997 resultados para GALAXIES: FUNDAMENTAL PARAMETERS
Resumo:
Food and Nutrition Security (FNS) must be ensured to everybody. The school environment is favorable to the formation of healthy habits and citizenship. The National Curriculum Parameters (PCNs) guide the promotion of health concepts in a transversal way in the school curriculum. This study aimed to identify and analyze the approach used for food and nutrition themes in Fundamental Education's teaching material and its interface with the concept of FNS and the PCNs. Documental research was conducted on the teaching material from 5th to 8th grades of Fundamental Education in Public School of the state of Sao Paulo. The diffuse presence of food and nutrition themes was found in most disciplines in all bimesters in the four series, which shows the interdisciplinarity in health. It was found that the PCNs are related to the concept of SAN in its various aspects and that most subjects include topics that approach this relationship. In the correlation between themes, there is emphasis to health promotion and food production. The methodology used in the teaching material presents the theme, but not the correspondent content, what made the analysis of its suitability impossible. We conclude that there is the approach of the issues related to food and nutrition in the teaching material, some of them in an inconsistent way; it is the educators' task to select the contents and the appropriate strategy, doing an effort of constant update. This isbeing proposed by the State, however it is not accessible to all professionals and therefore still depends on the initiative of each teacher.
Resumo:
We revisit the issue of the constancy of the dark matter (DM) and baryonic Newtonian acceleration scales within the DM scale radius by considering a large sample of late-type galaxies. We rely on a Markov Chain Monte Carlo method to estimate the parameters of the halo model and the stellar mass-to-light ratio and then propagate the uncertainties from the rotation curve data to the estimate of the acceleration scales. This procedure allows us to compile a catalogue of 58 objects with estimated values of the B-band absolute magnitude M-B, the virial mass M-vir, and the DM and baryonic Newtonian accelerations (denoted as g(DM)(r(0)) and g(bar)(r(0)), respectively) within the scale radius r(0) which we use to investigate whether it is possible to define a universal acceleration scale. We find a weak but statistically meaningful correlation with M-vir thus making us argue against the universality of the acceleration scales. However, the results somewhat depend on the sample adopted so that a careful analysis of selection effects should be carried out before any definitive conclusion can be drawn.
Resumo:
Objective: to compare acoustic and perceptual parameters regarding the voice of cochlear implanted children, with normal hearing children. Method: this is a cross-sectional, quantitative and qualitative study. Methods: Thirty six cochlear implanted children aged between 3y and 3 m to 5y and 9 m and 25 children with normal hearing, aged between 3y and 11 m and 6y and 6 m, participated in this study. The recordings and the acoustics analysis of the sustained vowel/a/and spontaneous speech were performed using the PRAAT program. The parameters analyzed for the sustained vowel were the mean of the fundamental frequency, jitter, shimmer and harmonic-to-noise ratio (HNR). For the spontaneous speech, the minimum and maximum frequencies and the number of semitones were extracted. The perceptual analysis of the speech material was analyzed using visual-analogical scales of 100 points, composing the aspects related to the overall severity of the vocal deviation, roughness, breathiness, strain, pitch, loudness and resonance deviation, and instability. This last parameter was only analyzed for the sustained vowel. Results: The results demonstrated that the majority of the vocal parameters analyzed in the samples of the implanted children disclosed values similar to those obtained by the group of children with normal hearing. Conclusion: implanted children who participate in a (re) habilitation and follow-up program, can present vocal characteristics similar to those vocal characteristics of children with normal hearing. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
Resumo:
A Segurança Alimentar e Nutricional (SAN) deve ser assegurada a todos. A escola é ambiente propício à formação de hábitos saudáveis e à construção de cidadania. Os Parâmetros Curriculares Nacionais (PCNs) orientam a promoção de concepções de saúde de modo transversal no currículo escolar. Este estudo teve como objetivo identificar e analisar a abordagem dos temas alimentação e nutrição no material didático do ensino fundamental e sua interface com o conceito de SAN e com os PCNs. Foi realizada pesquisa documental mediante o material didático de 5ª a 8ª séries do ensino fundamental da rede pública do Estado de São Paulo. A presença difusa do tema alimentação e nutrição na maioria das disciplinas, por todos os bimestres, nas quatro séries, traz à tona a interdisciplinaridade em saúde. Verificou-se que os PCNs estão relacionados ao conceito de SAN nos seus diversos aspectos e que a maioria das disciplinas contém temas que abordam esta relação. Na interface entre os temas, destaca-se a promoção da saúde e a produção dos alimentos. A metodologia utilizada no material didático apresenta o tema, mas não o conteúdo correlato, o que impossibilitou a análise de sua adequação. Conclui-se que existe a abordagem dos temas relacionados à alimentação e nutrição no material didático, alguns de forma inconsistente, e cabe aos educadores a seleção do conteúdo e da estratégia adequada, além de sua constante atualização, o que está sendo proposto pelo Estado, mas não está ao alcance de todos os profissionais e, portanto, ainda depende da iniciativa de cada docente.
