The ‘migratory connectivity’ concept, and its applicability to insect migrants

Migratory connectivity describes the degree of linkage between different parts of an animal’s migratory range due to the movement trajectories of individuals. High connectivity occurs when individuals from one particular part of the migratory range move almost exclusively to another localized part of the migratory range with little mixing with individuals from other regions. Conversely, low migratory connectivity describes the situation where individuals spread over a wide area during migration and experience a large degree of mixing with individuals from elsewhere. The migratory connectivity concept is frequently applied to vertebrate migrants (especially birds), and it is highly relevant to conservation and management of populations. However, it is rarely employed in the insect migration literature, largely because much less is known about the migration circuits of most migratory insects than is known about birds. In this review, we discuss the applicability of the migratory connectivity concept to long-range insect migrations. In contrast to birds, insect migration circuits typically comprise multigenerational movements of geographically unstructured (non-discrete) populations between broad latitudinal zones. Also, compared to the faster-flying birds, the lower degree of control over movement directions would also tend to reduce connectivity in many insect migrants. Nonetheless, after taking account of these differences, we argue that the migratory connectivity framework can still be applied to insects, and we go on to consider postulated levels of connectivity in some of the most intensively studied insect migrants. We conclude that a greater understanding of insect migratory connectivity would be of value for conserving threatened species and managing pests

The ‘migratory connectivity’ concept, and its applicability to insect migrants

Migratory connectivity describes the degree of linkage between different parts of an animal’s migratory range due to the movement trajectories of individuals. High connectivity occurs when individuals from one particular part of the migratory range move almost exclusively to another localized part of the migratory range with little mixing with individuals from other regions. Conversely, low migratory connectivity describes the situation where individuals spread over a wide area during migration and experience a large degree of mixing with individuals from elsewhere. The migratory connectivity concept is frequently applied to vertebrate migrants (especially birds), and it is highly relevant to conservation and management of populations. However, it is rarely employed in the insect migration literature, largely because much less is known about the migration circuits of most migratory insects than is known about birds. In this review, we discuss the applicability of the migratory connectivity concept to long-range insect migrations. In contrast to birds, insect migration circuits typically comprise multigenerational movements of geographically unstructured (non-discrete) populations between broad latitudinal zones. Also, compared to the faster-flying birds, the lower degree of control over movement directions would also tend to reduce connectivity in many insect migrants. Nonetheless, after taking account of these differences, we argue that the migratory connectivity framework can still be applied to insects, and we go on to consider postulated levels of connectivity in some of the most intensively studied insect migrants. We conclude that a greater understanding of insect migratory connectivity would be of value for conserving threatened species and managing pests

Musculoskeletal deformities following repair of large congenital diaphragmatic hernias

Split-abdominal wall muscle flap Purpose: Large congenital diaphragmatic hernias (CDH) can be repaired with either a muscle flap or prosthetic patch. The purpose of this study was to assess the frequency and severity of scoliosis, chest wall, and abdominal wall deformities following these repairs. Methods: Neonates who underwent CDH repair (1989-2012) were retrospectively reviewed. We then validated our retrospective review by comparing results of a focused radiologic evaluation and clinical examination of patients with large defects seen in prospective follow-up clinic. Tests for association were made using Fisher's exact test. Results: 236 patients survived at least 1 year. Of these patients, 30 had a muscle flap, and 13 had a patch repair. Retrospectively, we identified pectus in 9% of primary repairs, 47% of flap repairs, and 54% of patch repairs. We identified scoliosis in 7% of primary repairs, 13% of flap repairs, and 15% of patch repairs. Prospectively, 75% of flap patients and 67% of patch patients had pectus and 13% of flap patients and 33% of patch patients had scoliosis. There was no significant difference between flap and patch patients. Conclusions: Scoliosis and pectus deformity were common in children with large CDH. The operative technique did not appear to affect the incidence of subsequent skeletal deformity. © 2014 Elsevier Inc. All rights reserved. Large congenital diaphragmatic hernias (CDHs) require repair with either a patch or an autologous tissue transfer. Repair with a prosthetic patch is the technique used by most surgeons Methods Study population After obtaining approval from the Institutional Review Board, a retrospective review of all children with CDH repair at our regional tertiary care children's hospital from 1989 to 2012 was performed. The patients were categorized by the technique of their repair. Repair types included primary repair, split abdominal wall muscle flap and synthetic patch. Paper and electronic medical records were reviewed to obtain demographic data, and diagnosis of skeletal deformities as well as any treatment for the skeletal deformities. Electronic charts were searched for the key words "pectus" and "scoliosis," and those specific notes were reviewed. These diagnoses were made by a variety of physicians including radiologists, orthopedists and primary care physicians and were not always confirmed by a focused follow-up visit by a pediatric surgeon. In order to check the validity of our retrospective review, patients with large defects were seen prospectively for focused follow-up and a single pediatric radiologist (G.H.) reviewed the most current chest radiograph to evaluate for scoliosis greater than 10 degrees. The results of follow-up were correlated with our retrospective review

