413 research outputs found
Patrimônio e conceito antropológico de cultura: uma longeva relação
Abstract:
This work aimed at discussing the association made between the anthropological concept of culture and the broadening of the scope of the notion of heritage that has occurred since the beginning of the 21st century, specifically with regard to the policies established for the protection of intangible cultural heritage. It has been argued that because it is polysemic, the anthropological concept of culture had been related to the notion of heritage since the first quarter of the 20th century, that is, almost a century before. What has changed is the meaning attributed to both categories. In addition, it was discussed that an expansion of the heritage category is the result of the action of the most diverse social actors in the demand for differential cultural rights, operating with a specific political-cultural grammar, which dynamized enunciations such as multiculturalism, cultural diversity and representation, seeking a non-hierarchical vision of culture, which directly impacted on the conceptualization of heritage and the policy of protection of cultural goods. To this end, as a way of delimiting the discussion, it was decided to work with documents produced by the United Nations Educational, Scientific and Cultural Organization (UNESCO) in the period, since it is a protagonist agent and arena with regard to policies for the protection of cultural goods.
Keywords: heritage, anthropological concept of culture, immaterial heritage, cultural diversity.O trabalho buscou discutir a associação feita entre o conceito antropológico de cultura e o alargamento do escopo da noção de patrimônio que ocorreu a partir do início do século XXI, especificamente no que diz respeito às políticas estabelecidas para a proteção do patrimônio cultural imaterial. Argumentou-se que, por ser polissêmico, o conceito antropológico de cultura manteve relação com a noção de patrimônio desde o primeiro quarto do século XX, ou seja, quase um século antes. Verifica-se que o sentido atribuído às duas categorias se transformou. Ademais, discutiu-se que uma ampliação da categoria patrimônio é fruto da ação dos mais diversos atores sociais na demanda por direitos culturais diferenciais, operando com uma gramática político-cultural específica, que dinamizou enunciados como multiculturalismo, diversidade cultural e representação, buscando uma visão não hierarquizante de cultura, o que impactou diretamente na conceitualização de patrimônio e na política de proteção de bens culturais. Para tanto, como maneira de delimitar a discussão, optou-se por trabalhar com documentos produzidos pela Organização das Nações Unidas para a Educação, a Ciência e a Cultura (UNESCO) no período, visto ser agente e arena protagonista no que diz respeito às políticas de proteção a bens culturais.
Palavras-chave: patrimônio, conceito antropológico de cultura, patrimônio imaterial, diversidade cultural
Experimental quantum imaging distillation with undetected light
Imaging based on the induced coherence effect makes use of photon pairs to
obtain information of an object without detecting the light that probes it.
While one photon illuminates the object, only its partner is detected, so no
measurement of coincidence events are needed. The sought-after object's
information is revealed observing a certain interference pattern on the
detected photon. Here we demonstrate experimentally that this imaging technique
can be made resilient to noise. We introduce an imaging distillation approach
based on the interferometric modulation of the signal of interest. We show that
our scheme can generate a high-quality image of an object even against noise
levels up to 250 times the actual signal of interest. We also include a
detailed theoretical explanation of our findings.Comment: 18 pages, 6 figures, and 1 table + 11 pages, 3 figures, and 1 tabl
Quantum holography with undetected light
Holography exploits the interference of light fields to obtain a systematic
reconstruction of the light fields wavefronts. Classical holography techniques
have been very successful in diverse areas such as microscopy, manufacturing
technology, and basic science. Extending holographic methods to the level of
single photons has been proven challenging, since applying classical holography
techniques to this regime pose technical problems. Recently the retrieval of
the spatial structure of a single photon, using another photon under
experimental control with a well-characterized spatial shape as reference, was
demonstrated using the intrinsically non-classical Hong-Ou-Mandel interference
on a beam splitter. Here we present a method for recording a hologram of single
photons without detecting the photons themselves, and importantly, with no need
to use a well-characterized companion reference photon. Our approach is based
on quantum interference between two-photon probability amplitudes in a
nonlinear interferometer. As in classical holography, the hologram of a single
photon allows retrieving the complete information about the "shape" of the
photon (amplitude and phase) despite the fact that the photon is never
detected.Comment: 29 pages with 11 figures, submitted to Nature Communication
A combined theoretical and experimental study of the low temperature properties of BaZrO3
Low temperature properties of BaZrO3 are revealed by combining experimental
techniques (X-ray diffraction, neutron scattering and dielectric measurements)
with theoretical first-principles-based methods (total energy and linear
response calculations within density functional theory, and effective
Hamiltonian approaches incorporating/neglecting zero-point phonon vibrations).