Resumo:
In this Thesis, we investigate the cosmological co-evolution of supermassive black holes (BHs), Active Galactic Nuclei (AGN) and their hosting dark matter (DM) halos and galaxies, within the standard CDM scenario. We analyze both analytic, semi-analytic and hybrid techniques and use the most recent observational data available to constrain the assumptions underlying our models. First, we focus on very simple analytic models where the assembly of BHs is directly related to the merger history of DM haloes. For this purpose, we implement the two original analytic models of Wyithe & Loeb 2002 and Wyithe & Loeb 2003, compare their predictions to the AGN luminosity function and clustering data, and discuss possible modifications to the models that improve the match to the observation. Then we study more sophisticated semi-analytic models in which however the baryonic physics is neglected as well. Finally we improve the hybrid simulation of De Lucia & Blaizot 2007, adding new semi-analytical prescriptions to describe the BH mass accretion rate during each merger event and its conversion into radiation, and compare the derived BH scaling relations, fundamental plane and mass function, and the AGN luminosity function with observations. All our results support the following scenario: • The cosmological co-evolution of BHs, AGN and galaxies can be well described within the CDM model. • At redshifts z & 1, the evolution history of DM halo fully determines the overall properties of the BH and AGN populations. The AGN emission is triggered mainly by DM halo major mergers and, on average, AGN shine at their Eddington luminosity. • At redshifts z . 1, BH growth decouples from halo growth. Galaxy major mergers cannot constitute the only trigger to accretion episodes in this phase. • When a static hot halo has formed around a galaxy, a fraction of the hot gas continuously accretes onto the central BH, causing a low-energy “radio” activity at the galactic centre, which prevents significant gas cooling and thus limiting the mass of the central galaxies and quenching the star formation at late time. • The cold gas fraction accreted by BHs at high redshifts seems to be larger than at low redshifts.
Resumo:
Bread dough and particularly wheat dough, due to its viscoelastic behaviour, is probably the most dynamic and complicated rheological system and its characteristics are very important since they highly affect final products’ textural and sensorial properties. The study of dough rheology has been a very challenging task for many researchers since it can provide numerous information about dough formulation, structure and processing. This explains why dough rheology has been a matter of investigation for several decades. In this research rheological assessment of doughs and breads was performed by using empirical and fundamental methods at both small and large deformation, in order to characterize different types of doughs and final products such as bread. In order to study the structural aspects of food products, image analysis techniques was used for the integration of the information coming from empirical and fundamental rheological measurements. Evaluation of dough properties was carried out by texture profile analysis (TPA), dough stickiness (Chen and Hoseney cell) and uniaxial extensibility determination (Kieffer test) by using a Texture Analyser; small deformation rheological measurements, were performed on a controlled stress–strain rheometer; moreover the structure of different doughs was observed by using the image analysis; while bread characteristics were studied by using texture profile analysis (TPA) and image analysis. The objective of this research was to understand if the different rheological measurements were able to characterize and differentiate the different samples analysed. This in order to investigate the effect of different formulation and processing conditions on dough and final product from a structural point of view. For this aim the following different materials were performed and analysed: - frozen dough realized without yeast; - frozen dough and bread made with frozen dough; - doughs obtained by using different fermentation method; - doughs made by Kamut® flour; - dough and bread realized with the addition of ginger powder; - final products coming from different bakeries. The influence of sub-zero storage time on non-fermented and fermented dough viscoelastic performance and on final product (bread) was evaluated by using small deformation and large deformation methods. In general, the