8,619 research outputs found

    Paisajes culturales agrarios del estado Mérida,Venezuela

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    Este trabalho aborda a interpretação das paisagens culturais agrárias no estado de Mérida, na Cordilheira dos Andes venezuelanos, adaptado a uma classificação dos tipos bioclimáticos. No "Andar SubAndino", acima de 400m de altitude, domina a paisagem com banana, árvores de fruto, e criação de gado (para produção de carne e leite), enquanto que entre 400 e 1700m a paisagem predominante é café sob sombra em ambientes úmidos e campos de cana de açúcar em ambientes secos. No "Andar Andino", entre 1700 e 2300m predomina uma produção intensiva de hortaliças e tubérculos (principalmente de batatas) em ambientes húmidos, enquanto ambientes secos apresentam uma paisagem relíquia de antigos campos de trigo. O sector da pecuária é dominado por gado de leite. Elevações de 2300 a 3000m são dominadas pela agricultura comercial intensiva dos pequenos e médios produtores de legumes, batatas e flores; assim como a pecuária leiteira e piscicultura de truta. No "Andar AltiAndino" existem culturas intensivas e extensivas, e criação de gado de leite entre 3000 e 4000m, enquanto acima de 4000m há uma pastagem básica muito extensa.En este trabajo se aborda la interpretación de los paisajes culturales agrarios del estado Mérida, en los Andes venezolanos, utilizando una clasificación por pisos bioclimáticos. En el “Piso Subandino”, hasta los 400m de elevación, predomina el paisaje con plátano (banana), árboles frutales, y ganadería vacuna extensiva (producción de carne y leche), mientras que entre los 400 y 1700m el paisaje predominante es el de cafetales bajo sombra en ambientes húmedos y de caña de azúcar en ambientes más secos. En el “Piso Andino”, entre los 1700 y 2300m predomina la producción intensiva de hortalizas, papa y ajo en ambientes húmedos, mientras que en ambientes secos queda un paisaje relicto del cultivo del trigo de épocas pretéritas. En el sector pecuario predomina la ganadería de altura para producción láctea. En elevaciones de 2300 a 3000m predomina una agricultura de tipo comercial e intensiva de pequeños y medianos productores de hortalizas, papas y flores; así como ganadería de altura y piscicultura de truchas. En el “Piso Altiandino” hay cultivos intensivos y extensivos, y ganadería extensiva entre 3000 y 4000m, mientras que en las tierras por sobre 4000m existe un pastoreo básico muy extensivo.This work deals with the interpretation of agrarian cultural landscapes in Mérida State, in the Venezuelan Andes, adapted to a classification of bioclimatic belts. In the "SubAndean bealt", up to 400m of elevation, the landscape with banana, fruit trees and cattle ranching (for meat and milk production) dominates, while between 400 and 1700m the predominant landscape is coffee plantations under shade in moist environments and sugarcane fields in dry environments. In the "Andean bealt", between 1700 and 2300m predominates an intensive production of vegetables and tubercles (mainly potatoes) in humid environments, while the dry environments exhibit a relict landscape of past wheat fields. The livestock sector is dominated by dairy-cattle ranching. Elevations of 2300 to 3000m are dominated by intensive commercial agriculture of small and medium producers of vegetables, potatoes and flowers, as well as dairy-cattle ranching and trout fish-farming. In the "HighAndean bealt" there are intensive and extensive crops, and cattle ranching between 3000 and 4000m, while above 4000m there is a very basic extensive-grazing

    THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy

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    This is the first of a series of papers presenting the THROES (A caTalogue of HeRschel Observations of Evolved Stars) project, intended to provide a comprehensive overview of the spectroscopic results obtained in the far-infrared (55-670 microns) with the Her- schel space observatory on low-to-intermediate mass evolved stars in our Galaxy. Here we introduce the catalogue of interactively reprocessed PACS (Photoconductor Array Camera and Spectrometer) spectra covering the 55-200 microns range for 114 stars in this category for which PACS range spectroscopic data is available in the Herschel Science Archive (HSA). Our sample includes objects spanning a range of evolutionary stages, from the asymptotic giant branch to the planetary nebula phase, displaying a wide variety of chemical and physical properties. The THROES/PACS catalogue is accessible via a dedicated web-based inter- face (https://throes.cab.inta-csic.es/) and includes not only the science-ready Herschel spectroscopic data for each source, but also complementary photometric and spectroscopic data from other infrared observatories, namely IRAS (Infrared Astronomical Satellite), ISO (Infrared Space Observatory) or AKARI, at overlapping wavelengths. Our goal is to create a legacy-value Herschel dataset that can be used by the scientific community in the future to deepen our knowledge and understanding of these latest stages of the evolution of low-to-intermediate mass stars.Comment: 38 page

