558 research outputs found
Growth, Inequality and Poverty: Some Empirical Evidence from Minas Gerais State, Brazil
This chapter is motivated by the fact that the Brazilian economy has one of the highest income inequality index in the world. According to Paes de Barros et al(2000), average income of the 10% richest people in Brazil is 28 times higher than the average income of the 40% poorest people. In Argentina, it is 10 times, 13 times in Costa Rica and 5 times in France. Brazilian growth did not benefit all classes and inequality is increasing since the 60´s. While the 10% richest people get 48% of total income, the 10% poorest people get 0,8% of total income. The inequality problem also arises in the Brazilian regional income analysis. Minas Gerais is a rich and dynamic state with 300.000 km2 divided into 10 different regions, 66 microregions and 853 towns. It is located in the Southeast developed part of the country and is responsible for 10% of Brazilian GDP. As the rest of Brazil, it has a dual economy with prosperity and poverty and social and economic heterogeneity. This chapter empirically analyses the economic growth and income inequality behavior in Minas Gerais towns and microregions from 1970 to 2000, using the income convergence hypothesis. Convergence tests such as Barro and Sala-i-Martin(1992), σ- convergence, Drennan & Lobo(1999) and Quah(1993) are performed. The role of human capital in growth is analysed for Minas Gerais 66 microregions. A comparison is also made between very rich regions and very poor regions of this state to see the relationship between regional inequality and poverty.
Searching for Gravitational Waves with a Geostationary Interferometer
We analyze the sensitivities of a geostationary gravitational wave
interferometer mission operating in the sub-Hertz band. Because of its smaller
armlength, in the lower part of its accessible frequency band ( Hz) our proposed Earth-orbiting detector will be less
sensitive, by a factor of about seventy, than the Laser Interferometer Space
Antenna (LISA) mission. In the higher part of its band instead ( Hz), our proposed interferometer will have the capability of
observing super-massive black holes (SMBHs) with masses smaller than M. With good event rates for these systems, a geostationary
interferometer will be able to accurately probe the astrophysical scenarios
that account for their formation.Comment: 33 pages, 9 eps figure
Does hepatocellular carcinoma in non-alcoholic steatohepatitis exist in cirrhotic and non-cirrhotic patients?
Non-alcoholic steatohepatitis (NASH) has been associated with hepatocellular carcinoma (HCC) often arising in histologically advanced disease when steatohepatitis is not active (cryptogenic cirrhosis). Our objective was to characterize patients with HCC and active, histologically defined steatohepatitis. Among 394 patients with HCC detected by ultrasound imaging over 8 years and staged by the Barcelona Clinic Liver Cancer (BCLC) criteria, we identified 7 cases (1.7%) with HCC occurring in the setting of active biopsy-proven NASH. All were negative for other liver diseases such as hepatitis C, hepatitis B, autoimmune hepatitis, Wilson disease, and hemochromatosis. The patients (4 males and 3 females, age 63 ± 13 years) were either overweight (4) or obese (3); 57% were diabetic and 28.5% had dyslipidemia. Cirrhosis was present in 6 of 7 patients, but 1 patient had well-differentiated HCC in the setting of NASH without cirrhosis (fibrosis stage 1) based on repeated liver biopsies, the absence of portal hypertension by clinical and radiographic evaluations and by direct surgical inspection. Among the cirrhotic patients, 71.4% were clinically staged as Child A and 14.2% as Child B. Tumor size ranged from 1.0 to 5.2 cm and 5 of 7 patients were classified as early stage; 46% of all nodules were hyper-echoic and 57% were <3 cm. HCC was well differentiated in 1/6 and moderately differentiated in 5/6. Alpha-fetoprotein was <100 ng/mL in all patients. HCC in patients with active steatohepatitis is often multifocal, may precede clinically advanced disease and occurs without diagnostic levels of alpha-fetoprotein. Importantly, HCC may occur in NASH in the absence of cirrhosis. More aggressive screening of NASH patients may be warranted
Orchid bees: a new assessment on the rarity of diploid males in populations of this group of Neotropical pollinators
International audienceAbstractThe incidence of diploid males among 1457 individuals of different populations of six euglossine bee species (Eufriesea violacea, Eulaema cingulata, Euglossa annectans, Euglossa iopoecila, Euglossa pleosticta and Euglossa truncata) was investigated with microsatellite markers. Bees were surveyed in Atlantic Forest fragments showing different sizes and degrees of human interference. Our analyses revealed that, although the frequencies of diploid males remained below 10 % for five out of six species studied, the frequencies of these males in three populations of Eg. annectans were above 15.0 %. For this species, while the average estimate of diploid males was around 11.0 %, the highest percentage (27 %) of such males was found for the population from an island. Our findings indicate that the frequency of diploid males can vary substantially among species and this fact should be taking into consideration in studies and conservation actions involving different euglossine bees