longer the sub-zero storage time the lower the positive viscoelastic attributes. The effect of fermentation time and of different type of fermentation (straight-dough method; sponge-and-dough procedure and poolish method) on rheological properties of doughs were investigated using empirical and fundamental analysis and image analysis was used to integrate this information throughout the evaluation of the dough’s structure. The results of fundamental rheological test showed that the incorporation of sourdough (poolish method) provoked changes that were different from those seen in the others type of fermentation. The affirmative action of some ingredients (extra-virgin olive oil and a liposomic lecithin emulsifier) to improve rheological characteristics of Kamut® dough has been confirmed also when subjected to low temperatures (24 hours and 48 hours at 4°C). Small deformation oscillatory measurements and large deformation mechanical tests performed provided useful information on the rheological properties of samples realized by using different amounts of ginger powder, showing that the sample with the highest amount of ginger powder (6%) had worse rheological characteristics compared to the other samples. Moisture content, specific volume, texture and crumb grain characteristics are the major quality attributes of bread products. The different sample analyzed, “Coppia Ferrarese”, “Pane Comune Romagnolo” and “Filone Terra di San Marino”, showed a decrease of crumb moisture and an increase in hardness over the storage time. Parameters such as cohesiveness and springiness, evaluated by TPA that are indicator of quality of fresh bread, decreased during the storage. By using empirical rheological tests we found several differences among the samples, due to the different ingredients used in formulation and the different process adopted to prepare the sample, but since these products are handmade, the differences could be account as a surplus value. In conclusion small deformation (in fundamental units) and large deformation methods showed a significant role in monitoring the influence of different ingredients used in formulation, different processing and storage conditions on dough viscoelastic performance and on final product. Finally the knowledge of formulation, processing and storage conditions together with the evaluation of structural and rheological characteristics is fundamental for the study of complex matrices like bakery products, where numerous variable can influence their final quality (e.g. raw material, bread-making procedure, time and temperature of the fermentation and baking).
Resumo:
The goal of this thesis is to analyze the possibility of using early-type galaxies to place evolutionary and cosmological constraints, by both disentangling what is the main driver of ETGs evolution between mass and environment, and developing a technique to constrain H(z) and the cosmological parameters studying the ETGs age-redshift relation. The (U-V) rest-frame color distribution is studied as a function of mass and environment for two sample of ETGs up to z=1, extracted from the zCOSMOS survey with a new selection criterion. The color distributions and the slopes of the color-mass and color-environment relations are studied, finding a strong dependence on mass and a minor dependence on environment. The spectral analysis performed on the D4000 and Hδ features gives results validating the previous analysis. The main driver of galaxy evolution is found to be the galaxy mass, the environment playing a subdominant but non negligible role. The age distribution of ETGs is also analyzed as a function of mass, providing strong evidences supporting a downsizing scenario. The possibility of setting cosmological constraints studying the age-redshift relation is studied, discussing the relative degeneracies and model dependencies. A new approach is developed, aiming to minimize the impact of systematics on the “cosmic chronometer” method. Analyzing theoretical models, it is demonstrated that the D4000 is a feature correlated almost linearly with age at fixed metallicity, depending only minorly on the models assumed or on the SFH chosen. The analysis of a SDSS sample of ETGs shows that it is possible to use the differential D4000 evolution of the galaxies to set constraints to cosmological parameters in an almost model-independent way. Values of the Hubble constant and of the dark energy EoS parameter are found, which are not only fully compatible, but also with a comparable error budget with the latest results.
