6,055 research outputs found
NIR spectroscopy of the Sun and HD20010 - Compiling a new linelist in the NIR
Context: Effective temperature, surface gravity, and metallicity are basic
spectroscopic stellar parameters necessary to characterize a star or a
planetary system. Reliable atmospheric parameters for FGK stars have been
obtained mostly from methods that relay on high resolution and high
signal-to-noise optical spectroscopy. The advent of a new generation of high
resolution near-IR spectrographs opens the possibility of using classic
spectroscopic methods with high resolution and high signal-to-noise in the NIR
spectral window. Aims: We aim to compile a new iron line list in the NIR from a
solar spectrum to derive precise stellar atmospheric parameters, comparable to
the ones already obtained from high resolution optical spectra. The spectral
range covers 10 000 {\AA} to 25 000 {\AA}, which is equivalent to the Y, J, H,
and K bands. Methods: Our spectroscopic analysis is based on the iron
excitation and ionization balance done in LTE. We use a high resolution and
high signal-to-noise ratio spectrum of the Sun from the Kitt Peak telescope as
a starting point to compile the iron line list. The oscillator strengths (log
gf) of the iron lines were calibrated for the Sun. The abundance analysis was
done using the MOOG code after measuring equivalent widths of 357 solar iron
lines. Results: We successfully derived stellar atmospheric parameters for the
Sun. Furthermore, we analysed HD20010, a F8IV star, from which we derived
stellar atmospheric parameters using the same line list as for the Sun. The
spectrum was obtained from the CRIRES- POP database. The results are compatible
with the ones found in the literature, confirming the reliability of our line
list. However, due to the quality of the data we obtain large errors.Comment: 9 pages and 9 figure
Maternal Diet and Breastfeeding. Influence of Myths and Preconceptions
Introdução. Durante a gravidez e amamentação, algumasmães alteram a sua dieta com o propósito de aumentar a quantidade
e/ou qualidade do seu leite.
Objectivos. Caracterizar as alterações dietéticas maternas durante a gravidez e amamentação, identificar factores associados
a essas alterações e a sua relação com a manutenção do aleitamento materno aos três meses de vida.
Metodologia. Estudo observacional, descritivo, transversal bifásico de uma amostra de 122 díades mãe-filho, realizado
num hospital de apoio perinatal diferenciado. Primeira fase:
auto-preenchimento de um inquérito nas 48h após o parto, avaliando variáveis sócio-demográficas, história prévia de
amamentação, conhecimentos e atitudes face à amamentação e a dieta materna. Segunda fase: inquérito telefónico três meses após o parto, avaliando a duração da amamentação,
alterações dietéticas realizadas e eventuais associações a sintomas no lactente.
Resultados. A idade materna média foi 30 anos; 43% frequentou o ensino superior; 81% referiu ter alterado a dieta durante a gravidez. Noventa e nove por cento pretendia amamentar e 98% planeava alterar a dieta durante a amamentação: café, chocolate, refrigerantes com cafeína, enchidos,
conservas e feijão seriam os alimentos a evitar/eliminar. Aos três meses, 67% das díades mantinha o aleitamento materno;
89% das mães alterou a sua dieta neste período, com um padrão de alimentos evitados/eliminados semelhante ao referido
na primeira fase; em 39% dos casos foi associada sintomatologia do lactente, sobretudo cólicas, a alimentos da dieta
materna. Não foi encontrada associação entre o número de alimentos evitados/eliminados durante a gravidez/amamentação e a manutenção da amamentação aos três meses de vida.
Conclusões. Este estudo evidencia as restrições dietéticas efectuadas pelas mães durante a gravidez e amamentação. A
limitação da dieta materna na gravidez e amamentação reduz a experiência de sabores a que é exposto o feto e o lactentecom potencial prejuízo na diversificação alimentar. É necessário implementar medidas de ensino dietético para superar
preconceitos
Past and future blurring at fundamental length scale
We obtain the -deformed versions of the retarded and advanced Green
functions and show that their causality properties are blurred in a time
interval of the order of a length parameter . The functions also
indicate a smearing of the light cone. These results favor the interpretation
of as a fundamental length scale below which the concept of a point in
spacetime should be substituted by the concept of a fuzzy region of radius ,
as proposed long ago by Heisenberg.Comment: Essentially, this is the version published in the Phys. Rev. Lett.
105, 211601 (2010). It has 4 pages and contains 2 figure
Struggling and juggling: a comparison of assessment loads in research and teaching-intensive universities
In spite of the rising tide of metrics in UK higher education, there has been scant attention paid to assessment loads, when evidence demonstrates that heavy demands lead to surface learning. Our study seeks to redress the situation by defining assessment loads and comparing them across research-and teaching intensive universities. We clarify the concept of ‘assessment load’ in response to findings about high volumes of summative assessment on modular degrees. We define assessment load across whole undergraduate degrees, according to four measures: the volume of summative assessment; volume of formative assessment; proportion of examinations to coursework; number of different varieties of assessment. All four factors contribute to the weight of an assessment load, and influence students’ approaches to learning. Our research compares programme assessment data from 73 programmes in 14 UK universities, across two institutional categories. Research-intensives have higher summative assessment loads and a greater proportion of examinations; teaching-intensives have higher varieties of assessment. Formative assessment does not differ significantly across both university groups. These findings pose particular challenges for students in different parts of the sector. Our study questions the wisdom that ‘more’ is always better, proposing that lighter assessment loads may make room for ‘slow’ and deep learning
Corporate social responsibility, job satisfaction, and customer orientation in Angola
This study sought to examine the effect of corporate social responsibility (CSR) on employees' costumer orientation through the mediating role of job satisfaction for a sample of tourism and hospitality employees in Angola. Data were collected from 125 respondents using anonymously completed structured questionnaires. Perceived CSR was assessed by the scale developed by Martínez et al. (2013), which includes social, economic and environmental issues. Job satisfaction was measured using Lima et al.'s (1994) job-facet scale, while customer orientation was evaluated using a reduced version of Saxe and Weitz's (1982) customer-orientation scale. The three dimensions of CSR in question have dissimilar levels of association with customer orientation. Only perceptions of company engagement in social CSR practices explain employees' customer orientation, and the relationship is partially mediated by job satisfaction. Additional studies with larger samples and longitudinal designs are needed to determine further the influence of CSR on employees' job satisfaction and customer orientation.info:eu-repo/semantics/acceptedVersio
Competição de capim-arroz (Echinochloa crusgalli) em arroz irrigado: épocas de controle e prejuízos à cultivar BRS Querência.
bitstream/item/30397/1/boletim-63.pd
Interference and complementarity for two-photon hybrid entangled states
In this work we generate two-photon hybrid entangled states (HES), where the
polarization of one photon is entangled with the transverse spatial degree of
freedom of the second photon. The photon pair is created by parametric
down-conversion in a polarization-entangled state. A birefringent double-slit
couples the polarization and spatial degrees of freedom of these photons and
finally, suitable spatial and polarization projections generate the HES. We
investigate some interesting aspects of the two-photon hybrid interference, and
present this study in the context of the complementarity relation that exists
between the visibilities of the one- and two-photon interference patterns.Comment: 10 pages, 4 figures. Accepted in Physical Review
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