516 research outputs found
Ingesta de macronutrientes y prevalencia de malnutrición por exceso en escolares de 5o y 6o básico de distinto nivel socioeconómico de la región metropolitana
Obesity in childhood has become an important publie health problem in Chile. Objetive: to study macronutrient intake and nutritional status in school-age children attending5th andóth grade inprimary schoolsfrom different socioeconomic status located in 6 counties in Santiago, Chile. Methods: A total of 1,732 children between 9 and 12 years oldjrom both sexes were studied. Anthropometric evaluation included weight, height, and tricipital and subescapular thickness. Macronutrient intake was determined using a 24-hours recall survey. Socioeconomic status was estimated using the ESOMAR survey. Results: In this sample overweight and obesity prevalence reached 40%. Prevalence was higher in boys and in the lower socio-economic groups. A higher consumption ofproteins andfat wasfound in the wealthier groups, while a higher intake of carbohydrates was present in the poorer ones. Comparison with the daily recommended allowancesfound that both males andfemales hada 75% ofadequacy of all ofmacronutrients with the exception offiber. Conclusión: The study revealeda highprevalence ofmalnutrition in both sexes with a better nutrition standard among children in higher socioeconomic status.El sobrepeso y la obesidad infantil se han transformado en un importante problema en salud pública. Objetivo: evaluar la ingesta de macronutrientes y determinar la prevalencia de malnutrición en escolares de 5° y 6o año básico de distintos niveles socioeconómicos de 6 comunas de la Región Metropolitana. Sujetos y método: se evaluaron 1732 niños de ambos sexos de 9 a 12 años de edad. La evaluación antropométrica incluyo peso, talla, pliegue tricipital y subescapular. La ingesta de macronutrientes se evaluó mediante la aplicación de una encuesta recordatorio de 24 hrs; el nivel socioeconómico se evaluó mediante la aplicación la encuesta ESOMAR. Resultados: la prevalencia de malnutrición por exceso fue de 40%, siendo más importante en hombres de los estratos socioeconómicos de menores ingresos. Encontramos un mayor consumo de proteínas y grasas totales en el nivel socioeconómico más alto, mientras que el nivel de menores ingresos tuvo una mayor ingesta de carbohidratos. Tanto hombres como mujeres presentaron una adecuación superior al 75% en todos los macronutrientes con excepción de la fibra. Conclusión: El estudio arrojó una elevada prevalencia de malnutrición por exceso en ambos sexos con un mejor patrón de alimentación en los niños de nivel socioeconómico alto
A dark scenario for Cerrado plant species: effects of future climate, land-use, and protected areas ineffectiveness
Aim: The anthropogenic climate change and land-use change are considered two of the main factors that are altering biodiversity at the global scale. An evaluation that combined both factors can be relevant to detect which species could be the most vulnerable and reveal the regions of highest stability or susceptibility to biodiversity.We aimed to (i) assess the effect of the climate change and land-use on the distribution of the Cerrado plant species for different countries where it occurs, (ii) evaluate the efficiency of the current protected areas (PAs) network to safeguards species under different greenhouse gas (GHG) emissions and land-use and (iii) estimate the vulnerability of species caused by protection efficiency and habitat loss.Location: Bolivia, Brazil, and ParaguayMethods: We modeled the distribution of 1,553 plant species of Cerrado and evaluated species range loss caused by present and future land-use and two GHG for 2050 and 2080. We assessed the species vulnerability combining the representativeness of a species´ distribution within conservation units and the loss of species range outside PAs.Results: We found that climate change and land-use will cause great damage to Cerrado flora by 2050 and 2080, even under optimistic conditions. Unfortunately, the greatest intensity and extent of land-use will have to overcome on the regions where the greatest richness will be harbored. The conservation of the species will be seriously affected since the PAs network is not as efficient in safeguarding them under current or future conditions. Main conclusions: The low level of protection together with the losses caused by the advance of the agricultural frontier will lead to most species being highly vulnerable. Due to the climate and land-use, effects showed different interactions in each country, conservation strategies should be implemented at transboundary and national levels.Fil: Velazco, Santiago José Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina. Universidade Federal do Paraná; BrasilFil: Villalobos, Fabricio. Instituto de Ecología; México. Universidade Federal de Goiás; BrasilFil: Galvao, Franklin. Universidade Federal do Paraná; BrasilFil: de Marco Junior, Paulo. Universidade Federal de Goiás; Brasi
Monotonous continuous-time random walks with drift and stochastic reset events
In this paper we consider a stochastic process that may experience random
reset events which bring suddenly the system to the starting value and analyze
the relevant statistical magnitudes. We focus our attention on monotonous
continuous-time random walks with a constant drift: the process increases
between the reset events, either by the effect of the random jumps, or by the
action of the deterministic drift. As a result of all these combined factors
interesting properties emerge, like the existence|for any drift strength|of a
stationary transition probability density function, or the faculty of the model
to reproduce power-law-like behavior. General formulas for two extreme
statistics, the survival probability and the mean exit time, are also derived.
