Assessment of Cranial Neural Crest Proliferation Patterns between the Redeye Tetra \u3cem\u3eMoenkhausia Sanctaefilomenae\u3c/em\u3e and the Zebrafish \u3cem\u3eDanio Rerio\u3c/em\u3e

Among teleost fishes, there is a substantial amount of diversity regarding craniofacial morphology. This study investigated the cellular processes directing the morphological variations observed in the Meckel’s and ceratohyal cartilages of the zebrafish Danio rerio and the redeye tetra Moenkhausia sanctaefilomenae. Utilizing BrdU incorporation, significant interspecific variations relating to cartilage formation were determined. Specifically, interstitial proliferation was found to be more important for the shaping and subsequent growth of the cartilages in D. rerio than in M. sanctaefilomenae. Correspondingly, the expansion of the pharyngeal arches was more dramatic in M. sanctaefilomenae than in D. rerio. This study demonstrates that differential developmental mechanisms underlie the apparent disparities in craniofacial morphology between these two species of fishes

A leader election algorithm for dynamic networks with causal clocks

An algorithm for electing a leader in an asynchronous network with dynamically changing communication topology is presented. The algorithm ensures that, no matter what pattern of topology changes occurs, if topology changes cease, then eventually every connected component contains a unique leader. The algorithm combines ideas from the Temporally Ordered Routing Algorithm for mobile ad hoc networks (Park and Corson in Proceedings of the 16th IEEE Conference on Computer Communications (INFOCOM), pp. 1405–1413 (1997) with a wave algorithm (Tel in Introduction to distributed algorithms, 2nd edn. Cambridge University Press, Cambridge, MA, 2000), all within the framework of a height-based mechanism for reversing the logical direction of communication topology links (Gafni and Bertsekas in IEEE Trans Commun C–29(1), 11–18 1981). Moreover, a generic representation of time is used, which can be implemented using totally-ordered values that preserve the causality of events, such as logical clocks and perfect clocks. A correctness proof for the algorithm is provided, and it is ensured that in certain well-behaved situations, a new leader is not elected unnecessarily, that is, the algorithm satisfies a stability condition.National Science Foundation (U.S.) (0500265)Texas Higher Education Coordinating Board (ARP-00512-0007-2006)Texas Higher Education Coordinating Board (ARP 000512-0130-2007)National Science Foundation (U.S.) (IIS-0712911)National Science Foundation (U.S.) (CNS-0540631)National Science Foundation (U.S.) (Research Experience for Undergraduates (Program) (0649233)

Development of indices of larval bluefin tuna (Thunnus thynnus) in the western Mediterranean sea

Fishery independent indices of bluefin tuna larvae in the western Mediterranean Sea are presented utilizing ichthyoplankton survey data collected from 2001 through 2005 by the Spanish Institute of Oceanography. Indices were developed using larval catch rates collected using two different types of bongo gear by employing a delta-lognormal modeling approach, including following covariates: water temperature at 25 m, salinity at 25 m, water depth, time of day, geostrophic water velocities, year, and a gear variable for the combined modelSe presentan índices de larvas de atún rojo independientes de la pesquería en el mar Mediterráneo occidental utilizando datos de prospecciones de ictioplancton recopilados desde 2001 hasta 2005 por el Instituto Español de Oceanografía. Los índices se desarrollaron utilizando tasas de captura larval recopiladas utilizando dos tipos diferentes de red bongo y empleando un enfoque delta-lognormal de modelación, que incluía las siguientes covariables: temperatura del agua a 25 m, salinidad a 25 m, profundidad del agua, hora del día, velocidad del agua geostrófica, año y una variable de arte para el modelo combinad

Core Services in the Architecture of the National Digital Library for Science Education (NSDL)

We describe the core components of the architecture for the (NSDL) National Science, Mathematics, Engineering, and Technology Education Digital Library. Over time the NSDL will include heterogeneous users, content, and services. To accommodate this, a design for a technical and organization infrastructure has been formulated based on the notion of a spectrum of interoperability. This paper describes the first phase of the interoperability infrastructure including the metadata repository, search and discovery services, rights management services, and user interface portal facilities

Channel diffusion of sodium in a silicate glass

We use classical molecular dynamics simulations to study the dynamics of sodium atoms in amorphous Na$_2$O-4SiO$_2$. We find that the sodium trajectories form a well connected network of pockets and channels. Inside these channels the motion of the atoms is not cooperative but rather given by independent thermally activated hops of individual atoms between the pockets. By determining the probability that an atom returns to a given starting site, we show that such events are not important for the dynamics of this system.Comment: 10 pages of Latex, 5 figures, one figure added, text expande

Testing robustness of CPUE standardization and inclusion of environmental variables with simulated longline catch datasets

