2,597 research outputs found
Anthropology, ethnography, and narrative: intersecting paths in understanding the processes of health and sickness
Discorre sobre antropologia, método etnográfico e narrativa como possibilidades de acessar os sentidos atribuÃdos e a experiência dos sujeitos. De uma perspectiva antropológica, o universo sociocultural é tomado como referência para a compreensão do significado do processo saúde-doença, através de uma descrição etnográfica densa, cuja análise tem inspiração interpretativista. Nesse contexto, as narrativas revelam-se como possibilidades para a compreensão do modo como as experiências humanas subjetivas são compartilhadas e de como são organizados os comportamentos, enfatizando-se o significado, o processo de produção de histórias, as relações entre o narrador e os demais sujeitos, os processos de conhecimento e a multiplicidade de formas para se captar experiências.The article discusses anthropology, ethnographic method, and narrative as possible ways of coming to know subjects' experiences and the feelings they attribute to them. From an anthropological perspective, the sociocultural universe is taken as a point of reference in understanding the meaning of the processes of health and sickness, using a dense ethnographic description from an interpretivist analytical approach. In this context, narratives afford possible paths to understanding how subjective human experiences are shared and how behavior is organized, with a special focus on meaning, the process by which stories are produced, relations between narrator and other subjects, processes of knowledge, and the manifold ways in which experience can be captured
Syntectonic Variscan magmatism in the Aguiar da Beira region (Iberian Massif, Portugal)
The Aguiar da Beira region (Portugal) is located in the core of the Iberian Massif, more precisely in the Central-Iberian Zone, which is dominantly composed by abundant volumes of plutonic rocks, emplaced into Late Proterozoic – Early Cambrian and Palaeozoic metasediments, mainly during or slightly after the third deformation phase of the Variscan Orogeny (D3). A considerable amount of these granitoids are syntectonic, intruded during the peak of this deformation event (D3). In particular, at the Aguiar da Beira region, there are two syntectonic granitoids that represent two distinct magmatic series: a medium- to coarse-grained porphyritic biotite granodiorite-granite (322 Ma), which belongs to the early granodiorite series, and a medium-grained muscovite-biotite granite (317 Ma) that is part of the two-mica peraluminous leucogranites suite.
The petrographical, geochemical (whole-rock and mineral compositions) and isotopical (Sr-Nd, 18O-wr and 18O-zr) study of the two intrusions revealed their remarkably different character, and allowed to conclude that they correspond to two independent magma pulses, derived from distinct sources and petrogenetic processes. The biotite granodiorite-granite is a weakly peraluminous intrusion, characterized by intermediate to felsic SiO2 contents (66 – 68%), high Ba, Sr and REE, and high Al and Mg biotite contents, typical of the calc-alkaline associations. The Sr-Nd initial ratios are homogeneous and overlap the lower crustal felsic metaigneous granulites signatures (Villaseca et al. 1999) which might suggest an origin by the anatexis of lower felsic metaigneous rocks, and is further supported by 18O-wr and 18O-zr data. However, the data, allied to the presence of microgranular enclaves present in this intrusion also raises the hypothesis of an origin by mixing of lower crustal derived magmas and mantle melts. Based on the available data these seem to be the two genetic scenarios that can best explain the geochemical signature of the biotite granodiorite-granite, not being possible to opt for any of the options. By contrast, the muscovite-biotite granite has an entirely distinct geochemical signature, typical of S-type granites: a highly evolved and strongly peraluminous character (SiO2 = 72 - 74%; CaO = 0.3-0.6%; A/CNK = 1.18 - 1.36, low Mg, Ti, Ba, Sr, REE, HFSE contents, and high Al2O3/TiO2 e Rb/Sr ratios), high (87Sr/86Sr)317 (0.71037 - 0.71459), low Ndi (-7.7 to -8.7), and high 18O (18O-wr = 11.33 ‰; 18O-zr = 9.5 ± 0.2‰). The data suggest that this magma was derived from the partial melting of metasedimentary middle crustal protoliths, which has been successfully modeled. The observed major and trace element composition variation suggests an evolution controlled by fractionation crystallization of a mineral association composed by plagioclase + biotite + apatite + zircon ± monazite ± ilmenite
Distribution of 1.68 eV emission from diamond films
Free-standing polycrystalline chemical vapor deposition diamond films grown on a silicon wafer, with electrical behavior similar to values currently mentioned in the literature, present microheterogeneity. A detailed analysis by micro Raman shows how the diamond and nondiamond phases are distributed within the film and also the distribution of the silicon related luminescence. This luminescence is discussed in terms of two emitting centers close in energy. Absolute intensity of the diamond peak is not correlated with the good quality of the film as assessed by the Raman linewidth and ratio of this line to the nondiamond Raman line
Plagioclase and biotite compositions tracing granite genesis and evolution: insights from two syntectonic granitoids from Aguiar da Beira (N Portugal)
The Aguiar da Beira area (N Portugal) is located within the Central-Iberian Zone (CIZ) of the Iberian Variscan Belt. It is mainly composed by granitoids emplaced during (syntectonic) or slightly after (late- to post-tectonic) the last ductile deformation event of the Variscan orogeny (D3). From the petrological and geochemical point of view, the syntectonic granitoids from the CIZ can be included into two genetically distinct suites: (a) calc-alkaline granodiorites and biotite granites, and (b) strongly peraluminous leucogranites and two-mica granites. In the Aguiar da Beira area, the first group is represented by a small intrusion of a medium- to coarse-grained porphyritc biotite granodiorite-granite, emplaced 322 Ma ago, characterized by a slightly peraluminous and moderately evolved composition. The second group comprises a NW-SE elongated pluton of a strongly peraluminous and highly evolved medium- to fine-grained muscovite-biotite granite (317 Ma), showing occasionally a gneissic foliation concordant with the D3 variscan structures.
