2,083 research outputs found
New X-ray Selected Pre-Main Sequence Members of the Serpens Molecular Cloud
The study of young stars no longer surrounded by disks can greatly add to our
understanding of how protoplanetary disks evolve and planets form. We have used
VLT/FLAMES optical spectroscopy to confirm the youth and membership of 19 new
young diskless stars in the Serpens Molecular Cloud, identified at X-ray
wavelengths. Spectral types, effective temperatures and stellar luminosities
were determined using the optical spectra and optical/near-IR photometry.
Stellar masses and ages were derived based on PMS evolutionary tracks. The
results yield remarkable similarities for age and mass distribution between the
diskless and disk-bearing stellar populations in Serpens. We discuss the
important impli- cations these similarities may have on the standard picture of
disk evolution.Comment: Accepted for publication at the Astronomical Journal. 21 pages, 7
figures and 5 table
The Physical Structure of Protoplanetary Disks: the Serpens Cluster Compared with Other Regions
Spectral energy distributions are presented for 94 young stars surrounded by
disks in the Serpens Molecular Cloud, based on photometry and Spitzer IRS
spectra. Taking a distance to the cloud of 415 pc rather than 259 pc, the
distribution of ages is shifted to lower values, in the 1-3 Myr range, with a
tail up to 10 Myr. The mass distribution spans 0.2-1.2 Msun, with median mass
of 0.7 Msun. The distribution of fractional disk luminosities in Serpens
resembles that of the young Taurus Molecular Cloud, with most disks consistent
with optically thick, passively irradiated disks in a variety of disk
geometries (Ldisk/Lstar ~ 0.1). In contrast, the distributions for the older
Upper Scorpius and Eta Chamaeleontis clusters are dominated by optically thin
lower luminosity disks (Ldisk/Lstar ~ 0.02). This evolution in fractional disk
luminosities is concurrent with that of disk fractions. The actively accreting
and non-accreting stars (based on Ha data) in Serpens show very similar
distributions in fractional disk luminosities, differing only in the brighter
tail dominated by strongly accreting stars. In contrast with a sample of Herbig
Ae/Be stars, the T Tauri stars in Serpens do not have a clear separation in
fractional disk luminosities for different disk geometries: both flared and
flat disks present wider, overlapping distributions. This result is consistent
with previous suggestions of a faster evolution for disks around Herbig Ae/Be
stars. Furthermore, the results for the mineralogy of the dust in the disk
surface do not show any correlation to either stellar and disk characteristics
or mean cluster age in the 1-10 Myr range probed here. A possible explanation
for the lack of correlation is that the processes affecting the dust within
disks have short timescales, happening repeatedly, making it difficult to
distinguish long lasting evolutionary effects. [abridged]Comment: ApJ in pres
Development and validation of a newtest for assessment of plantar-flexor muscle strength in older adults
Background: The Calf-raise (CR) test is often used as a screening tool to assess anklemuscle functioning in clinical practice. Most studies restrict the administration of thistest to the young adult population and, of our knowledge, no study has evaluated thevalidityand reliability of this test with elderly people. Purpose: This study aimed to develop a new field test protocol with a standardizedmeasurement of strength and power in plantar flexor muscles targeted to functionallyindependent older adults, the calf-raise senior (CRS) test, and also evaluate its reliabilityand validity. Patients and methods: Forty-one subjects aged 65 years and older of bothsexesparticipated in five different cross-sectional studies: 1) pilot (n=12); 2) inter and intra-rater agreement (n=12); 3) construct (n=41); 4) criterion validity (n=33); and 5) test–retest reliability (n=41). Different motion parameters were compared in order to defineaspecifically designed protocol for seniors. Two raters evaluated each participant twice, and the results of the same individual were compared between raters and participantstoassess the interrater and intra-rater agreement. The validity and reliability studies involvedthree testing sessions that lasted 2 weeks, including a battery of functional fitness tests, CRS test in two occasions, accelerometry, and strength assessments in an sokineticdynamometer. Results: The CRS test presented an excellent test–retest reliability (intra-class correlationcoefficient [ICC] =0.90, standard error of measurement =2.0) and interrater reliability(ICC=0.93–0.96), as well as a good intra-rater agreement (ICC =0.79–0.84). Participantswithbetter results in the CRS test were younger and presented higher levels of physical activity and functional fitness. A significant association between test results andall strength parameters (isometric, r=0.87, r=0.75; isokinetic, r=0.86, r=0.74; and rateof orcedevelopment, r=0.77, r=0.59) was shown. Conclusion: This study was successful in demonstrating that the CRS test can meet thescientific criteria of validity and reliability. The test can be a good indicator of anklestrength in older adults and proved to discriminate significantly between individualswithimproved functionality and levels of physical activity.Background: The assessment of the plantar-flexors muscle strength in the elderly peopleis of the utmost importance since they are strongly associated o the performanceof fundamental tasks of daily life. Purpose: Our study aims at strengthen the validity of the Calf-Raise Senior (CRS) test byassessing the biomechanical movement pattern of calf muscles in elderly participantswithdifferent functional fitness profiles. Patients and methods: Twenty-six older adults with different levels of functional fitness(FF) and physical activity (PA) participated in this study. CRS test was administered together with a FF battery, accelerometry, strength tests, kinematics and electromyography (EMG). Older adults with the best and worst CRS scores