4,270 research outputs found
Micro-doppler-based in-home aided and unaided walking recognition with multiple radar and sonar systems
Published in IET Radar, Sonar and Navigation. Online first 21/06/2016.The potential for using micro-Doppler signatures as a basis for distinguishing between aided and unaided gaits is considered in this study for the purpose of characterising normal elderly gait and assessment of patient recovery. In particular, five different classes of mobility are considered: normal unaided walking, walking with a limp, walking using a cane or tripod, walking with a walker, and using a wheelchair. This presents a challenging classification problem as the differences in micro-Doppler for these activities can be quite slight. Within this context, the performance of four different radar and sonar systems – a 40 kHz sonar, a 5.8 GHz wireless pulsed Doppler radar mote, a 10 GHz X-band continuous wave (CW) radar, and a 24 GHz CW radar – is evaluated using a broad range of features. Performance improvements using feature selection is addressed as well as the impact on performance of sensor placement and potential occlusion due to household objects. Results show that nearly 80% correct classification can be achieved with 10 s observations from the 24 GHz CW radar, whereas 86% performance can be achieved with 5 s observations of sonar
Classical Tensors and Quantum Entanglement II: Mixed States
Invariant operator-valued tensor fields on Lie groups are considered. These
define classical tensor fields on Lie groups by evaluating them on a quantum
state. This particular construction, applied on the local unitary group
U(n)xU(n), may establish a method for the identification of entanglement
monotone candidates by deriving invariant functions from tensors being by
construction invariant under local unitary transformations. In particular, for
n=2, we recover the purity and a concurrence related function (Wootters 1998)
as a sum of inner products of symmetric and anti-symmetric parts of the
considered tensor fields. Moreover, we identify a distinguished entanglement
monotone candidate by using a non-linear realization of the Lie algebra of
SU(2)xSU(2). The functional dependence between the latter quantity and the
concurrence is illustrated for a subclass of mixed states parametrized by two
variables.Comment: 23 pages, 4 figure
Using step width to compare locomotor biomechanics between extinct, non-avian theropod dinosaurs and modern obligate bipeds
How extinct, non-avian theropod dinosaurs locomoted is a subject of considerable interest, as is the manner in which it evolved on the line leading to birds. Fossil footprints provide the most direct evidence for answering these questions. In this study, step width—the mediolateral (transverse) distance between successive footfalls—was investigated with respect to speed (stride length) in non-avian theropod trackways of Late Triassic age. Comparable kinematic data were also collected for humans and 11 species of ground-dwelling birds. Permutation tests of the slope on a plot of step width against stride length showed that step width decreased continuously with increasing speed in the extinct theropods (p < 0.001), as well as the five tallest bird species studied (p < 0.01). Humans, by contrast, showed an abrupt decrease in step width at the walk–run transition. In the modern bipeds, these patterns reflect the use of either a discontinuous locomotor repertoire, characterized by distinct gaits (humans), or a continuous locomotor repertoire, where walking smoothly transitions into running (birds). The non-avian theropods are consequently inferred to have had a continuous locomotor repertoire, possibly including grounded running. Thus, features that characterize avian terrestrial locomotion had begun to evolve early in theropod history
Marine Biodiversity and Ecosystem Health of Ilhas Selvagens, Portugal
In September 2015, National Geographic's Pristine Seas project, in conjunction with the Instituto Universitário-Portugal, The Waitt Institute, the University of Western Australia, and partners conducted a comprehensive assessment of the rarely surveyed Ilhas Selvagens to explore the marine environment, especially the poorly understood deep sea and open ocean areas, and quantify the biodiversity of the nearshore marine environment
Enzymes as Feed Additive to Aid in Responses Against Eimeria Species in Coccidia-Vaccinated Broilers Fed Corn-Soybean Meal Diets with Different Protein Levels
This research aimed to evaluate the effects of adding a combination of exogenous enzymes to starter diets varying in protein content and fed to broilers vaccinated at day of hatch with live oocysts and then challenged with mixed Eimeria spp. Five hundred four 1-d-old male Cobb-500 chickens were distributed in 72 cages. The design consisted of 12 treatments. Three anticoccidial control programs [ionophore (IO), coccidian vaccine (COV), and coccidia-vaccine + enzymes (COV + EC)] were evaluated under 3 CP levels (19, 21, and 23%), and 3 unmedicated-uninfected (UU) negative controls were included for each one of the protein levels. All chickens except those in unmedicated-uninfected negative controls were infected at 17 d of age with a mixed oral inoculum of Eimeria acervulina, Eimeria maxima, and Eimeria tenella. Live performance, lesion scores, oocyst counts, and samples for gut microflora profiles were evaluated 7 d postinfection. Ileal digestibility of amino acids (IDAA) was determined 8 d postinfection. Microbial communities (MC) were analyzed by G + C%, microbial numbers were counted by flow cytometry, and IgA concentrations were measured by ELISA. The lowest CP diets had poorer (P ≤ 0.001) BW gain and feed conversion ratio in the preinfection period. Coccidia-vaccinated broilers had lower performance than the ones fed ionophore diets during pre- and postchallenge periods. Intestinal lesion scores were affected (P ≤ 0.05) by anticoccidial control programs, but responses changed according to gut section. Feed additives or vaccination had no effect (P ≥ 0.05) on IDAA, and diets with 23% CP had the lowest (P ≤ 0.001) IDAA. Coccidial infection had no effect on MC numbers in the ileum but reduced MC numbers in ceca and suppressed ileal IgA production. The COV + EC treatment modulated MC during mixed coccidiosis infection but did not significantly improve chicken performance. Results indicated that feed enzymes may be used to modulate the gut microflora of cocci-vaccinated broiler chickens
Towards a definition of quantum integrability
We briefly review the most relevant aspects of complete integrability for
classical systems and identify those aspects which should be present in a
definition of quantum integrability.