Environmental variability changes the distribution, migratory patterns, and susceptibility to various fishing gears for highly migratory marine fish. These changes become especially problematic when they affect the indices of abundance (such as those based on catch-per-unit-effort: CPUE) used to assess the status of fish stocks. The use of simulated CPUE data sets with known values of underlying population trends has been recommended by ICCAT (International Commission for the Conservation of Atlantic Tunas) to test the robustness of CPUE standardization methods. A longline CPUE data simulator was developed to meet this objective and simulate fisheries data from a population with distinct habitat preferences. The simulation was used to test several statistical hypotheses regarding best practices for index standardization aimed at accurate estimation of population trends. Effort data from the US pelagic longline fleet was paired with a volume-weighted habitat suitability model for blue marlin (Makaira nigricans) to derive a simulated time series of blue marlin catch and effort from 1986 to 2015 with four different underlying population trends. The simulated CPUE data were provided to stock assessment scientists to determine if the underlying population abundance trend could accurately be detected with different methods of CPUE standardization that did or did not incorporate environmental data. While the analysts’ approach to the data and the modeling structure differed, the underlying population trends were captured, some more successfully than others. In general, the inclusion of environmental and habitat variables aided the standardization process. However, differences in approaches highlight the importance of how explanatory variables are categorized and the criteria for including those variables. A set of lessons learned from this study was developed as recommendations for best practices for CPUE standardization.FCT IF/00253/2014info:eu-repo/semantics/publishedVersio

Contesting the Public Sphere: Within and against Critical Theory

This chapter examines how European thinkers working from within and without the Frankfurt School of critical theory have understood the public sphere as a distinctive political category. First-generation members of the school rejected institutional democracy and mass politics as ideologies that mask domination. The succeeding generation, whose most important representative is Jürgen Habermas, rejected that diagnosis. Habermas’s more optimistic assessment of the emancipatory potential of the public sphere as a medium of rational learning sought a middle ground between critics and defenders of liberal democracy. This ambivalence provoked strong counter-reactions from systems theorists, such as Niklas Luhmann, and from adherents of theories of agonal democracy descended from Carl Schmitt, on the right, and Hannah Arendt, on the Left. As we shall see, these reactions are amplified by those who seek to extend the public sphere beyond the boundaries of the nation state

Implementación y evaluación de tres técnicas de marca de agua en imágenes digitales

229 p.Las marcas de agua en imágenes digitales son utilizadas para la protección de los derechos de autor y para comprobar autenticidad de una imagen propietaria. Una marca de agua es un mensaje incrustado en la imagen mediante alguna técnica, la cual debe ser imperceptible, resistente a ataques y segura.En esta memoria se presenta un resumen de las marcas de agua en imágenes digitales, se documentan tres técnicas de marca de agua y se investigan los parámetros de incrustacion propios de cada técnica. Utilizando esta información, se implementa una biblioteca de marcas de agua en imágenes digitales en el lenguaje de programación C++ que incluye las técnicas de marca de agua Bit Menos Signi cativo, Basada en la Correlaci on y Transformada Discreta del Coseno. Ademas, se utiliza esta biblioteca para experimentar con los valores de los parámetros de incrustado de cada técnica, con el objetivo de encontrar el valor optimo de los parámetros de incrustacion, de tal forma que mantengan equilibrada la relación entre Imperceptibilidad y Robustez de una marca./ABSTRACT: Watermarks in digital images are used to protect the copyright of authors and to check authenticity of a proprietary image. A watermark is a message embedded in an image using a watermarking technique and must be imperceptible, resistant to attacks and secure. In this memoria, a summary of watermarking in digital images is presented. Three watermarking techniques are documented and the embedding parameters of each technique are investigated. Using this information, a watermarking software library for digital images is implemented in the C++ programming language that includes the watermarking techniques Least signi cant bit, Correlation-based watermarking and DCT transformation-based. Furthermore, this software library is utilised for experimenting to obtain the embedding parameter values for each technique. Optimal parameters are then obtained that maintain a balance between imperceptibility and robustness

Comparison of Age and Growth Parameters of Invasive Red Lionfish (\u3ci\u3ePterois volitans\u3c/i\u3e) Across the Northern Gulf of Mexico

Invasive red lionfish (Pterois volitans) have spread rapidly throughout the northern Gulf of Mexico (GOM) partly because of their high growth rate. Red lionfish were collected from the northern GOM across 3 ecological regions from 2012 through 2015. For male and female red lionfish, relationships between weight and total length (TL) were differnt by ecological region. Males acheives a greater mean weight adjusted for TL (333.6 g [standar errer (SE) 3.6]) than females (195.1 g [SE 3.7]). A subsample of 1607 pairs of sagittal otoliths (from 744 males, 716 females, and 147 fish of unknown or undetermined sex) was used to assign ages. Ages ranged from 0.0 to 4.5 years (mean: 1.4 years), and these estimated ages and the dates of capture for specimens confirm the presence of red lionfish in the northern GOM in 2008, 2 years prior to the first detection of this species there. There were differences in age and rowth between sexes within and among ecological regions, with males achieving higher growth rates and larger asympototic lengths than females (all comparions: