514 research outputs found
Time-Series BVI Photometry for the Globular Cluster NGC 6981 (M72)
We present new BVI photometry of the globular cluster NGC 6981 (M72), based
mostly on ground-based CCD archive images. We present a new color-magnitude
diagram (CMD) that reaches almost four magnitudes below the turn-off level. We
performed new derivations of metallicity and morphological parameters of the
evolved sequences, in good agreement with previous authors, obtaining a value
of [Fe/H] ~ -1.50 in the new UVES scale. We also identify the cluster's blue
straggler population. Comparing the radial distribution of these stars with the
red giant branch population, we find that the blue stragglers are more
centrally concentrated, as found in previous studies of blue stragglers in
globular clusters. Taking advantage of the large field of view covered by our
study, we analyzed the surface density profile of the cluster, finding
extratidal main sequence stars out to r ~ 14.1 arcmin or about twice the tidal
radius. We speculate that this may be due to tidal disruption in the course of
M72's orbit, in which case tidal tails associated with the cluster may exist.
We also take a fresh look at the variable stars in the cluster, recovering all
previous known variables, including three SX Phoenicis stars, and adding three
previously unknown RR Lyrae (1 c-type and 2 ab-type) to the total census.
Finally, comparing our CMD with unpublished data for M3 (NGC 5272), a cluster
with similar metallicity and horizontal branch morphology, we found that both
objects are essentially coeval.Comment: Accepted for publication in A
Ventilatory function in young adults and dietary antioxidant intake
Artículo de publicación ISIDietary antioxidants may protect against poor ventilatory function. We assessed the relation between ventilatory function and antioxidant components of diet in young Chileans. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and the ratio FEV1/FVC were measured in 1232 adults aged 22-28 years, using a Vitalograph device. Dietary intake was ascertained with a food frequency questionnaire (FFQ) designed for this study, from which nutrient and flavonoid intakes were estimated. Dietary patterns were derived with Principal Component Analysis (PCA). After controlling for potential confounders, dietary intake of total catechins was positively associated with FVC (Regression coefficient (RC) of highest vs. lowest quintile of intake 0.07; 95% CI 0.01 to 0.15; p per trend 0.006). Total fruit intake was related to FVC (RC of highest vs. lowest quintile 0.08; 95% CI 0.003 to 0.15; p per trend 0.02). Intake of omega 3 fatty acids was associated with a higher FEV1 (RC for highest vs. lowest quintile 0.08; 95% CI 0.01 to 0.15 L; p per trend 0.02) and with FVC 0.08 (RC in highest vs. lowest quintile of intake 0.08, 95% CI 0.001 to 0.16; p per trend 0.04). Our results show that fresh fruits, flavonoids, and omega 3 fatty acids may contribute to maintain ventilatory function.Wellcome Trust 059448Z
NGC 5694: another foster son of the Galactic Halo
We present the results of the analysis of high-resolution spectra obtained
with UVES-FLAMES@VLT for six red giant branch stars in the outer-halo
metal-poor ([Fe/H]I=-1.98 and [Fe/H]II=-1.83) Galactic globular cluster NGC
5694, which has been suggested as a possible incomer by Lee et al. (2006) based
on the anomalous chemical composition of a single cluster giant. We obtain
accurate abundances for a large number of elements and we find that: (a) the
six target stars have the same chemical composition within the uncertainties,
except for Na and Al; (b) the average cluster abundance of \alpha\ elements
(with the only exception of Si) is nearly solar, at odds with typical halo
stars and globular clusters of similar metallicity; (c) Y, Ba, La and Eu
abundances are also significantly lower than in Galactic field stars and star
clusters of similar metallicity. Hence we confirm the Lee et al. classification
of NGC 5694 as a cluster of extra-galactic origin. We provide the first insight
on the Na-O and Mg-Al anti-correlations in this cluster: all the considered
stars have very similar abundance ratios for these elements, except one that
has significantly lower [Na/Fe] and [Al/Fe] ratios, suggesting that some degree
of early self-enrichment has occurred also in this cluster.Comment: Accepted for publication by MNRAS. 15 pages, 8 figures, 4 table
Kinematics of a globular cluster with an extended profile: NGC5694
We present a study of the kinematics of the remote globular cluster NGC5694
based on GIRAFFE@VLT medium resolution spectra. A sample of 165 individual
stars selected to lie on the Red Giant Branch in the cluster Color Magnitude
Diagram was considered. Using radial velocity and metallicity from Calcium
triplet, we were able to select 83 bona-fide cluster members. The addition of
six previously known members leads to a total sample of 89 cluster giants with
typical uncertainties <1.0 km/s in their radial velocity estimates. The sample
covers a wide range of projected distances from the cluster center, from ~0.2
arcmin to 6.5 arcmin = 23 half-light radii (r_h). We find only very weak
rotation, as typical of metal-poor globular clusters. The velocity dispersion
gently declines from a central value of sigma=6.1 km/s to sigma = 2.5 km/s at
~2 arcmin = 7.1= r_h, then it remainins flat out to the next (and last)
measured point of the dispersion profile, at ~4 arcmin = 14.0 r_h, at odds with
the predictions of isotropic King models. We show that both isotropic
single-mass non-collisional models and multi-mass anisotropic models can
reproduce the observed surface brightness and velocity dispersion profiles.Comment: Accepted for publication by MNRAS. Pdflatex, 10 pages, 10 figure
Data reduction by randomization subsampling for the study of large hyperspectral datasets
