458 research outputs found
Non-Riemannian vortex geometry of rotational viscous fluids and breaking of the acoustic Lorentz invariance
Acoustic torsion recently introduced in the literature (Garcia de
Andrade,PRD(2004),7,64004) is extended to rotational incompressible viscous
fluids represented by the generalised Navier-Stokes equation. The fluid
background is compared with the Riemann-Cartan massless scalar wave equation,
allowing for the generalization of Unruh acoustic metric in the form of
acoustic torsion, expressed in terms of viscosity, velocity and vorticity of
the fluid. In this work the background vorticity is nonvanishing but the
perturbation of the flow is also rotational which avoids the problem of
contamination of the irrotational perturbation by the background vorticity. The
acoustic Lorentz invariance is shown to be broken due to the presence of
acoustic torsion in strong analogy with the Riemann-Cartan gravitational case
presented recently by Kostelecky (PRD 69,2004,105009). An example of analog
gravity describing acoustic metric is given based on the teleparallel loop
where the acoustic torsion is given by the Lense-Thirring rotation and the
acoustic line element corresponds to the Lense-Thirring metric
Primordial magnetic fields constrained by CMB anisotropies and dynamo cosmology
Magneto-curvature stresses could deform magnetic field lines and this would
give rise to back reaction and restoring magnetic stresses [Tsagas, PRL
(2001)]. Barrow et al [PRD (2008)] have shown in Friedman universe the
expansion to be slow down in spatial section of negative Riemann curvatures.
From Chicone et al [CMP (1997)] paper, proved that fast dynamos in compact 2D
manifold implies negatively constant Riemannian curvature, here one applies the
Barrow-Tsagas ideas to cosmic dynamos. Fast dynamo covariant stretching of
Riemann slices of cosmic Lobachevsky plane is given. Inclusion of advection
term on dynamo equations [Clarkson et al, MNRAS (2005)] is considered. In
absence of advection a fast dynamo is also obtained. Viscous and restoring
forces on stretching particles decrease, as magnetic rates increase. From COBE
data (), one computes stretching
.
Zeldovich et al has computed the maximum magnetic growth rate as
. From COBE data one computes
a lower growth rate for the magnetic field as
, well-within Zeldovich et al
estimate. Instead of the Harrison value one obtains the
lower primordial field which yields the
at the Big Bang time.Comment: Dept of theoretical physics-UERJ-Brasi
Evaluation of a numerical method to predict the polyphenol content in monovarietal olive oils
Three monovarietal virgin olive oils obtained from olives grown under biological agricultural system, in Portugal, with different ripening
stages, were studied in what concerns the parameters usually related with oxidation status (total polyphenols, tocopherols, chlorophylls
and carotenoids, peroxide values, oxidative stability, specific extinction coefficients K232 and K270 and titratable acidity). A total
of 18 samples were analyzed: seven from Cv. Cobranc¸osa (maturation indices 1–7), five from Cv. Madural (maturation indices 3–7) and
six from Cv. Verdeal Transmontana (maturation indices 1–6). Oxidative stability and polyphenols profile presented high correlation coef-
ficients. Given this high correlation, a numerical method was developed and evaluated to predict total polyphenols contents in olive oil.
The method is based on the kinetic equation of the oxidation process in the presence of antioxidants and on Rancimat profiles. Total
polyphenols contents obtained with this method were similar to those obtained by the Folin-Ciocalteau method
Traversable Wormholes Construction in 2+1 Dimensions
We study traversable Lorentzian wormholes in the three-dimensional low energy
string theory by adding some matter source involving a dilaton field. It will
be shown that there are two-different types of wormhole solutions such as BTZ
and black string wormholes depending on the dilaton backgrounds, respectively.