were compared and the associationbetween the scores and EMG pattern of ankle muscles was determined. Results: Older participants with the best CRS scores presented higher levels of FF, PA, strength, power, speed and range of movement, and also a more efficient movement pattern during the test. Subjects who scored more at the CR test demonstratedthepossibly to use a stretch-shortening cycle type of action in the PF muscles to increasepower during the movements. Conclusion: Older adults with different levels of functional fitness can be tratifiedbythemuscular activation pattern of the calf muscles and the scores in CRS test. . This studyreinforced the validity of CRS for evaluating ankle strength and power in elderlyBackground: Mobility significantly depends on the ankle muscles’ strength, whichisparticularly relevant for the performance of daily activities. There are few tools available, with all of the measurement properties tested, to assess ankle strength. Purpose: The purpose of this study was to test the responsiveness of Calf-RaiseSenior Test (CRS) in a sample of elderly participants undergoing a 24 weeks communityexercise program.. Patients and methods: 82 older adults participated in an exercise programandwereassessed with CRS Test and 30-seconds chair stand test (CS) at baseline and at follow- up. Effect size (ES), standardized response mean (SRM) and minimal detectablechange(MDC) measures were calculated for the CRS and CS tests scores. ROC curves analysiswas used to define a cut-off representing the minimally important difference of Calf-RaiseSenior test. Results: Results revealed a small (ES = 0.42) to moderate (SRM = 0.51) responsivenessin plantar-flexion strength and power across time, which was lower than that of CStest (ES = 0.64, SRM = 0.67). The responsiveness of CRS test was more evident in groupsof subjects with lower initial scores. A minimal important difference (MID) of 3.5 repetitionsand a minimal detectable change (MDC) of 4.6 was found for the CRS. Conclusion: Calf-Raise Senior Test is a useful field test to assess elderly ankle function, with moderate responsiveness properties. The cutoff scores of MDC and MIDpresentedin this study can be useful in determining the success of interventions aiming at improvingmobility in senior participants
O processo de planejamento territorial em pequenos municípios e a atuação da Associação de Municípios do Alto Vale do Itajaí em Santa Catarina
In general terms, it is understood that the territory is defined by a set of objects and actions, flows and fixed. So, to think about territorial planning is to accompany/manage the development process of the territories. Based on this premise, the text presents reflections on the performance of the Association of Municipalities of Alto Vale do Itajaí (AMAVI) in promoting Territorial Planning through Terms of Cooperation for the elaboration of Municipal Master Plans in the small municipalities of this region in the interior of Santa Catarina. The theoretical-methodological path used deals with qualitative, exploratory, non-systematic bibliographical research based on analysis of the activities of the aforementioned Association. As a result: i) it was verified the relevance and necessity of AMAVI's performance in conducting the elaboration of the Master Plans of the municipalities that make up the region object of study, in view of its limitations (technical and structural); ii) there was also an indication of improvements in the approach perspectives, for example, with regard to the constitution of multi and interdisciplinary teams; and iii) implementing ideas to increase / encourage social participation in the context.En términos generales, se entiende que el territorio está definido por un conjunto de objetos y acciones, flujos y fijos. Entonces, pensar en la planificación territorial es acompañar/gestionar el proceso de desarrollo de los territorios. A partir de tal premissa, o texto apresenta reflexões sobre a atuação da Associação de Municípios do Alto Vale do Itajaí (AMAVI) na promoção de Planejamento Territorial por meio de Termos de Cooperação à elaboração de Planos Diretores Municipais nos pequenos municípios dessa região do interior de Santa Catarina. La ruta teórico-metodológica utilizada trata de una investigación bibliográfica cualitativa, exploratoria, no sistemática y basada en el análisis del desempeño de la referida Asociación. Como resultado: i) se constató la pertinencia y necesidad de la actuación de AMAVI en la conducción de la elaboración de los Planes Directores de los municipios que integran la región objeto de estudio, dadas sus limitaciones (técnicas y estructurales); ii) también se indicaron mejoras en las perspectivas de abordaje, por ejemplo, en cuanto a la constitución de equipos multi e interdisciplinarios; y iii) implementar ideas para aumentar/fomentar la participación social en el contexto.Em termos gerais, compreende-se que o território é definido por um conjunto de objetos e ações, de fluxos e fixos. Então, pensar em planejamento territorial é acompanhar / gerir o processo de desenvolvimento dos territórios. A partir de tal premissa, o texto apresenta reflexões sobre a atuação da Associação de Municípios do Alto Vale do Itajaí (AMAVI) na promoção de Planejamento Territorial por meio de Termos de Cooperação à elaboração de Planos Diretores Municipais nos pequenos municípios dessa região do interior de Santa Catarina. O percurso teórico-metodológico utilizado versa sobre pesquisa qualitativa, exploratória, bibliográfica não-sistemática e por base de análise da atuação da Associação supracitada. Como resultados: i) constatou-se a relevância e necessidade da atuação da AMAVI na condução da elaboração dos Planos Diretores dos municípios que compõem a região objeto de estudo tendo em vista suas limitações (técnicas e estruturais); ii) evidenciou-se também indicação de melhorias nas perspectivas de abordagem, por exemplo, no que tange à constituição de equipes multi e interdisciplinares; e iii) na implementação de ideias para aumentar / estimular a participação social no contexto.