Large amount of information in hyperspectral images (HSI) generally makes their analysis (e.g., principal component analysis, PCA) time consuming and often requires a lot of random access memory (RAM) and high computing power. This is particularly problematic for analysis of large images, containing millions of pixels, which can be created by augmenting series of single images (e.g., in time series analysis). This tutorial explores how data reduction can be used to analyze time series hyperspectral images much faster without losing crucial analytical information. Two of the most common data reduction methods have been chosen from the recent research. The first one uses a simple randomization method called randomized sub-sampling PCA (RSPCA). The second implies a more robust randomization method based on local-rank approximations (rPCA). This manuscript exposes the major benefits and drawbacks of both methods with the spirit of being as didactical as possible for a reader. A comprehensive comparison is made considering the amount of information retained by the PCA models at different compression degrees and the performance time. Extrapolation is also made to the case where the effect of time and any other factor are to be studied simultaneously.J.P Cruz-Tirado acknowledges scholarship funding from FAPESP, grant number 2020/09198–1
Sobre el aislamiento de la población de Cheilanthes guanchica C. Bolle (Sinopteridaceae, Monilophyta) en Galicia
El pequeño helecho Cheilanthes guanchica, relativamente común en Andalucía e Islas Canarias fue descubierto
hace menos de 3 décadas en una pequeña población al sur de la provincia de Lugo, población que mostraba un
llamativo alejamiento con respecto al resto de las conocidas en la Península Ibérica. Aunque recientemente se
ha publicado un mapa de distribución que mostraba una presencia más numerosa de este helecho en localidades
de Castilla-León, e incluso otra localidad en Galicia, estudiando detenidamente las citas que respaldaban esas
presencias y su posible justificación con pliegos depositados en Herbarios, concluimos que ha habido numerosos
casos de confusión con otras especies, bien con Ch. maderensis, bien con Ch. acrostica. La localidad de donde
estimamos que procede la cita fiable más próxima a la gallega se sitúa a más de 420 km del sur de Lugo. La
población gallega de Ch. guanchica ocupa una superficie inferior a 1 km2 y muestra una competencia por su
mismo hábitat con Ch. tinaei, resultado de lo cual es la presencia del híbrido entre ambos Ch. ×insularis. Concluimos
que Ch. guanchica es una especie amenazada en Galicia por pequeño tamaño poblacional, aislamiento
geográfico e hibridación con Ch. tinaei
Changes in symptoms of asthma and rhinitis by sensitization status over ten years in a cohort of young Chilean adults
BACKGROUND:
We investigated the net changes in prevalence of symptoms of asthma and rhinitis over 10 years in a cohort of young by baseline sensitization status.
METHODS:
One thousand one hundred ninety three Chilean adults subjects aged 22-28 living in a semi-rural area of central Chile answered a lifestyle and the European Community Respiratory Health Survey (ECRHS) questionnaires. Bronchial hyper-responsiveness (BHR) and skin prick test (SPT) to eight allergens were measured at baseline in 2001. Ten years later, 772 participants completed the questionnaires again. Estimates of adjusted net changes in prevalence of symptoms by sensitization status at baseline and association between sensitization status at baseline and respiratory symptoms ten years later were assessed.
RESULTS:
A quarter of the participants were sensitized to at least one allergen in 2001. Prevalence of wheeze had a net change per year of -0.37 % (95 % Confidence Interval -0.71 to 0.02 %; p = 0.067). Self-reported nasal allergies in the last 12 months increased by 0.83 % per year (95 % CI 0.49 to 1.17 %; p < 0.001). Those sensitized to either cat fur (OR 1.76; CI 1.01 to 3.05), cockroach, (OR 2.09; 1.13 to 3.86) blend of grass and pollens (1.78; 95 % CI 1.08 to 2.92), or weeds (OR 1.77; 95 % CI 1.01 to 3.12) in 2001 were more likely to have wheeze in the last 12 months 10 years later.
CONCLUSION:
Symptoms of asthma remained stable or slightly changed over 10 years in adults, whilst rhinitis and nasal allergies greatly increased. Being sensitized to at least one allergen is a risk factor for persistent symptoms of asthma and rhinitis, but not for determining net changes of symptoms over time. The underlying causes for the contrasting trends between asthma and nasal allergy are unknow
Strategi Pengembangan Perkebunan Bunga Di Kenangan Baru, Kec. Percut Sei Tuan, Kabupaten Deli Serdang, Sumatera Utara
Indonesia has great potential in horticulture, including floriculture, because it is one of the world's centers of biodiversity. The purpose of this research is to study the marketing strategies used by the Ibal Flower Flower Shop in Medan, North Sumatra, to sell their decorative flower products. This research uses a qualitative descriptive approach and collects data through direct observation, interviews and literature study. As a result of this research, Ibal Flower Flower Shop has succeeded in building a business that focuses on high quality products and services. However, to face increasing competition, these businesses must step up their digital marketing campaigns through e-commerce and social media platforms, hold promotional events, and collaborate with plant-loving communities. Supplier diversification, improving packaging quality, optimizing pricing, and effective inventory management are some of the suggestions for product development. Ibal Flower Flower Shop is expected to increase sales and maintain its sustainability in a dynamic market by using creative and effective marketing strategies.
 
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