228 research outputs found

    Evaluación de la cohorte occidental de invierno-primavera del calamar volador neon (Ommastrephes bartramii) utilizando modelos de producción excedente dependientes del medio ambiente

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    The western winter-spring cohort of neon flying squid, Ommastrephes bartramii, is targeted by Chinese squidjigging fisheries in the northwest Pacific from August to November. Because this squid has a short lifespan and is an ecological opportunist, the dynamics of its stock is greatly influenced by the environmental conditions, which need to be considered in its assessment and management. In this study, an environmentally dependent surplus production (EDSP) model was developed to evaluate the stock dynamics of O. bartramii. Temporal variability of favourable spawning habitat with sea surface temperature (SST) of 21-25°C (Ps) was assumed to influence carrying capacity (K), while temporal variability in favourable feeding habitat areas with different SST ranges in different months (Pf) was assumed to influence intrinsic growth rate (r). The parameters K and r in the EDSP model were thus assumed to be linked to temporal variability in the proportion of Ps and Pf, respectively. According to Deviance Information Criterion values, the estimated EDSP model with Ps was considered to be better than the conventional surplus production model or other EDSP models. For this model, the maximum sustainable yield (MSY) varied from 210000 to 262500 t and biomass at MSY level varied from 360000 to 450000 t. The fishing mortality rates of O. bartramii from 2003 to 2013 were much lower than the fishing mortality at target level and MSY level (Ftar and FMSY) and stock biomass was higher than BMSY, suggesting that this squid was not in the status of overfishing and stock was not overfished. The management reference points in the EDSP model for O. bartramii were more conservative than those in the conventional model. This study suggests that the environmental conditions on the spawning grounds should be considered in squid stock assessment and management in the northwest Pacific Ocean.La cohorte occidental de invierno-primavera de los calamares voladores neon, Ommastrephes bartramii, es objeto de las pesquerías chinas de calamares que operan con jigging en el Pacifico Noroeste, desde agosto a noviembre. Debido a que esta especie tiene un ciclo de vida corto y es ecológicamente oportunista, la dinámica de este stock de calamares está muy influenciada por las condiciones ambientales, las cuales necesitan ser consideradas en su evaluación y manejo. En este estudio fue desarrollado un modelo de producción excedente ambientalmente dependiente (PEAD), para evaluar la dinámica del stock de O. bartramii. Se asumió que la variabilidad temporal de un hábitat favorable para el desove sea a una temperatura superficial del mar de 21-25°C (Ps), para influir en la capacidad de carga (K); mientras que la variabilidad temporal en áreas con hábitat favorable para la alimentación, fue asumida con diferentes rangos de temperatura superficial del mar en diferentes meses (Pf), para influir la tasa intrínseca de crecimiento (r). Los parámetros K y r en el modelo PEAD fueron asumidos como vinculados a la variabilidad temporal en la proporción Ps y Pf , respectivamente. De acuerdo a los valores del Criterio de Información de la Desvianza, el modelo PEAD estimado con Ps fue considerado el mejor, comparado con los modelos de producción excedente convencionales, así como otros modelos PEAD. Para este modelo el rendimiento máximo sostenible (RMS) estuvo entre 210000 a 262500 t y la biomasa al nivel RMS, entre de 360000 a 450000 t. Las tasas de mortalidad por pesca de O. bartramii entre 2003 a 2013 fueron mucho menores que la mortalidad por pesca a nivel objetivo y nivel de RMS (Ftar and FRMS) y la biomasa del stock fue superior a BRMS, sugiriendo que este calamar no estuvo en el estado de sobrepesca y el stock no fue sobrepescado. Los puntos de referencia de manejo (PRMs) en el modelo PEAD para O. bartramii fueron más conservativos que aquéllos obtenidos en los modelos convencionales. Este estudio sugiere que las condiciones ambientales sobre las zonas de desove deberían ser consideradas en las evaluaciones y en el manejo de stock de calamares en el Océano Pacifico Noroeste

    Anisotropic Quasi-Wilson Element with Conforming Finite Element Approximation for Coupled Continuum Pipe-Flow/Darcy Model in Karst Aquifers

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    This paper presents a numerical method for solving systems of partial differential equations describing flow in porous media with an embedded and inclined conduit pipe. This work considers a coupled continuum pipe-flow/Darcy model. The numerical schemes presented are based on combinations of the quasi-Wilson element on anisotropic mesh and the conforming finite element on regular mesh. The existence and uniqueness of the approximation solution are obtained. Optimal error estimates in both L2 and H1 norms are obtained independent of the regularity condition on the mesh. Numerical examples show the accuracy and efficiency of the proposed scheme

    Shengu'an exerts anti-osteoporotic effect in rats via TGFβ1-Smad2/3 signal pathway, and enhancement of bone and cartilage metabolism