The twofold debris disk around HD 113766 A - Warm and cold dust as seen with VLTI/Midi and Herschel/Pacs
Warm debris disks are a sub-sample of the large population of debris disks,
and display excess emission in the mid-IR. Around solar-type stars, very few
objects show emission features in mid-IR spectroscopic observations, that are
attributed to small, warm silicate dust grains. The origin of this warm dust
can possibly be explained either by a collision between several bodies or by
transport from an outer belt. We present and analyse new far-IR Herschel/Pacs
observations, supplemented by ground-based data in the mid-IR (VLTI/Midi and
VLT/Visir), for one of these rare systems: the 10-16 Myr old debris disk around
HD 113766 A. We improve an existing model to account for these new
observations, and better constrain the spatial distribution of the dust and its
composition. We underline the limitations of SED modelling and the need for
spatially resolved observations. We find that the system is best described by
an inner disk located within the first AU, well constrained by the Midi data,
and an outer disk located between 9-13 AU. In the inner dust belt, our previous
finding of Fe-rich crystalline olivine grains still holds. We do not observe
time variability of the emission features over at least a 8 years time span, in
a environment subjected to strong radiation pressure. The time stability of the
emission features indicates that {\mu}m-sized dust grains are constantly
replenished from the same reservoir, with a possible depletion of
sub-{\mu}m-sized grains. We suggest that the emission features may arise from
multi-composition aggregates. We discuss possible scenarios concerning the
origin of the warm dust. The compactness of the innermost regions as probed by
Midi, as well as the dust composition, suggest that we are witnessing the
outcomes of (at least) one collision between partially differentiated bodies,
in an environment possibly rendered unstable by terrestrial planetary
formation
Industrialização de Joinville (SC) : da genese as exportações
Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciencias HumanasEstudo da gênese, evolução e dinâmica atual das indústrias de Joinville, utilizando o referencial explicativo do economista Ignácio Rangel e o geógrafo Armen Mamigonian. O processo de industrialização de Joinville iniciou com uma fase artesanal e a implantação das primeiras indústrias ocorreu a partir de 1880. Quando no Brasil completava-se a substituição das importações de produtos têxteis (década de 30) em Joinville já existiam, precocemente, diversos estabelecimentos do setor metal-mecânico. A Segunda Guerra Mundial e a política urbana industrial dos governos dos anos 50 e 60 propiciaram a entrada da produção industrial joinvilense no mercado nacional, além da fundação de outras empresas pioneiras. As crises econômicas brasileiras, nos anos 70 e 80 e a competitividade alcançada pelas indústrias de Joinville desencadearam a ida ao mercado externo. A participação das exportações das indústrias de Joinville, no conjunto catarinense, é crescente e empresas como Embraco, Consul, Tupy, Döhler, Metalúrgia Wetzel, Nielson e Incasa respondem por aproximadamente 15% do total das vendas externas do Estado. A produção destina-se a diversos países do mundo, onde concorrem com poderosas empresas do centro do sistema e a competitividade é alcançada pela constante inovação na administração e produção industrial
A linguagem dos quadrinhos: estudos de estética, linguística e semiótica
O livro A linguagem dos quadrinhos: estudos de estética, linguística e semiótica organizado por Waldomiro Vergueiro e Roberto Elísio dos Santos, publicado em 2015 pela editora Criativo reúne trabalhos sobre a linguagem dos quadrinhos. A obra traz no seu cerne discussões em torno de uma das referências teóricas em quadrinhos e semiótica no Brasil: Antonio Luiz Cagnin
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