We finally obtain the desirable solutions which confine exotic matter near the
throat of wormhole by adjusting NS charge.Comment: 12 pages, 4 figures, JHEP style, one reference adde
Chemometric characterization of three varietal olive oils (Cvs. cobrancosa, madural and verdeal Transmontana) extracted from olives with different maturation indices
This paper evaluates the usefulness of three chemical parameters (compositions on tocopherols, sterols and fatty acids) as a tool to
discriminate three varietal olive oils (Cvs. Cobrançosa, Madural and Verdeal Transmontana), which are permitted cultivars for the production
of ‘‘Trás-os-Montes olive oil’’, a Portuguese protected designation of origin (PDO) product. The olives were collected during the
year crop 2000/2001 from the same orchard, in order to eliminate the geographical and climatic influences. Lots with different maturation
indices were prepared to allow the evaluation of the ripening stage on the characteristics of varietal olive oils produced from each cultivar.
Statistical methods such as multivariate analysis of variance (MANOVA), principal components analysis (PCA) and cluster analysis
were used to evaluate significant differences on the studied parameters. Regarding the results, the three cultivars were clearly
discriminated
Primary Melanoma Of The Uterine Cervix Figo Stage Iii B.
The primary malignant melanoma of the uterine cervix is rare, usually diagnosed at an advanced stage and with poor prognosis. The diagnosis is made through histological evaluation and confirmed by special staining procedures. Radical surgery has been used and advocated. However in its advanced stages chemotherapy, immunotherapy or radiotherapy can be employed. A case of a patient with malignant melanoma of the uterine cervix, Stage IIIb, is presented in addition to a clinical and pathological discussion.11641778178
Cistus monspeliensis L. as a potential species for rehabilitation of soils with multielemental contamination under Mediterranean conditions
Conservation Biolog
Waves of family hope: narratives of families in the context of pediatric chronic illness
Incluye versión en inglésObjetivo: analizar las narrativas sobre la experiencia de esperanza de las familias en el contexto de la enfermedad crónica pediátrica. Método: investigación narrativa que utilizó la EnfermerÃa de Sistemas Familiares como marco conceptual. En este estudio participaron tres familias de niños y adolescentes diagnosticados con enfermedades crónicas complejas, con un total de 10 participantes. La recogida de datos se desarrolló mediante entrevistas familiares con foto-elicitación. Se construyeron y analizaron narrativas familiares siguiendo el análisis temático inductivo con triangulación teórica de los de datos. Resultados: el tema analÃtico - Olas de esperanza familiar en el contexto de la enfermedad crónica pediátrica - se compone de cuatro tipos diferentes de esperanza: esperanza incierta, esperanza cuidadora, esperanza latente y esperanza expectante. El movimiento a través de estas esperanzas genera una fuerza motriz y dependiente de varios factores: apoyo, información, búsqueda de la normalidad, pensamientos y comparaciones. Conclusión: los resultados destacan la interacción y reciprocidad de los miembros de la unidad familiar, la dinámica de la esperanza, e ilustran los diferentes tipos de esperanza y los factores que los influyen. Este estudio destaca la experiencia de la esperanza como un recurso familiar, en vez de un recurso individual, y apoya a los profesionales de la salud en la planificación del cuidado familiar considerando la esperanza como un recurso familiar esencial y dinámico.Objective: to analyze narratives about the experience of hope of families in the context of pediatric chronic illness. Method: a narrative research using Family Systems Nursing as a conceptual framework. Three families of children and adolescents diagnosed with complex chronic illness participated in this study, totaling 10 participants. Data collection was developed using family photo-elicitation interviews. Family narratives were constructed and analyzed according to inductive thematic analysis with theoretical data triangulation. Results: the analytical theme – Waves of Family Hope in the Context of Pediatric Chronic Illness – is composed of four different types of hope: uncertain hope, caring hope, latent hope, and expectant hope. Movement through these hopes generates a driving energy and depends on a number of factors: support, information, searching for normality, and thoughts and comparisons. Conclusion: the results highlight the interaction and reciprocities of the members of the family unit, and the dynamics of hope, and illustrate the different types of hope and the factors that influence them. This study highlights the experience of hope as a family resource rather than just an individual resource, and supports health professionals in the planning of family care considering hope as an essential and dynamic family resource. © 2021 Revista Latino-Americana de Enfermagem.This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES) – Finance Code 001, and by Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq), Brazil