Based on geochemical and Sr-Nd and 18O isotopic data, the biotite granodiorite-granite melt is interpreted either as the result of partial melting of heterogeneous lower crustal materials, or as the product of mixing of mantle derived magmas and lower crustal felsic anatectic melts. In contrast, the muscovite-biotite gneissic granite magma appears to have been exclusively generated by partial melting of upper crustal metasediments and suffered a subsequent evolution dominantly controlled by fractional crystallization processes.
Plagioclase and biotite major and trace element compositions can be used to constrain the origin and evolution of the two granitoids and provide strong evidence in support of the proposed petrogenetic models. In the biotite granodiorite-granite, the plagioclase is characterized by a wide compositional range (An20-33), high Sr (749 – 869 ppm) and Ba (32 – 351 ppm) contents and a Sr discontinuous zonation pattern, whilst the biotite shows high TiO2 (2.92 – 3.30 wt%), Ba (407 – 589 ppm), V (214 – 234 ppm), and low Al2O3 (16.83 – 18.03 wt%), Li (335 – 367 ppm), Zn (262 – 279 ppm) and Fet/(Fet + Mg) (0.54 – 0.55) contents. These data confirm the typical calc-alkaline affinity of this intrusion and reveal that these phase minerals crystallized under disequilibrium conditions. In contrast, the plagioclase from the muscovite-biotite granite displays a narrower compositional range (An1-7), unzoned or normally zoned compositional patterns and lower Sr (19 – 33 ppm) and Ba (1.1 – 2.0 ppm) contents, reflecting the highly evolved character of this intrusion and near equilibrium crystallization conditions. The biotite crystals from the muscovite-biotite granite plot in the field of the alumino-potassic series in the AlVI versus Mg diagram (Nachit et al., 1983), supporting a major contribution of metasedimentary rocks for the genesis of this magma. Their AlVI contents increase with decreasing Mg suggesting an important role for fractional crystallization processes during magmatic evolution. The range of AlVI and Fet/(Fet + Mg) values (AlVI: 0.482 – 0.487; Fet/(Fet + Mg): 0.72 – 0.83) displayed by the biotites show that the muscovite-biotite granite crystallized from a reduced magma (low O2), which is consistent with its inferred sedimentary provenance
Morphology and structure of acorn starches isolated by enzymatic and alkaline methods
Research articleMorphology and structure of starch from fruits
of two acorns species, Quercus rotundifolia Lam. (QR) and
Quercus suber Lam. (QS), isolated by enzymatic (ENZ)
and alkaline (A3S) methods were studied. Acorn starches
granules presented a round and oval shape, consisting of
medium/small granules, with a mean granule size ranging
between 9 and 13 μm. Isolated acorn starches appear
as light grayish-brown in naked eye, with high values
of L* for starches isolated by the ENZ method, and
QR starches were duller than QS. No differences were
observed for all the samples in FTIR spectra results.
Acorn starches showed a C-type pattern, with a relative
crystallinity between 43.1 and 46.6%. The 13C CP/MAS
NMR spectra are different for the used isolation methods
but are similar for both acorn species. However, acornisolated
starches presented a predominant A-type allomorph
packing type, and the A3S starches showed a
higher degree of crystalline material. Those differences
in the structure of acorn starches would be helpful to
better understand the relationships among structure and
functional properties for a possible potential industrial
application of chestnut starchesinfo:eu-repo/semantics/publishedVersio
New U-Pb zircon ages for Early Ordovician magmatism in Central Portugal
The Mundão anatectic complex is located in the axial zone of the Iberian massif of Central Northern Portugal
(Central Iberian Zone). It consists of lenticular bodies of felsic gneisses and stromatic metatexites derived from
metasedimentary protoliths of Neoproterozoic-Lower Cambrian age, both showing evidence of incipient to
extensive partial melting during the Variscan orogeny. Although the precise age of the migmatization event is still
unknown, field and structural evidence show that the partial melting conditions were reached in the last stages
of crustal thickening (D1), continued during subsequent extensional deformation (D2) and culminated with the
emplacement of large volumes of S-type granite magmas in a transcurrent tectonic regime (D3). The upper limit
for crustal melting is provided by the Late Carboniferous age of the S-type granitoids (312.4 2.7 Ma) intruding
the Mundão anatectic complex.