Epydemiologic study of estereotypies in military horses
Seventy two horses, forty three geldings and twenty nine no pregnant females, from five to seventeen years old were inspectioned. It has been observed the type and regularity of stereotypies, diet and stalls where the equines were stayed. The stereotypies more observed were coprophagy (80%) followed by trough, walls and chains licking (23,6%). Six equines did repetitive vertical head movement (8,3%), three had wood and chain cribbing (4,2%) and two did aerophagy (2,8%). The coprophagy was observed more frequently during the night, at time that the horses didn’t eat forrage (during forteen to sixteen hours) and the stalls weren’t clean. The trough and chains licking ocurred during the day, between meals. According to the findings, the equine stereotypies are variable and were founded many importants predisposed factors.Para estudar a prevalência de estereotipias em eqüinos de cavalaria, foram inspecionados 72 animais, sendo 43 machos castrados e 29 fêmeas não gestantes, com idade entre 5,5 e 17 anos. Foram observados o tipo e a repetibilidade das estereotipias, a dieta e as instalações. As estereotipias mais observadas foram a coprofagia (80%) e a lambedura de cochos, paredes e correntes (23,6%). Seis eqüinos (8,3%) manifestavam movimentos verticais repetitivos de cabeça, três mordiam corrente ou madeira (4,2%) e dois eqüinos realizavam aerofagia (2,8%). A coprofagia foi observada com freqüência maior durante a noite, correspondendo ao intervalo de tempo maior entre as ofertas de volumoso, ou seja, de 14 a 16 horas, e também com os horários em que as fezes não eram recolhidas das baias. A lambedura de cochos e correntes ocorria prevalentemente durante o dia, entre os intervalos das refeições. Entre as condições de manejo e regime alimentar, foram identificados fatores de risco importantes. Concluiu-se que as estereotipias em eqüinos de cavalaria são diversas e freqüentes
Inverse flux quantum periodicity of magnetoresistance oscillations in two-dimensional short-period surface superlattices
Transport properties of the two-dimensional electron gas (2DEG) are
considered in the presence of a perpendicular magnetic field and of a {\it
weak} two-dimensional (2D) periodic potential modulation in the 2DEG plane. The
symmetry of the latter is rectangular or hexagonal. The well-known solution of
the corresponding tight-binding equation shows that each Landau level splits
into several subbands when a rational number of flux quanta pierces the
unit cell and that the corresponding gaps are exponentially small. Assuming the
latter are closed due to disorder gives analytical wave functions and
simplifies considerably the evaluation of the magnetoresistivity tensor
. The relative phase of the oscillations in and
depends on the modulation periods involved. For a 2D modulation
with a {\bf short} period nm, in addition to the Weiss oscillations
the collisional contribution to the conductivity and consequently the tensor
show {\it prominent peaks when one flux quantum passes
through an integral number of unit cells} in good agreement with recent
experiments. For periods nm long used in early experiments, these
peaks occur at fields 10-25 times smaller than those of the Weiss oscillations
and are not resolved
The Casimir force and the quantum theory of lossy optical cavities
We present a new derivation of the Casimir force between two parallel plane
mirrors at zero temperature. The two mirrors and the cavity they enclose are
treated as quantum optical networks. They are in general lossy and
characterized by frequency dependent reflection amplitudes. The additional
fluctuations accompanying losses are deduced from expressions of the optical
theorem. A general proof is given for the theorem relating the spectral density
inside the cavity to the reflection amplitudes seen by the inner fields. This
density determines the vacuum radiation pressure and, therefore, the Casimir
force. The force is obtained as an integral over the real frequencies,
including the contribution of evanescent waves besides that of ordinary waves,
and, then, as an integral over imaginary frequencies. The demonstration relies
only on general properties obeyed by real mirrors which also enforce general
constraints for the variation of the Casimir force.Comment: 18 pages, 6 figures, minor amendment
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