1,551 research outputs found
INFLUÊNCIA DO DIÂMETRO DE ESTACAS NO DESENVOLVIMENTO DOS BROTOS DE Platanus x acerifolia
O objetivo do presente trabalho foi determinar o diâmetro ideal de estacas para a produção de mudas de Platanus x acerifolia. As estacas utilizadas foram coletadas em árvores cuja a brotação apresentava-se com um ano de idade. Foram comparados três diâmetros de estacas: diâmetros inferiores a 1 cm, diâmetros entre 1 e 2 cm e diâmetros superiores a 2 cm. Todas as estacas possuiam 30 cm de comprimento. Decorridos 90 dias do plantio das estacas, foram medidas as alturas dos brotos, onde na qual o maior desenvolvimento foi observado nas estacas com diâmetro entre 1 e 2 centímetros
Synchrotron radiation photoionization mass spectrometry of laser ablated species
The present paper describes an experimental apparatus suitable to create and study free clusters by combining laser ablation and synchrotron radiation. First tests on sulfur samples, S, showed the production, through laser ablation, of neutral Sn clusters (n = 1–8). These clusters were ionized using synchrotron radiation at photon energies from 160 eV to 175 eV, across the S 2p core edge. The feasibility of such combined ablation–synchrotron radiation experiments is demonstrated, opening new possibilities on the investigation of free clusters and radical
Bribeproof mechanisms for two-values domains
Schummer (Journal of Economic Theory 2000) introduced the concept of
bribeproof mechanism which, in a context where monetary transfer between agents
is possible, requires that manipulations through bribes are ruled out.
Unfortunately, in many domains, the only bribeproof mechanisms are the trivial
ones which return a fixed outcome.
This work presents one of the few constructions of non-trivial bribeproof
mechanisms for these quasi-linear environments. Though the suggested
construction applies to rather restricted domains, the results obtained are
tight: For several natural problems, the method yields the only possible
bribeproof mechanism and no such mechanism is possible on more general domains.Comment: Extended abstract accepted to SAGT 2016. This ArXiv version corrects
typos in the proofs of Theorem 7 and Claims 28-29 of prior ArXiv versio
Psychometric properties of the Caregiver Preparedness Scale in caregivers of stroke survivors
Objective: To evaluate the psychometric characteristics of the Caregiver Preparedness Scale (CPS) in
caregivers of stroke survivors.
Background: Caregiver preparedness can have an important impact on both the caregiver and the stroke
survivor. The validity and reliability of the CPS has not been tested for the stroke-caregiver population.
Methods: We used a cross-sectional design to study a sample of 156 caregivers of stroke survivors.
Construct validity of the CPS was evaluated by confirmatory factor analysis (CFA). Internal consistency
and test-retest reliability were also evaluated.
Results: Caregivers were, on average, 54 year old (SD ¼ 13.2) and most were women (64.7%). CFA supported
the unidimensionality of the scale (comparative fit index ¼ 0.98). Reliability was also supported:
item-reliability index and itemetotal correlations above 0.30; composite reliability index ¼ 0.93;
Cronbach’s alpha ¼ 0.94; factor score determinacy ¼ 0.97; and test-retest reliability ¼ 0.92.
Conclusion: The CPS is valid and reliable in caregivers of stroke survivors. Scores on this scale may assist
health-care providers in identifying caregivers with less preparedness to provide specific interventions
Confirmation of the Luminous Blue Variable status of MWC 930
We present spectroscopic and photometric observations of the emission-line
star MWC 930 (V446 Sct) during its long-term optical brightening in 2006--2013.
Based on our earlier data we suggested that the object has features found in
Luminous Blue Variables (LBV), such as a high luminosity (~3 10^5 Lsun, a low
wind terminal velocity (~ 140 km/s), and a tendency to show strong brightness
variations (~1 mag over 20 years). For the last ~7 years it has been exhibiting
a continuous optical and near-IR brightening along with a change of the
emission-line spectrum appearance and cooling of the star's photosphere. We
present the object's --band light curve, analyze the spectral variations,
and compare the observed properties with those of other recognized Galactic
LBVs, such as AG Car and HR Car. Overall we conclude the MWC 930 is a bona fide
Galactic LBV that is currently in the middle of an S Dor cycle.Comment: 12 pages, 7 figure
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