Unlike most of the perovskite systems, BaZrO3 does not undergo any
(long-range-order) structural phase transition and thus remains cubic and
paraelectric down to 2 K, even when neglecting zero-point phonon vibrations. On
the other hand, these latter pure quantum effects lead to a negligible thermal
dependency of the cubic lattice parameter below ~ 40 K. They also affect the
dielectricity of BaZrO3 by inducing an overall saturation of the real part of
the dielectric response, for temperatures below ~ 40 K. Two fine structures in
the real part, as well as in the imaginary part, of dielectric response are
further observed around 50-65 K and 15 K, respectively. Microscopic origins
(e.g., unavoidable defects and oxygen octahedra rotation occurring at a local
scale) of such anomalies are suggested. Finally, possible reasons for the facts
that some of these dielectric anomalies have not been previously reported in
the better studied KTaO3 and SrTiO3 incipient ferroelectrics are also
discussed.Comment: 8 pages, 5 figures, submitted to Physical Review
Analytical solution of generalized Burton--Cabrera--Frank equations for growth and post--growth equilibration on vicinal surfaces
We investigate growth on vicinal surfaces by molecular beam epitaxy making
use of a generalized Burton--Cabrera--Frank model. Our primary aim is to
propose and implement a novel analytical program based on a perturbative
solution of the non--linear equations describing the coupled adatom and dimer
kinetics. These equations are considered as originating from a fully
microscopic description that allows the step boundary conditions to be directly
formulated in terms of the sticking coefficients at each step. As an example,
we study the importance of diffusion barriers for adatoms hopping down
descending steps (Schwoebel effect) during growth and post-growth equilibration
of the surface.Comment: 16 pages, REVTeX 3.0, IC-DDV-94-00
Sustainable and green persulfate-based chemiluminescent method for on-site estimation of chemical oxygen demand in waters
The standard method for estimating the chemical oxygen demand (COD) of water bodies uses dichromate as the
main oxidant, a chemical agent whose use has been restricted in the European Union since 2017. This method is
hazardous, time-consuming, and burdensome to adapt to on-site measurements. As an alternative and following
the current trends of sustainable and green chemistry, a method using the less toxic reagent sodium persulfate as
the oxidizing agent has been developed. In this method an excess of persulfate, activated through heating in an
alkaline solution, oxidizes the chemically degradable organic fraction through a 2-step radical mechanism. The
remaining persulfate is evaluated by chemiluminescence (CL) using luminol and a portable charge-coupled
device (CCD) camera. The method provided quantitative recoveries and a sample throughput of >60 samples
h. It was validated in river water samples by comparison of COD estimations with the standard dichromate
method (R = 0.973, p < 0.05) and with a UV–Vis permanganate-based method (R = 0.9998, p < 0.05), the latter
being also used for drinking waters. The proposed method is a sustainable and green alternative to the previous
used methods. Overall, the method using activated persulfate is suitable for use as COD quantitation/screening
tool in surface waters. Considering that its main components are portable, it can be ultimately adapted for in situ
analysis at the point of need
Age and petrogenesis of the Sarmiento ophiolite complex of southern Chile
Zircon fractions separated from fine-grained plagiogranites, interpreted to be cogenetic with the mafic rocks of the Sarmiento ophiolite complex in southern Chile, yield slightly to grossly discordant age patterns for which the lower concordia intercept U-Pb ages of 140.7 +/- 0.7 Ma (Lolos Fjord) and 137.1 +/- 0.6 Ma (Encuentro Fjord) are well constrained. These dates are interpreted as formation ages for the northern portion of the igneous floor of the Rocas Verdes basin, and they are younger than the age of 150 Ma determined for a more southern portion of the floor of this basin on South Georgia Island. Coarse-grained trondjemites within the gabbro units of the Sarmiento complex yield a lower concordia intercept U-Pb age of 147 +/- 10 Ma and a poorly defined upper intercept reflecting an inherited zircon component, possibly of Proterozoic age. These rocks are interpreted as remobilized fragments of country rocks entrapped within the essentially mantle-derived rocks of the ophiolite complex.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29957/1/0000318.pd
Índice de masa corporal materno pre-embarazo y riesgo de malformaciones congénitas específicas: evidencia de una relación dosis-respuesta
Antecedentes: Este estudio investiga la relación entre el índice de masa corporal (IMC) previo al embarazo y 26 malformaciones al nacer identificadas en el Registro de Defectos de Nacimientos de Florida. Métodos: El IMC (kg/m2) previo al embarazo se categorizó en bajo peso (<18,5), normopeso (18,524,9), sobrepeso (25-29,9) y obesidad (≥30) entre las madres residentes de Florida sin diabetes pre-gestacional y que tuvieron partos de embarazos únicos entre marzo de 2004 y diciembre de 2009. La obesidad se clasificó en tres categorías: Obesidad I (30,0-34,9), Obesidad II (35,0-39,9) y Obesidad III (≥40,0). Se utilizó regresión logística para calcular los Odds Ratios ajustados con un intervalo de confianza de 95%, representando la asociación entre el IMC pre-embarazo y cada uno de los 26 defectos específicos al nacer y un compuesto de "cualquier malformación al nacer". Los modelos fueron ajustados según edad materna, raza/etnia, educación, tabaquismo, estado civil y origen. Resultados: En nacidos vivos la prevalencia de cualquier defecto al nacer aumenta con el incremento del IMC, de 3,9% en mujeres con bajo peso a 5,3% en mujeres con Obesidad III (p<0,001). Los resultados muestran una relación directa dosis-respuesta entre el IMC materno pre-embarazo y 10 malformaciones en estudio (fisura palatina sin fisura labial, hernia diafragmática, hidrocefalia sin espina bífida, síndrome de hipoplasia de ventrículo izquierdo, atresia y estenosis de válvula pulmonar, estenosis pilórica, estenosis y atresia rectal e intestinal, transposición de grandes arterias, tetralogía de Fallot y defectos septales ventriculares) y la categoría de "cualquier malformación al nacer". Al contrario, la gastrosquisis mostró una relación inversa y estadísticamente significativa con el IMC pre-embarazo. Conclusiones: Este estudio entrega evidencia del riesgo aumentado de malformaciones con el aumento de la obesidad pre-embarazo. Reducir la obesidad pre-embarazo, incluso entre las mujeres obesas, podría reducir la ocurrencia de estos defectos al nacer
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