298 research outputs found
Gause's exclusion principle revisited: artificial modified species and competition
Gause's principle of competition between two species is studied when one of
them is sterile. We study the condition for total extinction in the niche,
namely, when the sterile population exterminates the native one by an optimal
use of resources. A mathematical Lotka-Volterra non linear model of interaction
between a native and sterile species is proposed. The condition for total
extinction is related to the initial number of sterile individuals
released in the niche. In fact, the existence of a critical sterile-population
value is conjectured from numerical analysis and an analytical
estimation is found. When spatial diffusion (migration) is considered a
critical size territory is found and, for small territory, total extinction
exist in any case. This work is motived by the extermination agriculture
problem of fruit flies in our region.Comment: 11 pages. Published in Jour.Phys.A Math.Gen. 33, 4877 (2000
An annotated list of the Lepidoptera of Honduras
A biodiversity inventory of the Lepidoptera of Pico Bonito National Park and vicinity, in the Department of Atlantida of northern Honduras, was initiated in 2009 to obtain baseline data. We present a revised checklist of Honduran butterfly species (updated from the initial 1967 lists), as well as the first comprehensive list of Honduran moths. Our updated list includes 550 species of Papilionoidea, 311 Hesperioidea, and 1,441 moth species
An annotated list of the Lepidoptera of Honduras
A biodiversity inventory of the Lepidoptera of Pico Bonito National Park and vicinity, in the Department of Atlantida of northern Honduras, was initiated in 2009 to obtain baseline data. We present a revised checklist of Honduran butterfly species (updated from the initial 1967 lists), as well as the first comprehensive list of Honduran moths. Our updated list includes 550 species of Papilionoidea, 311 Hesperioidea, and 1,441 moth species
The duality between care and education in a nursery daily activities
This article has the as objective to verify concepts related to care and to educate, with nursery professionals. Some documents about children education were studied and some interviews and observations of the work were done with seven nursery professionals. The main focus were the activities related to care developed with children. Data were organized following the degrees: function of the nursery, education and care concepts. Data were submitted of quality analysis, allowing the confrontation between the theorical and empirical material. The results showed that official documents do not worry about the phase under discussion, letting inaccurate the relation between the activities of care and its educational role. This inexactness is noticed in the nursery professionals' speech. The activities of care are enclosed in child education, once in the vision of the professionals it has a corrective function. This aspect is justified by the lack of formation and by the fact of they entail this activity to their mothers' experience.Esse trabalho objetivou verificar conceitos relativos ao cuidar e educar, junto a profissionais de berçário. Foram estudados documentos sobre educação infantil e realizadas entrevistas e observações da prática de sete profissionais de berçários, com enfoque nas atividades de cuidados desenvolvidas com as crianças. Os dados foram organizados segundo categorias: função do berçário, conceito de educar e de cuidar e sofreram análise qualitativa, permitindo a confrontação entre o material empÃrico e o teórico. Os resultados mostraram que os documentos oficiais pouco discutem a fase em questão, deixando imprecisa a relação entre as atividades de cuidado e seu papel educacional. Essa imprecisão se reflete no discurso das profissionais do berçário. As atividades de cuidados passam a estar contidas na educação da criança, na medida em que, na visão das profissionais, têm função disciplinadora. Esse aspecto justifica-se pela falta de formação e pelo fato de vincularem esta atividade à s suas experiências de mães
Inclusão escolar e avaliações inclusivas
Como ensinar nos tempos de hoje, em meio aos desafios que nos cercam, e transpor as barreiras do não aprender em busca de aprendizagens significativas e autônomas? Nos dias atuais, é essencial um planejamento sólido e relevante, através do diagnóstico pontual sobre como se constituem as aprendizagens de cada estudante. Muitas são as facetas que consolidam as aprendizagens, sejam elas visuais, auditivas, cinestésicas; portanto, é preciso repensar a prática que respeite cada aprendente com suas necessidades, sejam especiais ou não, como sujeito único na sua forma de aprender
Two approaches in scanner-printer calibration: colorimetric space-based vs. "closed-loop"