We show that a naive extension of classical concepts to the quantum framework
would not work because all infinite dimensional Hilbert spaces are unitarily
isomorphic and, as a consequence, it would not be easy to define degrees of
freedom. We argue that a geometrical formulation of quantum mechanics might
provide a way out.Comment: 37 pages, AmsLatex, 1 figur
Chelator free gallium-68 radiolabelling of silica coated iron oxide nanorods via surface interactions
The commercial availability of combined magnetic resonance imaging (MRI)/positron emission tomography (PET) scanners for clinical use has increased demand for easily prepared agents which offer signal or contrast in both modalities. Herein we describe a new class of silica coated iron–oxide nanorods (NRs) coated with polyethylene glycol (PEG) and/or a tetraazamacrocyclic chelator (DO3A). Studies of the coated NRs validate their composition and confirm their properties as in vivo T₂ MRI contrast agents. Radiolabelling studies with the positron emitting radioisotope gallium-68 (t1/2 = 68 min) demonstrate that, in the presence of the silica coating, the macrocyclic chelator was not required for preparation of highly stable radiometal-NR constructs. In vivo PET-CT and MR imaging studies show the expected high liver uptake of gallium-68 radiolabelled nanorods with no significant release of gallium-68 metal ions, validating our innovation to provide a novel simple method for labelling of iron oxide NRs with a radiometal in the absence of a chelating unit that can be used for high sensitivity liver imaging
NANoREG evaluation: Fish acute exposure to TiO2, ZnO and SiO2.
The Laboratory of Ecotoxicology and Biosafety from Embrapa Environment participated in nanomaterial ecotoxicity evaluation inside the NANOoREG approach. Toxicity test were performed with Brachydanio rerio (zebrafish), according to Nanoreg SOPFish, Acute Toxicity Test for NANoREG core nanomaterials, Version 1 (Souza, Freitas and Zucolotto, 2015). Fish were maintained in reconstituted water (pH 7±0.5, conductivity 600±50 mS/cm, 28oC ± 1oC), under a 14/10h light /dark cycle, they were not feed during the test. The Nanoreg material tested were ZnO (2883578/JRCNM01101a/99070), TiO2 (2883578/ JRCNM01001a/990407) and SiO2 (PRA02/7625, 7627, 7629, 7630). A nanomaterial stock suspension of 1 g/L in ultrapure water was sonicated during 15 min, 400 W/L, 20 kHz before preparing the test suspension. All materials were tested at a maximum concentration of 100 mg/L with and without NOM Suwanee River (10 mg/L). Fish were exposed in a proportion of 1.0 g fish/L during 96 hours in a static system with constant aeration. Animals wereevaluated concerning mortality and behavior abnormalities (loss of equilibrium, swimming behavior, respiratory function, etc.). There was no mortality or abnormal behavior. So, the estimated LC50 is greater than 100 mg/L to all nanomaterials tested. Results obtained by these SOP were useful to provide information for regulatory decisions
Statistics and Nos\'e formalism for Ehrenfest dynamics
Quantum dynamics (i.e., the Schr\"odinger equation) and classical dynamics
(i.e., Hamilton equations) can both be formulated in equal geometric terms: a
Poisson bracket defined on a manifold. In this paper we first show that the
hybrid quantum-classical dynamics prescribed by the Ehrenfest equations can
also be formulated within this general framework, what has been used in the
literature to construct propagation schemes for Ehrenfest dynamics. Then, the
existence of a well defined Poisson bracket allows to arrive to a Liouville
equation for a statistical ensemble of Ehrenfest systems. The study of a
generic toy model shows that the evolution produced by Ehrenfest dynamics is
ergodic and therefore the only constants of motion are functions of the
Hamiltonian. The emergence of the canonical ensemble characterized by the
Boltzmann distribution follows after an appropriate application of the
principle of equal a priori probabilities to this case. Once we know the
canonical distribution of a Ehrenfest system, it is straightforward to extend
the formalism of Nos\'e (invented to do constant temperature Molecular Dynamics
by a non-stochastic method) to our Ehrenfest formalism. This work also provides
the basis for extending stochastic methods to Ehrenfest dynamics.Comment: 28 pages, 1 figure. Published version. arXiv admin note: substantial
text overlap with arXiv:1010.149
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