3,842 research outputs found
Relationship between top executive compensation and corporate governance: evidence from large Italian listed companies
The modernization of corporate governance aims the alignment of the interests of managers with those of companies, promoting a new discipline of internal controls and risk analysis with an enforcement of shareholder rights of information. This research investigates the impact of corporate governance variables –ownership, board of directors and remuneration committee– on executive compensation. A balanced sample of 52 Italian listed companies has been adopted to test the hypotheses, covering 55.98% and 47.13% of market capitalization in 2011 and 2015 respectively and including 669 board members. Theoretical models evidence a certain stability of compensation schemes for Italian managers over time. Findings suggest that there is a statistically significant positive effect of familiar ownership on the amount of compensation. Along with nature of ownership, the number of directors in the remuneration committee appointed by minorities assume a determinant role. With statistical significance, it affects negatively the compensation level, but, contrarily to best practices, it affects negatively the adoption of forms of incentive compensation.info:eu-repo/semantics/acceptedVersio
A new analysis of the GJ581 extrasolar planetary system
We have done a new analysis of the available observations for the GJ581
exoplanetary system. Today this system is controversial due to choices that can
be done in the orbital determination. The main ones are the ocurrence of
aliases and the additional bodies - the planets f and g - announced in Vogt et
al. 2010. Any dynamical study of exoplanets requires the good knowledge of the
orbital elements and the investigations involving the planet g are particularly
interesting, since this body would lie in the Habitable Zone (HZ) of the star
GJ581. This region,for this system, is very attractive of the dynamical point
of view due to several resonances of two and three bodies present there. In
this work, we investigate the conditions under which the planet g may exist. We
stress the fact that the planet g is intimately related with the orbital
elements of the planet d; more precisely, we conclude that it is not possible
to disconnect its existence from the determination of the eccentricity of the
planet d. Concerning the planet f, we have found one solution with period
days, but we are judicious about any affirmation concernig this
body because its signal is in the threshold of detection and the high period is
in a spectral region where the ocorruence of aliases is very common. Besides,
we outline some dynamical features of the habitable zone with the dynamical map
and point out the role played by some resonances laying there.Comment: 12 pages, 9 figure
Risks of Maternal Obesity in Pregnancy: A Case-control Study in a Portuguese Obstetrical Population
Objective The present study aims to understand to what extent obesity is related to adverse maternal, obstetrical, and neonatal outcomes in a Portuguese obstetrical population. Methods A retrospective case-control study was conducted at the Department of Obstetrics of a differentiated perinatal care facility. The study compared 1,183 obese pregnant women with 5,399 normal or underweight pregnant women for the occurrence of gestational diabetes, hypertensive pregnancy disorders, and preterm birth. Mode of delivery, birthweight, and neonatal intensive care unit (ICU) admissions were also evaluated. Mean blood glucose values were evaluated and compared between groups, in the first and second trimesters of pregnancy. Only singleton pregnancies were considered. Results The prevalence of obesity was 13.6%. Obese pregnant women were significantly more likely to have cesarean sections (adjusted odds ratio [aOR] 2.0, p < 0.001), gestational diabetes (aOR 2.14, p < 0.001), hypertensive pregnancy disorders (aOR 3.43, p < 0.001), and large-for-gestational age or macrosomic infants (aOR 2.13, p < 0.001), and less likely to have small-for-gestational age newborns (aOR 0.51, p < 0.009). No significant differences were found in terms of preterm births, fetal/neonatal deaths, low birthweight newborns, and neonatal ICU admissions among cases and controls. Maternal obesity was significantly associated with higher mean blood glucose levels, in the first and second trimesters of pregnancy. Conclusion Obesity is associated with increased risks of adverse pregnancy and neonatal outcomes. These risks seem to increase progressively with increasing body mass index (BMI) class. Female obesity should be considered a major public health issue and has consequences on maternal-fetal health
Dynamics of Enceladus and Dione inside the 2:1 Mean-Motion Resonance under Tidal Dissipation
In a previous work (Callegari and Yokoyama 2007, Celest. Mech. Dyn. Astr.
vol. 98), the main features of the motion of the pair Enceladus-Dione were
analyzed in the frozen regime, i.e., without considering the tidal evolution.
