4,348 research outputs found
Magnetic local time dependency on cusp ion velocity dispersions in the mid-altitude cusp
Observations of cusp ion velocity dispersions made by the TIMAS instrument on the Polar spacecraft in the mid-altitude cusp during intervals of northward interplanetary magnetic field (IMF) reveal a clear ordering with magnetic local time (MLT). Between 1100 and 1300 MLT the injected ion velocity increased with invariant latitude for 78% of the cusp crossings, between 0900 and 1100 MLT this percentage reduced to 35% and between 1300 and 1500 MLT the percentage reduced to 57%. In contrast similar observations made during intervals of southward IMF revealed no MLT dependency. Between 0900 and 1500 MLT the injected ion velocity increased with invariant latitude for only 17% of the observed cusp crossings. We suggest that the difference in the MLT dependency between northward and southward IMF can be best explained by the different characteristics of polar convection patterns for sub-solar and lobe reconnection
The tetrapod Caerorhachis bairdi Holmes and Carroll from the Lower Carboniferous of Scotland
The tetrapod Caerorhachis bairdi, probably from the Pendleian Limestone Coal
Group in the Scottish Midland Valley, is redi agnosed and redescribed, and its affinities are
discussed. Caerorachis was originally interpreted as a temnospondyl amphibian, based on
characters that are now regarded as primitive for tetrapods, or of uncertain polarity. Several
features of Caerorhachis (e.g. gastrocentrous vertebrae, curved trunk ribs, reduced dorsal iliac
blade, L-shaped tarsal intermedium) are observed in certain primitive amniotes. In particular,
Caerorhachis resembles ‘anthracosaurs’, generally considered to be among the most primitive of
stem-group amniotes.
The phylogenetic position of Caerorhachis is considered in the light of recently published cladistic
analyses of Palaeozoic tetrapods. Most analyses place Caerorhachis at the base of, or within, ‘anthra-
cosaurs’. When multiple, equally parsimonious solutions are found, its ‘anthracosaur’ affinities are
shown in at least some trees, and are supported by several informative and, generally, highly
consistent characters. Alternative phylogenetic placements (e.g. sister taxon to temnospondyls) are
usually less well corroborated.
If the fundamental evolutionary split of most early tetrapods into stem-group lissamphibians (e.g.
temnospondyl s) and stem-group amniotes (e.g. ‘anthracosaurs’) is accepted, then the revised
interpretation of Caerorhachi s sheds light on near-ancestral conditions for Amniota
A robust design methodology suitable for application to one-off products
Robust design is an activity of fundamental importance when designing large, complex, one-off engineering products. Work is described which is concerned with the application of the theory of design of experiments and stochastic optimization methods to explore and optimize at the concept design stage. The discussion begins with a description of state-of-the-art stochastic techniques and their application to robust design. The content then focuses on a generic methodology which is capable of manipulating design algorithms that can be used to describe a design concept. An example is presented, demonstrating the use of the system for the robust design of a catamaran with respect to seakeeping
The Influence of infographics in accessing information: Multidimensionality in visual representation and configuration of different media
Infographics are powerful tools for presenting information and information design has distinguished itself as a specific discipline that has efficient communication of information as main task. With new online revolu- tion, concept of infographics has evolved by combining several ways of pre- sentation in many formats and there are different denominations; simultaneously, information designers should consider some principles and differences when designing for internet or printed material. This article presents a theoretical reflection and practical examples that pretend to reflect these matters, trying to create a relationship between infographic typologies, objec- tives and how information is presented, considering final users.
All types of infographics exploded in popularity a few years ago and the amount of information we must filter and understand will continue to grow; information design states itself as one of the best disciplines to share and communicate things we learn.CIAUD - Centro de Investigação em Arquitetura Urbanismo e Design, Faculdade de Arquitetura, Universidade de Lisbo
Styracopterid ( A ctinopterygii) ontogeny and the multiple origins of post‐ H angenberg deep‐bodied fishes
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99621/1/zoj12054.pd
Extracellular vesicle signatures and protein citrullination are modified in shore crabs (Carcinus maenas) infected with Hematodinium sp
Epizootiologists recurrently encounter symbionts and pathobionts in the haemolymph (blood equivalent) of shellfish. One such group is the dinoflagellate genus , which contains several species that cause debilitating disease in decapod crustaceans. The shore crab acts as a mobile reservoir of microparasites, including sp., thereby posing a risk to other co-located commercially important species, e.g. velvet crabs ( ). Despite the widespread prevalence and documented seasonality of infection dynamics, there is a knowledge gap regarding host-pathogen antibiosis, namely, how avoids the host's immune defences. Herein, we interrogated the haemolymph of -positive and -negative crabs for extracellular vesicle (EV) profiles (a proxy for cellular communication), alongside proteomic signatures for post-translational citrullination/deimination performed by arginine deiminases, which can infer a pathologic state. Circulating EV numbers in parasitized crab haemolymph were reduced significantly, accompanied by smaller EV modal size profiles (albeit non-significantly) when compared to -negative controls. Differences were observed for citrullinated/deiminated target proteins in the haemolymph between the parasitized and control crabs, with fewer hits identified overall in the former. Three deiminated proteins specific to parasitized crab haemolymph were actin, Down syndrome cell adhesion molecule (DSCAM), and nitric oxide synthase - factors that contribute to innate immunity. We report, for the first time, sp. could interfere with EV biogenesis, and that protein deimination is a putative mechanism of immune-modulation in crustacean- interactions
Practitioner review: pathways to care for ADHD - a systematic review of barriers and facilitators
Background. Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder starting in childhood that may persist into adulthood. It can be managed through carefully monitored medication and nonpharmacological interventions. Access to care for children at risk of ADHD varies both within and between countries. A systematic literature review was conducted to investigate the research evidence related to factors which influence children accessing services for ADHD
Loss of hyperbolicity and tachyons in generalized Proca theories
Various groups recently demonstrated that the time evolution of simplest
self-interacting vector fields, those with self-interaction potentials, can
break down after a finite duration in what is called loss of hyperbolicity. We
establish that this is not an isolated issue, and other generalizations of the
Proca theory suffer from the same problem. Specifically, we show that vector
field theories with derivative self-interactions have a similar pathology. For
this, we derive the effective metric that governs the dynamics, and show that
it can change signature during time evolution. We also show that, generalized
Proca theories may suffer from tachyonic instabilities as well, which lead to
another form of unphysical behavior.Comment: 10 pages, 4 figure
- …