Local Causal States and Discrete Coherent Structures

Coherent structures form spontaneously in nonlinear spatiotemporal systems and are found at all spatial scales in natural phenomena from laboratory hydrodynamic flows and chemical reactions to ocean, atmosphere, and planetary climate dynamics. Phenomenologically, they appear as key components that organize the macroscopic behaviors in such systems. Despite a century of effort, they have eluded rigorous analysis and empirical prediction, with progress being made only recently. As a step in this, we present a formal theory of coherent structures in fully-discrete dynamical field theories. It builds on the notion of structure introduced by computational mechanics, generalizing it to a local spatiotemporal setting. The analysis' main tool employs the \localstates, which are used to uncover a system's hidden spatiotemporal symmetries and which identify coherent structures as spatially-localized deviations from those symmetries. The approach is behavior-driven in the sense that it does not rely on directly analyzing spatiotemporal equations of motion, rather it considers only the spatiotemporal fields a system generates. As such, it offers an unsupervised approach to discover and describe coherent structures. We illustrate the approach by analyzing coherent structures generated by elementary cellular automata, comparing the results with an earlier, dynamic-invariant-set approach that decomposes fields into domains, particles, and particle interactions.Comment: 27 pages, 10 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/dcs.ht

External validation of a model to predict the survival of patients presenting with a spinal epidural metastasis

The surgical treatment of spinal metastases is evolving. The major problem is the selection of patients who may benefit from surgical treatment. One of the criteria is an expected survival of at least 3 months. A prediction model has been previously developed. The present study has been performed in order to validate externally the model and to demonstrate that this model can be generalized to other institutions and other countries than the Netherlands. Data of 356 patients from five centers in Germany, Spain, Sweden, and the Netherlands who were treated for metastatic epidural spinal cord compression were collected. Hazard ratios in the test population corresponded with those of the developmental population. However, the observed and the expected survival were different. Analysis revealed that the baseline hazard function was significantly different. This tempted us to combine the data and develop a new prediction model. Estimating iteratively, a baseline hazard was composed. An adapted prediction model is presented. External validation of a prediction model revealed a difference in expected survival, although the relative contribution of the specific hazard ratios was the same as in the developmental population. This study emphasized the need to check the baseline hazard function in external validation. A new model has been developed using an estimated baseline hazar

A Happy Abundance : Tales, Memoirs and More Past and Present in Wayne, Maine

https://digitalmaine.com/wayne_books/1002/thumbnail.jp

Amenability of groups and GG-sets

This text surveys classical and recent results in the field of amenability of groups, from a combinatorial standpoint. It has served as the support of courses at the University of G\"ottingen and the \'Ecole Normale Sup\'erieure. The goals of the text are (1) to be as self-contained as possible, so as to serve as a good introduction for newcomers to the field; (2) to stress the use of combinatorial tools, in collaboration with functional analysis, probability etc., with discrete groups in focus; (3) to consider from the beginning the more general notion of amenable actions; (4) to describe recent classes of examples, and in particular groups acting on Cantor sets and topological full groups