    Cost Benefits of Centralizing Service Processing in 5G Network Infrastructures

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    We assess the benefits of centralizing service processing in a few high-scale data center locations within an operator infrastructure. Results show up to 74% less cost while provisioning latency and availability constrained services

    Warm CO in evolved stars from the THROES catalogue. II. Herschel/PACS spectroscopy of C-rich envelopes

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    This is the second paper of a series making use of Herschel/PACS spectroscopy of evolved stars in the THROES catalogue to study the inner regions of their circumstellar envelopes (CSEs). We analyze the CO emission spectra, including a large number of high-JJ CO lines (from JJ=14-13 to JJ=45-44), as a proxy for the warm molecular gas in the CSEs of a sample of bright carbon-rich stars spanning different evolutionary stages from the Asymptotic Giant Branch (AGB) to the young planetary nebulae (PNe) phase. We use the rotational diagram (RD) to derive rotational temperatures (TrotT_{\rm rot}) and masses (MH2M_{\rm H_2}) of the envelope layers where the CO transitions arise. We also obtain a first order estimate of the mass-loss rates and assess the impact of the opacity correction for a range of characteristic envelope radii. We use multi-epoch spectra for the well studied C-rich envelope IRC+10216 to investigate the impact of CO flux variability on the values of TrotT_{\rm rot} and MH2M_{\rm H_2}. PACS sensitivity allowed the study of higher rotational numbers than before, indicating the presence of a significant amount of warmer gas (\sim200-900 K) not traceable with lower-JJ CO observations at sub-mm/mm wavelengths. The masses are in the range 102105M\sim10^{-2}-10^{-5}\,\rm M_{\odot}, anti-correlated with temperature. For some strong CO emitters we infer a double temperature (warm TrotT_{\rm rot}\sim400 K and hot TrotT_{\rm rot}\sim820 K) component. From the analysis of IRC+10216, we corroborate that the effect of line variability is perceptible on the TrotT_{\rm rot} of the hot component only, and certainly insignificant on MH2M_{\rm H_2} and, hence, the mass-loss rate. Therefore, the parameters derived from the RD are robust even when strong line flux variability occurs, with the major source of uncertainty in the estimate of the mass-loss rate being the size of the CO-emitting volume.Comment: accepted in A&

