorporation of lipophilic and hydrophilic bioactive compounds protecting them against degradation, maintaining its active and functional performance. Nevertheless, the physicochemical properties of such structures (e.g., size and charge) could change significantly their behavior in the gastrointestinal (GI) tract. The main challenges in the development of these nanostructures are the proper characterization and understanding of the processes occurring at their surface, when in contact with living systems. This is crucial to understand their delivery and absorption behavior as well as to recognize potential toxicological effects. This review will provide an insight into the recent innovations and challenges in the field of delivery via GI tract using bio-based nanostructures. Also, an overview of the approaches followed to ensure an effective deliver (e.g., avoiding physiological barriers) and to enhance stability and absorptive intestinal uptake of bioactive compounds will be provided. Information about nanostructures potential toxicity and a concise description of the in vitro and in vivo toxicity studies will also be given.Joana T. Martins, Oscar L. Ramos, Ana C. Pinheiro, Ana I. Bourbon, Helder D. Silva and Miguel A. Cerqueira (SFRH/BPD/89992/2012, SFRH/BPD/80766/2011, SFRH/BPD/101181/2014, SFRH/BD/73178/2010, SFRH/BD/81288/2011, and SFRH/BPD/72753/2010, respectively) are the recipients of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, POPH-QREN and FSE, Portugal). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes," REF.NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. We also thank to the European Commission: BIOCAPS (316265, FP7/REGPOT-2012-2013.1) and Xunta de Galicia: Agrupamento INBIOMED (2012/273) and Grupo con potencial de crecimiento. The support of EU Cost Action FA1001 is gratefully acknowledged

    Sorption of PAHs onto marine clay

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    In this study, sorption/desorption behaviors of three PAHs (Naphthalene, Phenanthrene and Pyrene) were studied utilizing batch equilibrium techniques.Master of Engineering (CEE

    A Combinatorial Benders' Cuts Algorithm for the Local Container Drayage Problem

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    This paper examines the local container drayage problem under a special operation mode in which tractors and trailers can be separated; that is, tractors can be assigned to a new task at another location while trailers with containers are waiting for packing or unpacking. Meanwhile, the strategy of sharing empty containers between different customers is also considered to improve the efficiency and lower the operation cost. The problem is formulated as a vehicle routing and scheduling problem with temporal constraints. We adopt combinatorial benders' cuts algorithm to solve this problem. Numerical experiments are performed on a group of randomly generated instances to test the performance of the proposed algorithm

    A Hybrid Heuristic Algorithm for Maximizing the Resilience of Underground Logistics Network Planning

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    In recent times, there has been a sharp increase in the congestion of ground transportation, the scarcity of land resources, and various disasters. Hence, there is an urgent need to find an effective and sustainable approach to transportation. The construction of an underground logistics network, where transportation activities occur beneath the surface of the ground, is anticipated to emerge as a future trend. This study aims to formulate a resilient-maximizing plan for the underground logistics network, ensuring optimal meeting of transportation demands in the aftermath of ground disasters. Accordingly, a two-stage linear programming model is established to determine the layout plan for the most resilient underground logistics network. The first phase of the model is designed to generate viable layouts for the underground logistics network, while the second phase is dedicated to evaluating the resilience of the proposed layout plan. During the evaluation of network resilience, Monte Carlo simulations are used to simulate disaster scenarios. Given the inherent complexity of the model, the traditional solver cannot efficiently solve the problem. Thus, a new hybrid heuristic algorithm is designed to obtain solutions that maximize network resilience. The results show the effectiveness of the designed algorithm and the significant improvement in network resilience achieved by numerical experiments. Moreover, sensitivity analyses are conducted to reveal the relationships between resilience and budget, as well as resilience and the capacity of underground pipelines. It has a significant impact on sustainability when making decisions regarding network planning

    Lyapunov-Function-Based Feedback Linearization Control Strategy of Modular Multilevel Converter–Bidirectional DC–DC Converter for Vessel Integrated Power Systems

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    The modular multilevel converter–bidirectional DC–DC converter (MMC–BDC) has been proposed to be utilized in the vessel integrated power system to interconnect the medium voltage bus and the distributed energy storage elements. In the shipboard applications, MMC–BDC faces unbalanced sub-module power operation because of the inconsistent state-of-charge (SOC) of the energy storage elements. Researchers have investigated into the unbalanced operation principle of MMC–BDC and proposed some unbalanced operation control strategies, but these traditional strategies do not perform well in both aspects of operating range and efficiency. Therefore, this paper proposes a novel Lyapunov-function-based feedback linearization control strategy for the independent sub-module voltage control of MMC–BDC, which not only shows wide unbalanced operation range and high efficiency, but also realizes the decoupling and symmetrical control of the sub-module capacitor voltages
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