Norepinephrine stimulates progesterone production in highly estrogenic bovine granulosa cells cultured under serum-free, chemically defined conditions

Background: Since noradrenergic innervation was described in the ovarian follicle, the actions of the intraovarian catecholaminergic system have been the focus of a variety of studies. We aimed to determine the gonadotropin-independent effects of the catecholamine norepinephrine (NE) in the steroid hormone profile of a serum-free granulosa cell (GC) culture system in the context of follicular development and dominance. Methods: Primary bovine GCs were cultivated in a serum-free, chemically defined culture system supplemented with 0.1% polyvinyl alcohol. The culture features were assessed by hormone measurements and ultrastructural characteristics of GCs. Results: GCs produced increasing amounts of estradiol and pregnenolone for 144h and maintained ultrastructural features of healthy steroidogenic cells. Progesterone production was also detected, although it significantly increased only after 96h of culture. There was a highly significant positive correlation between estradiol and pregnenolone production in high E2-producing cultures. The effects of NE were further evaluated in a dose response study. The highest tested concentration of NE (10 (-7) M) resulted in a significant increase in progesterone production, but not in estradiol or pregnenolone production. The specificity of NE effects on progesterone productio n was further investigated by incubating GCs with propranolol (10 (-8) M), a non-selective beta-adrenergic antagonist. Conclusions: The present culture system represents a robust model to study the impact of intrafollicular factors, such as catecholamines, in ovarian steroidogenesis and follicular development. The results of noradrenergic effects in the steroidogenesis of GC have implications on physiological follicular fate and on certain pathological ovarian conditions such as cyst formation and anovulation.

Atuação missionária jesuítica na América portuguesa: a peculiar via renascentista, sacramental e tridentina à salvação no(s) Novo(s) Mundo(s)

A Companhia de Jesus foi o emblema mais representativo da transformação e realização da nova prática da catequese na sua atuação missionária,durante a primeira Idade Moderna. A transformação vinha ocorrendo a partir da contraposição entre Reforma e Contrarreforma, no estabelecimento de analogias e diferenças da missão entre Europa, América e Ásia, e, finalmente, na esteira dos ecos das decisões conciliares de Trento em Lima. A partir dos tópicos que dividem o texto, o presente trabalho percorre - em uma síntese inevitavelmente esquemática, mas aberta à perspectiva de recentes investigações sobre o tema - essas problemáticas. Pensamos assim que elas possam ganhar clareza e coerência expositiva, mas, sobretudo, uma capacidade de inteligibilidade dos temas propostos, tendo em vista um resultado que não seja apenas uma aquisição (sempre parcial), mas, sobretudo, um novo ponto de partida para ulteriores investigações sobre as diretrizes apontadas.

Magnetic color-flavor-locked stars

Using the solutions of the gap equations of the magnetic-color-flavor-locked (MCFL) phase of paired quark matter in a magnetic field, and taking into consideration the separation between the longitudinal and transverse pressures due to the field-induced breaking of the spatial rotational symmetry, the equation of state (EoS) of the MCFL phase is self-consistently determined. Implications for stellar models of magnetized (self-bound) strange stars and hybrid (MCFL core) stars are discussed.

Chemically Resolved Particle Fluxes Over Tropical and Temperate Forests

Chemically resolved submicron (PM1) particlemass fluxes were measured by eddy covariance with a high resolution time-of-flight aerosolmass spectrometer over temperate and tropical forests during the BEARPEX-07 and AMAZE-08 campaigns. Fluxes during AMAZE-08 were small and close to the detection limit (<1 ng m−2 s−1) due to low particle mass concentrations (<1 μg m−3). During BEARPEX-07, concentrations were five times larger, with mean mid-day deposition fluxes of −4.8 ng m−2 s−1 for total nonrefractory PM1 (Vex,PM1 = −1 mm s−1) and emission fluxes of +2.6 ng m−2 s−1 for organic PM1 (Vex,org = +1 mm s−1). Biosphere–atmosphere fluxes of different chemical components are affected by in-canopy chemistry, vertical gradients in gas-particle partitioning due to canopy temperature gradients, emission of primary biological aerosol particles, and wet and dry deposition. As a result of these competing processes, individual chemical components had fluxes of varying magnitude and direction during both campaigns. Oxygenated organic components representing regionally aged aerosol deposited, while components of fresh secondary organic aerosol (SOA) emitted. During BEARPEX-07, rapid incanopy oxidation caused rapid SOA growth on the timescale of biosphere-atmosphere exchange. In-canopy SOA mass yields were 0.5–4%. During AMAZE-08, the net organic aerosol flux was influenced by deposition, in-canopy SOA formation, and thermal shifts in gas-particle partitioning.Wet deposition was estimated to be an order ofmagnitude larger than dry deposition during AMAZE-08. Small shifts in organic aerosol concentrations from anthropogenic sources such as urban pollution or biomass burning alters the balance between flux terms. The semivolatile nature of the Amazonian organic aerosol suggests a feedback in which warmer temperatures will partition SOA to the gas-phase, reducing their light scattering and thus potential to cool the region.