Studies two different table-based approaches for the calibration of electronic imaging systems. The first approach, which is the classical one, uses the device-independent CIE-XYZ colorimetric space as an intermediate standard space. Input and output devices such as scanners, displays and printers are calibrated separately with respect to the objective CIE-XYZ space. The calibration process requires establishing a 3D mapping between a scanner's device-dependent RGB space and a device-independent colorimetric space such as CIE-XYZ. Measured samples belonging to the calibration set are used for splitting the colorimetric space into Delaunay tetrahedrons. The second approach, the so-called “closed-loop” approach, directly calibrates scanner-printer pairs, without any reference to an objective colorimetric space. It enables a 3D mapping to be built between the scanner's RGB space and the printer's CMY space without requiring any colorimetric measurement. It offers very accurate calibrated output for input samples having the same characteristics (halftone dot, ink spectral reflectance) as the printed samples used for the calibration process. When the desktop scanners' RGB sensibilities are not a linear transform of the CIE x¯,y¯,z¯ matching curves, an accurate calibration can only be made if input color patches are based on the same primary inks as the patches used for device calibratio
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Ground-based off-line aerosol measurements at Praia, Cape Verde, during the Saharan Mineral Dust Experiment: Microphysical properties and mineralogy
A large field experiment of the Saharan Mineral Dust Experiment (SAMUM) was performed in Praia, Cape Verde, in
January and February 2008. This work reports on the aerosol mass concentrations, size distributions and mineralogical
composition of the aerosol arriving at Praia. Three dust periods were recorded during the measurements, divided by
transitional periods and embedded in maritime-influenced situations. The total suspended particle mass/PM10/PM2.5
were 250/180/74μg/m3 on average for the first dust period (17–21 January) and 250/230/83μg/m3 for the second (24–26
January). The third period (28 January to 2 February) was the most intensive with 410/340/130 μg/m3. Four modes were
identified in the size distribution. The first mode (50–70 nm) and partly the second (700–1100 nm) can be regarded as
of marine origin, but some dust contributes to the latter. The third mode (2–4 μm) is dominated by advected dust, while
the intermittently occurring fourth mode (15–70 μm) may have a local contribution. The dust consisted of kaolinite
(dust/maritime period: 35%wt./25%wt.),K-feldspar (20%wt./25%wt.), illite (14%wt./10%wt.), quartz (11%wt./8%wt.),
smectites (6%wt./4%wt.), plagioclase (6%wt./1%wt.), gypsum (4%wt./7%wt.), halite (2%wt./17%wt.) and calcite
(2%wt./3%wt.)
Integrated management of a Swiss cropland is not sufficient to preserve its soil carbon pool in the long term
Croplands are involved in the exchange of carbon dioxide (CO2)
between the atmosphere and the biosphere. Furthermore, soil carbon (C) stocks
play an important role in soil fertility. It is thus of great interest to
know whether intensively managed croplands act as a net source or sink of
atmospheric CO2 and if soil C stocks are preserved over long
timescales. The FluxNet site CH-Oe2 in Oensingen, Switzerland, has been
operational since the end of 2003. This cropland is managed under the Swiss
framework of the Proof of Ecological Performance (PEP, a variant of
integrated management) with a crop rotation centred on winter wheat, which
also includes winter barley, winter rapeseed, peas, potato and intermediate
cover crops. In addition to eddy covariance measurements, meteorological and
soil measurements were available along with information on C imports and
exports from organic fertilisation, sowing and harvesting. This study
investigates cropland C budgets over 13Â years and assesses whether the PEP
regulations resulted in a balanced C budget. The strongest CO2 uptake was
observed during cereal seasons. C export through harvest, however, offset the
strong uptake of the cereal crops. The largest net CO2 emissions to
the atmosphere were observed during pea and cover crop seasons. Net biome
production, representing the overall C budget (assuming carbon leaching to
groundwater to be negligible), typically ranged between close to C neutral to
C losses of up to 407 g C m−2 per season, with peas being the largest
source. Overall, the field lost 1674 g C m−2 over 13 years
(129 g C m−2 yr−1), which was confirmed by soil C stock
measurements at the beginning and the end of the study period. Although
managing the field under the regulations of PEP did not result in an overall
C sink, model simulations showed that the use of cover crops reduced the C
losses compared to leaving the field bare. The use of solid manure improved
the C budget by importing substantial amounts of C into the soil, while liquid
manure had only a small effect. We thus conclude that additional efforts are
needed to bring Swiss management practices closer to the goal of preserving
soil C in the long term.</p
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