Temporally robust spatial structure in ecosystems explained by local biodiversity regulation

The distribution in species' site occupancy is a fundamental pattern in spatial ecology. Despite decades of research, the mechanisms responsible for the shape of the distribution remain incompletely understood. Here, we simultaneously examining both spatial and temporal patterns of site occupancy in communities of macroinverterbrates, macrophytes and diatoms. We show that a simple patch dynamics model explains both the spatial structure and temporal dynamics in English rivers. The key mechanism responsible for the emergent spatial structure in the model are intrinsic regulation of biodiversity at the local scale which, when combined with inter-site dispersal and regional-scale invasion, drives local colonisation and extinction. Our analysis supports the notion that metacommunities exist in a kind of dynamic steady state arising from local ecological constraints and that this intrinsic regulation can drives the emergence of a wide variety of macroecological patterns.

The evolutionary origins and diversity of the neuromuscular system of paired appendages in batoids

Appendage patterning and evolution have been active areas of inquiry for the past two centuries. While most work has centred on the skeleton, particularly that of amniotes, the evolutionary origins and molecular underpinnings of the neuromuscular diversity of fish appendages have remained enigmatic. The fundamental pattern of segmentation in amniotes, for example, is that all muscle precursors and spinal nerves enter either the paired appendages or body wall at the same spinal level. The condition in finned vertebrates is not understood. To address this gap in knowledge, we investigated the development of muscles and nerves in unpaired and paired fins of skates and compared them to those of chain catsharks. During skate and shark embryogenesis, cell populations of muscle precursors and associated spinal nerves at the same axial level contribute to both appendages and body wall, perhaps representing an ancestral condition of gnathostome appendicular neuromuscular systems. Remarkably in skates, this neuromuscular bifurcation as well as colinear Hox expression extend posteriorly to pattern a broad paired fin domain. In addition, we identified migratory muscle precursors (MMPs), which are known to develop into paired appendage muscles with Pax3 and Lbx1 gene expression, in the dorsal fins of skates. Our results suggest that muscles of paired fins have evolved via redeployment of the genetic programme of MMPs that were already involved in dorsal fin development. Appendicular neuromuscular systems most likely have emerged as side branches of body wall neuromusculature and have been modified to adapt to distinct aquatic and terrestrial habitats.

The evolutionary origins and diversity of the neuromuscular system of paired appendages in batoids

Appendage patterning and evolution have been active areas of inquiry for the past two centuries. While most work has centered on the skeleton, particularly that of amniotes, the evolutionary origins and molecular underpinnings of the neuromuscular diversity of fish appendages have remained enigmatic. The fundamental pattern of segmentation in amniotes, for example, is that all muscle precursors and spinal nerves enter either the paired appendages or body wall at the same spinal level. The condition in finned vertebrates is not understood. To address this gap in knowledge, we investigated the development of muscles and nerves in unpaired and paired fins of skates and compared them to those of chain catsharks. During skate and shark embryogenesis, cell populations of muscle precursors and associated spinal nerves at the same axial level contribute to both appendages and body wall, perhaps representing an ancestral condition of gnathostome appendicular neuromuscular systems. Remarkably in skates, this neuromuscular bifurcation as well as colinear Hox expression extend posteriorly to pattern a broad paired fin domain. In addition, we identified migratory muscle precursors (MMPs), which are known to develop into paired appendage muscles with Pax3 and Lbx1 gene expression, in the dorsal fins of skates. Our results suggest that muscles of paired fins have evolved via redeployment of the genetic program of MMPs that were already involved in dorsal fin development. Appendicular neuromuscular systems most likely have emerged as side branches of body wall neuromusculature and have been modified to adapt to distinct aquatic and terrestrial habitats.

Análisis biomecánico del pie protésico Bioc-dm2

Walking is one of the aspects directly compromising human wellbeing, as it has a physical and emotional impact in daily life.For this study, we delve into the challenge of improving some walking conditions in a patient suffering lower limb loss, specifically at transtibialor transfemoral levels. Given that our purpose was the analysis, design and manufacture of a lower-limb prosthetic component, which fills the needsfor functionality, it became necessary to build a foot with all the quality standards associated to each and all movements required to form thecomplex fundamental pattern of walking. Besides, this foot should also easily endure weight, daily use and physical characteristics of the patientobject of this study. When performing physical validation and during human walk, a proper response is observed in terms of mechanics, materialsand dynamics of the component, thus making evident proper construction and assembly. On the other hand, it is feasible that design and verificationof the component provided a competitive element, as compared to existing elements currently in the market. The previous situation generated theneed for verification from the National Institute for Medications and Food (INVIMA), as well as the revision of the use replying device, forcomponent verification, in accordance with ISO 10328.

Central Banks, Systemic Risk and Financial Sector Structural Reform

This chapter contribution to an edited volume examines financial sector structural reform as a critical, though largely under-appreciated to date, dimension of central banks’ post-crisis systemic risk prevention agenda. By limiting the range of permissible transactions or organizational affiliations among different types of financial firms, structural reforms alter the fundamental pattern of interconnectedness in the financial system. In that sense, the chapter argues, reforming the institutional structure of the financial industry operates as a deeper form of the currently evolving macroprudential regulation. The chapter identifies three principal models that form a continuum of potential financial sector structural reform choices and applies this conceptual framework to analysis of post-crisis structural reforms in the U.K., EU, and U.S. It further examines how deeply issues of financial industry structure are embedded in central banks’ regulatory and policy agenda and, in light of this connection, discusses potential implications of current structural reforms for central banks’ post-crisis financial stability mandate.

The Romantic Quest for Identity: Re-reading the First Part of The Rime of the Ancient Mariner

This paper proposes a re-reading of Samuel Taylor Coleridge’s poetic masterpiece, The Rime of the Ancient Mariner, in an attempt to deepen the critical discussion about one of the major themes explored in the poem, that is the search for identity. In particular, this attempt will consist of a close reading of the first section of the ballad, inasmuch as it contains the fundamental pattern of the whole text. The conceptual framework underlying this analysis is based on Coleridge’s key principle of “the coincidence of opposites”, which the Author develops in his critical work Biographia Literaria. Indeed, the whole of Coleridge’s oeuvre is permeated by the idea of a dialectical tension between contrary forces, which struggle against each other so as to be joined, at last, in the dynamic unity of a superior harmony. In the light of this conception, the Romantic quest for identity takes the form of a struggle between two opposing forces: the impact of otherness with its confounding effects on the one side, and the irrepressible aspiration towards a unified self on the other. Such a conflicting dynamics appears to structure the entire ballad, starting from the incipit of the poem and involving all the characters – especially the two opposite figures of the ancient Mariner and the Wedding Guest.

Soliton, Breather, and Rogue Wave for a (2+1)-Dimensional Nonlinear Schrödinger Equation

In this paper, a (2+1)-dimensional nonlinear Schrödinger (NLS) equation, which is a generalisation of the NLS equation, is under investigation. The classical and generalised N-fold Darboux transformations are constructed in terms of determinant representations. With the non-vanishing background and iterated formula, a family of the analytical solutions of the (2+1)-dimensional NLS equation are systematically generated, including the bright-line solitons, breathers, and rogue waves. The interaction mechanisms between two bright-line solitons and among three bright-line solitons are both elastic. Several patterns for first-, second, and higher-order rogue wave solutions fixed at space are displayed, namely, the fundamental pattern, triangular pattern, and circular pattern. The two-dimensional space structures of first-, second-, and third-order rogue waves fixed at time are also demonstrated.