    Utilization of nitrogen from corn plant residues and green manures by corn

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    A qualidade dos resíduos vegetais de culturas comerciais e adubos verdes influencia a taxa de mineralização/imobilização de N e o respectivo aproveitamento desse nutriente pelas subseqüentes culturas. Com o objetivo de avaliar a utilização do N mineralizado da parte aérea e do sistema radicular da crotalária (Crotalaria juncea) e milheto (Pennisetum americanum) e da palha de milho, marcados com 15N, realizou-se um estudo, em casa de vegetação, no Centro de Energia Nuclear na Agricultura - CENA/USP, Piracicaba (SP), em vasos com 5 kg de solo de um Latossolo Vermelho distroférrico. Foram utilizados seis tratamentos e quatro repetições, dispostos num delineamento inteiramente casualizado, compreendendo: T1 = palha de milho-15N (parte aérea, exceto os grãos) (80 mg kg-1 de N no solo); T2 = raiz de milheto-15N (30 mg kg-1 de N no solo); T3 = parte aérea de milheto-15N (80 mg kg-1 de N no solo); T4 = raiz de crotalária-15N (30 mg kg-1 de N no solo); T5 = parte aérea de crotalária-15N (80 mg kg-1 de N no solo) e T6 = tratamento sem adição de fonte orgânica de N. Para os tratamentos que receberam raiz marcada com 15N, adicionou-se parte aérea sem marcação isotópica na mesma quantidade que naqueles que receberam parte aérea marcada, e vice-versa. As raízes foram incorporadas ao solo e a parte aérea adicionada sobre a superfície. Para avaliar absorção de N da palha de milho-15N (7,35 Mg ha-1, equivalente a 56 kg ha-1 de N) pela cultura do milho, realizou-se também um experimento de campo, na mesma área em que foi coletado solo para o experimento de casa de vegetação. A quantidade de N no milho proveniente da crotalária (111,80 mg vaso-1 N ) foi superior à do milheto (30,98 mg vaso-1 N ), que foi superior à da palha de milho (11,80 mg vaso-1N ). A crotalária proporcionou maior absorção de N e produtividade de matéria seca ao milho. O aproveitamento pelo milho do N da parte aérea da crotalária foi superior ao do N do sistema radicular, mas não houve diferença para o N do milheto. A absorção do N dos restos culturais de milho pela cultura do milho, no campo, foi de 4,1 % da quantidade inicial.The quality of commercial crop residues and green manure influences the N mineralization-immobilization rate and the respective use by subsequent crops. With the objective of evaluating N utilization by corn of N from the shoot and root system of sunnhemp (Crotolaria juncea) and millet (Pennicetum americanum) and corn straw, labeled with 15N, a green house experiment was carried out at the Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, S. Paulo, Brazil, in 5 kg pots with dystroferric Red Latosol in a completely randomized design, with four replications and the following six treatments: T1 = 15N labeled corn straw (above ground part, except grains) (80 mg kg-1 N in soil); T2 = 15N labeled millet root (30 mg kg-1 in soil); T3 = 15N labeled millet shoot (80 mg kg-1 N in soil); T4 = 15N labeled sunnhemp root (30 mg kg-1 N in soil); T5 = 15N labeled sunnhemp shoot (80 mg kg-1 N in soil) and T6 = treatment without addition of organic N source. In the treatments with 15N labeled root application, unlabeled shoot at the same amount added as in those where labeled shoot was applied, and vice-versa. The roots were incorporated into the soil and shoots left on the surface. To evaluate N absorption from 15N corn straw (7.35 Mg ha-1, equivalent to 56 kg ha-1 N) by corn crop, a field experiment was carried out, in the same area where the soil for the green house experiment had been collected. The amount of corn N derived from sunnhemp (111.80 mg pot-1 N) was higher than from millet (30.98 mg pot-1 N), which in turn higher was than from corn plant residues (11.80 mg pot-1 N). Sunnhemp resulted in highest nitrogen absorption and dry matter weight of the corn crop. The corn utilized more N from sunnhemp shoot than from roots, but there was no difference in N derived from millet. The N absorption of corn from corn straw was 4.1 % of the initial amount in the field experiment

    The Analyticity of a Generalized Ruelle's Operator

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    In this work we propose a generalization of the concept of Ruelle operator for one dimensional lattices used in thermodynamic formalism and ergodic optimization, which we call generalized Ruelle operator, that generalizes both the Ruelle operator proposed in [BCLMS] and the Perron Frobenius operator defined in [Bowen]. We suppose the alphabet is given by a compact metric space, and consider a general a-priori measure to define the operator. We also consider the case where the set of symbols that can follow a given symbol of the alphabet depends on such symbol, which is an extension of the original concept of transition matrices from the theory of subshifts of finite type. We prove the analyticity of the Ruelle operator and present some examples

    Angiomyolipoma of the upper lip : case report and review of the literature

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    Angiomyolipoma (AML) is a hamartomatous growth that usually affects the kidney. One third of patients with AML present with manifestations of tuberous sclerosis. Oral AML is rare with only 6 cases reported in the English-language literature. In the present case, AML was located in the upper lip of a 43 year-old woman. Clinically, it presented as a firm nodule, well circumscribed and measuring 1x2 cm. It was surgically excised. Histopathological analysis showed a lesion composed of an admixture of smooth muscle cells, blood vessels, and adipose tissue. The immunohistochemical study revealed positivity for vimentin, smooth muscle actin, pan specific muscle actin and desmin. CD68, CD34 and mast cell antibodies showed focal immunoreactivity. S100 protein, Ki-67, and HMB-45 were negative. Based on these histological and immunohistochemical features the diagnosis was of oral AML. No recurrence was observed after 2 years of follow-up

    Deep eutectic solvents for improved biomass pretreatment: current status and future prospective towards sustainable processes

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    Pretreatment processes - recognized as critical steps for efficient biomass refining - have received much attention over the last two decades. In this context, deep eutectic solvents (DES) have emerged as a novel alternative to conventional solvents representing a step forward in achieving more sustainable processes with both environmental and economic benefits. This paper presents an updated review of the state-of-the-art of DES-based applications in biorefinery schemes. Besides describing the fundamentals of DES composition, synthesis, and recycling, this study presents a comprehensive review of existing techno-economic and life cycle assessment studies. Challenges, barriers, and perspectives for the scale-up of DES-based processes are also discussed.publishe
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