Resumo:
The aim of this study was to investigate cortisol and progesterone (P4) trends in hair from birth up to postweaning in Italian trotter foals. Hair sampling is non-invasive and hair concentrations provide retrospective information of integrated hormone secretion over periods of several months. Samples were collected at birth and at a distance of 30 days, collecting only regrowth hair, up to post weaning. From birth to 3 months, foals cortisol falls from 47.64±5.6 to 4.9±0.68 pg/mg (mean±standard error), due to the interruption of foetal-placental connection and progressive adaptation to extrauterine life. From the third month of life to post weaning concentrations don’t vary significantly, underlining a non-chronic activation of the HPA axis. Hair P4 significantly decreases in the first two samples (from 469.68±72,54 to 184.65±35.42 pg/mg). At 2 (111.78±37.13 pg/mg) and 3 months (35.96±6.33 pg/mg) hair concentrations don’t show significant differences. These concentrations are not due to interactions of the utero-placental tissues with foals, animals are still prepuberal and P4 isn’t produced by adrenals as a result of high stress. We could therefore hypothesize that the source of foal hair P4 could be milk, suckled from mares. The high individual variability in hair at 2 and 3 months is due to a gradual and subjective change in foal diet, from milk to solid food, and to the fact that mares do not allow to suckle. From fourth month to post weaning P4 concentration in hair remains around 37.56±6.45 pg/mg. In conclusion, hair collected at birth, giving information about last period of gestation, could be used along with traditional matrices, to evaluate foals maturity. Hair cortisol could give indications about foals capacity to adapt to extra-uterine life. Finally milk, configuring as a bringer of nutrients and energy and assuming the characteristic of a nutraceutical, could give fundamental information about parental care.
Resumo:
In this Thesis, we study the physical properties and the cosmic evolution of AGN and their host galaxies since z∼3. Our analysis exploits samples of star forming galaxies detected with Herschel at far-IR wavelengths (from 70 up to 500 micron) in different extragalactic surveys, such as COSMOS and the deep GOODS (South and North) fields. The broad-band ancillary data available in COSMOS and the GOODS fields, allows us to implement Herschel and Spitzer photometry with multi-wavelength ancillary data. We perform a multicomponent SED-fitting decomposition to decouple the emission due to star formation from that due to AGN accretion, and to estimate both host-galaxy parameters (such as stellar mass, M* and star formation rate, SFR), and nuclear intrinsic bolometric luminosities. We use the individual estimates of AGN bolometric luminosity obtained through SED-fitting decomposition to reconstruct the redshit evolution of the AGN bolometric luminosity function since z∼3. The resulting trends are used to estimate the overall AGN accretion rate density at different cosmic epochs and to trace the first ever estimate of the AGN accretion history from an IR survey. Later on, we focus our study on the connection between AGN accretion and integrated galaxy properties. We analyse the relationships of AGN accretion with galaxy properties in the SFR-M* plane and at different cosmic epochs. Finally, we infer what is the parameter that best correlates with AGN accretion, comparing our results with previous studies and discussing their physical implications in the context of current scenarios of AGN/galaxy evolution.
Resumo:
The main result in this work is the solution of the Jeans equations for an axisymmetric galaxy model containing a baryonic component (distributed according to a Miyamoto-Nagai profile) and a dark matter halo (described by the Binney logarithmic potential). The velocity dispersion, azimuthal velocity and some other interesting quantities such as the asymmetric drift are studied, along with the influence of the model parameters on these (observable) quantities. We also give an estimate for the velocity of the radial flow, caused by the asymmetric drift. Other than the mathematical beauty that lies in solving a model analytically, the interest of this kind of results can be mainly found in numerical simulations that study the evolution of gas flows. For example, it is important to know how certain parameters such as the shape (oblate, prolate, spherical) of a dark matter halo, or the flattening of the baryonic matter, or the mass ratio between dark and baryonic matter, have an influence on observable quantities such as the velocity dispersion. In the introductory chapter, we discuss the Jeans equations, which provide information about the velocity dispersion of a system. Next we will consider some dynamical quantities that will be useful in the rest of the work, e.g. the asymmetric drift. In Chapter 2 we discuss in some more detail the family of galaxy models we studied. In Chapter 3 we give the solution of the Jeans equations. Chapter 4 describes and illustrates the behaviour of the velocity dispersion, as a function of the several parameters, along with asymptotic expansions. In Chapter 5 we will investigate the behaviour of certain dynamical quantities for this model. We conclude with a discussion in Chapter 6.