Ruminal Degradability Of Agro-industrial Fruit Residues
The aim of this study was to evaluate the chemical composition and ruminal degradability of the dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of fruit residues. Three fistulated sheep were held collectively in a pen, and fed daily with the studied residues in a diet consisting of canarana grass (Echinochloa pyramidalis) and a concentrate of corn and soybeans. The animals were allowed an adjustment period of seven days. The residues were dried in the sun, crushed in a forage machine, sorted using a 4.0-mm sieve, and incubated for 3, 6, 12, 24, 48, 72, and 96 h using nonwoven bags (weight 60g/m2, 14 ×12 cm2). Chemical analyses of the residues were performed using a randomized block experimental design with split plots. The cherimoya and tamarind residues showed the highest concentrations of CP (12.66% and 11.79%) the ether extract of cherimoya residue was the highest at 22.30%stands out the sour soup residue. The cashew and guava residues showed the highest levels of lignin (22.13 and 18.34%). The effective degradability of DM for the pineapple and tamarind residues to a passage rate of 5%/h were 53.04% and 42.61%, respectively. The guava, cherimoya, and cashew residues showed lower values at 19.16%, 26.86%, and 29.21%, respectively. The cherimoya, guava and pineapple residues showed the highest values of potential degradability for CP at 87%, 81%, 86.02% and 90.94%, respectively, with an average effective degradability of 50.0% at the rate of 5%/h. The pineapple (35.38%) and tamarind residues (34.49%) showed higher values of the effective degradability of NDF at a passage rate of 5%/h. Among the studied residues, the pineapple residue showed the greatest potential for use in animal feed based on chemical composition and rates of degradability.37127929
In silico analysis of cytochrome p450 genes involved in the metabolism of diterpenes in Coffea.
Brazil is the largest world producer and exporter of coffee, being also the second largest consumer market. Among the main goals of coffee breeders, studies aiming the improvement of cup quality and plant tolerance to biotic and abiotic stresses have extreme importance. Beverage nutraceutical properties and plant defense mechanisms are directly linked to diterpenes present in the lipid fraction of coffee beans, such as cafestol (Caf ) and caveol (Cav). Many members of P 450 gene family are involved in plant secondary metabolism, including diterpenes synthesis. In order to depict biochemical and genetic aspects of diterpenes byosinthesis, we did an in silico characterization of p450 gene family in Coffea spp., and we also quantified Caf and Cav in coffee fruit tissues for further gene expression studies involving diterpens metabolism. Using keyword and Blast search, 1396 ESTs related to Cyt p450 were selected from the Brazilian Coffee Genome Project (http://www.lge.ibi. unicamp.br/cafe). After assembling, we observed 157 putative unigenes, distributed in 92 contigs and 65 singlets. The contigs were analyzed using BLAST X versus public sequences databases (GenBank and Harvest Coffea), confirming their identity to 91 Cyt P450 genes. Expression profiles were inferred by electronic Northern blot of all contigs, allowing the selection of 7 candidate genes for transcriptional analysis based in fruit cDNA library expression. Caf and Cav were measured using HPLC in two different fruit developmental stages: 90 DAF (Days After Flowering) vs 120 DAF and in fruits (120 DAF) treated with 2?M methyl Jasmonate (MJ). Fruits at 120 DAF had an increase of 42% in Cav and 19% in Caf levels in relation to 90DAF fruits. MJ treatment resulted in samples with an average increase of 18% of Cav and 35% of Caf. RNAs were extracted from these samples for future transcriptional analyses. This study establish a platform for expression analysis of cyt P450 candidate genes in RNA samples from tissues with contrasting accumulation of Cav and Caf. (Texte intégral
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