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    Purpose: To study the anti-osteoporotic effect of Shengu'an in rats, and elucidate the mechanism of action involved.Methods: Forty healthy female SPF mice were randomly divided into control group, saline-treated group, TGFβRⅡ receptor inhibitor group, and shengu'an group. The expressions of type Ⅱ collagen (Co1-II) and platelet endothelial cell adhesion factor (CD-31) were determined. The expressions of transforming growth factor β1 (TGF-β1), p-smad2/3, matrix metalloproteinase-9 (MMP-9) and osteoblast specific transcription factor (osterix) were assayed by western blotting.Results: The expression of Co1-II in the vertebral body was significantly lower in model mice than in control mice, but was significantly higher in shengu'an mice when compared with model mice (p < 0.05). In shengu'an mice, CoI-I was markedly upregulated, relative to model mice, and the expressions of CD31 in TGFβRⅡreceptor inhibitor group and shengu'an group were lower than in model group (p < 0.05). There were significantly lower expressions of TGF-β1 and p-smad2/3 in the vertebral body of shengu'an group than in model mice, but osterix was upregulated relative to model mice (p < 0.05).Conclusion: Shengu'an exerts anti-osteoporotic effect by downregulating TGFβ/smad signal pathway. There is thus a potential for its clinical application in the management of osteoporosis. Keywords: Shengu'an, TGFβ1-Smad2/3 signal, Bone cartilage metabolism, Osteoporosi

    Reconfigurable Distributed Antennas and Reflecting Surface: A New Architecture for Wireless Communications

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    Distributed Antenna Systems (DASs) employ multiple antenna arrays in remote radio units to achieve highly directional transmission and provide great coverage performance for future-generation networks. However, the utilization of active antenna arrays results in a significant increase in hardware costs and power consumption for DAS. To address these issues, integrating DAS with Reconfigurable Intelligent Surfaces (RIS) offers a viable approach to ensure transmission performance while maintaining low hardware costs and power consumption. To incorporate the merits of RIS into the DAS from practical consideration, a novel architecture of ``Reconfigurable Distributed Antennas and Reflecting Surfaces (RDARS)'' is proposed in this paper. Specifically, based on the design of the additional direct-through state together with the existing high-quality fronthaul link, any element of the RDARS can be dynamically programmed to connect with the base station (BS) via fibers and perform the connected mode as remote distributed antennas of the BS to receive or transmit signals. Additionally, RDARS also inherits the low-cost and low-energy-consumption benefits of fully passive RISs by default configuring the elements as passive to perform the reflection mode. As a result, RDARS offers flexible control over the trade-off between distribution gain and reflection gain to enhance performance. The ergodic achievable rate under the RDARS architecture is analyzed and closed-form expression with meaningful insights is derived. The theoretical analysis and simulation results prove that the RDARS achieves a higher achievable rate than both DAS and RIS. A RDARS prototype with 256 elements is built for real experiments which shows that the RDARS-aided system can achieve an additional 21% and 170% throughput improvement over DAS and RIS-aided systems, respectively.Comment: 13 pages, 9 figure

    Multifocal laser direct writing through spatial light modulation guided by scalable vector graphics

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    Multifocal laser direct writing (LDW) based on phase-only spatial light modulator (SLM) can realize flexible and parallel nanofabrication with high throughput potential. In this investigation, a novel approach of combining two-photon absorption, SLM and vector path guided by scalable vector graphics (SVG) has been developed and tested preliminarily, for fast, flexible and parallel nanofabrication. Three laser focuses are independently controlled with different paths, which are according to SVG, to optimize fabrication and promote time efficiency. The minimum structure width can be as low as 74 nm. Accompanied with a translation stage, a carp structure of 18.16 μ\mum by 24.35 μ\mum has been fabricated. This method shows the possibility of developing LDW techniques towards full-electrical system, and provides a potential way to efficiently engrave complex structures on nanoscales

    IEEE Transactions on Broadcasting Special Issue on: 5G for Broadband Multimedia Systems and Broadcasting

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    [EN] The upcoming fifth-generation ( 5G ) of wireless communications technologies is expected to revolutionize society digital transformation thanks to its unprecedented wireless performance capabilities, providing speeds of several Gbps, very low latencies well below 5 ms, ultra-reliable transmissions with up to 99.999% success probability, while being able to handle a huge number of devices simultaneously connected to the network. The first version of the 3GPP specification (i.e., Release 15) has been recently completed and many 5G trials are under plan or carrying out worldwide, with the first commercial deployments happening in 2019."© 2019 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works."Gomez-Barquero, D.; Li, W.; Fuentes, M.; Xiong, J.; Araniti, G.; Akamine, C.; Wang, J. (2019). IEEE Transactions on Broadcasting Special Issue on: 5G for Broadband Multimedia Systems and Broadcasting. IEEE Transactions on Broadcasting. 65(2):351-355. https://doi.org/10.1109/TBC.2019.2914866S35135565

    Research on Power Load Data Acquisition and Integrated Transmission Systems in Electric Energy Calculation and Detection

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    This paper presents the crucial area of power load data acquisition with an integrated transmission system for precise calculation and detection of electric energy. With the advances in technology, management and optimization of energy has become critical for sustainability and economic reasons. Thus, we have targeted the cutting-edge methods for data gathering of power load along with its efficient transmission previously reviewed. We scrutinized the current methods and technologies used in power load data acquisition and identified their limitations along with areas of improvements. We followed advanced sensors and measuring devices for data collection employed an integrated transmission system with up-to-the-minute communication protocols and data processing algorithms. These were experimentally verified to improve the accuracy and reliability of the electric energy calculations. The real-world case studies were included for its practical implementations to provide an insight into its impacts. The results of this study provide a maturing outlook along with valuable analysis for electric energy calculation and detection. The system due to its potential for enhancing the energy management and efficiency can have a real-life and profound significance in sustainable and economic handling of the increasing load of energy
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