Resumo:
Holding the major share of stellar mass in galaxies and being also old and passively evolving, early-type galaxies (ETGs) are the primary probes in investigating these various evolution scenarios, as well as being useful means to provide insights on cosmological parameters. In this thesis work I focused specifically on ETGs and on their capability in constraining galaxy formation and evolution; in particular, the principal aims were to derive some of the ETGs evolutionary parameters, such as age, metallicity and star formation history (SFH) and to study their age-redshift and mass-age relations. In order to infer galaxy physical parameters, I used the public code STARLIGHT: this program provides a best fit to the observed spectrum from a combination of many theoretical models defined in user-made libraries. the comparison between the output and input light-weighted ages shows a good agreement starting from SNRs of ∼ 10, with a bias of ∼ 2.2% and a dispersion 3%. Furthermore, also metallicities and SFHs are well reproduced. In the second part of the thesis I performed an analysis on real data, starting from Sloan Digital Sky Survey (SDSS) spectra. I found that galaxies get older with cosmic time and with increasing mass (for a fixed redshift bin); absolute light-weighted ages, instead, result independent from the fitting parameters or the synthetic models used. Metallicities, instead, are very similar from each other and clearly consistent with the ones derived from the Lick indices. The predicted SFH indicates the presence of a double burst of star formation. Velocity dispersions and extinctiona are also well constrained, following the expected behaviours. As a further step, I also fitted single SDSS spectra (with SNR∼ 20), to verify that stacked spectra gave the same results without introducing any bias: this is an important check, if one wants to apply the method at higher z, where stacked spectra are necessary to increase the SNR. Our upcoming aim is to adopt this approach also on galaxy spectra obtained from higher redshift Surveys, such as BOSS (z ∼ 0.5), zCOSMOS (z 1), K20 (z ∼ 1), GMASS (z ∼ 1.5) and, eventually, Euclid (z 2). Indeed, I am currently carrying on a preliminary study to estabilish the applicability of the method to lower resolution, as well as higher redshift (z 2) spectra, just like the Euclid ones.
Resumo:
The kinematics is a fundamental tool to infer the dynamical structure of galaxies and to understand their formation and evolution. Spectroscopic observations of gas emission lines are often used to derive rotation curves and velocity dispersions. It is however difficult to disentangle these two quantities in low spatial-resolution data because of beam smearing. In this thesis, we present 3D-Barolo, a new software to derive the gas kinematics of disk galaxies from emission-line data-cubes. The code builds tilted-ring models in the 3D observational space and compares them with the actual data-cubes. 3D-Barolo works with data at a wide range of spatial resolutions without being affected by instrumental biases. We use 3D-Barolo to derive rotation curves and velocity dispersions of several galaxies in both the local and the high-redshift Universe. We run our code on HI observations of nearby galaxies and we compare our results with 2D traditional approaches. We show that a 3D approach to the derivation of the gas kinematics has to be preferred to a 2D approach whenever a galaxy is resolved with less than about 20 elements across the disk. We moreover analyze a sample of galaxies at z~1, observed in the H-alpha line with the KMOS/VLT spectrograph. Our 3D modeling reveals that the kinematics of these high-z systems is comparable to that of local disk galaxies, with steeply-rising rotation curves followed by a flat part and H-alpha velocity dispersions of 15-40 km/s over the whole disks. This evidence suggests that disk galaxies were already fully settled about 7-8 billion years ago. In summary, 3D-Barolo is a powerful and robust tool to separate physical and instrumental effects and to derive a reliable kinematics. The analysis of large samples of galaxies at different redshifts with 3D-Barolo will provide new insights on how galaxies assemble and evolve throughout cosmic time.
