4,008 research outputs found
Developing a Meta-Population Framework for Caribbean Spiny Lobster (Panulirus argus) Stocks
The Caribbean spiny lobster (Panulirus argus) provides many ecological and economic benefits to the Southeast United States, as well as many South American and Caribbean countries. However, limited knowledge on the recruitment dynamics of this valuable species has long been an issue for the fishery management. Panulirus argus has a pelagic larval stage called the phyllosoma. During the larval stage, a phyllosoma can drift with currents from six to nine months. This long pelagic life stage leads to the hypothesis that P. argus stocks in the Caribbean are demographically open. Evidences from biophysical modeling and genetic analysis have supported this hypothesis. However, this new knowledge contradicts the assumption that each stock is isolated from others during the fishery assessment and management procedure. Previous studies have shown that misspecification of the spatial structure among stocks could lead to bias estimation on the stock status (e.g., spawning stock biomass) and reduce the effectiveness of the management. Therefore, understanding the spatial structure among stocks, as well as the impacts of spatial structure on stock assessment and management, are crucial to the
development of a sustainable spiny lobster fishery in the Southeast US and Caribbean Region.
In the present dissertation, stable isotope analysis, genetic markers and bio-physical modeling were applied to monthly recruit samples arriving at the Florida Keys from August 2014 to July 2016. The purpose of these analyses was to investigate the connectivity between the Florida stock and upstream stocks in the Caribbean. Then, a meta-population framework was developed on the basis of this connectivity. This framework was then used to evaluate the impact of spatial structure on stock assessment, as well as the effectiveness of fishery management scenarios.
The results of my studies have revealed, by applying stable isotope analysis, genetic markers and biophysical modeling, high levels of connectivity between the Florida stock and upstream Caribbean stocks. This therefore bolsters the hypothesis that the Florida stock is demographically open. Furthermore, my studies also detected significant bias in results from the stock assessment in which spatial structure was ignored. Finally, the results of management strategies evaluations have suggested that the Florida stock condition could be heavily influenced by the management of other stocks in the Caribbean, and an international cooperation of fisheries management could be highly beneficial for this species
Emergence of multicluster chimera states
We thank Prof. L. Huang for helpful discussions. This work was partially supported by ARO under Grant No. W911NF-14-1-0504 and by NSF of China under Grant No. 11275003. The visit of NY to Arizona State University was partially sponsored by Prof. Z. Zheng and the State Scholarship Fund of China.Peer reviewedPublisher PD
Epitaxial Cu3Ge Thin Film: Fabrication, Structure, and Property
In this paper, the fabrication and electrical property characterization of epitaxial Cu3Ge thin film are performed. By adjusting deposition parameters, the crystallinity of the asâgrown Cu3Ge thin films is improved, with the formation of twins within it. The average work function of epitaxial Cu3Ge thin film is measured to be âŒ4.47 + 0.02 eV, rendering it a desirable midâgap gate metal for applications in complementary metalâoxide semiconductor (CMOS) devices. The present study therefore shows an epitaxial Cu3Ge thin film that is promising for applications
In Situ Transmission Electron Microscopy Studies in Gas/Liquid Environment
Conventional transmission electron microscopy (TEM) typically operates under high vacuum conditions. However, in situ investigation under real-world conditions other than vacuum, such as gaseous or liquidus environment, is essential to obtain practical information for materials including catalysts, fuel cells, biological molecules, lithium ion batteries, etc. Therefore, the ability to study gas/liquidâsolid interactions with atomic resolution under ambient conditions in TEM promises new insights into the growth, properties, and functionality of nanomaterials. Different platforms have been developed for in situ TEM observations in ambient environment and can be classified into two categories: open-cell configuration and sealed gas/liquid cell configuration. The sealed cell technique has various advantages over the open-cell approach. This chapter serves as a review of windowed gas/liquid cells for in situ TEM observations
Estimating Growth of Caribbean Spiny Lobster Using MarkâRecapture Data
To estimate the growth of the hardâtoâage Caribbean spiny lobster Panulirus argus in the southeastern USA, a doubleâmaximumâlikelihoodâestimation method (referred to as the âlikelihood modelâ) has been applied to the markârecapture data collected in the Florida Keys from 1967 to 2003. Parameters related to the intermolt period and the growth increment have been assessed, and the uncertainty of the parameters has been estimated using the bootstrap resampling method. For better comparison with the previously published stepâwise growth models, an individualâbased model, in which the variance and covariance of model parameters were fully considered, has been developed to simulate growth transition matrices. The simulation results were compared directly by using the Frobenius Norm. The results indicated that the likelihood model produces a more conservative growth estimate with lower uncertainty. However, the likelihood weights should be set with caution. This study can improve our understanding of the growth of the Caribbean spiny lobster. The products can be directly used in the future for integrated sizeâstructured, stock assessment models for Caribbean spiny lobster; the methods can be easily adaptable to other crustacean species
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