Here, the results of a great deal of numerical simulations of a pair of
satellites similar to Enceladus and Dione crossing the 2:1 mean-motion
resonance are shown. The resonance crossing is modeled with a linear tidal
theory, considering a two-degrees-of-freedom model written in the framework of
the general three-body planar problem. The main regimes of motion of the system
during the passage through resonance are studied in detail. We discuss our
results comparing them with classical scenarios of tidal evolution of the
system. We show new scenarios of evolution of the Enceladus-Dione system
through resonance not shown in previous approaches of the problem.Comment: 36 pages, 12 figures. Accepted in Celestial Mechanics and Dynamical
Astronom
Doped carrier formulation of the t-J model: the projection constraint and the effective Kondo-Heisenberg lattice representation
We show that the recently proposed doped carrier Hamiltonian formulation of
the t-J model should be complemented with the constraint that projects out the
unphysical states. With this new important ingredient, the previously used and
seemingly different spin-fermion representations of the t-J model are shown to
be gauge related to each other. This new constraint can be treated in a
controlled way close to half-filling suggesting that the doped carrier
representation provides an appropriate theoretical framework to address the t-J
model in this region. This constraint also suggests that the t-J model can be
mapped onto a Kondo-Heisenberg lattice model. Such a mapping highlights
important physical similarities between the quasi two-dimensional heavy
fermions and the high-T superconductors. Finally we discuss the physical
implications of our model representation relating in particular the small
versus large Fermi surface crossover to the closure of the lattice spin gap.Comment: corrected and enlarged versio
Coffee crop coefficient prediction as a function of biophysical variables identified from RGB UAS images
Because of different Brazilian climatic conditions and the different plant conditions,
such as the stage of development and even the variety, wide variation may exist in the crop
coefficients () values, both spatially and temporally. Thus, the objective of this study was to
develop a methodology to determine the short-term using biophysical parameters of coffee
plants detected images obtained by an Unmanned Aircraft System (UAS). The study was
conducted in Travessia variety coffee plantation. A UAS equipped with a digital camera was
used. The images were collected in the field and were processed in Agisoft PhotoScan software.
The data extracted from the images were used to calculate the biophysical parameters: leaf area
index (LAI), leaf area (LA) and . GeoDA software was used for mapping and spatial analysis.
The pseudo-significance test was applied with p < 0.05 to validate the statistic. Moran's index (I)
for June was 0.228 and for May was 0.286. Estimates of values in June varied between 0.963
and 1.005. In May, the values were 1.05 for 32 blocks. With this study, a methodology was
developed that enables the estimation of using remotely generated biophysical crop data
RGB vegetation indices applied to grass monitoring: a qualitative analysis
ArticleIn developing countries such as Brazil, research on low-cost remote sensing and
computational techniques become essential for the development of precision agriculture (PA),
and improving the quality of the agricultural products. Faced with the scenario of increasing
production of emerald grass (Zoysia Japônica) in Brazil, and the value added the quality of this
agricultural product. The objective of this work was to evaluate the performance of RGB (IV)
vegetation indices in the identification of exposed soil and vegetation. The study was developed
in an irrigated area of 58 ha cultivated with emerald grass at Bom Sucesso, Minas Gerais, Brazil.
The images were obtained by a RGB digital camera coupled to an remotely piloted aircraft. The
flight plan was setup to take overlapping images of 70% and the aircraft speed was 10 m s
-1
. Six
RGB Vegetation index (MGVRI, GLI, RGBVI, MPRI, VEG, ExG) were evaluated in a mosaic
resulting from the images of the study area. All of the VIs evaluated were affected by the
variability of lighting conditions in the area but MPRI and MGVRI were the ones that presented
the best results in a qualitative evaluation regarding the discrimination of vegetation and soil
Capybara (Hydrochoerus hydrochaeris) distribution in agroecosystems: a cross-scale habitat analysis.
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Previous issue date: 2007-01-0
Seleção de cultivares de alfafa em condições tropicais.
A produção de leite bovino pode ter seus custos reduzidos por meio do pastejo intensivo sob condições irrigadas, se forem utilizadas para isso forrageiras de alto potencial de produção, alto valor nutritivo e baixa estacionalidade. Uma boa opção de forrageira seria a alfafa sob pastejo, pois reduz o uso de fertilizantes nitrogenados e custo de Alimentação. No Brasil, os aspectos agronômicos dos cultivares dessa espécie ainda não são muito conhecidos para isso, o experimento teve como objetivo avaliar a resposta de 20 cultivares de alfafa sob pastejo em lotação rotacionada, durante 12 meses. Os parâmetros avaliados foram: produção de MS, estacionalidade, florescimento, relação folha: haste e sobrevivência. O delineamento experimental foi o de blocos completos casualizados. As cultivares Crioula Itapuã e Crioula RS foram consideradas materiais promissores para pastejo já que seus resultados para produção de matéria seca, número final de hastes e florescimento foram bastante satisfatórios, apesar de terem apresentado baixa relação folha:haste
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