To corroborate in an independent way the results of the paper, Monte Carlo
methods were used. These numerical estimations are in full agreement with the
analytical predictions.Comment: 15 pages, 4 figures, revtex4-1; considerable revision, 4 appendices
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A bright triple transient that vanished within 50 minutes
We report on three optically bright, ~15th mag, point-sources within 10
arcsec of each other that vanished within 1 hour, based on two consecutive
exposures at Palomar Observatory on 1952 July 19 (POSS I Red and Blue). The
three point-sources have continued to be absent in telescope exposures during
71 years with detection thresholds of ~21st mag. We obtained two deep exposures
with the 10.4-m Gran Telescopio Canarias on 25 and 27 April 2023 in r and
g-band, both reaching magnitude 25.5 (3-sigma). The three point-sources are
still absent, implying they have dimmed by more than 10 magnitudes within an
hour. When bright in 1952, the most isolated transient source has a profile
nearly the same as comparison stars, implying the sources are sub-arcsec in
angular size and they exhibit no elongation due to movement. This triple
transient has observed properties similar to other cases where groups of
transients ("multiple transients") have appeared and vanished in a small region
within a plate exposure. The explanation for these three transients and the
previously reported cases remains unclear. Models involving background objects
that are optically luminous for less than one hour coupled with foreground
gravitational lensing seem plausible. If so, a significant population of
massive objects with structure serving as the lenses, to produce three images,
are required to explain the hundreds of sub-hour transients.Comment: 9 pages, 7 figures. Submitted to MNRA
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When nothing is what it seems. A Digital Marketing Research Agenda
Digital breakthroughs continue to challenge prevailing understandings of markets and marketing practices, bringing exciting opportunities to reimagine our offerings. Looking through the lens of digital surrealism, we identify key trends emerging in the field: (1) Is AR (Augmented Reality) for real?; (2) There is no better PR than GDPR (General Data Protection Regulation); (3) A persona is not a persona; (4) Min(e)d your language, and; (4 ¾) Raise your voice. Maybe. Based on these trends we develop an agenda for future research that enables the realization of the opportunities that the digital space offers
Exploring nine simultaneously occurring transients on April 12th 1950
Nine point sources appeared within half an hour on a region within 10
arcmin of a red-sensitive photographic plate taken in April 1950 as part of the
historic Palomar Sky Survey. All nine sources are absent on both previous and
later photographic images, and absent in modern surveys with CCD detectors
which go several magnitudes deeper. We present deep CCD images with the
10.4-meter Gran Telescopio Canarias (GTC), reaching brightness mag,
that reveal possible optical counterparts, although these counterparts could
equally well be just chance projections. The incidence of transients in the
investigated photographic plate is far higher than expected from known
detection rates of optical counterparts to e.g.\ flaring dwarf stars, Fast
Radio Bursts (FRBs), Gamma Ray Bursts (GRBs) or microlensing events. One
possible explanation is that the plates have been subjected to an unknown type
of contamination producing mainly point sources with of varying intensities
along with some mechanism of concentration within a radius of 10 arcmin
on the plate. If contamination as an explanation can be fully excluded, another
possibility is fast (t s) solar reflections from objects near
geosynchronous orbits. An alternative route to confirm the latter scenario is
by looking for images from the First Palomar Sky Survey where multiple
transients follow a line.Comment: 21 pages, 3 figures, 1 table. Published in Scientific Reports.
Supplementary information can be found on the publishers webpage (open
access
Kaolinite-based zeolites synthesis and their application in CO2 capture processes
In light of the urgent need of reducing the atmospheric CO2 emissions, the use of low-cost adsorbents, that exhibit a high affinity and CO2 adsorption capacity, is a promising method from the economic and environmental point of view to separate CO2 from the flue gas emitted from large sources of emissions like power-fueled plants. Clay minerals are low-cost raw materials with high availability all over planet and great versatility in the fields of adsorption and catalysis processes. The present study pretends to elucidate the link between the reaction conditions during the synthesis of the zeolite from kaolinite and its CO2 adsorption capacity. For that purpose, the type A zeolite was synthesized via hydrothermal process in alkaline solution using metakaolinite as a starting material. The metakaolinite was obtained by calcination of kaolinite at 600 degrees C and some parameters such as temperature and synthesis time were modified to optimize the synthesis aiming for a high CO2 adsorption capacity adsorbent. Synthesized materials were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), N-2 adsorption-desorption at -196 degrees C and CO2 adsorption at 0 degrees C (up to 10 bars) isotherms and Nuclear Magnetic Resonance of solids (NMR). In addition, the adsorption capacity of CO2 was evaluated by means of CO2 adsorption-desorption isotherms at 25 degrees C up to atmospheric pressure. The obtained results indicated that synthesized zeolite 4A can be successfully prepared from natural kaolinite (via metakaolinization) at 100 degrees C for 48 h under alkaline conditions, showing chemical and physical properties similar to that of the commercial 4A zeolite
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