8,619 research outputs found
Paisajes culturales agrarios del estado Mérida,Venezuela
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
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
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
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- CO lines (from =14-13 to =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 () and masses () 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 and .
PACS sensitivity allowed the study of higher rotational numbers than before,
indicating the presence of a significant amount of warmer gas (200-900 K)
not traceable with lower- CO observations at sub-mm/mm wavelengths. The
masses are in the range , anti-correlated
with temperature. For some strong CO emitters we infer a double temperature
(warm 400 K and hot 820 K) component. From
the analysis of IRC+10216, we corroborate that the effect of line variability
is perceptible on the of the hot component only, and certainly
insignificant on 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
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
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
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
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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