394 research outputs found
Surveys of Canine Filarioids In Nigeria: The Path Travelled and the Way Forward
Filarioid worms infecting dogs have recently received increased attention globally because of their zoonotic potential. In Africa and, particularly, in Nigeria, however, where there is preponderance of the risk factors for vector-borne diseases transmission, there are few reports of the disease in the canid and felid definitive hosts, the wild/domestic reservoirs and humans. Thus, the epidemiology of the disease in Nigeria remains sketchy and needs to be investigated. A retrospective analysis of reported canine filarioids in Nigeria was undertaken with the view to highlight what has been done and reported, existing gaps in knowledge, what needs to be done to bridge the gap and possibly how it could be done. Thirteen published works on canine filarioids using classical laboratory methods in Nigeria, reported the finding of Dirofilaria immitis (0.4–15.1%), Dirofilaria repens (0.1–9.4%), Acanthocheilonema reconditum (0.4–9.2%) and a case of A. dracunculoides in an unspecified dog population. In most instances, the species identification of the filarioids reported was not conclusive due to limitation of the diagnostic methods employed. No human infection due to any zoonotic canine filarioid has been reported in Nigeria. Suggestions for prospective filarioids research in Nigeria were made.
Keywords: Filarioids, dog, zoonosis, diagnosis, Nigeri
Anomalous Quantum Hall Effect on Sphere
We study the anomalous quantum Hall effect exhibited by the relativistic
particles living on two-sphere S^2 and submitted to a magnetic monopole. We
start by establishing a direct connection between the Dirac and Landau
operators through the Pauli--Schr\"odinger Hamiltonian H_{s}^{SP}. This will be
helpful in the sense that the Dirac eigenvalues and eigenfunctions will be
easily derived. In analyzing H_{s}^{SP} spectrum, we show that there is a
composite fermion nature supported by the presence of two effective magnetic
fields. For the lowest Landau level, we argue that the basic physics of
graphene is similar to that of two-dimensional electron gas, which is in
agreement with the planar limit. For the higher Landau levels, we propose a
SU(N) wavefunction for different filling factors that captures all symmetries.
Focusing on the graphene case, i.e. N=4, we give different configurations those
allowed to recover some known results.Comment: 23 pages, clarifications, references added, misprints corrected.
Version to appear in NP
Language Stimulation in Early Childhood Education. First part
El artĂculo trata la importancia de la estimulaciĂłn del lenguaje en la etapa infantil, haciendo un breve recorrido de su evoluciĂłn en los tres niveles de la etapa de infantil. Hace referencia a un trabajo realizado en un curso escolar y llevado a la práctica por profesionales de la educaciĂłn infantil asĂ como el especialista de audiciĂłn y lenguaje. En la segunda parte veremos la metodologĂa, biografĂa y webgrafĂa utilizada asĂ como las actividades realizadas clasificadas por edades y aspecto tratado, incluyendo imágenes del material utilizado.The article discisses the importance of lenguage stimulacion in the infant stage, making a brief tour of its evolution in the three levels of infante stage. It refers to a work in a school year and implemented by child education professionals as well as hearing and language specialist. In the second part we wil see the methodology, biography and webgraphy used as well as the activities classified by age and appearance trety, including images of the material used
Language Stimulation. Second part
Este artĂculo complementa a un primera parte donde se expuso la importancia de la estimulaciĂłn del lenguaje en la etapa de la educaciĂłn infantil, viendo su evoluciĂłn en los tres niveles educativos. AquĂ podremos ver las actividades utilizadas clasificadas por aspecto trabajado y la edad.Algunas contienen imágenes de los materiales y desarrollo de dichas actividades.. TambiĂ©n se refleja la metodologĂa utilizada para llevar a cabo este proyecto en nuestro centro, asĂ como la bibliografĂa y webgrafĂa que hemos tomado de referencia.This article complements a first part where the importance of language stimulation at the stage of early childhood education was exposed, seeing his evolution in the three educational levels. Here we can see the activities used classified by appearance and worked edad.Algunas contain images of materials and development of such activities.. the methodology used to carry out this project in our center as well as the literature and webgraphy we have taken reference is also reflecte
Urea Is Both a Carbon and Nitrogen Source for Microcystis aeruginosa: Tracking 13C Incorporation at Bloom pH Conditions
The use of urea as a nitrogenous fertilizer has increased over the past two decades, with urea itself being readily detected at high concentrations in many lakes. Urea has been linked to cyanobacterial blooms as it is a readily assimilated nitrogen (N) - source for cyanobacteria that possess the enzyme urease. We tested the hypothesis that urea may also act as a carbon (C) source to supplemental growth requirements during the alkaline conditions created by dense cyanobacterial blooms, when concentrations of dissolved CO2 are vanishingly low. High rates of photosynthesis markedly reduce dissolved CO2 concentrations and drive up pH. This was observed in Lake Erie during the largest bloom on record (2015) over long periods (months) and short periods (days) of time, suggesting blooms experience periods of CO2-limitation on a seasonal and daily basis. We used 13C-urea to demonstrate that axenic cultures of the model toxic cyanobacterium, Microcystis aeruginosaNIES843, assimilated C at varying environmentally relevant pH conditions directly into a spectrum of metabolic pools during urea hydrolysis. Primarily, 13C from urea was assimilated into central C metabolism and amino acid biosynthesis pathways, including those important for the production of the hepatotoxin, microcystin, and incorporation into these pathways was at a higher percentage during growth at higher pH. This corresponded to increased growth rates on urea as the sole N source with increasing pH. We propose this ability to incorporate C from urea represents yet another competitive advantage for this cyanobacterium during dense algal blooms
Differences in carbon and nitrogen abundances between field and cluster early-type galaxies
Central line-strength indices were measured in the blue spectral region for a
sample of 98 early-type galaxies in different environments. For most indices
(Mgb and in particular) ellipticals in rich clusters and in low-density
regions follow the same index-sigma relations. However, striking spectral
differences between field ellipticals and their counterparts in the central
region of the Coma cluster are found for the first time, with galaxies in the
denser environment showing significantly lower C4668 and CN2 absorption
strengths. The most convincing interpretation of these results is a difference
in abundance ratios, arising from a distinct star formation and chemical
enrichment histories of galaxies in different environments. An scenario in
which elliptical galaxies in clusters are fully assembled at earlier stages
than their low-density counterparts is discussed.Comment: 12 pages, including 3 figures, accepted for publication in ApJ
Interdependent binary choices under social influence: phase diagram for homogeneous unbiased populations
Coupled Ising models are studied in a discrete choice theory framework, where
they can be understood to represent interdependent choice making processes for
homogeneous populations under social influence. Two different coupling schemes
are considered. The nonlocal or group interdependence model is used to study
two interrelated groups making the same binary choice. The local or individual
interdependence model represents a single group where agents make two binary
choices which depend on each other. For both models, phase diagrams, and their
implications in socioeconomic contexts, are described and compared in the
absence of private deterministic utilities (zero opinion fields).Comment: 17 pages, 3 figures. This is the pre-peer reviewed version of the
following article: Ana Fern\'andez del R\'io, Elka Korutcheva and Javier de
la Rubia, Interdependent binary choices under social influence, Wiley's
Complexity, 2012; which has been published in final form at
http://onlinelibrary.wiley.com/doi/10.1002/cplx.21397/abstrac
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