Resumo:
Reform is a word that, one might easily say, characterizes more than any other the history and development of Buddhism. Yet, it must also be said that reform movements in East Asian Buddhism have often taken on another goal—harmony or unification; that is, a desire not only to reconstruct a more worthy form of Buddhism, but to simultaneously bring together all existing forms under a single banner, in theory if not in practice. This paper explores some of the tensions between the desire for reform and the quest for harmony in modern Japanese Buddhism thought, by comparing two developments: the late 19th century movement towards ‘New Buddhism’ (shin Bukkyō) as exemplified by Murakami Senshō 村上専精 (1851–1929), and the late 20th century movement known as ‘Critical Buddhism’ (hihan Bukkyō), as found in the works of Matsumoto Shirō 松本史朗 and Hakamaya Noriaki 袴谷憲昭. In all that has been written about Critical Buddhism, in both Japanese and English, very little attention has been paid to the place of the movement within the larger traditions of Japanese Buddhist reform. Here I reconsider Critical Buddhism in relation to the concerns of the previous, much larger trends towards Buddhist reform that emerged almost exactly 100 years previous—the so-called shin Bukkyō or New Buddhism of the late-Meiji era. Shin Bukkyō is a catch-all term that includes the various writings and activities of Inoue Enryō, Shaku Sōen, and Kiyozawa Manshi, as well as the so-called Daijō-hibussetsuron, a broad term used (often critically) to describe Buddhist writers who suggested that Mahāyāna Buddhism is not, in fact, the Buddhism taught by the ‘historical’ Buddha Śākyamuni. Of these, I will make a few general remarks about Daijō-hibusseturon, before turning attention more specifically to the work of Murakami Senshō, in order to flesh out some of the similarities and differences between his attempt to construct a ‘unified Buddhism’ and the work of his late-20th century avatars, the Critical Buddhists. Though a number of their aims and ideas overlap, I argue that there remain fundamental differences with respect to the ultimate purposes of Buddhist reform. This issue hinges on the implications of key terms such as ‘unity’ and ‘harmony’ as well as the way doctrinal history is categorized and understood, but it also relates to issues of ideology and the use and abuse of Buddhist doctrines in 20th-century politics.
Resumo:
Results of studying isotopic composition of helium in underground fluids of the Baikal-Mongolian region during the last quarter of XX century are summarized. Determinations of 3He/4He ratio in 139 samples of gas phase from fluids, collected at 104 points of the Baikal rift zone and adjacent structures are given. 3He/4He values lie within the range from 1x10**-8 (typical for crustal radiogenic helium) to 1.1x10**-5 (close to typical MORB reservoir). Repeated sampling in some points during more than 20 years showed stability of helium isotopic composition in time in each of them at any level of 3He/4He values. There is no systematic differences of 3He/4He in samples from surface water sources and deeper intervals of boreholes in the same areas. Universal relationship between isotopic composition of helium and general composition of gas phase is absent either, but the minimum 3He/4He values occurred in methane gas of hydrocarbon deposits, whereas in nitrogen and carbon dioxide gases of helium composition varied (in the latter maximum 3He/4He values have been measured). According to N2/Ar_atm ratio nitrogen gases are atmospheric. In carbonic gas fN2/fNe ratio indicates presence of excessive (non-atmogenic) nitrogen, but the attitude CO2/3He differs from one in MORB. Comparison of helium isotopic composition with its concentration and composition of the main components of gas phase from fluids shows that it is formed under influence of fractionation of components with different solubility in the gas-water system and generation/consumption of reactive gases in the crust. Structural and tectonic elements of the region differ from the spectrum of 3He/4He values. At the pre-Riphean Siberian Platform the mean 3He/4He = (3.6+/-0.9)x10**- 8 is very close to radiogenic one. In the Paleozoic crust of Khangay 3He/4He = (16.3+/-4.6)x10**-8, and the most probable estimate is (12.3+/-2.9)x10**-8. In structures of the eastern flank of the Baikal rift zone (Khentei, Dauria) affected by the Mz-Kz activization 3He/4He values range from 4.4x10**-8 to 2.14x10**-6 (average 0.94x10**-6). Distribution of 3He/4He values across the strike of the Baikal rift zone indicates advective heat transfer from the mantle not only in the rift zone, but also much further to the east. In fluids of the Baikal rift zone range of 3He/4He values is the widest: from 4x10**-8 to 1.1x10**-5. Their variations along the strike of the rift zone are clearly patterned, namely, decrease of 3He/4He values in both directions from the Tunka depression. Accompanied by decrease in density of conductive heat flow and in size of rift basins, this trend indicates decrease in intensity of advective heat transfer from the mantle to peripheral segments of the rift zone. Comparing this trend with data on other continental rift zones and mid-ocean ridges leads to the conclusion about fundamental differences in mechanisms of interaction between the crust and the mantle in these environments.