Due to their transitional contacts with the stromatic metatexites, the felsic gneisses were previously interpreted as
diatexites resulting from anatexis of the same pelitic and/or metagreywacke protolith. However, new U–Pb dating
by ID-TIMS show that the zircon fractions from one sample of the leucocratic gneisses are concordant and yield
a 206Pb/238U weighted average age of 474.5 1.5 Ma. The results obtained reveal that these rocks correspond
to orthogneisses instead of sedimentary-derived diatexites and provide a good estimate for the crystallization
age of their magmatic protolith. In contrast, the monazite fractions show distinct 207Pb/235U ages of 341.8
2.1 Ma and 453.4 2.0 Ma and may therefore have lost Pb to different extent during Variscan deformation and
metamorphism.
The preservation of inherited ages of the igneous protolith in the Mundão leucocratic gneisses suggests that zircon
was mainly incorporated as restitic material, with only minor precipitation and/or recrystallization during crustal
anatexis.
The new age of the Mundão orthogneiss brackets the so-called Early Ordovician Sardic unconformity, characteristic
of the Central Iberian Zone
Study about attitudes, perceptions and knowledge regarding edible insects in Portugal
Os insetos têm sido apontados como uma fonte alternativa e mais sustentável de proteÃna animal, que pode ajudar a alimentar a crescente população mundial. Devido à menor pegada e impacto ambiental, a substituição parcial da proteÃna animal por insetos pode contribuir para a preservação do meio ambiente e dos ecossistemas naturais. No entanto, o consumo de insetos comestÃveis, embora culturalmente aceite em algumas comunidades, não é prontamente aceite noutras. Assim, este trabalho investigou o conhecimento, atitudes, hábitos de consumo e grau de aceitabilidade de insetos ou produtos derivados entre consumidores portugueses. Este estudo foi baseado numa pesquisa por questionário, realizada numa amostra de 213
participantes.
Os resultados mostraram que os portugueses tendem a ter perceções corretas sobre as questões de sustentabilidade relacionadas com a utilização de insetos como alternativa a carnes convencionais. No entanto, o grau de conhecimento sobre o valor nutritivo dos insetos e possÃveis efeitos na saúde é baixo. Entre os indivÃduos pesquisados, apenas uma pequena percentagem indicou já ter comido insetos, consumidos maioritariamente no estrangeiro, por iniciativa própria, seja em restaurantes ou em festas/eventos sociais. Não surpreendentemente, observou-se que há uma maior relutância em consumir insetos inteiros do que em ingeri-los como ingredientes utilizados em preparações alimentares. Assim, em conclusão, a investigação revelou que os portugueses ainda apresentam alguma resistência para aderir ao consumo de insetos como
alternativa a outros produtos cárneos, mas não se descarta que o mercado de produtos à base de insetos possa ser uma forma de ultrapassar a neofobia associada a este tipo de alimentos num paÃs tradicionalmente não comedor de insetos.Insects have been pointed out as an alternative and more sustainable source of animal protein that might help feed the growing world population. Because of the lower footprint and environmental impact, replacing partly the animal protein by insects can contribute to the preservation of the environment and natural ecosystems. However, the consumption of edible insects, although culturally accepted for some communities, is not readily accepted for others. Hence this work investigated the knowledge, attitudes, consumption habits, and degree of acceptability of edible insects or derived products among Portuguese consumers. This study was based on a questionnaire survey undertaken on a sample of 213 participants. The results showed that the Portuguese tend to have correct perceptions about the sustainability issues related to the utilization of edible insects as an alternative to conventional meats. Nevertheless, the degree of knowledge about the nutritive value of
insects and possible health effects is low. Among the individuals surveyed, only a small percentage indicated they had already eaten insects, consumed mostly abroad, by self-initiative, and either in restaurants or at parties/social events. Not surprisingly, it was observed that there is a higher reluctance to consume whole insects than to ingest them as ingredients used in food preparations. So, in conclusion, the research revealed that the Portuguese still present some resistance to adhere to the consumption of insects as an alternative to other meat products, but it is not discarded that the market of insect based products can be a way to surpass the neophobia associated with this type of food on a traditionally non-insect-eating country.info:eu-repo/semantics/publishedVersio
Ricci-flat deformation of orbifolds and localized tachyonic modes
We study Ricci-flat deformations of orbifolds in type II theory. We obtain a
simple formula for mass corrections to the twisted modes due to the
deformations, and apply it to originally tachyonic and massless states in
several examples. In the case of supersymmetric orbifolds, we find that
tachyonic states appear when the deformation breaks all the supersymmetries. We
also study nonsupersymmetric orbifolds C^2/Z_{2N(2N+1)}, which is T-dual to N
type 0 NS5-branes. For N>=2, we compute mass corrections for states, which have
string scale tachyonic masses. We find that the corrected masses coincide to
ones obtained by solving the wave equation for the tachyon field in the smeared
type 0 NS5-brane background geometry. For N=1, we show that the unstable mode
representing the bubble creation is the unique tachyonic mode.Comment: 20 pages, minor collection
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