Kinematic distances of pre-main-sequence stars in the Lupus star-forming region

To reliably determine the main physical parameters (masses and ages) of young stars, we must know their distances. While the average distance to nearby star-forming regions (<300 pc) is often known, the distances to individual stars are usually unknown. Individual distances to members of young moving groups can be derived from their radial velocities and proper motions using the convergent-point strategy. We investigate the kinematic properties of the Lupus moving group with the primary objective of deriving individual distances to all group members.

Observational effects of stellar rotation on Be stars' disks

Be stars are known to be fast rotators. At high rotation rates a profound modification of the radiation field reaching the circumstellar environment is expected. The origin of this modification is the decrease of the effective gravity on stellar surface leading to the stellar geometrical flattening and the gravity darkening effect predicted by Von Zeipel. Making use of the radiative transfer code HDUST we discuss the consequences of such stellar rotation on the structure of Be star disks based on the Viscous Decretion Disk model. Observational predictions are also made, as SED, IR-excess and Hydrogen line profiles. The modified illumination of the circumstellar disk generates significant changes in these quantities. Ascertaining these changes is useful to set some of the fundamental parameters of the Be system and to unveil the role of stellar rotation over the stellar evolution.

The Gemini planet-finding campaign: the frequency of giant planets aroud debris disk stars

We have completed a high-contrast direct imaging survey for giant planets around 57 debris disk stars as part of the Gemini NICI Planet-Finding Campaign. We achieved median H-band contrasts of 12.4 mag at 0.''5 and 14.1 mag at 1'' separation. Follow-up observations of the 66 candidates with projected separation <500 AU show that all of them are background objects. To establish statistical constraints on the underlying giant planet population based on our imaging data, we have developed a new Bayesian formalism that incorporates (1) non-detections, (2) single-epoch candidates, (3) astrometric and (4) photometric information, and (5) the possibility of multiple planets per star to constrain the planet population. Our formalism allows us to include in our analysis the previously known β Pictoris and the HR 8799 planets. Our results show at 95% confidence that <13% of debris disk stars have a ≥5 M Jup planet beyond 80 AU, and <21% of debris disk stars have a ≥3 M Jup planet outside of 40 AU, based on hot-start evolutionary models. We model the population of directly imaged planets as d 2 N/dMdavpropm α a β, where m is planet mass and a is orbital semi-major axis (with a maximum value of a max). We find that β < –0.8 and/or α > 1.7. Likewise, we find that β < –0.8 and/or a max < 200 AU. For the case where the planet frequency rises sharply with mass (α > 1.7), this occurs because all the planets detected to date have masses above 5 M Jup, but planets of lower mass could easily have been detected by our search. If we ignore the β Pic and HR 8799 planets (should they belong to a rare and distinct group), we find that <20% of debris disk stars have a ≥3 M Jup planet beyond 10 AU, and β < –0.8 and/or α < –1.5. Likewise, β < –0.8 and/or a max < 125 AU. Our Bayesian constraints are not strong enough to reveal any dependence of the planet frequency on stellar host mass. Studies of transition disks have suggested that about 20% of stars are undergoing planet formation; our non-detections at large separations show that planets with orbital separation >40 AU and planet masses >3 M Jup do not carve the central holes in these disks.

The Gemini NICI planet-finding campaign: the frequency of giant planets around young B and A stars

We have carried out high contrast imaging of 70 young, nearby B and A stars to search for brown dwarf and planetary companions as part of the Gemini NICI Planet-Finding Campaign. Our survey represents the largest, deepest survey for planets around high-mass stars (≈1.5-2.5 M ☉) conducted to date and includes the planet hosts β Pic and Fomalhaut. We obtained follow-up astrometry of all candidate companions within 400 AU projected separation for stars in uncrowded fields and identified new low-mass companions to HD 1160 and HIP 79797. We have found that the previously known young brown dwarf companion to HIP 79797 is itself a tight (3 AU) binary, composed of brown dwarfs with masses 58$^{+21}_{-20}$ M Jup and 55$^{+20}_{-19}$ M Jup, making this system one of the rare substellar binaries in orbit around a star. Considering the contrast limits of our NICI data and the fact that we did not detect any planets, we use high-fidelity Monte Carlo simulations to show that fewer than 20% of 2 M ☉ stars can have giant planets greater than 4 M Jup between 59 and 460 AU at 95% confidence, and fewer than 10% of these stars can have a planet more massive than 10 M Jup between 38 and 650 AU. Overall, we find that large-separation giant planets are not common around B and A stars: fewer than 10% of B and A stars can have an analog to the HR 8799 b (7 M Jup, 68 AU) planet at 95% confidence. We also describe a new Bayesian technique for determining the ages of field B and A stars from photometry and theoretical isochrones. Our method produces more plausible ages for high-mass stars than previous age-dating techniques, which tend to underestimate stellar ages and their uncertainties.